A Cosmic Flying Pencil — with Hair!

Pencil Nebula (NGC 2736) captured by ESO’s La Silla Observatory in Chile. Credit: ESO

This odd-shaped cloud of gas and dust is nicknamed the Pencil Nebula, as the brightest part resembles a pencil. But this pencil looks like it has hair, flying off into the breeze! But that’s no simple breeze: these glowing filaments in NGC 2736 were created by a supernova explosion that took place about 11,000 years ago, and they are moving through the interstellar medium at about 650,000 kilometers (403,000 miles) per hour.

NGC 2736, also called Herschel’s Ray, as it was discovered by British astronomer John Herschel in 1835, is a small part of a supernova remnant in the southern constellation of Vela (The Sails). This detailed new image was taken by the Wide Field Imager on the MPG/ESO 2.2-metre telescope at the La Silla Observatory in Chile. A wider view, below, shows the full view of the Pencil Nebula’s place in the region.

Wide-field view of the sky around the Pencil Nebula. Credit: ESO

The Vela supernova remnant is an expanding shell of gas that originated from the supernova explosion. Initially the shock wave was moving at millions of kilometers per hour, but as it expanded through space it plowed through the gas between the stars, which has slowed it considerably and created strangely shaped folds of nebulosity. The Pencil Nebula is the brightest part of this huge shell.

This new image shows large, wispy filamentary structures, smaller bright knots of gas and patches of diffuse gas. The nebula’s luminous appearance comes from dense gas regions that have been struck by the supernova shock wave. As the shock wave travels through space, it rams into the interstellar material. At first, the gas was heated to millions of degrees, but it then subsequently cooled down and is still giving off the faint glow that was captured in the new image.

By looking at the different colors of the nebula, astronomers have been able to map the temperature of the gas. Some regions are still so hot that the emission is dominated by ionized oxygen atoms, which glow blue in the picture. Other cooler regions are seen glowing red, due to emission from hydrogen.

The Pencil Nebula measures about 0.75 light-years across. ESO says that remarkably, even at its distance of approximately 800 light-years from Earth, at the speed it is traveling means that it will noticeably change its position relative to the background stars within a human lifetime.

The video below zooms in to the Pencil Nebula:

Source: ESO

Weekly SkyWatcher’s Forecast: September 3-9, 2012

Greetings, fellow SkyWatchers! With the change in seasons becoming quickly apparent, it’s time to put some early hours dark skies to good use and enjoy some favorite nebulae. If you’ve enjoyed the Mars-mania, then you’ll also enjoy the return of Mars in the pre-dawn hours. Speaking of early mornings, be sure to watch as the Moon and Jupiter head for a splendid conjunction this coming Saturday. When you’re ready, grab your binoculars and set up your telescopes… It’s time to dance!

Monday, September 3 – Tonight it’s time for us to head directly between the two lower stars in the constellations of Lyra and grab the “Ring”.

First discovered by French astronomer, Antoine Darquier in 1779, the “Ring” was cataloged later that year by Charles Messier as M57 (Right Ascension: 18 : 53.6 – Declination: +33 : 02). In binoculars the “Ring” will appear as slightly larger than a star, yet it cannot be focused to a sharp point. To a modest telescope at even low power, the M57 turns into a glowing donut against a wonderfully stellar backdrop. The average accepted distance to this unusual structure is believed to be around 1,400 light years and how you see the “Ring” on any given night is highly attributable to conditions. As aperture and power increase, so do details and it is not impossible to see braiding in the nebula structure with scopes as small as eight inches on a fine night, or to pick up the star caught on the edge in even smaller apertures.

Like all planetary nebula, seeing the central star is considered the ultimate of viewing. The central itself is a peculiar bluish dwarf which gives off a continuous spectrum and might very well be a variable. At times, this shy, near 15th magnitude star can be seen with ease with a 12.5? telescope, yet be elusive to 31? in aperture weeks later. No matter what details you may see, reach for the “Ring” tonight. You’ll be glad you did.

Tuesday, September 4 – Of course, studying some of the summer’s finest means that we’d be very remiss if we didn’t look at another cosmic curiosity – “The Blinking Planetary”.

Located a couple of degrees east of visible star Theta Cygnii, and in the same lower power field as 16 Cygnii, the NGC 6826 (Right Ascension: 19 : 44.8 – Declination: +50 : 31) is often referred to as the “Blinking Planetary” nebula. Viewable in even small telescopes at mid to high power, you’ll learn very quickly how it came about its name. When you look directly at it, you can only see the central 9th magnitude star. Now, look away. Focus your attention on visual double 16 Cygnii. See that? When you avert, the nebula itself is visible. This is actually a trick of the eye. The central portion of our vision is more sensitive to detail and will only see the central star. At the edge of our vision, we are more likely to see dim light, and the planetary nebula appears. Located around 2,000 light years from our solar system, it doesn’t matter if the “Blinking Planetary” is a trick of the eye or not… Because it’s cool!

