Category: What’s Up

Lunar Map courtesy of The Sky Plus. Click to enlarge.
Monday, May 16 – With the Moon now approaching first quarter, this would be an excellent time to look for it in late afternoon skies. If you’re not busy this evening, why don’t we take the opportunity to explore the lunar surface and look at four very cool features.

Central on the terminator tonight will be Sinus Medii – the adopted “center” of the lunar disc and the point from which latitude and longitude are measured. This smooth plain may look small, but covers about as much area as the states of Massachusetts and Connecticut combined. On a curious note, in 1930 Sinus Medii was chosen by Edison Petitt and Seth Nicholson for surface temperature measurements during full Moon. Experiments of this type were began by Lord Rosse as early as 1868, and they found the surface to be just slightly warmer than boiling water. Around a hundred years after such experiments began, Surveyor 6 successfully landed in Sinus Medii on November 9, 1967 confirming Surveyor 5’s findings – and became the very first probe to “lift off” from the lunar surface.

To the south/southeast of the Sinus Medii is the unmistakable Albategnius. It is an old formation, with its walls broken by many more recent craters, like Klein on its southwestern edge. Albategnius is historic as well, because in 1962, it became the target of the laser beam projected onto the lunar surface. To the north, look for the long dark scar of the Alpine Valley as it angles across the lunar Alps and the Sun beginning to rise on the single, unusual peak of pyramid-like Mons Piton.

Tuesday, May 17 – Today in 1835, J. Norman Lockyer was born. While that name might not stand out, Lockyer was the first to note previously unknown absorption lines while making visual spectroscopic studies of the Sun in 1868. Little did he know at the time, he had correctly identified the most simple and second most abundant element in our universe – helium – an element not discovered on Earth until 1891! Also known as the “Father of Archeoastronomy”, Sir Lockyer was one of the first to make the connection with ancient astronomical structures such as Stonehenge and the Egyptian pyramids. (As a curious note, 14 years after Lockyer’s notation of helium, a sun-grazing comet made its appearance in photographs of the solar corona taken during a total eclipse in 1882… It hasn’t been seen since.)

If you would like to see a helium rich star, look no further tonight than Alpha Viginis – Spica. As the sixteen brightest star in the sky, this brilliant blue/white “youngster” appears to be about 275 light years away and is about 2300 times brighter than our own Sun. Although we can not see it visually, Spica is a double star. Its spectroscopic companion is roughly half its size and is also helium rich.

Feeling like some peaceful contemplation? Then visit the lunar surface tonight and spend some time with crater Plato. This huge ellipse to the lunar north has an unusual dark stained lava floor that has been the site of many unconfirmed changes. Visit along its east wall where the shadow play among its many crests will appear almost like a distant city skyline.

Wednesday, May 18 – On this day in 1910, Comet Halley transited the Sun, but could not be detected visually. Since the beginning of astronomical observation, transits, eclipses and occultations have provided science with some very accurate determinations of size. Since Comet Halley could not be spotted against the solar surface, we knew almost a century ago that the nucleus had to be smaller than 100 km.

So, would you like to get a grasp on that concept? Then have a look at the lunar surface tonight and the most prominent crater of all – Copernicus. In a study done by Shoemaker, this ancient crater is no doubt formed by a gigantic impact. Feature after feature so closely resembles geological impact craters seen here on Earth, that we can say with complete certainty that this crater was formed by a large meteoritic body. And just how large is crater Copernicus? Oh, about the size of a certain famous comet’s nucleus – 100 km…

Thursday, May 19 – Tonight on this universal date, the Moon will occult Jupiter for viewers in a small portion of south Africa and the northern tier of South America. Please visit this IOTA webpage for specific times in your location. For viewers in North America, the Moon and Jupiter will make a very picturesque sight as they pass very closely to each other.

While watching this pair tonight, take the time to look at the lunar surface and enjoy the “Bay of Rainbows” – Sinus Iridium. If you’re watching Jupiter, a great many viewers will get to enjoy the both the transits of Io and Europa as well as their shadows and the “Great Red Spot” will happily join the show at 22:10 UT.

Friday, May 20 – Tonight let’s skip the Moon and head for the stars as we set our sights towards the fourth brightest star in the sky – Arcturus.

Located around 37 light years from us, the orange giant is heading our way at about 5 kilometers per second and will pass us in a couple of thousand years. With a diameter of roughly 33 million kilometers, this population II star was one of the very first to be observed during the daylight in 1635 and is often referred to as the “Watcher of the Bear”. Oddly enough, it reached fame in 1933 when its light was focused telescopically on a photoelectric cell and the power it generated used to turn on a switch. That switch was connected to the floodlights at the Chicago Exposition “Century of Progress” – with Arcturus chosen for the honors because the light that reached the Earth that night had left the star during the Chicago 1893 Exposition. Here’s to guessing you couldn’t see Arcturus once the lights were on….

But keep your lights off and your eyes trained on the finderscope as we explore four “neighbors” of Arcturus. About a fist width east, you will see four dim stars that will require optical aid with tonight’s “lunacy”. To the north is Xi – a very pretty double star with a yellowish primary and a more orange secondary. The next star to the south is Omicron and then Pi. You will find Pi to be a 5th magnitude double with a 6th magnitude companion relatively close to the east/southeast. For larger scopes, keep heading south for double Zeta, which are matched magnitudes and close enough to need high power and steady skies to split.

Saturday, May 21 – In 1961, United States President John F. Kennedy launches the country on a journey to the Moon as he makes one of his most famous speeches to Congress: “I believe this nation should commit itself to achieving the goal, before this decade is out, of landing a man on the Moon and returning him safely to Earth. No single space project in this period will be more impressive to mankind, or more important for the long-range exploration of space…”

Tonight let’s explore the lunar surface with binoculars as we view the areas of all the historic Apollo missions. Starting with Apollo 11, you will find its landing site on the southwest corner of Mare Tranquillitatus where it meets with Mare Nectaris. Apollo 12 is near the terminator to the west and just north of the small, bright punctuation of Euclid. Apollo 14’s remains lay due east on the border of Mare Cognitum. Look to the north for shallow Archimedes and the Apennine Mountain range where you will find Apollo 15 forever waiting in Palus Putredinus. Look southeast of Apollo 11’s site in the rugged terrain west of Theophilus for Apollo 16, and Apollo 17 ends the lunar tour on the southeastern shore of Mare Serenitatis where it joins Mare Nectaris.

Since you’re out with binoculars, tonight would be a great opportunity to spot an asteroid as well! At close to 7th magnitude, you’ll find Ceres just about a degree south of Delta Librae. Check the minor planets listing at Heaven’s Above for a locator chart.

Sunday, May 22 – Tonight the Moon will be at minimum libration tipping crater Otto Struve our way. You will find this strange, tomato-shaped crater on the extreme limb just west of bright Aristarchus.

Since Struve was the master of double stars, let’s make it easy to find one of his discoveries! Start with reasonably accurate equatorial alignment and take the time to enjoy fantastic double Cor Caroli again. Turn off any drive units, or just wait… Wide, white double, Struve 1702 will “drift” into the eyepiece in 150 seconds.

Until next week? Ask for the Moon, but keep reaching for the stars! May all your journeys be at Light Speed… ~Tammy Plotner

Photo of galaxy NGC 2903. Image credit: Zsolt Frei and James E. Gunn. Click to enlarge.
Monday, May 9 – Can you spot the very slender crescent Moon tonight? Look for it just after sunset low on the western horizon. Both bright Venus and the Plieades are to its west and will present a delightful challenge.

