When you see both the light echo and simultaneously hear a likeness of it in the video below, then you know those attentive comprehensions will again produce accords of sights and sounds. Love it.
^ Image credit: NASA, ESA, J. Muzerolle (STScI), E. Furlan (NOAO and Caltech), K. Flaherty (University of Arizona/Steward Observatory), Z. Balog (Max Planck Institute for Astronomy), and R. Gutermuth (University of Massachusetts, Amherst)
I’ve been doing this astronomy gig for a while now, and I’ve seen some weird stuff. It takes a lot to surprise me.
The binary star LRLL 54361 surprised me. It is seriously weird and seriously cool.
L54361 (for short) is a pair of stars orbiting each other. They are very young, probably only a hundred thousand years old (the Sun is more than 4 billion, for comparison), and are located near the edge of a gas cloud called IC 348 (seen in the gorgeous infrared Spitzer image above), itself about 950 light years from Earth. Observations taken over seven years show L54361 to be variable, changing in brightness every 25.34 days. The change is huge, too, with the system getting 10 times brighter, then fading over about a week.
Because the system is so young, it’s still surrounded by the dense material from which it formed. In detailed Hubble Space Telescope images (see the sequence below near the bottom of this post) you can see a dark line across the middle of the brightest part of the structure; that’s a thick opaque disk of dust enveloping the stars and hiding them directly from view. That makes understanding the system a little tricky; we have to infer some things given its behavior.
^ Image credit: NASA, ESA, and R. Hurt (Caltech/Spitzer Science Center)
After eliminating few possibilities, the astronomers studying L54361 came to an interesting conclusion. Clearly, the binary is throwing a rave.
No! Wait! That’s not it. Actually, the two stars are probably on very elliptical orbits around each other, passing close to each other every 25.34 days. As they orbit, they drag some of that surrounding material around with them. When they get to their closest approach this material falls onto one or both of the stars and gets incredibly hot. Like a detonation of flash powder, the material gets tremendously bright for a short period of time, sending out a huge and intense pulse of light.
But there’s more to this story. That light illuminates the surrounding material, reflecting off of it. But that stuff stretches out for a long way. A long way. Hundreds of billions of kilometers, in fact, which means it takes that pulse of light several days to make its way across. So if you observe it over time, you can see the light pulse moving through the material.
Like, say, this:
How flipping awesome is that? This phenomenon is called a light echo, because really that’s what you’re seeing: an echo made of light instead of sound. And like the way dolphins and bats use echoes to sense their environment, we can learn a lot from watching a light echo, too. The speed it appears to move through the material tells you how big the structure is (though the trigonometry can be a little tricky). You can also tell which side is the front of the material and which is the back, because the light takes longer to hit the material on the far side of the star and then reflect off it to make its way to Earth.
In this case, we can see the echo moving up what looks like a conical shell, like an ice cream cone with its tip near the stars. The interior is dark, so it must be relatively hollow, devoid of gas and dust inside the cone. That is very interesting indeed: It looks like there’s material falling inward toward the stars—the stars are still forming, still growing—but there must have been some outflow, some blow back, that carved out that empty region. It may be in part due to these episodic flashes, or it might be a wind from the young stars, like the solar wind but much stronger.
^ Image credit: NASA, ESA, and Z. Levay (STScI)
This sort of periodic episode where stuff falls in, heats up, and flashes intense bursts of light is called pulsed accretion (accretion means to grow by adding material onto something). It’s been seen a few times, but always with stars much older than this pair, usually ten times older. Clearly, with L54361 this is something unusual. Binary stars on wide elliptical orbits are rare too, plus we’re seeing them when they are very young. Astronomers really hit the lottery here.
Back when I was working on my PhD, I was studying something similar. This time, though, it was at the end of its life. It exploded, setting off a vast and short burst of light that illuminated everything around it. Because of the light echo effect, I was able to figure out a lot about that surrounding material, and researching light echoes was a lot of fun. I found a paper from the 1920s describing it, and then had to rework and rederive all the math to apply it to the object I was studying. It was tough, but solvable, and one of those times when the pure joy of just finding things out swept over me.
And that’s the reason I love these observations of L54361 so much. Once again, we have something new in the sky to figure out, and we can watch it change right before our eyes on a time scale that’s palatable to our human sensibilities.
Astronomy is so much fun! And it’s simply wonderful that even after all this time, the Universe can still manage to surprise and delight us.