Wednesday, September 5 – If you’re up before dawn, maybe you’ve noticed the return of Mars? It’s been on the move and this universal date marks its official change in position from the constellation of Virgo into the constellation of Libra.

Don’t put away your binoculars tonight just because you think this next study is beyond you… Just lift your sights three degrees higher than the “Omega” and tonight we’ll return again to fly with the “Eagle” – M16 (Right Ascension: 18 : 18.8 – Declination: -13 : 47)

Small binoculars will have no trouble distinguishing the cluster of stars discovered by de Cheseaux in 1746, but larger binoculars and small telescopes from a dark sky site will also see a faint nebulosity to the region that was reported by Messier in 1764. This “faint light” will remind you highly of the reflection that is seen within the Pleiades, or “Rosette” nebula. While the most outstanding views of the “Eagle” nebula are in photographs, larger telescopes will have no problem picking out a vague cloud of nebula, encased stars and an unusual dark obscuration in the center which has always reminded this author as a “Klingon Bird of Prey”. While all of this is very grand, what’s really interesting is the little notch on the northeast edge of the nebula. This is easily seen under good conditions with scopes as small as 8? and is undeniable in larger aperture. This tiny “notch” rocketed to worldwide fame when viewed through the eyes of the Hubble. It’s name? “The Pillars of Creation”.

Thursday, September 6 – Today celebrates the founding of the Astronomical and Astrophysical Society of America. Started in 1899, it is now known as the American Astronomical Society.

Tonight let’s relax a little bit and have a look at a superb open cluster that stays superb no matter if you use small binoculars or a big telescope. Of whom do I speak so highly? M34 (Right Ascension: 2 : 42.0 – Declination: +42 : 47)…

Easily found on Perseus west border by scanning between Beta Perseii (Algol) and Gamma Andromeda (Almach), the M34 was discovered by Messier in 1764. Containing around 80 members, the central knot of stars is what truly makes it beautiful. At around 1400 light years away, this stellar collection is believed to be around 10 million years old. While binocular users are going to be very happy with this object, scopists are going to appreciate the fact that there is a double right in the heart of M34. This fixed pair is around magnitude 8 and separated by about 20?.

Friday, September 7 – Tonight we are going to take a journey once again toward an area which has intrigued this author since I first laid eyes on it with a telescope. Some think it difficult to find, but there is a very simple trick. Look for the primary stars of Sagitta just to the west of bright Albireo. Make note of the distance between the two brightest and look exactly that distance north of the “tip of the arrow” and you’ll find the M27 (Right Ascension: 19 : 59.6 – Declination: +22 : 43).

Discovered in 1764 by Messier in a three and a half foot telescope, I discovered this 48,000 year old planetary nebula for the first time in a 4.5? telescope. I was hooked immediately. Here before my eager eyes was a glowing green “apple core” which had a quality about it that I did not understand. It somehow moved… It pulsated. It appeared “living”.

For many years I quested to understand the 850 light year distant M27, but no one could answer my questions. I researched and learned it was made up of doubly ionized oxygen. I had hoped that perhaps there was a spectral reason to what I viewed year after year – but still no answer. Like all amateurs, I became the victim of “aperture fever” and I continued to study the M27 with a 12.5? telescope, never realizing the answer was right there – I just hadn’t powered up enough.

Several years later while studying at the Observatory, I was viewing through a friend’s identical 12.5? telescope and as chance would have it, he was using about twice the magnification that I normally used on the “Dumbbell”. Imagine my total astonishment as I realized for the very first time that the faint central star had an even fainter companion that made it seem to wink! At smaller apertures or low power, this was not revealed. Still, the eye could “see” a movement within the nebula – the central, radiating star and its companion.

Do not sell the “Dumbbell” short. It can be seen as a small, unresolved area in common binoculars, easily picked out with larger binoculars as an irregular planetary nebula, and turns astounding with even the smallest of telescopes. In the words of Burnham, “The observer who spends a few moments in quiet contemplation of this nebula will be made aware of direct contact with cosmic things; even the radiation reaching us from the celestial depths is of a type unknown on Earth…”

Saturday, September 8 – Heads up for early risers! This morning is a beautiful conjunction of Jupiter and the Moon. For viewers in the western regions of Southern America, this is an occultation event, so be sure to check for times in your area!