Before the Moon steals our early dark skies, let’s begin the week by studying a galaxy very similar to our own Milky Way – NGC 2903. Located less than two degrees south of Lambda Leonis, this magnificent 9.7 magnitude barred spiral can be spotted with binoculars from a dark location, and will be an easy small scope object. While the NGC 2903’s size and central bar closely resembles our own galaxy’s structure, the Hubble Space Telescope crossed the 25 million light year gap and found evidence of young globular clusters in its galactic halo – unlike our own old structures. This widespread star forming region is believed to be attributed to the gravity of the central bar. Small telescopes will show it as a lateral concentration across the central structure, while larger aperture will reveal spiral arms and concentrations of stars.

Tuesday, May 10 – Tonight give the Moon time to set and the constellation of Canes Venatici to rise as we go hunting the “Sunflower Galaxy” – M63. Located about a fist width southwest of the M51, you can normally spot it easily by scanning the area midway between Alkaid and Cor Caroli.

Originally discovered in 1779 by my hero Mechain, this bright galaxy is located about 37 million light years away and is believed to be part of a group of galaxies that includes M51. To binoculars it will appear as a faint misty oval, but larger scopes with optimal sky conditions will reveal the galaxy’s spiral arms as a grainy background that brightens considerably towards its center. Perhaps the most interesting feature of the M63 is its spiral arms. Most typical spiral galaxies contain two or three distinct spiral arms, yet this one’s structure is multiple short spiral arcs that remind many observers of a “celestial flower”. Scientific study of the M63 reveals that the galactic material at the edges of these arms is moving much faster than normal. Given the gravity of visible matter, this indicates the existence of dark matter within its structure.

Wednesday, May 11 – For viewers in south/central Australia and New Zealand, the Moon will occult Beta Taurii on this universal date. Please check IOTA webpages for details and times in your area.

So how about if we wait until the Moon sets and do a little comet hunting tonight? Let’s start with a familiar face – the “Magnificent Macholz”. Now faded to a soft magnitude 9, it can still be found with larger binoculars from a dark sky location. This evening will put the comet about equo-distant between Epsilon and Gamma Ursae Majoris and in the same field as star 73. Telescope users should still be able to see remnants of Macholz’ tail. For a little more challenge, locate 9/P Tempel 1 about 2 degrees southwest of Epsilon Virginis. At an estimated magnitude 10, Tempel 1 will be a bit fainter than Macholz, but far brighter than 13.5 magnitude NGC 4779 in the same lower power field.

Thursday, May 12 – For viewers in Florida, Bermuda and eastern Canada, the Moon will occult open cluster NGC 2331 on this universal date. Please check out this IOTA webpage for details. NGC 2331 is located roughly halfway between Beta and Epsilon Geminorum. At roughly magnitude 8, this scattered open cluster will be best detected with larger scopes during the occultation.

If you chose to view the Moon tonight, look for splendid dark crater Endymion on the terminator to the north. Normally its floor appears very smooth and very dark, but tonight it will seem to match its surroundings as the sunrise illuminates its west wall and the broad shadow of east wall defines its borders.

For viewers in western Europe, tonight would be a wonderful opportunity to spend some quality time with Jupiter. The great “Red Spot” will transit at 21:23 UT. Two of the galieans will add to the excitement as Europa’s shadow crosses the surface between 18:50 and 21:31 – followed by the ingress of Io’s shadow at 21:51.

Friday, May 13 – For viewers in Australia and New Zealand, the Moon will occult Iota Geminorum on the universal date. Please check IOTA webpages for further details.

If you are exploring the lunar surface tonight, be sure to look closely along the east boundary of Mare Nectaris. The bright cliff you see will be the Pyranees Mountains which holds crater Gutenburg in their grasp. This is a crater that has been filled with lava and terribly eroded over its lifetime. Its northeast wall has been broken by an impact known as Gutenburg E before the lava flood. The southern edge contains a very unusual mountain walled enclosure.

Saturday, May 14 – Tonight the Moon will be at apogee and will have reached its greatest distance of 404,600 km (251,407 miles). Let’s journey away to the lunar surface to view a very fine old crater – Theophilus. Slightly south of mid-point on the terminator, this crater contains an unusually large multiple peaked central mountain which can be spotted in binoculars. Theophilus is an odd crater, one that is a parabola – with no area on the floor being flat. Tonight it will appear dark, shadowed by its massive west wall, but look for sunrise on its summit!

Let’s turn our attention now to a splendid double star for the small telescope – Delta Corvi. Known as Algorab, this highly visible third magnitude star lies at the northeastern corner of the odd rectangle that forms the major pattern of Corvus. Its 9th magnitude companion is a wide split at 24 arcseconds away.

Sunday, May 15 – Would you like to see two planets in the same field of view? Then this morning would be well worth getting up early for as Mars and Uranus will only be about one degree apart. At +0.5 magnitude, reddish Mars will make a nice contrast with the 6th magnitude greenish Uranus. This will be very viewable in small binoculars and outstanding with the telescope.

Today is the birthday of Nicholas Louis de la Caille (or de Lacaille). Born in 1731, the French astronomer and mapmaker was the first to demonstrate Earth’s bulge at its equator. From 1751 to 1753, he had the great fortune to observe southern skies from the Cape of Good Hope. Putting his cartography skills to use, he mapped the southern skies and established the 14 constellations that remain in use to this day.

For lunar viewers tonight, enjoy the bright crests of the Caucasus Mountains with prominent craters Eudoxus and Aristoteles to the north.

Until next week? Ask for the Moon, but keep reaching for the stars! May all your journeys be at Light Speed… ~Tammy Plotner

Galaxy M51. Image credit: Todd Boroson/NOAO/AURA/NSF. Click to enlarge.
Monday, May 2 – If you’re up before dawn today, look closely at the Moon – ruddy Mars will make its appearance less than 3 degrees north of its waning form.

With early evening dark skies, this would be an excellent time for mid-sized binoculars and telescope users to discover anew the fantastic “Whirlpool Galaxy”. Designated as NGC 5194, this impressive face-on spiral galaxy was discovered by Charles Messier in October of 1773 and cataloged as the M51. You can find it easily by heading about three finger-widths southwest of Eta Ursa Majoris (the end star in the handle of “the Big Dipper”) and in the same finderscope of binocular field as faint star 24 Canes Venaticorum.

At around 35 million light years away, the “Whirlpool” is a spiral delight to all optical aid. Binoculars at a dark location will see it as a large, round “haze” with a brightness toward the center. Small scopes will reveal its galactic nature and satellite galaxy, NGC 5195. With large aperture, this galaxy comes alive with detail. 10″ will clearly show spiral arm structure, while at 12.5″ knots, clusters, stellar condensations and dark dustlanes become wonderfully apparent – making the M51 one of the very few deep space objects that look like a photograph in the eyepiece. Absolutely one of the finest in the night sky!

Tuesday, May 3 – During the very early morning hours, take the opportunity that darker skies provide and view the Alpha Scorpiid meteor shower during its peak. The radiant is near Antares. Later in the morning, try using binoculars to locate Uranus as it appears a little more than three degrees north of the Moon.

Tonight’s destination is a very compact and bright little galaxy that can be seen in larger binoculars and is an easy telescope target – M94. Start by identifying past study Cor Caroli (Alpha Canum). About half a fist width to its northwest you will see Beta. Aim your scopes or binocular mid-way between the two and move slightly more than a degree towards the last star in the handle of the Big Dipper – Alkaid. The M94 was discovered in 1781 by my hero, Mechain, and this small galaxy has a powerful central core. At around 20 million light years away, smaller scopes will have difficulty resolving detail, but larger apertures under ideal conditions will pick up on its tightly-wound spiral structure.

Wednesday, May 4 – If you missed your chance to catch a “shooting star” yesterday morning, then why not try again today as the Eta Aquarids reach their peak? With a fall rate of about 21 per hour, this highly dependable annual shower is the offspring of Comet Halley. With far less Moon to interfere, these bright yellow meteors with outstanding trails are well worth looking for. If skies are cloudy, don’t worry. The Eta Aquarid stream stays active for another week.