Art will be the last bastion when all else fades away. ~ Timothy White (b 1952), American rock music journalist _________________
The two videos in this post might make your day. If you watch them, I hope you enjoy them! There have been many videos as well as, say, History and Discovery teevee documentaries in which the music drowns out the voiced storyteller, but not so for the NASA SDO video, below. I guess I’ve alternated viewings a half-a-dozen times now between the Tomlinson vimeo and NASA SDO YouTube production.
Three years ago today—Feb. 11, 2010—NASA launched the most sophisticated and capable Sun watcher in history: SDO, the Solar Dynamics Observatory. Equipped with a huge range of detectors, SDO has kept an unblinking eye on the Sun 24 hours a day for over 1000 days now.
It has returned to Earth valuable data on our tempestuous star, including pictures that wring dry my supply of adjectives. Jaw-dropping. Mind-blowing. Spectacular.
In its honor, NASA’s Goddard Space Flight Center put together a simply gorgeous and moving video about SDO. Take the time to soak this in; make sure it’s set to the highest definition and make it full screen.
^ NASA SDO Year Three
They have downloadable versions and links to more info on the GSFC site. I found myself smiling through this video, recognizing many of the segments, including several I’ve featured here on the blog over time. My favorites are the Transit of Venus (of course!), an erupting pillar of plasma, a huge arching prominence erupting from the Sun’s side (shown above at the top of this post), and an eclipse of the Sun by the Earth itself, when SDO passed through the Earth’s shadow.
As the Sun enters the peak of its magnetic cycle over the next few months we’ll be seeing more activity from it, and SDO will be out there in space watching carefully, helping us understand the nearest star in the Universe.
…and let me leave you with this: Video of the launch of SDO taken in 2010 by my friend Barbara Tomlinson. When the Atlas V rocket breaks the speed of sound, the shock wave sends ripples through the clouds, just as it passes a rainbow-hued sundog in the sky. It happens at 1:50 in the video, and you just have to see it to believe it.
Barbara posted a slow-motion version as well. NoisyAstronomer has a still photo from the event, too.
My thanks and congratulations to everyone on the SDO team. Here’s to many, many more years of staring at the Sun.
_________________ Music for video NASA SDO Year Three | Mistake (Davide Rossi Instrumental Re-Work) courtesy of Moby Gratis.
Art will be the last bastion when all else fades away. ~ Timothy White (b 1952), American rock music journalist _________________
^ The black hole that has grown the most can be found in the Sombrero galaxy. The researchers estimate that this black hole has been swallowing the equivalent of one Sun every twenty years and is now over 500 million times as heavy as the Sun. ESO Public Image Release
In a new study led by University of Central Lancashire astronomer Dr. Victor Debattista, researchers are looking into the mystery of how black holes grow and evolve. For many years, astronomers surmised black holes took on mass when their host galaxies merged, but now new modeling techniques show that black holes in spiral galaxies are forced to take on mass.
“Recent Hubble Space Telescope (HST) observations have revealed that a majority of active galactic nuclei (AGN) are resident in isolated disk galaxies, contrary to the usual expectation that AGN are triggered by mergers,” says Debattista. “Here we develop a new test of the cosmic evolution of supermassive black holes (SMBHs) in disk galaxies by considering the local population of SMBHs. We show that substantial SMBH growth in spiral galaxies is required as disks assemble.”
Weighing in a range of one million to one billion times that of the Sun, the black holes located at the core of most galaxies would appear to be gaining at much quicker rates than expected. These are not just exceptions – more like rules. Even the Milky Way’s quiescent black hole might be gaining as much mass as the Sun every 3,000 years. Past observations have shown growth during collision events, when huge amounts of gas around the black hole become intensely hot and shine as an active galactic nucleus. This is a process which can be spotted as far back as the first formations in our Universe. However, these new simulations are giving insight into large scale growth without the need for violence.
“The X-ray-selected sample of moderate luminosity AGN consists of more than 50% disk galaxies, with ongoing mergers evident no more frequently than in nonactive galaxies,” explains the research team. “Some show that even heavily obscured quasars are hosted largely by disks, not by mergers. Studies of star-formation using Herschel find that the specific star formation rates of X-ray selected AGN hosts are no different from those of inactive galaxies, also indicating that AGN hosts are not undergoing fundamentally different behaviors.”
These modeling techniques, combined with current observations done with the Hubble Space Telescope, give credence to the theory that black holes can gain significant mass even in “quiet” spiral galaxies. As a matter of fact, there is a strong possibility that AGNs present in some spiral galaxies may even outnumber galaxy mergers. To make this concept even more exciting, astronomers are anticipating an event later this year in our own galaxy – an event where a gas cloud near the Milky Way’s nucleus will encounter our own central black hole. According to predictions, our black hole may take on as much as 15 Earth masses in a period of 10 years from this cloud.