Today in 1966, a legend was born as the television program Star Trek premiered. Created by Gene Roddenberry, its enduring legacy inspired several generations to an interest in space, astronomy, and technology. Its five-year mission still airs – along with numerous movie and series sequels. May Star Trek continue to “live long and prosper!”

Tonight a great opportunity to have another look at all the things we’ve studied this week. However, I would encourage those of you with larger binoculars and telescopes to head for a dark sky location, because tonight we are going on a quest… The quest for the holy “Veil”.

By no means is the Veil Nebula Complex an easy one. The brightest portion, NGC 6992 (Right Ascension: 20 : 56.4 – Declination: +31 : 43), can be spotted in large binoculars and you can find it just slightly south of a central point between Epsilon and Zeta Cygnii. The NGC 6992 is much better in a 6-8? scope however, and low power is essential to see the long ghostly filaments which span more than a degree of sky. About two and a half degrees west/southwest, and incorporating star 52 is another long narrow ribbon of what may be classified as a supernova remnant. When aperture reaches the 12? range, so does the true breadth of this fascinating complex. It is possible to trace these long filaments across several fields of view. They sometimes dim and at other times widen, but like a surreal solar flare, you will not be able to tear your eyes away from this area. Another undesignated area lies between the two NGCs, and the whole 1,500 light year distant area spans over two and a half degrees. Sometimes known as the “Cygnus Loop”, it’s definitely one of the summer’s finest objects.

Sunday, September 9 – On this day in 1839, John Herschel froze time by making the very first glass plate photograph – and we’re glad he did. His photo was of his father William’s famous 40-foot telescope in Slough, England. The scope had not been used in decades and was disassembled shortly after the photograph was taken. Later in 1892, on this same day, Edward Emerson Barnard was busy at Lick Observatory discovering Jupiter’s innermost moon – Amalthea.

Do I always save the best for last? You bet. And tonight it’s my favorite galaxy structure – edge-on.

The NGC 7814 (Right Ascension: 0 : 03.3 – Declination: +16 : 09) is easy enough to find. Just head towards Gamma Pegasi and look in your finderscope for a star that is around 3 degrees to the northwest. At low power you will see the galaxy to the southeast of this star as a scratch of light. Up the power in both aperture and magnification and enjoy! This galaxy has a deeply concentrated nucleus and a very prominent dissecting dark dustlane. By the way… It’s Caldwell 43.

Until next week? Wishing you clear skies!

Four views of M57 – Credit: NOAO/AURA/NSF

WISE Spies a Hunter’s Flame

A vast star-forming cloud of gas and dust in the constellation Orion shines brightly in this image from NASA’s WISE space telescope, where infrared light is represented in visible wavelengths. It’s part of a recent data release from WISE, a trove of infrared images acquired during the telescope’s second sky scan from August to September of 2010 — just as it began to run out of its essential cryogenic coolant.

Shining brightly in infrared radiation, the Flame nebula (NGC 2024) is at the heart of the cloud.  Just below it is the reflection nebula NGC 2023, and the small, bright loop protruding from the edge of the gas and dust cloud just to its lower right is the Horsehead nebula  — whose famous equine profile appears quite different in infrared light than it does in visible.

The two bright blue stars at the upper right portion of the image are both stars in Orion’s belt. Alnitak, the brighter one closer to the Flame nebula, is a multiple star system located 736 light-years away whose stellar wind is responsible for ionizing the Flame nebula and causing it to shine in infrared. Alnilam, the dimmer star at the uppermost corner, is a blue supergiant 24 times the radius of our Sun and 275,000 times as bright, but 1,980 light-years distant.

The red arc at lower right is the bow shock of Sigma Orionis, a multiple-star system that’s hurtling through space at a speed of 5,260,000 mph (2,400 kilometers per second). As its stellar wind impacts the interstellar medium and piles up before it, an arc of infrared-bright radiation is emitted.

Sigma Orionis is also the star responsible for the glow of the Horsehead nebula.

This rich astronomical scene is an expanded view from WISE’s previously-released image of the region (at right) which used data from only three of its four infrared detectors. In contrast, all four detectors were used in the image above, making more of the nebulae’s intricate structures visible as well as providing comparative information for researchers.

“If you’re an astronomer, then you’ll probably be in hog heaven when it comes to infrared data,” said Edward (Ned) Wright of UCLA, the principal investigator of the WISE mission. “Data from the second sky scan are useful for studying stars that vary or move over time, and for improving and checking data from the first scan.”

Read more on the NASA news release here.