Tonight let’s further our understanding of distance and how it effects what we see. As you know, light travels at an amazing speed of about 300,000 kilometers per second. To get a grasp on this concept, how many seconds are there in a minute? An hour? A week? A month? How about a year? Ah, you’re beginning to see the light! For every second – 300,000 kilometers. Now, go back to previous study M3 located between Arcturus and Cor Caroli. This great globular cluster is about 40,000 light years away. In terms of kilometers – that’s far more zeros than most of us can possibly understand – yet we can still see this great globular cluster.

Now let’s locate M53. Roughly halfway between Arcturus and Denebola is faint star Alpha Comae. Aim your binoculars or telescopes there and you will find the M53 about a degree northeast. This very rich, magnitude 8.7 globular cluster is almost identical to the M3, but look at what a difference an additional 25,000 light years can make to how we see it! Larger telescopes will enjoy the compact bright core as well as resolution at the cluster’s outer edges. As a bonus for scopes, look one degree to the southeast for peculiar round cluster NGC 5053. Classed as a very loose globular, this magnitude 10.5 grouping is one of the least luminous objects of its type due to low stellar population and wide separation of members – yet its distance is almost the same.

Thursday, May 5 – Today in 1961, astronaut Alan Shepard made history as he became the first American in “space”. Onboard the Mercury craft, Freedom 7, Shephard spent 15 minutes in a sub-orbital ride of a lifetime. By today’s standards this is considered “shallow space”, but your chance to view something far more distant and every bit as history making is now here.

If you did not get an opportunity to view Comet 9/P Tempel 1 last week, then try again as it will be about two degrees west/southwest of Epsilon Virginis. Projected magnitudes show that Tempel 1 should be around magnitude 10 at this time and recent observing reports indicate that it is condensing well and will be easily distinguishable as cometary. In two months time, the “Deep Impact” mission will have reached Tempel 1 and the result of its experimentation may make the comet flare brightly enough to be seen with the unaided eye. Stay tuned!

Friday, May 6 – Looking for your chance to spot Mercury? Then let the Moon be your guide as the two will appear just before dawn. The swift inner planet will appear about 3 degrees south of the slender crescent Moon for most observers.

Tonight let’s have a little bit of fun. For binocular users, we’re going to visit a large star cluster and a small galaxy. Our beginning destination is Melotte 111, a large hazy patch of stars visible to the unaided eye in Coma Berenices. Known as the “Queen’s Hair”, this five degree span of 5th to 10th magnitude stars is wonderfully rich and colorful. As legend has it, Queen Berenices offered her beautiful long tresses to the gods for the King’s safe return from battle. Touched by her love, the god’s took Berenices’ sacrifice and immortalized it in the stars.

While our next destination isn’t quite so romantic, I think you’ll enjoy getting a “Blackeye”. Located 1 degree east/northeast of 35 Comae, this small bright galaxy can be caught in the same wide binocular field northwest of previous study – M53. Originally discovered by Bode about a year before Messier cataloged it, the M64 is about 25 million light years away and holds the distinction of being one of the more massive and luminous of spiral galaxies. Telescope users will find this particular galaxy most endearing for its namesake – a very wide dark dustlane to the northeast side of the galaxy’s bright core. Power up and enjoy this very unusual treasure!

Saturday, May 7 – Tonight at at about 11:03 p.m. PDT for western United States observers in a rough line between Sacramento to Barstow and San Diego, CA (including Yuma, AZ and northern Mexico), a unique opportunity arrives to help contribute to science. A magnitude 11.7 star is being occulted by a large, and possible binary asteroid named Ophelia. According to Dr. Raoul Behrend of Geneva Observatory, “The recent lightcurve of asteroid (171) Ophelia, shows strong similarities with other binary asteroids.” While the dual nature of this asteroid is still being debated, only radar and observations during an occultation can help to help confirm it, and a single-body theory is not ruled out. “We are working on the interpretation of the lightcurve using various models:
– a single body – a pear which can reproduce the lightcurve, but with departure which seem to be significative – a single body with a huge crater (like Mathilde) – which seems to be ruled out, and
– two bodies – the most difficult to model, but preliminary results are nice. So, as we can’t exclude the single body (at 2/3 level), our preference goes actually to the binary system.” The work with Ophelia’s light curve continues further in this working document which explores sizes in the event of binarity. In a call to observers, Dr. Behrend says, “Good occultations by Ophelia are extremely rare; the last one for *many years* is around 2005-05-08 at 6h UT, over California, Arizona, and Mexico”. If Ophelia should prove to be a binary asteroid, the resulting separation would be near a maximum as predicted by Behrend’s lightcurve. “Every positive, every negative observation is important to determine the binarity state (yes or no), and the size(s). If binarity if confirmed, then the mass, scale, density, albedo and other important physical parameters could be determined with an impressive precision.”

For further information on this event, view the prediction by Steve Preston. If you are in the path of the occultation and wish further information on how to view, record and time the event, please contact Derek Breit or access this page for further instructions.

For the rest of us, we can still have lots of fun viewing another asteroid. In a matter of hours, Ceres will reach opposition and an admirable magnitude of 7. You can spot it easily tonight just northwest (and in the same binocular field) as Beta Librae. Best of luck!

Sunday, May 8 – Tonight is New Moon and time to dish you up a very special galactic treat. Located just a little less than two degrees east of 17 Comae, the NGC 4565 is one of the largest and most beautiful of edge-on galaxies. For the small telescope, it will appear as a very thin scratch of light. As aperture progresses, so does the view. With mid-sized scopes, this impressive galaxy becomes a bright, needle-like silver scratch with a small, almost stellar nucleus. For larger scopes and the trained eye, you will see perfect edge-on form with a dark dissecting dustlane. This is one extremely fine galaxy… Enjoy!

Until next week? May all your journeys be at Light Speed! ….~Tammy Plotner

Image credit: NOAO/AURA/NSF
Monday, April 25 – Today marks the 15th anniversary of the deployment of Hubble Space Telescope. While everyone in the astronomical community is well aware of what this magnificent telescope “sees”, did you know that you can see it with just your eyes? The HST is a satellite that can be tracked and observed. Visit Heaven’s Above and enter your location. This page will provide you with a list of visible passes for your area. Although you can’t see details of the scope itself, it’s great fun to track with binoculars or see the Sun glinting off its surface in a scope.

Before the Moon rises tonight, let’s use our binoculars and telescopes to hunt down one of the best globular clusters for the northern hemisphere – M3. You can locate it easily by identifying last week’s study stars, Cor Caroli and Arcturus. Sweep your binoculars in a line between the two and you will discover this ancient beauty about halfway between the pair just east of Beta Comae. The more aperture you use – the more stars you will resolve.

Discovered by Charles Messier on May 3, 1764, this ball of approximately a half million stars is one of the oldest formations in our galaxy. At around 35-40,000 light years away, this awesome globular cluster spans about 220 light years and is believed to be as much as 10 billion years old. To get a grasp on that concept – our own Sun is less than half that age!

Keep a watch on the skies tonight as the Mu Virginid meteor shower reaches its peak at 7 to 10 per hour. Although the rising Moon will hamper observations, you still might catch one of these medium speed meteors radiating from a point near the constellation of Libra.

Tuesday, April 26 – This morning Mercury will reach its greatest western elongation. Southern hemisphere views are highly favoured for this apparition, and you may spot the swift inner planet just before dawn about a handspan above the east/northeast horizon.

On this date in 1920, the Shapely-Curtis debate raged in Washington on the nature and distance of spiral nebula. Shapely claimed they were part of one huge galaxy to which we all belonged, while Curtis maintained they were distant galaxies of their own. Thirteen years later on the same date, Arno Penzias was born. He went on to become a Nobel Prize winner for his part in the discovery of the cosmic microwave background radiation through a simple horn antenna. His discovery helped further our understanding of cosmology in ways that Shapely and Curtis could have never dreamed.