This concept of black hole growth isn’t entirely new, though. According to other research done with the Hubble Space Telescope and led by Dr. Stelios Kazantzidis of Ohio State University and Professor Frank C. van den Bosch of Yale University, they had previously pinpointed mass properties of black holes – making size predictions which utilized the speed of stars residing in the galaxies. In this instance, the team disproved previous assumptions that black holes were unable to grow while the host galaxy grew. Their comparison of spiral and elliptical galaxies “found there is no mismatch between how big their black holes are.” This means black holes would be gaining in mass – growing along at the same rate as the galaxy itself.
“These simulations show that it is no longer possible to argue that black holes in spiral galaxies do not grow efficiently,” comments Debattista on this new research. “Our simulations will allow us to refine our understanding of how black holes grew in different types of galaxies.”
Art will be the last bastion when all else fades away. ~ Timothy White (b 1952), American rock music journalist _________________
^ Illustration of gas cloud G2 approaching Sgr A* (ESO/MPE/M.Schartmann/J.Major)
The heart of our Milky Way galaxy is an exotic place. It’s swarming with gigantic stars, showered by lethal blasts of high-energy radiation and a veritable cul-de-sac for the most enigmatic stellar corpses known to science: black holes. And at the center of the whole mélange is the granddaddy of all the black holes in the galaxy — Sagittarius A*, a supermassive monster with 4 million times more mass than the Sun packed into an area smaller than the orbit of Mercury.
Sgr A* dominates the core of the Milky Way with its powerful gravity, trapping giant stars into breakneck orbits and actively feeding on anything that comes close enough. Recently astronomers have been watching the movement of a large cloud of gas that’s caught in the pull of Sgr A* — they’re eager to see what exactly will happen once the cloud (designated G2) enters the black hole’s dining room… it will, in essence, be the first time anyone watches a black hole eat.
But before the dinner bell rings — estimated to be sometime this September — the cloud still has to cover a lot of space. Some scientists are now suggesting that G2′s trip through the crowded galactic nucleus could highlight the locations of other smaller black holes in the area, revealing their hiding places as it passes.
In a new paper titled “G2 can Illuminate the Black Hole Population near the Galactic Center” researchers from Columbia University in New York City and the Harvard-Smithsonian Center for Astrophysics (CfA) in Cambridge, Massachusetts propose that G2, a cloud of cool ionized gas over three times more massive than Earth, will likely encounter both neutron stars and other black holes on its way around (and/or into) SMBH Sgr A*.
^ Estimated number of stellar- mass black holes to be encountered by G2 along its trajectory (Bartos et al.)The team notes that there are estimated to be around 20,000 stellar-mass black holes and about as many neutron stars in the central parsec of the galaxy. (A parsec is equal to 3.26 light-years, or 30.9 trillion km. In astronomical scale it’s just over 3/4 the way to the nearest star from the Sun.) In addition there may also be an unknown number of intermediate-mass black holes lurking within the same area.
These ultra-dense stellar remains are drawn to the center region of the galaxy due to the effects of dynamical friction — drag, if you will — as they move through the interstellar material.
Of course, unless black holes are feeding and actively throwing out excess gobs of hot energy and matter due to their sloppy eating habits, they are very nearly impossible to find. But as G2 is observed moving along its elliptical path toward Sgr A*, it could very well encounter a small number of stellar- and intermediate-mass black holes and neutron stars. According to the research team, such interactions may be visible with X-ray spotting spacecraft like NASA’s Chandra and NuSTAR.
^ NuSTAR X-ray image of a flare emitted by Sgr A* in July 2012 (NASA/JPL-Caltech)
The chances of G2 encountering black holes and interacting with them in such a way as to produce bright enough x-ray flares that can be detected depends upon a lot of variables, like the angles of interaction, the relative velocities of the gas cloud and black holes, the resulting accretion rates of in-falling cloud matter, and the temperature of the accretion material. In addition, any observations must be made at the right time and for long enough a duration to capture an interaction (or possibly multiple interactions simultaneously) yet also be able to discern them from any background X-ray sources.
Still, according to the researchers such observations would be important as they could provide valuable information on galactic evolution, and shed further insight into the behavior of black holes.