Top and right images: NASA/JPL-Caltech/WISE team. Horsehead nebula visible light image was taken with the 0.9-meter telescope at Kitt Peak National Observatory. Photo credit & copyright: Nigel Sharp (NOAO), KPNO, AURA, NSF. Comparison by J. Major/Universe Today.

By Thor’s Mighty Helmet!

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Going to see the new Avengers movie this weekend, either for the first or fortieth time? You may not see much of Thor’s helmet in the film (as he opts for more of a “Point Break” look) but astronomers using the Isaac Newton Group of telescopes on the Canary Islands have succeeded in spotting it… in this super image of the Thor’s Helmet nebula!

Named for its similarity to the famous horned Viking headgear (seen horizontally), the Thor’s Helmet nebula is a Wolf-Rayet structure created by stellar winds from the star seen near the center blowing the gas of the bluish “helmet” outwards into space via pre-supernova emissions.

The colors of the image above, acquired with the ING’s Isaac Newton Telescope, correspond to light emitted in hydrogen alpha, doubly-ionised oxygen and single-ionised sulfur wavelengths.

Super-sized for the thunder god himself, Thor’s Helmet measures at about 30 light-years across. It’s located in the constellation Canis Major, approximately 15,000 light-years from Earth. (You’d think Thor would have left his favorite accessory in a more convenient location… I suspect Loki may be behind this.)

Astronomers, assemble!

Read more about this and see other images from the ING telescopes here.

The Isaac Newton Group of Telescopes (ING) is owned by the Science and Technology Facilities Council (STFC) of the United Kingdom, and it is operated jointly with the Nederlandse Organisatie voor Wetenschappelijk Onderzoek (NWO) of the Netherlands and the Instituto de Astrofísica de Canarias (IAC) of Spain. The telescopes are located in the Spanish Observatorio del Roque de los Muchachos on La Palma, Canary Islands, which is operated by the Instituto de Astrofísica de Canarias (IAC).

Alien Life May Not Be So Alien – If It Exists At All

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Are we too hopeful in our hunt for extraterrestrial life? Regardless of exoplanet counts, super-Earths and Goldilocks zones, the probability of life elsewhere in the Universe is still a moot point — to date, we still only know of one instance of it. But even if life does exist somehow, somewhere besides Earth, would it really be all that alien?

In a recent paper titled “Bit by Bit: the Darwinian Basis for Life” Gerald Joyce, Professor of Molecular Biology and Biochemistry at the Scripps Research Institute in La Jolla, CA discusses the nature of life as we know it in regards to its fundamental chemical building blocks — DNA, RNA — and how its ability to pass on the memory of its construction separates true biology from mere chemistry.

“Evolution is nothing more than chemistry plus history,” Joyce said during a Public Library of Science podcast.

The DNA structures that evolved here on Earth — the only place in the Universe we know for certain that life can thrive — have proven to be highly successful (obviously). So what’s to say that life elsewhere wouldn’t be based on the same basic building blocks? And if it is, is it really a “new” life form?

“Truly new ‘alternative life’ would be life of a different biology,” Joyce said. “It would not have the information in it that is part of the same heritage of our life form.”

To arise in the first place, according to Joyce, new life can take two possible routes. Either it begins as chemical connections that grow increasingly more complex until they begin to hold on to the memory of their specific “bit” structure, eventually “bit-flipping” — aka, mutating — into new structures that are either successful or unsuccessful, or it starts from a more “privileged” beginning as an offshoot of previous life, bringing bits into a totally new, immediately successful orientation.

With those two scenarios, anywhere besides Earth “there are no example of either of those conditions so far.”

That’s not saying that there’s no life elsewhere in the Universe… just that we have yet to identify any evidence of it. And without evidence, any discussion of its probability is still pure conjecture.

“In order to estimate probabilities, we need facts,” said Joyce. “The problem is, there is only one life form. And so it’s not possible to estimate probability of life elsewhere when you have only one example.”

Voyager included a golden record with images and sounds of Earthly life recorded on it... just in case. (NASA)

Even though exoplanets are being found on a nearly daily basis, and it’s only a matter of time before a rocky, Earthlike world with liquid water on its surface is confirmed orbiting another star, that’s no guarantee of the presence of alien life — despite what conclusions the headlines will surely jump to.

There could be a billion habitable planets in our galaxy. But what’s the relationship between habitable and inhabited?” Joyce asks. “We don’t know.”

Still, we will continue to search for life beyond our planet, be it truly alien in nature… or something slightly more familiar. Why?

“I think humans are lonely,” Joyce said. “I think humans are like Geppetto — we want to have a ‘real boy’ out there that we can point to, we want to find a Pinocchio living on some extrasolar planet… and then somehow we won’t be such a lonely life form.”

