NGC 4490/4485 – T. Grossman, D. Hager and R. Johnson
Way out yonder some 40 to 50 million light years away in the constellation of Canes Venetici is a pair of interacting galaxies sometimes referred to as “The Cocoon”. These two mis-shaped blobs of star stuff have already made their closest approach to each other and are now parting ways. Between them stretches a trail of stars that spans some 24,000 light years as they face each other showing off their numerous star-forming regions. But where there is life… There is death. Let’s put our finger right on the pulse of a supernova. Continue reading “Taking The Pulse Of A Supernova – NGC 4490”
ISS astronaut Soichi Noguchi has been sharing lots of amazing pictures he’s taken in space via Twitter, but this one is extra special. Noguchi was able to capture the plasma trail produced by space shuttle Endeavour as it streaked through Earth’s atmosphere. “Space Shuttle Endeavour making S-turn during atmospheric re-entry,” Noguchi wrote on his Twitpic page, where he post his space photos from Twitter, @Astro_Soichi. “The first time it was photographed from Space Station Cupola. Priceless.”
Just think of the precision it took to be able to take this image. Noguchi and the space station were flying about 354 km (220 miles) above Earth, going about 28,163 kph (17,500 mph), and the shuttle was likely flying just under Mach 25 — the speed it is going as it enters Earth’s atmosphere. Priceless indeed!
Have you been watching the sweet movements of Mars as it cruises across the starry nights? Perhaps, like many of us, you’re snowed in right now and could use a little mental and visual inspiration. If so, then step inside and let’s take a look at what it’s like to enjoy clear, dark skies while riding on the ecliptic plane…
This sumptuous image was taken.. well, tomorrow, actually. If you’re into stellar patterns, then it didn’t take you long to notice the stars were “upside down” in relation to the background – a sure clue it came from the southern hemisphere. And you’d be right! The photo is a ten-second exposure taken with a tripod mounted Nikon camera and done by the one and only “Tasmanian Devil” – Shevill Mathers. (And how I’d love to be exposed to 10 seconds of that kind of sky action!)
Can you imagine just stepping out your back door and seeing the stars so bright and beautiful? For those of us who may never get a chance to travel out of our earthly hemisphere, the vision would be incredible – but all wrong for what we know. Why? Because we’re simply accustomed to certain things being in a certain place in the sky, and one of the most imprinted of all is the ecliptic plane. Nope, it’s not a flight you can hop to another country where the weather is warmer, but it is the apparent path the Sun follows across the sky during the year and the projection of the Earth’s orbital plane onto the celestial sphere. The ecliptic plane would seem to move to the east along this imaginary spherical surface, the celestial sphere, in relation to the fixed stars. In this case, the (well, almost) fixed set of stars we’re looking at is Messier Object 44, but where will Mars go next? Not precisely in the direction you might think.
While we might believe the planets also follow the ecliptic plane exactly, that’s just not so. Our solar system members follow the invariable plane of a planetary system, also called Laplace’s invariable plane. Without getting too technical, this means a slight change in the magnitude of the angular momentum of the planets, as well as a change in their direction (precession) because the rotational axes are not parallel to the orbital axes. Add to that the galactic plane and set everything spinning. If you think that’s confusing, then just imagine the ecliptic being on the “wrong” side of the sky!
Whether it’s right or wrong, Mars and Messier 44 will still be dancing around with each other for many days yet to come. Be sure to catch this lovely vision and try not to get dizzy!
Many thanks to Shevill Mathers for sharing a southern summer night with us!
Friday’s close conjunction of the full Moon and Mars was spectacular… “if” you weren’t surrounded by clouds! Did you get a chance to see it – or better yet take a photo? Then why not share…
Thanks to some time zone differences, not only was the Moon “full” on January 29, 2010 – it was also the “blue” Moon for observers in Tasmania and Australia. Even though skies were cloudy there as well, Shevill Mathers of Southern Cross Observatory had an opportunity to photograph the pair just before an upcoming storm.
As luck would have it, the view was pretty much the same worldwide, but perhaps some of you caught the solar system dance in a photo of your own? Then why not share with the rest of us. Feel free to post a link to your image!
Twitpic of Golden Gate Bridge in San Francisco, CA from the ISS on Jan 30, 2010 Credit Astronaut Soichi Noguchi
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“Golden Gate Bridge, San Fransisco, CA. Beautiful shadow :-),” tweeted Astronaut Soichi Noguchi along with a live image he shot from space from inside the International Space Station.