Before the Moon rises tonight, why not take the telescopic challenge to view one of the largest and finest of face-on spiral galaxies? Located about a fist’s width east of last week’s study – Mizar and Alcor – you will find the large, diffuse M101 to be easily within range of the average mid-sized scope. At magnitude 9, you can spot it in larger binoculars, but will require at least a 10″ scope to detect its knotted arms.

For all of Europe and northeastern Africa, the Moon will occult Antares tonight. Be sure to check IOTA for precise times in your area. On this same universal date, it will also occult bright Sigma Scorpii for those in northwestern Australia.

Wednesday, April 27 – Let’s return to the binoculars and small telescopes tonight to find a fantastic galactic cluster known as the M67. Easily located by either going about a fist’s width south of the M44 or a thumb’s width west of Alpha Cancri – this rich, 2500 light year distant open cluster has a stellar population unlike any other. Located about 1500 light years above the plane of the galaxy, the M67 defies the rules by residing in an area not known for galactic clusters – and double defies them by containing population stars similar to a globular cluster. These stars are an indicator of great age, and the M67 may very well be near 10 million years old. For very small binoculars, this beautiful open cluster will appear almost galaxy-like, while progressively larger instruments will resolve it completely.

Thursday, April 28 – Now is your chance to get a first look at the returning Venus. Immediately after sunset, look for it very low on the west/northwest horizon. Try using binoculars to assist you.

Today was a very busy day in astronomy history. Newton published his Principia in 1686 on April 28. In 1774, Francis Baily was born – who went on to revise star catalogs and explain the phenomenon at the beginning and ending of a total solar eclipse which we know as “Baily’s Beads”. 1900 saw the birth of Jan Hendrick Oort, who quantified the Milky Way’s rotation characteristics and envisioned the vast, spherical area of comets outside our solar system that we call the Oort Cloud. Last, but not least was the birth of Bart Jan Bok in 1906 who studied the structure and dynamics of the Milky Way.

Tonight let’s take a look at a visitor from the Oort Cloud, comet 9P/Temple 1. Located just north of Epsilon Virginis, this 10th magnitude comet could be within range of large binoculars, but I would suggest a telescope since there will be many nearby galaxies that could resemble a cometary signature in such a wide field. Even at the eyepiece, this comet will strongly resemble a faint, face-on spiral – but don’t worry – it’s by far brighter than anything nearby. As 9P/Temple 1 is nearing it’s closest approach to the Earth, this will be an outstanding comet to watch in the weeks ahead. Think “Deep Impact”….

For skywatchers, no equipment is necessary to enjoy the Alpha Bootid meteor shower. Pull up a comfortable seat and face orange Arcturus as it climbs the sky in the east. These slow meteors have a fall rate of 6 to 10 per hour and leave very fine trails, making an evening of quiet contemplation most enjoyable.

Friday, April 29 – The Moon is at perigee, its closest approach to Earth – and as luck would have it, reaches maximum libration at 21:00 UT, tipping the north pole our way. If this doesn’t sound very exciting, think of SMART-1 currently up there looking for eternal sunlight! Although the Moon won’t rise until around local midnight, if you’re up late have a go at extreme northern features like Peary, Byrd, Gioja, Main, Challis and Scoresby.

Saturday, April 30 – Frederich Gauss was born on this day in 1777, Known as the “Prince of Mathematics”, Gauss contributed to the field of astronomy in many ways – from computing asteroid orbits to inventing the helioptrope. Out of Gauss’ many endeavors, he is most recognized for his work in magnetism. We understand the term “gauss” as a magnetic unit – a refrigerator magnet carries about 100 gauss while an average sunspot might go up to a 4000. On the most extreme ends of the magnetic scale, the Earth produces about 0.5 gauss at its poles, while a magnetar can produce as much as 10 to the 15th power in gauss units!

While we cannot directly observe a magnetar, those living in the Southern Hemisphere can view a region of the sky where magnetars are known to exist – the Large Magellanic Cloud. Located in the constellation of Dorado, this unaided eye gem is visible even during full moonlight. Stuffed with wonderful features such as the “Tarantula Nebula” – the largest diffuse nebula known in the Universe – and many star clusters, I urge you to get out your telescopes and binoculars and explore…

For southwestern Europe, the Moon will occult 4.5 magnitude star, 59 Saggitarius, on this universal date. Please check the IOTA webpage for details specific to your area.

Sunday, May 1 – On this day in 1949 Gerard Kuiper discovered Nereid, a satellite of Neptune. If you’re up before dawn, you can easily find Neptune less than 2 degrees northwest of bright Mars. While it can be see in binoculars as a bluish “star”, it takes around a 150mm telescope and some magnification to resolve its disc. Today’s imaging technology can even reveal its moons!

Tonight will mark the peak of the Phi Bootid meteor shower whose radiant is near the constellation of Hercules. While the best time to view a meteor shower is around 2:00 a.m. local time, you will have best success watching for these meteors during the late evening before moonrise. The average fall rate is about 6 per hour.

Keep those scopes warm – dark skies are on their way back again! May all your travels be at Light Speed…. ~Tammy Plotner

Image credit: NOAO/AURA/NSF
Monday, April 18 – Tonight let’s use two bright celestial objects to our advantage to help you locate an outstanding galactic cluster – M44. Because this great gathering of stars is located near the ecliptic plane, you will find it easily tonight in binoculars by scanning the area mid-point between Saturn and the Moon. Also known as the “Beehive”, this wonderful open cluster is sufficiently bright enough to be seen unaided under darker conditions. In ancient times it was used as a weather predicting tool – if it was not visible under otherwise clear skies – a major storm was on the way. This easy collection of bright pairs was known and recorded as far back as 260 B.C. – but in 1610 Galileo was the first to resolve it into individual stars with his newly invented telescope. Enjoy its stellar “swarm” tonight…

Continue on to the lunar surface to explore the very fine appearance of crater Copernicus located about mid-way along the terminator. It is not the largest, the deepest, the oldest, the most bright, nor the most unusual of lunar features – but it definitely holds the record at being the most spectacular!

Tuesday, April 19 – A little more than 35 years ago, the Apollo 13 crew was on a mission to land on the Moon in the Fra Mauro highlands. Although disaster kept them from completion, Apollo 14 carried out the plan a little less than a year later – and tonight we will be able to see this landing area on the lunar surface. Along the terminator to the south, you will see a dark expanse known as Mare Nubium. On its northern shore and nearing the terminator’s center, you will see a inlet of small shallow craters. The brightest of these small rings is crater Parry with Fra Mauro appearing larger and more shallow to its north. Power up! Fra Mauro has a long fissure that runs between its north and south borders. At the northern crater edge you will see the ruins of an ancient impact. Known as X, it definitely marks the spot of this successful lunar landing.

Wednesday, April 20 – Tonight the most prominent lunar feature will be the ancient and graceful Gassendi. Its bright ring stands on the north shore of Mare Humorum – an area about the size of the state of Arkansas. Around 113 km in diameter and 2012 meters deep, you will see a triple mountain peak in its center and the south wall eroded by lava flows. Gassendi offers a wealth of details to telescopic observers on its ridge and rille covered floor.