And who knows… if any aliens out there really are a lot like us, they may naturally be searching for evidence of our existence as well. If only to not be so lonely.

Listen to the full PLoS podcast here.

Weekly SkyWatcher’s Forecast – February 12-18, 2012

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Greetings, fellow SkyWatchers! As the Moon fades away, dark sky studies return and so do we as we take a look at a great collection of nebulae this week and expand your Herschel studies. Get out your binoculars and telescopes, because here’s what’s up!

Sunday, February 12 – Today is the anniversary (2001) of NEAR landing on asteroid Eros. The Near Earth Asteroid Rendezvous (NEAR) mission was the first to ever orbit an asteroid, successfully sending back thousands of images. Although it was not designed to land on Eros, it survived the low speed impact and continued to send back data. Would you like to view Eros for yourself? It will be visible a few hours after sky dark. At somewhere between magnitude 11 and 12, Eros will require at least a mid-sized telescope, but is very viewable to both hemispheres along the Hydra/Crater border… and about a handspan southwest of Mars! Be sure to check resources for a planetarium program or on-line service which will give you a precise location for your time and area.

Tonight we’ll continue onward with our studies of Lepus as we head for two more of the coveted Herschel 400 objects. Our hop starts with beautiful Gamma and NGC 2073. Located less than a fingerwidth northeast of Gamma (RA 05 45 53.90 Dec -21 59 59.0), NGC 2073 might be magnitude 12.4, but its small size makes it anything but easy. Even if it does have some highly studied molecular cloud structure, be prepared to see nothing but a tiny, egg-shaped contrast change in the elliptical Herschel 241.

Continue northeast a little more than 2 degrees (RA 05 54 52.30 Dec -20 05 03.0) to encounter Herschel 225 – NGC 2124. Although it is slightly fainter, we are at least picking up something with more recognizable structure. Oriented north/south, Herschel 225 is an inclined spiral with a bright nucleus. Set in a wonderfully rich star field, it’s difficult to spot at first with low power, but its slim structure holds up well to magnification. This one is really a pleasure.

Monday, February 13 – Today is the birthday of J.L.E. Dreyer. Born in 1852, the Danish-Irish Dreyer came to fame as the astronomer who compiled the New General Catalogue (NGC) published in 1878. Even with a wealth of astronomical catalogs to chose from, the NGC objects and Dreyer’s abbreviated list of descriptions still remain the most widely used today.

Tonight let’s make Dreyer proud as we finish up our Herschel 400 studies for Herschel 267. At magnitude 13, NGC 2076 (Right Ascension: 5 : 46.8 – Declination: -16 : 46 ) is a lot less forgiving of scope size and sky conditions than some galaxies, but if aperture and sky cooperate, you are in for a real treat! Although it is fairly small and somewhat faint, NGC 2076 is an edge-on that will show indications of a dark dustlane across its brighter nucleus, when using aversion. The lane itself has been highly studied for dust extinction and star forming properties and as recently as 2003 a supernova event was reported just south of the nucleus.

Now let’s drop south about one degree and pick up Herschel 270! Far brighter at magnitude 11.9, don’t let the ordinary elliptical NGC 2089 (Right Ascension: 5 : 47.8 – Declination: -17 : 36) fool you. What would appear to be a stellar nucleus is indeed stellar. Studies done by AAVSO have shown that the bright point of light is actually a line of sight star. Congratulations on your studies and be sure to write down your Herschel “homework!”

Tuesday, February 14 – Happy Valentine’s Day! Today is the birthday of Fritz Zwicky. Born in 1898, Zwicky was the first astronomer to identify supernovae as a separate class of objects. His insights also proposed the possibility of neutron stars. Among his many achievements, Zwicky also catalogued galaxy clusters and designed jet engines.

In mythology, Lepus the Hare is hiding in the grass at Orion’s feet. As we have seen, there are many objects of beauty hidden within what seems to be a very ordinary constellation. Before we leave the “Rabbit” for this year, there is one last object that is worthy of attention. If you look to the feet of Orion and the brightest star of Lepus, you will see that they make a triangle in the sky. Tonight we are headed towards the center of that triangle for a singular object – the Spirograph Nebula.

Shown in all its glory through the eye of the Hubble Telescope, the light you see tonight from the IC 408 (Right Ascension: 5 : 17.9 – Declination: -25 : 05) planetary nebula left in the year 7 AD. Its central star, much like our own Sol, was in the final stages of its life at that time, and but a few thousand years earlier was a red giant. As it shed its layers off into about a tenth of a light-year of space, only its superheated core remained – its ultraviolet radiation lighting up the expelled gas. Perhaps in several thousand years the nebula will have faded away, and in several billion years more the central star will have become a white dwarf – a fate that also awaits our own Sun.