The 5 man crew comprising Expedition 22 aboard the ISS now have the capability to transmit live, unfiltered views and comments from space. And whats more is that starting on Feb. 1 they’ll be streaming live video from the outpost, orbiting some 220 miles above the earth while speeding along at 17,500 MPH.
Astronaut TJ Creamer twittered the first unassisted post only 1 week ago on Jan 22.
Yesterday afternoon (Jan 30) he tweeted about his next picture targets, “Gonna try to take some pix of the Moon and the mesospheric clouds.”
“Noctilucent clouds. Antarctic. Priceless.” Credit: Astronaut Soichi NoguchiNoguchi sent down other beautiful shots, including “priceless” noctilucent clouds above Antarctica, city lights above Tokyo, and Port-Au-Prince, Haiti with “prayers” from the crew. He shot these In between his station work.
Noguchi tweeted on Jan 29, that he was working with the Japanese robotic arm (JEMRMS) which is attached to Japan’s giant “Kibo” science research module. “JMSRMS is working just fine-just like sim on the ground. I am very excited. The task is to check the status of external experiment facility. KOOL:-).” Kibo is the largest research laboratory on the ISS.
You can follow all the tweets from three of the crew; Astronauts Soichi Noguchi, TJ. Creamer and Jeff Williams at this link: http://twitter.com/NASA_Astronauts
“Great Saturday on board ISS. Taking photos of Earth, preparing for Shuttle arrival, Station maintenance, and calls home.” Reports Jeff Williams in the newest tweet.
“Our internal cameras wlll stream to the Web beginning Monday [Feb 1] ! Wave when you see us!! :)” tweets Creamer.
The live video will be available during all crew duty hours and when the complex is in contact with the ground through its high-speed communications antenna and NASA’s Tracking and Data Relay Satellite System. Live streaming video of the earth and the stations exterior has been available since March 2009.
Meanwhile, everything remains on schedule for the Feb. 7 launch of STS 130 to deliver the Tranquility and Cupola modules.
Away in Pegasus and 225 million light years from Earth, a barred spiral galaxy designated as NGC 7771 spans across 164,000 light years of space. It is a part of a small galaxy group consisting of lenticular galaxy NGC 7770 to the south and edge-on NGC 7771A to the west connected to magnificent spiral NGC 7769. But horsefeathers doesn’t mean this little clump of galactic partners is nonsense… Horsefeathers are what we need to make an intergalactic duster just to see them!
“This interacting group of galaxies reside behind an amazing amount of foreground dust. This high latitude dust reflects the light from our own galaxy.” says astrophotographer, Ken Crawford. “This dust makes color changes by scattering light, especially blue light making image processing a challenge. This dust is very faint and I enhanced it to make it easier to see its interesting structures.”
Not only does looking through a dust cloud make imaging galactic structure more difficult, but it also makes studying galactic structure more difficult, too. “We present a multiwavelength study of the interacting starburst galaxy NGC 7771, including new optical and ultraviolet spectra and a previously unpublished soft X-ray ROSAT image and spectrum. The FIR, radio, and X-ray fluxes suggest that a massive burst of star formation is currently in progress, but the small equivalent width of the Balmer emission lines, the weak UV flux, the low abundance of ionized oxygen, and the shape of the optical spectrum lead us to conclude that there are few O stars. This might normally suggest that star formation has ceased, but the barred gravitational potential and large gas reserves of the galaxy imply that this should not be so, and we therefore consider other explanations.” says Richard Davies, et al. “We argue that the observations cannot be due to effects of geometry, density-bounded nebulae, or dust within the nebulae, and conclude that a truncated IMF is required. The dwarf galaxy NGC 7770 appears to be in the initial stages of a merger with NGC 7771, and the resulting tidal perturbations may have induced the apparent two-armed spiral pattern, and driven a substantial fraction of the disk gas inwards. The presence of a bulge in NGC 7771 may be moderating the starburst so that, while still occurring on a large scale with a supernova rate of 0.8-1/yr, it is less violent and the IMF has a relatively low upper mass limit. We find that there is a cluster of stars obscuring part of the starburst region, and we offer an explanation of its origin.”
Through Ken’s mastery of imaging, we don’t need quite such sophisticated equipment to take a look at all the action going on with the NGC 7771 grouping. The primary galaxy’s well known starburst ring easily distinguishes itself and the tidal tails of its interacting companions come to light. Is it possible this giant molecular dust cloud could be contributing to the rapid formation of stars? Or… Is the region itself causing all the dust?