When you have finished with your lunar observations, let’s travel on to a fascinating double star. A little less than a handspan south of the last star in the handle of the “Big Dipper”, you will see a fairly bright star that is on the edge of unaided eye detection thanks to tonight’s gibbous Moon. Aim your telescopes or steady binoculars there for a real treat! Alpha Canum is more commonly known as Cor Caroli – or the “heart of Charles” – and is a true jewel easily split by the most modest of instruments. Although some observers may not be able to distinguish a color difference between the magnitude 2.8 and 5.6 companions, it has been my experience that most will see a faded blue primary (a magnetic spectrum variable) and pale orange secondary on this 120 light year distant pair. If you are equatorially aligned, turn off the drive and wait for 150 seconds. Widely separated Struve 1702 will be coming into view…

Thursday, April 21 – Tonight’s lunar observing will be a challenging one – worthy of the larger scope. Start by identifying past study craters, Hansteen and Billy. Due west of Hansteen you will find a small crater near the terminator known as Sirsalis. It will appear as a small, dark ellipse with a bright west wall with its twin, Sirsalis B on the edge. The feature you will be looking for is the Sirsalis Rille – the longest presently known. Stretching northeast of Sirsalis and extending for 459 kilometers south to the bright rays of Byrgius, this major “crack” in the lunar surface will show several branches – like a long dry river bed.

Tonight let’s go from one navigational extreme to another as viewers in the northern hemisphere try their hand at Polaris. As guide star for north, Polaris is also a wonderful double with an easily resolved, faint blue companion for the mid-sized telescope. But what about the south? Viewers in the southern hemisphere can never see Polaris – is there a matching star for the south? The answer is yes – Sigma Octantis – but at magnitude 5, it doesn’t make a very good unaided eye guide. Ancient navigators found better success with the constellation of Crux, better known as the “Southern Cross”. While Crux has many wonderful double stars, if southern hemispere viewers would like to see a star very similar to Polaris, then try your luck with Lambda Centauris. The magnitude difference between components and separation are about the same!

Friday, April 22 – Today celebrates the birthday of Sir Harold Jeffreys, who was born in 1891. Jeffreys was an astrogeophysicist and the first person to envision Earth’s fluid core. He also helped in our understanding of tidal friction, general planetary structure, and the origins of our solar system. Start your morning off before dawn with a chance to view the peak of the Lyrid meteor shower. Since the radiant is near Vega, you will improve your chances of spotting them when the constellation of Lyra is as high as possible and the Moon far to the west. This stream comes from parent Comet Thatcher and produces around 15 bright, long-lasting meteors per hour. (UPDATE: The current projected peak time has been upgraded to 10:30 UT.)

But what about later?

The Moon will be very busy tonight… On this universal date it will occult Jupiter in regions across mid-to-south Africa. Since we have many readers from that area, please watch! This IOTA webpage will give you precise universal times for your location. As the Earth turns, a wide swath across the southeast, central and western portions of both North and South America, will enjoy the Moon occulting Eta Viriginis. Be sure to visit this IOTA webpage for a list of universal times in your area.

Saturday, April 23 – Pioneer quantum physicist, Max Planck was born on this day in 1858. In 1900, Max developed the quantum – known as the Planck equation- to explain the shape of blackbody spectra (a function of temperature and wavelength of emission). A “blackbody” is any object that absorbs all incident radiation – regardless of wavelength. For example, a heated metal has blackbody properties because the energy it radiates is thermal. The blackbody spectrum’s shape remains a constant and the peak and height of an emitter can be measured against it – be it cosmic background radiation or our own bodies.

Now, let’s put this knowledge into action. Stars themselves approximate blackbody radiators, because their temperature directly controls the color we see. A prime example of a “hot” star is Alpha Viginis, better known as Spica. Compare its color to the cooler Arcturus… What colors do you see? There are other astronomical delights that radiate like blackbodies over some or all parts of the spectrum as well. You can observe a prime example in a nebulae, such as the M42 in Orion. By examining the radio portion of the spectrum, we find the temperature properly matches that of electrons involved in the process of flourescence. Much like a common household fixture, this process is what produces the visible light we can observe.

Sunday, April 24 – For central and western North America, this would be an excellent morning to set the alarm for the early hours as the Moon undergoes a penumbral eclipse – reaching its deepest at 09:55 UT. The effects of the shading of a penumbral eclipse are not as dramatic as the umbral portion, but it’s still fun! For viewers in Central America and western South America, the event will happen before dawn. Hawaii will catch the action around local midnight, while Australia, New Zealand and Japan will have their opportunity in the early evening.

Just because we have full Moon doesn’t mean we can’t have any fun. Tonight let’s explore the star in the middle of the handle of the “Big Dipper”. Its name is Mizar, but if you have exceptional eyes you may also see its companion Alcor as well! The ancient Arabs used this star as an “eye test” for their warriors – if you could see both components, you were given a horse. The name Mizar and Alcore literally translates to “the horse and rider”. If it’s not clear to you, even the slightest optical aid will separate the two, but a treat is in store for telescope users. Mizar itself is a double star! As the very first to be discovered and photographed, you will enjoy this pair. In the eyepiece, Alcor will appear to the east of Mizar A and B, but look for a faint star in between. It has the very impressive name of Sidus Ludovicianum and was once believed to be a planet.

Until next week? Ask for the Moon – but keep reaching for the stars! Light speed…. ~Tammy Plotner

Image credit: Sylvain Weiller
Monday, April 11 – For viewers in Alaska tonight, you will see the Moon will occult Delta Aquarii while in Chile the Moon will occult the Plieades on this universal date. Please consult the webpage for further details.

William Wallace Campbell was born today in 1862. He was a pioneer observer of stellar motions and radial velocities and served as a director of Lick Observatory. 98 years later, the first radio search for extraterrestrial civilizations was started by Frank Drake called Project Ozma and for those of us who were chasing comets in 1986, we were enjoying Halley’s closest approach to Earth on this date. Although it will be hard to best that, for northern observers, the “Magnificent Machholz” is still a large binocular or small telescope object. Skirting along the Draco – Ursa Major border, it has faded to around magnitude 8. For a nightly locator chart, please visit Heaven’s Above.

With only a slender crescent Moon, tonight would be a great time to just relax and enjoy a little skywatching. It’s the peak of the Virginid meteor shower! This shower is a very complex and tangled array of four streams with no clear radiant. While conditions are conducive, it is possible to see up to 30 faint streaks per hour, but this stream is well known for producing bolides.

Tuesday, April 12 – Today Yuri Gagarin became the first man in space making one orbit of the Earth in 1961 onboard Vostok 1. Only 20 years later, Columbia became the first space shuttle to launch. As this historic day stars, why not take the opportunity to look for a distant planet before dawn? Mars will be your guide – and you will find Neptune just slightly more than a degree north.

Let’s view the Moon tonight and locate shallow crater Cleomides just north of Mare Crisium. It is one of the most ancient features on the lunar surface and may be between 4 to 5 billion years old. Although its interior has been flooded by lava, you can still see the punctures of several young craters. For those wishing a challenge, power up to locate Rima Cleomides cutting diagonally across its northern shore.

Wednesday, April 13 – This evening will offer us an opportunity to view a crater that has long been an object of lunar transient phenomena study – Proclus. You will find this small, bright crater on the edge of Mare Crisium. It has a very high albedo (surface reflectivity) and has been known to show unusual brightenings. Depending on how far the terminator has progressed, you may get a glimpse of a highlighted rectangular feature in the shadows of its southeast wall.

Thursday, April 14 – Dutch scientist, Christian Huygens was born today in 1629. We know him as being the first to discover Saturn’s rings and large satellite Titan, but did you know Huygens held the patent for a pendulum clock? The clock ticks as the years go by on this date to reveal catastrophe. President Lincoln was shot in 1865, the Titanic sank in 1912, and who can forget that Apollo 13 met its disaster in 1970?

While today might be “bad luck” for some, it will be our good fortune to see a crater so old and ruined that it’s almost extinct. Start by identifying the three rings of Theophilus, Cyrillus and Catherina. To the south you will see the broad, bright wall of the Altai Scarp and further south a huge shallow crater on the terminator. This crater can only be seen during this particular stage of lunar sunrise and has become so dilapidated that it is unnamed. Younger craters, Lindenau and Rothman invade its northern wall and you will see a small collection of craters to the south that resemble a “paw print”. Enjoy it tonight, for it will be gone tomorrow..