At magnitude 11, it is well within reach of a small to mid-size telescope. Like all planetary nebulae, the more magnification – the better the view. The central star is easily seen against a slightly elongated shell and larger telescopes bring an “edge” to this nebula that makes it very worthwhile studying. Spend some quality time with this object. With larger scopes, there is no doubt a texture to this planetary that will delight the eye…and touch the heart!

Wednesday, February 15 – Born on this day in 1564 was the man who fathered modern astronomy – Galileo Galilei. Two and a half centuries ago, he became first scientist to use a telescope for astronomical observation and his first target was the Moon. Just before dawn this morning you will have the opportunity to observe the waning crescent and the tiny crater named for Galileo. Almost central along the terminator and caught near the edge of Oceanus Procellarum, you will see a small, bright ring. This is Reiner Gamma and you will find Galileo just a short hop to the northwest as a tiny, circular crater. What a shame the cartographers did not pick a more vivid feature to name after the great Galileo!

With absence of the Moon in our favor tonight, it’s time to learn the constellation of Monoceros as the skies darken and Orion begins to head west. By using the red giant Betelgeuse, diamond-bright Sirius and the beacon of Procyon, we can see these three stars form a triangle in the sky with Sirius pointing towards the south. The “Unicorn” is not a bright constellation, and most of its stars fall inside this area with its Alpha star almost a handspan south of Procyon.

Using the belt of Orion as a guide, look a handspan east, this is Delta. A fistwidth away to the southeast is Gamma; with Beta about two fingerwidths further along. About a palmwidth southeast of Betelguese is Epsilon. Although this might seem simplistic, knowing these stars will help you find many wonderful objects. Let’s start our journey tonight two fingerwidths northwest of Epsilon… NGC 2186 (Right Ascension: 6 : 12.2 – Declination: +05 : 2) is a triangular open cluster of stars set in a rich field that can be spotted with binoculars and reveals as many as 30 or more stars to even a small telescope. Not only is this a Herschel 400 object that can be spotted with simple equipment, but a highly studied galactic cluster that contains circumstellar discs!

Thursday, February 16 – On this day in 1948, Gerard Kuiper was celebrating his discovery of Miranda – one of Uranus’ moons. Just 42 years earlier on this day, both Kopff and Metcalf were also busy – discovering asteroids! Today is the birthday of Francois Arago. Born in 1786, Arago became the pioneer scientist in the wave nature of light. His achievements were many and he is also credited as the inventor of the polarimeter and other optical devices.

Tonight let’s celebrate Arago’s achievements in polarization as we return again to Epsilon Monocerotis. Our destination is around a fingerwidth east as we seek out another star cluster that has an interesting companion – a nebula!

NGC 2244 (Right Ascension: 6 : 32.4 – Declination: +04 : 52) is a star cluster embroiled in a reflection nebula spanning 55 light-years and most commonly called “The Rosette.” Located about 2500 light-years away, the cluster heats the gas within the nebula to nearly 18,000 degrees Fahrenheit, causing it to emit light in a process similar to that of a fluorescent tube. A huge percentage of this light is hydrogen-alpha, which is scattered back from its dusty shell and becomes polarized.

While you won’t see any red hues in visible light, a large pair of binoculars from a dark sky site can make out a vague nebulosity associated with this open cluster. Even if you can’t, it is still a wonderful cluster of stars crowned by the yellow jewel of 12 Monocerotis. With good seeing, small telescopes can easily spot the broken, patchy wreath of nebulosity around a well-resolved symmetrical concentration of stars. Larger scopes, and those with filters, will make out separate areas of the nebula which also bear their own distinctive NGC labels. No matter how you view it, the entire region is one of the best for winter skies.

Friday, February 17 – Tonight is a good time for us to go hunting some obscure objects that will require the darkest of skies. Once again, we’ll use our guide star Epsilon and tonight we’ll be heading about three fingerwidths northeast for a vast complex of nebulae and star clusters.

To the unaided eye, 4th magnitude S Monocerotis is easily visible and to small binoculars so are the beginnings of a rich cluster surrounding it. This is NGC 2264 (Right Ascension: 6 : 41.1 – Declination: +09 : 53). Larger binoculars and small telescopes will easily pick out a distinct wedge of stars. This is most commonly known as the “Christmas Tree Cluster,” its name given by Lowell Observatory astronomer Carl Lampland. With its peak pointing due south, this triangular group is believed to be around 2600 light-years away and spans about 20 light-years. Look closely at its brightest star – S Monocerotis is not only a variable, but also has an 8th magnitude companion. The group itself is believed to be almost 2 million years old.