Read the full report here, and watch an ESO news video about the anticipated behavior of the G2 gas cloud around the SMBH Sgr A* below:
This research was conducted by Imre Bartos, Zoltán Haiman, and Bence Kocsis of Columbia University and Szabolcs Márka of the Harvard-Smithsonian Center for Astrophysics.
Art will be the last bastion when all else fades away. ~ Timothy White (b 1952), American rock music journalist _________________
Those of you who’ve wanted to see more of the recent near-Earth asteroid, this post oughta keep your brain busy for a while. There are lots of links in the original.
^ A photo of Asteroid 2012 DA 14 as seen from the suburbs of Paris on February 15, 2013. Credit and copyright: Thierry Legault.
Yesterday a 50 meter (160 foot) rock passed just over 27,000 kilometers (17,000 miles) from the Earth’s surface. This big space rock, named 2012 DA14, dodged us while another smaller and unrelated asteroid gave us an extraterrestrial punch over Russia (read more about that here). Telescopes around the world — both big professional ones and smaller amateur ones — focused on the fast-moving 2012 DA14, whizzing along at 28,100 kilometers per hour (17,450 miles per hour), or 7.82 kilometers per second (4.8 miles per second) relative to Earth.
Here are some of the images from around the world of 2012 DA14. Noted French astrophotographer Thierry Legault sent Universe Today a note that he “easily spotted it visually through the 4″ refractor. It was running very fast amongst the stars!” he said.
In a really nice piece of astrophotography, François Colas from the Pic du Midi observatory in southern France captured the fast moving asteroid with just the right combination of exposure, allowing him to get the asteroid as a point and not a line. He used a Pentax K5 – 6400 ASA – 85mm f/1.4. Field of view 15°
^ 2012 DA14 - 2013 feb 15th - 20h01 => 20h16 UTC
Richard Fleet from Wiltshire, England also got a good capture of the asteroid. “Clouds were a problem most of the evening but I did manage to catch it going past the Coma Berenices cluster,” he said via email. “I saw the asteroid several times in 15×75 binoculars and the motion was obvious in seconds when it was near a star, though it took a bit longer to be sure in the more barren areas.”
He used a used a 200mm lens on a Canon 5D for the very nice sequence as it ‘ran among the stars’:
^ 2012 DA14 timelapse
^ Image taken remotely from Spain on February 15, 2013 at 22:31UT, 3 hours after the close approach. Credit: Ernesto Guido and Nick Howes/Remanzacco Observatory.
The Remanzacco Observatory team has been following 2012 DA14 for a few days (click on the image above for their animation if it not ‘animating’.) See their website for several different shots from various remote telescopes around the world.
^ This image shows asteroid 2012 DA14 and the Eta Carinae Nebula, with the white box highlighting the asteroid's path. The image was taken using a 3" refractor equipped with a color CCD camera. The telescope is located at the Siding Spring Observatory in Australia and is maintained and owned by iTelescope.net. Credit: Aaron Kingery/NASA/MSFC
The Talmassons astronomy club from Udine, Italy took this imagery:
^ ast2012DA14 CAST 130215
Shahrin Ahmad from Kuala Lumpur, Malaysia posted some of his images on Google+:
^ A 30 second exposure of Asteroid 2012 DA14 passing by Theta Crateris on Feb. 15, 2013 at 19:22 UTC, as seen from Malaysia. The Moon is added for comparison. Credit: Shahrin Ahmad
Nahum Mendez Chazarra from Spain’s Centro de Investigación y Divulgación Astronómica del Mediterráneo sent the video below. You can see more images on their Facebook page.
^ 2012DA14 on 15/02/2013 closest approach to Earth
The Bareket Observatory in Israel had a live webcast of 2012 DA14′s close pass, and they reported they had more than 150K viewers overall. Here is a video they put together of some of the highlights of their observations:
^ Asteroid 2012 DA14 flies by NGC 4244 at a distance of 14 million light years. Credit and copyright: David G. Strange.
Nick Rose from San Mateo, California tracked 2012 DA14 on its way as it headed away from Earth, using a 6″ reflector with a high end Orion CCD imager on a modified Vixen Super Polaris mount, on the evening of February 15. “I inverted the image to make it easier to see the asteroid,” Nick said, “and the video consists of 100 10 second Binned 1×1 images.”
^ 2012 DA14
Mikko Suominen, a freelance science journalist from Finland created this 3-D animation based on the JPL’s information graphics using rendering software called Blender. “They ar not extremely precise,” Suominen said via email, “but for popular science purposes I think they are accurate enough.”
^ Asteroid 2012 DA14 Earth flyby
Last edited by Allegro on Mon Feb 18, 2013 3:19 am, edited 1 time in total.