Friday, April 15 – In a wide swath, the Moon will occult open cluster NGC 2331 for observers across Europe. While no specific details are listed for times, you can visit the IOTA map to see where the event will take place. For the San Francisco Bay area, the Moon will deliver a splendid graze of Epsilon Geminorum on this date. Please consult with IOTA to plan for this event. For the rest of us? We’ll see the Moon about five degrees north of Saturn.

Tonight, let’s take a quiet journey on the lunar surface as we view the area highlighted in this week’s photo – the Caucasus Mountains. Easily spotted in both binoculars and small telescopes, this mountain range towers around 5182 meters above the surrounding plains – making its peaks as high as Mount Ararat. As the shadows throw the rugged terrain into bold relief, take the time to enjoy watching the terminator move on the lunar surface. As time passes you can easily note the mountain’s shadows shortening and details emerge in Crater Cassini. It’s a very peaceful experience…

While you are waiting for the sunlight to advance, keep a watch for the “April Fireballs”. This unusual name has been given to what may be a branch of the complex Virginid stream which began earlier in the week. The absolute radiant is unclear, but keep your eyes on the southeastern skies. These bright bolides can possibly arrive in a flurry depending on how much Jupiter’s gravity has perturbed the meteoroid stream. Even if you only see one tonight, keep watching in the days ahead. The time for “April Fireballs” will last for two more weeks!

Saturday, April 16 – Tonight the Moon is furthest (apogee) from Earth at 404,304 km, but a bright star – Pollux will visually appear much closer at slightly more than a degree to the north. For viewers in the southwestern portion of North America, the Moon will occult Epsilon Geminorium on this universal date. Please check IOTA for precise times in your area.

If you explore the lunar surface this evening, you will find a very curious feature known as the Alpine Valley. Located near the terminator in the north, binocular viewers might catch a glimpse of this long, narrow scar that creases through the foothills between Mare Frigorus and Mare Ibrium. Telescopically, it is fascinating. Running a distance of 177 kilometers and ranging between 1.6 to 21 kilometers wide, this gash through the Montes Alpes will show tiny crater Trouvelot to its south and stable conditions at high power will reveal a narrow fissure on its floor. It is speculated this valley was literally carved into the lunar surface as a result of a glancing impact. Enjoy it tonight!

Sunday, April 17 – Are you ready for even more meteors? Tonight is the peak of the Sigma Leonids. The radiant is located at the Leo/Virgo border, but has migrated to Virgo in recent years. Thanks to Jupiter’s gavity, this shower may eventually become part of the Virginid Complex as well. The fall rate is very weak at around one to two per hour, and the presence of the early evening Moon will definitely hamper viewing.

Since we’ve got to deal with the Moon, why not have a look at crater Eratosthenes? Just slightly north of lunar center and on the terminator, this easily spotted feature lay at the end of the Apennine Mountain range. Its rugose walls and central peaks make for excellent viewing.

Until next week? Ask for the Moon… But keep reaching for the stars! May all your journeys be at – Light Speed… ~Tammy Plotner

Monday, April 4 – Tonight our binocular and telescope study will take us to a place of intrigue… An interacting pair of galaxies that are easily observed in Ursa Major. Start by drawing an imaginary line between Phecda and Dubhe, and extend that just one step further into space as we explore the M81 and M82.

Discovered in December 1774 by JE Bode at Berlin and photographed as early as March 1899, these two deep sky favourites will appear as a pair to binoculars and low power telescope fields. The M81 is truly spiral perfection with its symmetrical structure and bright nucleus. Spanning approximately 36,000 light years in diameter, it is one of the densest known galaxies with one third of its mass concentrated at the core. Because it contains vast numbers of red and yellow giants, larger telescopes at power will see a golden “glow” to the structure – the combined luminosity of twenty billion suns.

Its neighbor – the M82 – is often mistaken in the small telescope for edge-on in appearance, but shows no sign of true spiral structure movement. Its light is polarized, leading science to believe it contains a super-massive magnetic field. The M82 is also a powerful radio source with huge masses of dust irradiated by stars possessing unusual spectral qualities. A violent outburst may have occurred within the galaxy as recently as 1.5 million years ago releasing the energy equivalent of several million exploding suns. Shock waves emanating from the M81 resemble the synchrotron radiation first associated with planetary nebula M1 – but on an enormous scale. Can you image a supernova remnant the size of an entire galactic core region?!

Roughly every one hundred million years, M81 and M82 make a “pass” at one another, reaching out with immensely powerful gravitational arms to intertwine the two galaxies. It is theorized that during the last interaction, M82 raised rippling density waves which circulated throughout M81. The result? Possibly the most perfectly formed spiral galaxy in all of space, but M81’s influence left M82 a broken galaxy – filled with exploded stars and colliding gas – a galaxy so violent it emits X-rays. Reactions induced by colliding dust and gas caused the birth of numerous brilliant stars – stars capable of creating dense atoms and extreme motion that causes immense magnetic fields. The end may already be envisioned for the M81 and M82. Scientists speculate within a few billion years, the two galaxies will combine, becoming indistinguishable but for the welter of radiation that the union leaves behind. We known this same fate may await our own galaxy as we combine with our largest neighbor – the Andromeda Galaxy – but don’t let that stop you from viewing the M81’s intense core and smooth spiral form – or the M82’s notched spindle shape tonight…

That’s billions of years in the future.

Tuesday, April 5 – This evening we will study another pair of galaxies that can be seen in large binoculars and are outstanding for telescopic study. Identify the triangle of stars that mark the “hips” of Leo. The southwestern star is Theta and about three finger widths to its south is Iota. If skies are transparent enough to see Eta between them, then you will have no problem locating the M65 and M66 to Eta’s east/southeast.

Discovered by Mechain in March 1780, apparently Mr. Messier didn’t notice the bright pair when a comet passed between them in 1773. At around 35 million light years away, you will find the M66 to be slightly brighter than its 200,000 light year distant western neighbor – the M65. While both are Sb classed spirals, the two couldn’t appear more different. The M65 has a bright nucleus and a smooth spiral structure with a dark dustlane at its eastern edge. The M66 has a more stellar core region with thick, bright arms that show knots to larger scopes – as well as a wonderful extension from the southern edge. If you are viewing with a larger scope, you may notice to the north of this famous pair yet another galaxy! The NGC 3628 is a similar magnitude edge-on beauty with a great dissecting dark dustlane. This pencil-slim, low surface brightness galaxy is a bit of a challenge for smaller scopes, but larger ones will find its warped central disc well worth high power study.

Congratulations! You’ve just conquered the “Leo Trio”.

Wednesday, April 6 – Tonight let’s head for another trio of galaxies that are suited best for mid-to-large aperture telescopes. Begin by heading west about a fist’s width from Regulus and identify 52 Leonis. Our mark is one and a half degrees south.

At lower power you will see a triangle of galaxies. The largest and brightest is the M105 discovered by Mechain on March 24, 1781. This dense elliptical galaxy would appear to be evenly distributed, but the Hubble Space Telescope revealed a huge area within its core to be equal to about 50 million solar masses. Companion elliptical to the northeast – NGC 3384 will reveal a bright nucleus as well as an elongated form. The most faint of this group – NGC 3389 is receding spiral and for larger scopes will reveal a “patchiness” in structure.

Continue another degree south and enjoy another galactic pair. The widely spaced M96 and M95 are part of this galaxy grouping known as Leo I. The dusty spiral – M96 – will appear as a silver oval, whose nucleus is much sharper than its faint spiral arms that contained a supernova as recently as 1998. To M96’s west, you will discover one very beautiful barred spiral – M95. While both of these were discovered by Mechain only four days earlier than the M105, it wasn’t until recent years that they became the prime target of the Hubble Space Telescope. We enjoy the M95 for its unique ring-like arms and unmistakable barred core, but the HST was looking for cephid variables and determining the Hubble Constant. While we don’t need a space telescope to view this group of galaxies, we can now appreciate knowing that we can see 38 million light years away from our own backyard!