The nebulosity is beyond the reach of a small telescope, but the brightest portion illuminated by one of its stars is the home of the Cone Nebula. Larger telescopes can see a visible V-like thread of nebulosity in this area which completes the outer edge of the dark cone. To the north is a photographic only region known as the Foxfur Nebula, part of a vast complex of nebulae that extends from Gemini to Orion.

Northwest of the complex are several regions of bright nebulae, such as NGC 2247, NGC 2245, IC 446 and IC 2169. Of these regions, the one most suited to the average scope is NGC 2245 (Right Ascension: 6 : 32.7 – Declination: +10 : 10), which is fairly large, but faint, and accompanies an 11th magnitude star. NGC 2247 (Right Ascension: 6 : 33.2 – Declination: +10 : 20) is a circular patch of nebulosity around an 8th magnitude star, and it will appear much like a slight fog. IC 446 is indeed a smile to larger aperture, for it will appear much like a small comet with the nebulosity fanning away to the southwest. IC 2169 is the most difficult of all. Even with a large scope a “hint” is all!

Enjoy your nebula quest…

Saturday, February 18 – On this day in 1930, a young man named Clyde Tombaugh was very busy checking out some photographic search plates taken with the Lowell Observatory’s 13″ telescope. His reward? The discovery of Pluto! And just where is the planet that isn’t a planet any more? You can find it before dawn! The little rascal is hiding out in a very stellar field just east of M25 and a couple of degrees northwest of the slender crescent Moon. How do you know which faint “star” is Pluto? Well, if you set a computerized telescope to RA 18h 24m 59s – Dec 19°18’44”, it will be precisely in the center of the field if you are perfectly polar aligned. If you are using a manual telescope, you will need to sketch the field and return over a period of several days to see which “star” moves. It would be a great lesson – since early astronomers did it that way!

This evening let us return to the realm of binoculars and small telescopes as we head now for Beta Monocerotis and a little more than a fingerwidth north for NGC 2232 (Right Ascension: 6 : 26.6 – Declination: -04 : 45). This wonderful collection of stars sparkles with chains and various magnitudes – the brightest of which is 5th magnitude 10 Monocerotis. Well resolved with a small telescope, its apparent size of about a full moon-width makes it a true delight and it can even be spotted unaided from a dark sky site. Be sure to note it, because it is on many open cluster study lists.

Now head back to Beta and about the same distance west for Class D cluster NGC 2215 (Right Ascension: 6 : 21.0 – Declination: -07 : 17). At magnitude 8, it is still within the realm of binoculars, but will look like a small fuzzy patch beyond resolution. Try this one with a telescope! Set in a rich field, the compressed area of near equal magnitude stars isn’t the most colorful in the sky, but you can add another to your Herschel hits!

Until next week, may all your journeys be at light speed!

Hitchcock Haunts a Nebula

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First impression after seeing this new image of NGC 3324? It’s Alfred Hitchcock, bulbous nose and all (see image below for comparison). The right edge of the wall of gas and dust in this star-forming region really bears a strong resemblance to the famous profile of the British film director and producer, notorious for his thriller movies from the 1940’s through the 1970’s.

NGC 3324 is located in the southern constellation of Carina, roughly 7500 light-years from Earth. It is on the northern outskirts of the chaotic environment of the Carina Nebula. All the gas and dust here fueled a burst of star birth several millions of years ago and led to the creation of several hefty and very hot stars that are prominent in the new picture.

Alfred Hitchcock. Via iwatchstuff.com

A nickname for the NGC 3324 region is the ‘Gabriela Mistral Nebula,’ after the Nobel Prize-winning Chilean poet but I think I’ll start a petition to call it the Hitchcock Nebula. Hitchcock liked to make cameo appearances in his own movies, and perhaps he is making a pareidoliaic guest appearance here.

The new image of NGC 3324 was taken with the Wide Field Imager on the the European Southern Observatory’s 2.2-metre telescope at the La Silla Observatory in Chile. Read more about it on the ESO website.

Dust in the Wind

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The stellar wind, that is! This beautiful image, taken by NASA’s Wide-Field Infrared Explorer (WISE) shows a vast ring of interstellar dust and gas being forced outwards by the wind and radiation from a massive star.

The star, HR8281, is located in the center of the image, the topmost star in a small triangular formation of blue stars to the upper left of the tip of a bright elongated structure – the end of the “elephant trunk” that gives the nebula its name. The star may not look like much, but HR8281’s powerful stellar wind is what’s sculpting the huge cloud of dust into the beautiful shapes seen in this infrared image.