“Many statistical studies of interacting galaxies have shown that galaxy interactions can enhance star-forming activity. Luminous infrared galaxies are galaxies which emit the bulk of their energy in the far-infrared (FIR) and often show signs of interaction, such as tidal tails, multiple nuclei, or disturbed outer envelopes. LIRGs are considered to be extreme objects, where strong starbursts are induced by galaxy interactions, because in many such objects star formation can account for the infrared emission.” says T. Hattori (et al). “Theoretical work supports the idea that interactions play an important role in stimulating starbursts in galaxies. Numerical simulations of merging gas-rich spiral galaxies show that during the merging process, gas clouds lose their angular momentum and flow into the circumnuclear region of the host galaxies. The resulting high concentration of molecular gas can fuel star-formation activity in the circumnuclear region. This is consistent with compact nuclear starbursts and gas condensation in ultra-luminous infrared galaxies observed in mid-infrared. Therefore, a nuclear starburst triggered by gas inflow has generally been assumed to be the mechanism for producing enhanced star formation in interacting galaxies.”
Although it sounds good in theory, the reality check is the dust is between us and the galaxy grouping – like a thin fog seen at a great distance. Says Ken, “The interesting fact is this dust is illuminated by our own galaxy and reflected back to us. This dust scatters light, especially the blue light and this scattering is called light extinction. Light extinction plays havoc on color balance when it is this prominent and it makes processing a challenge.”
It’s a challenge we’re glad you took on… Because the results are amazing!
Many thanks to outstanding astrophotographer Ken Crawford for sharing his amazing work with us…
Caption: Annular solar eclipse on January 15, 2009. Courtesy Daniel Fischer, “cosmos4u” on Twitter.
The first of two solar eclipses to occur in 2010 took place Friday, January 15. This was an annular eclipse, which means the Sun was not totally covered by the Moon, creating a “ring of fire.” The eclipse was visible from a 300-km-wide track that passed over central Africa, across the Indian Ocean, over the southern tip of India and the northern end of Sri Lanka, and then across parts of Bangladesh and Myanmar. At the center of the track, the eclipse endured for 11 minutes and eight seconds, setting a record that won’t be beaten until December 23, 3043. Weather cooperated in many regions, allowing good viewing conditions. Here are a few images and videos from Daniel Fischer, who was in Varkala, India, and another group who calls themselves Eclipse Hunt 2010 crew were in Jaffna, Sri Lanka. The image above is from Fischer, who said via Twitter that his travels to view the eclipse was a total success. “Deep blue sky, not a single cloud all day, photo plans worked.”
Annular eclipse, Jan 15, 2010 by Shehal Joseph and Romayne Anthony. Courtesy Elipse Hunt 2010 website
This image is from the Eclipse Hunt 2010 crew, in northern Sri Lanka. It was taken by Shehal Joseph and Romayne Anthony. They used a Celestron NexStar 5se telescope with a focal length of 1.25m, and an energy rejection filter.
Why the “ring of fire?” During an annular eclipse, the moon is a little further than average away from the earth and its angular size in the sky is therefore slightly smaller than the angular size of the sun. So it is like the Moon is silhouetted against the Sun, and it doesn’t cover the Sun entirely. A a ring, or annulus, of sunlight can be seen around the black disk of the moon.
The Moon casts a shadow on Earth, as seen by NASA's Aqua satellite from space. Credit: NASA
NASA’s Aqua satellite was looking down from space at 1:15 p.m. Calcutta time (7:45 UTC) on January 15, 2010, and saw the Moon’s shadow cast on Earth. The Moderate Resolution Imaging Spectroradiometer (MODIS) on Aqua images this shadowed area in India and the Bay of Bengal. The shadow spanned a north-south distance of about 300 kilometers (185 miles) on the surface, with the darkest part near the mid-point of the span.
The Sun's chromosphere was visible in a long exposure. Credit: T. Kampschulte
This is another image from the Fischer’s group of astrophotographers in India. By taking a long-exposure image, the sun’s chromosphere was able to be seen.
Normally with an annular eclipse, not a lot of science is able to be done, said Jay Pasachoff, who leads the IAU’s working group on eclipses. “Because it doesn’t get completely dark, we won’t be able to see the solar corona, the diamond ring, or the fantastically interesting and beautiful phenomena that one sees at a total solar eclipse, but still annular eclipses are interesting to see,” Pasachoff said on the 365 Days of Astronomy podcast. “You have to keep a solar filter on to look through for the whole time. The partial phases that last an hour and a half and the annular phase, which, for this eclipse, lasts, in many places, over ten minutes – very long for an eclipse.”