Thursday, April 7 – On this day in 1991, the Compton Gamma Ray Observatory (GRO) was deployed by space shuttle Atlantis. After serving for more than 9 years, the CRO plunged to a fiery death in the Pacific Ocean, but we can celebrate its accomplishments by viewing a source of gamma rays – the M87.

You may be able to detect the M87’s round glow with large binoculars slightly more than a fist’s width east of Epsilon Virginis with an 8th magnitude star, but telescope users will enjoy the most massive and luminous of all known galaxies. But there is much more here than meets the eye! Also known as Virgo A, the M87 is the fifth most intense radio source in the sky – 3C 274. It is also home to more than 4000 globular clusters (the Milky Way contains about 110) and a 4,000 light year long “jet” of high speed particles that could be associated with a black hole.

Friday, April 8 – Today’s highlight is a hybrid solar eclipse! Without the cursory lecture of safe solar observing techniques, observers in parts of Costa Rica, Panama, Venezuela and Columbia will enjoy the most exciting part of the show as the Sun moves from annular to total – and back to annular again around local sunset. For observers in Central America, the Caribbean and parts of South America, you will enjoy a spectacular partial eclipse that ranges anywhere from 80 to 90% coverage. Most of Mexico will get to see about half of the Sun in shadow, while the southern United States ranges from 20 to 40%. The northern-most limit cuts across central New Jersey, Pennsylvania, Ohio, Indiana, and southern Illinois and begins a southward arc ending in southern Arizona and California. For observers south of this line, it is still worth seeing a “bite” taken out of the Sun’s edge! For a list of times and many more details, please visit “Mr. Eclipse” – Fred Espenak – at this page.

Wishing you clear skies.

(Take advantage of tonight’s new moon to just roam around and enjoy the galaxy fields of Virgo. Never stress about identifying all you see, for the pleasure is just seeing them!)

Saturday, April 9 – This morning will present a unique opportunity for those who enjoy watching Jupiter’s moons. At 04:53 UT (12:43 a.m. ESDT), Io, Europa and Calisto will form a very close dance to Jupiter’s east. This formation will last for about an hour and will be well worth watching them move slowly apart.

Let’s use tonight’s dark sky to enjoy a “Jupiter-sized” planetary nebula – the M97. Often referred to as the “Owl”, you will find this sometimes difficult object about two and a half degrees south of Beta Ursae Majoris. Discovered on February 16, 1781 by the unsung hero Mechain, its visual brightness makes it a candidate for larger binoculars, but it takes a large aperture telescope to truly appreciate.

Graced by a 14th magnitude central star – one of the hottest known – this planetary nebula is highly unusual because we cannot clearly define its distance. The “Owl” is very complex, and its appearance has often been interpreted as a cylindrical torus viewed at an acute angle. What we see as “eyes” may be the less dense ends of the cylinder. The shell itself is encased by a fainter nebula or lower ionization. While we once believed this type of formation was the result of an ancient novae, the M97 re-defines our thinking. This quiet type of emission activity may just be the result of a star’s old age… Giving the ancient “Owl” a place of honour in the north.

Sunday, April 10 – Tonight’s singular destination can be detected as a faint glow in binoculars, can be found with the smallest of telescopes, but provides a stunning view with aperture. Set your sights on bright Spica and head eleven degrees due west…

Once again discovered by Mechain, the M104 – “Sombrero” – is one of the finest examples of an edge-on galaxy in the night sky. The “Sombrero” has a huge, bulging bright core region, well-defined spiral arms and a bold, dark dustlane. The core region is highly conspicuous and contains a vastly populated globular cluster system. As the dominating member of the 104 group, this fantastic galaxy is the one of the very first discovered in redshift. At around 400 million light years away, it is receding at about 700 miles per second, but that won’t stop you from enjoying its wonderful transparent qualities and star spangled field!

Until next week? Keep looking up and enjoying the wonders of the Cosmos! Light speed… ~Tammy Plotner

Image credit: NOAO/AURA/NSF
Monday, March 28 – This date is a very important one for Heinrich W. Olbers. It was on this night in 1802 that he discovered his second asteroid – Pallas – while observing Ceres (discovered 15 months earlier). Only five years later in 1807, Olbers discovered Vesta on this same night making it the fourth to be found.

Race ahead of the Moon tonight and head out early to view asteroid Pallas using just binoculars. At around magnitude 7, Pallas can be found tonight west of Epsilon Virginis, but telescope users are in for an exclusive treat! Using low power, locate M59 and M60 – asteroid Pallas will be in the same field of view for most observers just north of M59 and will be far brighter than any nearby star. Both the M59 and M60 are two of the most massive ellipticals in the Virgo cluster and both are roughly 60 million light years distant. Sharp-eyed observers with larger scopes will also see spiral galaxy NGC 4647 in the same lower power field, making this observation even better.

Wishing you clear skies for this event…

Tuesday, March 29 – For Southern Hemisphere viewers, try your hand at detecting Comet C/2005 A1 LINEAR while it passes near Zeta Phoenix on this universal date.

Tonight let’s use the later rise of the Moon to our advantage and head about 2 degrees northeast of star 13 in Monoceros. Our study will be NGC 2261 – more commonly known as “Hubble’s Variable Nebula”. Named for Edwin Hubble, this 10th magnitude object is not only very blue in appearance to larger apertures, but is a true enigma. Fuelling star, variable R Monoceros does not display normal stellar spectrum and may be a protoplanetary system. R is usually lost in the high surface brightness of the “comet-like” structure of the nebula, yet the nebula itself varies with no predictable timetable – perhaps due to dark masses shadowing the star. We do not even know how far away it is, because there is no detectable parallax!

Wednesday, March 30 – For observers in Hawaii, this will be your opportunity to watch the Moon occult Sigma Scorpii and Antares on this universal date. Please check this IOTA webpage for times in your area.

Our large binocular and telescope study for this evening is located roughly halfway between Sirius and Alpha Monoceros – NGC 2359. Known as “Thor’s Helmut”, this bubble-like emission nebula was blown into existence by a super-heated blue giant star in its center. The NGC 2359 spans about 30 light years and is about 15,000 light years away. The fuelling Wolf-Rayet star produces high speed stellar winds which may have interacted with a nearby molecular cloud, giving this strange nebula its curved shape. At magnitude 11, “Thor’s Helmut” is an unusual observation to add to your collection.

Thursday, March 31 – Did you miss your chance at Pallas? Then head back out tonight with the telescope as the moving asteroid will now be approximately one half degree east/southeast of the M90 for most observers. The M90’s outer arms no longer contain star-forming regions, but it’s one of the largest spiral galaxies in the Virgo cluster. Moving toward us, it is possible this galaxy has already escaped the cluster’s influence. (For those observing with large telescopes, magnify and see if you can catch 14th magnitude companion IC 3583.) Using low power, enjoy this wonderful 10th magnitude spiral galaxy and the bright “traveller” in the same field.

For a real challenge, try spotting IC 2118 about a thumb’s width west of Beta Orionis before it sets. “The Witch Head Nebula” is a huge area of reflection illuminated by Rigel, but is very faint. With excellent conditions you may be able to spot some patches of nebulosity.

Be sure to watch for any meteors which may be associated with the Eta Draconid meteor shower. These infrequent fliers can be attributed to Comet Abell (1954 X) and are still being studied.