Located 2,450 light-years from Earth, the Elephant’s Trunk Nebula spans 100 light-years. The “trunk” itself is about 30 light-years long. (That’s about, oh… 180 trillion miles!)

Structures like this are common in nebulae. They are formed when the stellar wind – the outpouring of ultraviolet radiation and charged particles that are constantly streaming off stars – blows away the gas and dust near a star, leaving only the densest areas. It’s basically erosion on a massive interstellar scale.

The tip of the "trunk" and the triangle of stars, the topmost of which is HR8281.

It’s not just a destructive process, though. Within those dense areas new stars can form… in fact, in the bright tip of the trunk above a small dark spot can be seen. That’s an area that’s been cleared by the creation of a new star. When a baby star “ignites” and its nuclear fusion factory turns on, its stellar wind clears away the dust and gas in the cloud it was formed from. Nebulae aren’t just pretty clouds in space… they’re stellar nurseries!

The red-colored stars in this image are other newborn stars, still wrapped in their dusty “cocoons”.

The colors used in this image represent specific wavelengths of infrared light. Blue and cyan (blue-green) represent light emitted at wavelengths of 3.4 and 4.6 microns, which is predominantly from stars. Green and red represent light from 12 and 22 microns, respectively, which is mostly emitted by dust.

Read more about this image on the WISE site here.

Image Credit: NASA/JPL-Caltech/WISE Team

Where are Stars Born?

Spitzer Uncovers Star Hatchery

Have you ever wondered where stars are born? Stars are formed in nebulas, interstellar clouds of dust and gas. Nebulas are either remnants of matter from the original big bang or the result of stars either collapsing or going supernova. Nebulas have long been noted and observed by astronomers but very little was known about them until the 21st century.

Galaxies because of their similar appearance were once thought of as nebulas. It was later determined that they were actually larger grouping of stars a great distance away from the Earth. So how are Nebulas star forming regions? The answers lie in the gravitational force and nuclear fusion.

Most nebulas are disparate clouds of gas and cosmic dust floating in the interstellar medium. Nebulas are the more dense parts of the gas and dust that exist in the space between stars and galaxies. We know due to the law of universal gravitation that every particle in the universe exerts an attractive force on every other particle. This happens over times with nebulas as the particles that make up the interstellar medium start to gather together.

Since gases have mass it is inevitable that the process will continue as great mass will create a stronger gravitational field. At some undefined point in time a tipping point between the gas pressure and the gravity of the nebula is crossed and the nebula collapses under its own gravity. Since molecular hydrogen is the most abundant element in the nebula the pressure from the collapse causes the nebula to undergo nuclear fusion. This starts the birth of a star.

As evidenced by how many stars and galaxies are in the universe you can see that is process that happens just about everywhere. More recently scientists have started become interested in how common it is for stars to from planets, especially those that are likely to support life. Scientists have recently discovered one such planet Gliese 581-g. This planet while closer to it star than Earth is well with in habitable zone necessary for liquid water and the right temperatures for life to occur.

The study of nebulas and the interstellar medium have yielded a lot important information about the formation and stars. As better telescopes and probes are created we will get a clearer picture about our universe and how it was formed and continues to grow over time.

We have written many articles about the birth of stars for Universe Today. Here’s an article about the star birth myth, and here’s an article about the birth of the biggest stars.

If you’d like more information on stars, check out Hubblesite’s News Releases about Stars, and here’s the stars and galaxies homepage.

We’ve done many episodes of Astronomy Cast about stars. Listen here, Episode 12: Where Do Baby Stars Come From?

References:
http://burro.astr.cwru.edu/stu/stars_birth.html
http://sunshine.chpc.utah.edu/labs/star_life/starlife_proto.html

Beautiful Cosmic Barbeque Pit

A new infrared image from NASA's Wide-field Infrared Survey Explorer, or WISE, shows a cosmic barbeque pit, full of PAHS. Image credit: NASA/JPL-Caltech/UCLA

NASA’s Wide-field Infrared Survey Explorer, or WISE has been a busy spacecraft since its launch on Dec. 14, 2009. It has found asteroids and comets, and now has found a cosmic barbeque pit. Well, not really, but the green material in the cloud of gas and dust surrounding the Berkeley 59 cluster is from heated polycyclic aromatic hydrocarbons, (PAHs) molecules that can be found on Earth in barbecue pits, exhaust pipes and other places where combustion has occurred. The “coals,” or the glowing red is warm dust heated by hot young stars within the nebula.
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