Interestingly, the images shown here by Fischer’s group used a very low-tech combination of a compact camera and their filters were two “rescue sheets,” the thin aluminum foil-like thermal blankets usually given out during emergency situations, such as the recent earthquake in Haiti.
A high resolution image from a telescope in India. Credit: T. Kampschulte
This high-resolution image obtained using a telescope was taken by Fischer’s group in India. “The Ring of Fire is closed, but just barely; it measures a few arc seconds only in places in this super-sharp telescopic image,” said Fischer, via Twitter.
The next solar eclipse will be a total eclipse, on July 11th, 2010. “That won’t be seen by very many people at all,” said Pasachoff. “It is largely over the Pacific Ocean, where it will cross some normally uninhabited atolls not far from Tahiti, so there’ll be some ships there and some few expeditions out of Tahiti to see that. The major land in the way is a very unusual island, Easter Island. It’s in the middle of the Pacific, some 4,000 miles west of the coast of Chile.”
Although there has been plenty of moonlight to go around and frigid temperatures in many parts of the world, that’s not going to stop what’s happening in the sky. Not only is Mars back on the observing scene, but it’s also getting close enough that details are becoming more and more clear. Would a little frost have stopped Percival Lowell? Darn right it wouldn’t…. And it hasn’t stopped John Chumack either.
“Despite the brutally cold weather last night, I decided to brave it for a couple of hours in my back yard to capture Mars.” said John, “Mars is looking pretty nice and growing fast as it get closest and brightest at the end of this month. Currently it is 97% lit. This is my first attempt this opposition with a DMK firewire camera and 10″ Schmidt Cassegrain Telescope.”
Although John claims “poor seeing”, using a camera helps to even the odds and his image reveals some outstanding details such as the North Polar Ice Cap (top), Acidalia Planitia (top center), Terra Meridiana (lower right), and Valles Marineris (lower left). For sharp-eyed observers, you can even spot some bright fluffy clouds forming on the far left limb and a small hint of a Southern Polar Cap, too. “Mars is only 12.87 arc seconds across” says Chumack, “Still small and a bit of a challenge to get details in less than good seeing.”
So why encourage you to start your observations of Mars when it’s difficult? Because not everyone everywhere is enjoying winter’s grip and the more you practice, the better you can train your eye to catch fine details. When a planetary observer or photographer mentions “poor seeing” conditions, it doesn’t necessarily mean clouds as much as it means an unstable atmosphere which causes the view to swim, or be difficult to bring into focus. You may find that a hazy night offers great stability, while a very clear one doesn’t! It’s all in chance, and you won’t know what your chances are unless you take them. Right now Mars is well positioned in Leo and an easy catch for even those who are just beginning in astronomy.
To help you understand what you are seeing, you’ll need to know which side of Mars you’re looking at at any given time. When it comes to map generation, no one does it finer than Sky & Telescope Magazine and their Mars Profiler page which will help you pinpoint what’s visible at the time and date you’re viewing. While at first you may only see a small orange dot with a few dark markings, the key is not to give up… You don’t need a camera to see details, only patience. It may take a few seconds, or several minutes before a moment of clarity and stability arrives, but when it does you will pick up a detail that you didn’t notice at first glance. It may be a polar cap, or dark wedge of a surface feature… But they will appear. A great way to help train your eyes to catch these types of details is to sketch what you are seeing. Don’t worry! No one will be around to grade your drawings. By focusing your attention and recording it on paper, you’ll soon find that you’re observing a lot more than you ever thought you could!
Move over, Percival… Mars is back and so are we.
Many thanks to Sky & Telescope Magazine and especially to John Chumack for braving the Ohio deep freeze and providing us all with some inspiration!
If you’re celebrating your Christmas Eve with clear skies and new optics, then why not have a little seasonal fun? Let’s begin before the Moon sets…
Earth as seen from Apollo 8 (credit—NASA).As you’re setting up, let your mind time travel back to December 22. 1968, when the first US live telecast from a manned spacecraft in outer space was transmitted at 3:01 p.m. from Apollo VIII. Earth appeared in this transmission as a blurred ball of light. The craft was 139,000 miles from Earth, 31 hours after launch. Once you’re ready, let’s take a look at the Moon and view some of these features through our telescope and binoculars as we remember astronaut Jim Lovell’s words…
Image taken through Apollo 8 window while passing over the lunar surface.‘‘Roger. For information, we’re passing over just to the side of the crater Langrenus at this time, going into the Sea of Fertility. The Moon is essentially gray, no color; looks like plaster of Paris or sort of a grayish beach sand. We can see quite a bit of detail. The Sea of Fertility doesn’t stand out as well here as it does back on Earth. There’s not as much contrast between that and the surrounding craters. The craters are all rounded off. There’s quite a few of them, some of them are newer. Many of them look like—especially the round ones—look like hit by meteorites or projectiles of some sort. Langrenus is quite a huge crater; it’s got a central cone to it. . .Okay over to my right are the Pyrenees Mountains coming up and we’re just about over Messier and Pickering [Messier A] right now…’’
Agrippa and Godin - Credit: Wes HigginsTonight there are craters galore to explore: Plato, Aristotle, Eudoxus, Archimedes. . . But let’s head to the north of Sinus Medii and have a look at a pair we’ve not yet encountered on our lunar travels – Agrippa and Godin. The larger of the two, Agrippa, measures around 46 kilometers in diameter and drops to a depth of 3,070 meters. To the south is Godin, which is somewhat smaller at 35 kilometers in diameter, but a bit deeper at 3,200 meters. Note how Godin’s interior slopes toward its central peak.