Friday, April 1 – Today in 1960 the first weather satellite – Tiros 1 – was launched. If weather provides you with clear skies this evening, let’s work on a study that is within both binocular and telescopic ability. Turn left at Betelgeuse and you will find open cluster NGC 2244 about 2 degrees east of Epsilon Monoceros.
Containing around two dozen resolvable stars, a good, dark night will treat binocular and low power telescope users to the NGC 2237 – “Rosette” nebula. Surrounding this pretty open cluster like a faint, misty wreath – the “Rosette” may be one of the most massive nebulae known. It is possible that the star cluster may have used all the “raw material” in formation, leaving the center clear… And it is equally probable that the intense radiation of these hot, young blue stars simply blew away the gas. Either way, this pair will become an annual favourite.

If you see a “shooting star” tonight, it could be one of the Tau Draconids!

Saturday, April 2 – Today in 1845, the first photograph of the Sun was taken. While solar photography and observing is the domain of properly filtered telescopes, no special equipment is necessary to see some effects of the Sun – only the correct conditions. Right now Earth’s magnetosphere and magnetopause (the point of contact) are positioned correctly to interact with the Sun’s influencing interplanetary magnetic field (IMF) – and the plasma stream which flows past us as solar winds. During the time around equinox, this leaves the door wide open for one of the most awesome signs of Spring – aurora! Visit the Geophysical Institute to sign up for aurora alerts and use their tools to help locate the position of the Earth’s auroral oval.

Sunday, April 3 – Tonight Jupiter will be at opposition – meaning its celestial longitude is 180 degrees from the Sun and will be visible all night long. You will be able to watch the transit of Europa’s shadow between 16:30 and 19:11 UT, and Io’s shadow from 23:23 until 01:35 UT on April 4. Also viewable will be the “Great Red Spot” which will make its appearance at 04:23 and 14:19 and for viewers further west, 00:15 UT on April 4.

While out observing, be on the lookout for the Kappa Serpentid meteor shower, whose radiant is near Corona Borealis. The fall rate will be about 5 per hour.

Until next week? Ask for the Moon, but keep reaching for the stars! Light speed… ~Tammy Plotner

Image credit: Alwyn Botha
Monday, March 21 – For readers looking for an exceptional morning challenge with either binoculars or small scopes, try 8th magnitude comet C/2003 T4 LINEAR. On this date it will be in the same binocular field west of the M2 and continue southeast toward Beta Aquarii over the next four mornings.

Tonight the most outstanding feature on the lunar surface will be the “Bay of Rainbows” – Sinus Iridum. Take the time to power up on the area and enjoy its many wonderful features such as bright Promontoriums LaPlace to the northeast and Heraclides to the southwest. It is ringed by the Juras Mountains where you will spot crater Bianchini in the center with Sharp to its west. Look for the punctures Helicon and Le Verrier in the smooth sands of Mare Ibrium and the long, smooth “dune” of Dorsae Heim interrupted by C. Herschel.

Tuesday, March 22 – Tonight there will be two meteor showers – the Camelopardalids and the March Geminids. While the Camelopardalids have no definite peak, they have a screaming fall rate of about one per hour and are the slowest recorded meteors at 7 kps. The March Geminids were discovered in 1973 and confirmed in 1975. The fall rate is usually about 40 per hour and they are considered “slow”. With the bright skies tonight, it will be difficult to distinguish them, but trace back to the point of origin to identify which stream.

While bright Aristarchus and the graceful old Gassendi will try to steal tonight’s lunar show, continue on towards the Southern Highlands to look for the long ellipse of crater Schiller near the limb. Small crater Bayer borders its northeastern edge.

Born on this day in 1799 was Friedrich Argelander, creator of the first international astronomical organization. Argelander also compiled star catalogues and studied variable stars. With deep sky studies improbable for the next few days, why don’t we try taking a look at a variable ourselves? RT (star 48) Aurigae is a bright cephid that is located roughly halfway between Epsilon Geminorum and Theta Aurigae. This perfect example of a pulsating star follows a precise timetable of 3.728 days and fluxes by close to one magnitude.

Wednesday, March 23 – Tonight let’s travel to the far southern edge of the lunar surface to visit three craters. Past study, the lava-filled Wargentin, is bordered by shallow Nasmyth to the east and Phoclydes to the southeast. This pair makes a wonderful “impression” on the Moon, for together they look like a giant shoe print!

The first photo of the Moon was taken tonight in 1840 by J.W. Draper. (Yes, it was done in 1839 by L.J.M. Daguerre – but contained no detail.) Why don’t you try as well? Camcorders, webcams and digital cameras are inexpensive ways of experimenting and even a common disposable camera can yield surprising results when held to the eyepiece of a telescope. Circle your thumb and index finger around the pair to aid in alignment and block stray light. Just click and say “green cheese”…

Thursday, March 24 – With the lunar terminator highlighting crater Grimaldi on the western limb, let’s try our hand at a more difficult feature. To Grimaldi’s east you will see the complex structure of crater Damoiseau. Extending from a break on its western rim edge is a long surface “crack” that runs north to south between the pair. This challenging feature is known as Rima Grimaldi.

On this night in 1893, Walter Baade – the developer of the concept of stellar population – became the first human to resolve the Andromeda Galaxy’s companions into individual stars. Tonight we’ll stay within our own galaxy as we travel 85 light years away to learn about “The Little King” – Regulus.

Ranking as the twenty-first brightest star in the night sky, Alpha Leonis is a helium type star about 5 times larger and 160 times brighter than our own Sun. Speeding away from us at 3.7 kilometers per second, Regulus is also a multiple system whose 8th magnitude companion is easily seen in small telescopes. The companion is itself a double at around magnitude 13 and is a dwarf of an uncertain type. There is also a 13th magnitude fourth star in this grouping, but it is believed that it is not associated with Regulus since the “Little King” is moving toward it and will be about 14″ away in 785 years.

Friday, March 25 – Tonight is Full Moon and time to explore the bright ray systems that criss-cross its surface. One of the strongest will eminate from crater Tycho and head toward the southwest limb. If libration is favourable in your area, you might catch a glimpse of the Doerful Mountains on the Moon’s edge. This incredible mountain range comes within a kilometer of being as tall as the Himalayas. If the Earth and the Moon were the same size, we would find the Doerfuls are three times higher than Everest!

On this date in 1655, Christian Huygens was still celebrating his earlier discovery of Saturn’s rings when he made an even more important contribution – Titan. 350 years later, the probe named for Huygens is now exploring Saturn’s largest satellite and you can as well. Even small telescopes can easily see the first moon discovered in our solar system to have an atmosphere. Before you observe, try checking the current positions of Saturn’s moons so you know precisely where to look.

Saturday, March 26 – Heads up southwestern Australia! The Moon will occult Jupiter for you on this this universal date. Please check this IOTA page to see a path map and compute times for your location. For the majority of northern hemisphere viewers, you will get to see a very pleasing conjunction of the two around 1 degree apart.

With the strong influence of the Moon to the east, let’s journey this evening towards another lovely multiple system as we explore Beta Monocerotis. Located about a fist width northwest of Sirius, Beta is one of the finest true triple systems for the small telescope. At low power, the 450 light year distant white primary will show the blue B and C stars to the southeast. If skies are stable, up the magnification to split the E/W oriented pair. All three stars are within a magnitude of each other and make Beta one of the finest sights for late winter skies.

Sunday, March 27 – Tonight as the Moon rises, check the eastern limb where you will see the terminator has advanced toward the eastern edge of Mare Crisium. With the shadows throwing its mountained walls into relief, we can see where this Washington state-sized area could possibly have been impact formed. Crisium is unique simply because it does not connect to any other mare. While the walls don’t seem that high at around 450 meters, that’s comparable to taking on the Vasques Cirque vertical drop at Winter Park, Colorado… without the skis!

Until next week? Keep smiling and looking up! May all your journeys be at light speed… ~Tammy Plotner