Earthrise (credit—Apollo 8/NASA)In 1968, Apollo 8 became the first manned spacecraft to orbit the Moon. Until this date, no one had seen with their own eyes what lay beyond. Frank Borman, James Lovell, and William Anders were to become the first to directly view the ‘‘dark side’’ – and so would be the first to witness Earthrise over the Moon. If you enjoyed this year’s lunar studies, let your mind take flight! What courage it took for these brave individuals to journey so far from hearth and home…
“And from the crew of Apollo 8, we close with good night, good luck, a Merry Christmas, and God bless all of you, all of you on the good Earth.” –Astronaut Frank Borman
Just as surely as Apollo passed over the terminator into lunar sunset, so the Moon shall set giving us a chance to explore tonight’s astronomical object – a celebration of both starlight and asterism. Located 10 degrees east of Betelgeuse, you’ll have to wait until later for it to be seen to advantage – but that only means enjoying some hot cocoa or eggnogg while you wait!
Monoceros MapNow head slightly more than a fist width northeast of Betelguese (RA 6:41.1 Dec +09:53) to put you in the area for NGC 2264 – also known as “the Christmas Tree” cluster. This bright asterism of two dozen bright and 100 fainter stars is embroiled in a faint nebulosity visible only through very dark skies, but its delightful “Christmas Tree” shape, adorned with stars, can be seen through the smallest binoculars or telescopes. The very brightest of these stars, S Monoceros, is 5th magnitude and shows clearly in the finderscope as a double. Steady skies will reveal that the “star” at the top of our “tree” is also a visual double and home to the beautiful, dark “Cone Nebula.” Many of the stars will also appear to have companions arrayed in faint hues of silver and gold.
Christmas Trees and Cones- JP MetsavainioThe “Christmas Tree Cluster,” was given its name 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.
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, which is fairly large, but faint, and accompanies an 11th magnitude star. NGC 2247 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.
This is one of many presents from the Cosmos… Enjoy!
Only one more day left until Christmas Eve, and astronomers have just discovered a unique feature on the lunar surface. Although accepted for many years to be a natural feature of selenography, modern astrophotography coupled with today’s high-powered telescopes have discovered an area near the lunar North Pole that’s apparently being used as a runway by a man in a red suit piloting an unusual spacecraft…
Be sure to spark the imaginations in your young viewers (or simply enjoy the holiday smile) as you show them the Alpine Valley!
Tonight’s outstanding feature will be the lunar Vallis Alpes. Located near the terminator in the lunar “North Pole”, this wonderful gash in the landscape very conspicuously cuts across the lunar Alps just west of crater Aristotle. As you view this 180 km long and (at points) less than 1 km wide feature, ask yourself how it was formed. While it looks very artificial with limited aperture and possibly like it could have been formed by a glancing blow from a small asteroid, it’s actually a volcanic/tectonic feature called a sinuous rille.
If Santa were to look up along the southeast side of the Alpine Valley, he’d see a very tall linear cliff that’s slightly concave – like an amphitheater. To the northwest would be a small series of hills leading up the the grand lunar Alps. To the south would be another curved mountain ring about 16 or 17 miles in length, and from 3 to 4 miles in width. This forms the gorge, bordered on the east by sheer vertical cliffs, towering thousands of feet above the bottom of the valley. The valley floor is a flat, lava-flooded surface that is divided by a slender, cleft-like rille. Chances are this “little runway” was once a graben that which was flooded with magma.
But tonight? It’s the most special place not on Earth!
Many thanks to Wes Higgins for the holiday smiles and to Dietmar Hager for his equally splendid lunar photography.