Art will be the last bastion when all else fades away. ~ Timothy White (b 1952), American rock music journalist _________________
What happens when you give 1,000,000 particles their own gravity and spring repulsion and send them out to play? Watch the video above and find out.
This was created by David Moore, a self-taught computer programmer, aspiring physicist and student at San Diego Miramar College. It’s a custom code made with SDL/C++ and 8 days of render time. According to David there’s a bug at the end “where particles can get arbitrarily high energy… but before that it’s very physically accurate!”
It’s fascinating to watch the attraction process take place — one might envision a similar process occurring in the early Universe with the formation of the first galaxies and galactic clusters out of a hot, uniform state. Plus it’s great to see young talented minds like David’s working on such projects for fun!
There just might be hope for us after all.
Video by David Moore
Art will be the last bastion when all else fades away. ~ Timothy White (b 1952), American rock music journalist _________________
Cecilia Payne was born in Wendover, England in 1900. In 1919 while at Newham college at Cambridge, she became interested in astronomy after hearing a lecture by Professor Eddington about his eclipse expedition to Brazil.
Because astronomy continued to be seen as a branch of mathematics she was unable to change her major field of study to astronomy from physics. She continued however to attend Eddington’s lectures. When she finally confessed her wish to become an astronomer to Eddington his response was, “I can see no insuperable objections.” After graduating from Cambridge she became concerned about the future for women in astonomy careers in England. She chose to head toward the United States where she thought a woman might be more accepted. She received a fellowship to study at Harvard Observatory and so she headed across the seas to continue her career.
Payne quickly settled in among the women at the Harvard Observatory, working there under the director Harlow Shapley. She quickly began an investigation of the stellar spectra being compiled for the Henry Draper catalog. In 1925 Cecilia Payne became the first person, woman or man, to receive an Ph.D. in astronomy from Harvard. Shapley had attempted to get her a Ph.D. in the already existing physics department, but the chair refused. To get around this roadblock she received her Ph.D. in astronomy instead.
Her thesis, later published as the observatory’s first monograph, Stellar Atmospheres, A contribution to the Observational Study of High Temperature in the Reversing Layer of Stars was labeled at the time and for many years afterwards as “the most brilliant Ph.D. thesis ever written in astronomy.” In this thesis Payne calculated a temperature scale to match the classification system which Annie Cannon had developed.
She also theorized about the composition of the stars. She suggested that the stars were mostly hydrogen. However, when Eddington heard this theory he told her that she was wrong because astronomers at the time felt that all celestial bodies had very similar compostions. As a result, Payne wrote in her thesis that her results were improbable and probably wrong. Today, of course, we know her results were actually fairly accurate.
After her fellowship was finished, Payne was hired by Harvard and worked with the various other women then employed at the Harvard Observatory. In 1932 Payne began a tour of Europe visiting various observatories around the continent. Her final destination was Berlin for the meeting of the Astronomische Gesellschaft. She documents in her autobiography the conditions both in Russia and in Nazi Germany at the time. While in Berlin she met a young Russian Astronomer Sergei Gaposchkin and heard his plight as a Russian Astronomer in Nazi Germany. She resolved to help him get out of Europe. She found him a position at Harvard and he arrived in November 1932. Less than two years later in March 1934 Sergei and Cecilia were married.
Cecilia continued to publish and wrote several other books, some of them coauthored by her husband. Payne, with Annie Cannon, eventually received the title of Astronomer from Harvard . Despite the fact that she lectured at the University, it was not until the 1950s that Payne received the title of Professor and eventually Chair of the Astronomy Department at Harvard. Cecilia Payne-Gaposchkin is one of the great women astronomers of this century.
By 1964 there were 1.5 million mobile phone users in the US
^ Orbit | Original stills courtesy of the Image Science & Analysis Laboratory, NASA Johnson Space Center; music | ‘Eve’ by Emancipator; edited by Brian Tomlinson (UK), btprints.com.
_________________ Saturn Gets Kinky | Phil Plait Bad Astronomy | 20FEB13
The first time you see Saturn’s rings through a telescope is amazing. It can change your life—literally, as it did for me when I was a wee lad.
The rings are shocking through a big telescope. Even through a small one you can see them clearly, and with a big one you can start to see some details, like the big Cassini Division, a dark gap slicing the main ring system in two.
But there’s nothing like being there. The Cassini spacecraft (named after the Italian astronomer Giovanni Cassini, who discovered his eponymous division) has been orbiting Saturn since 2004. A masterwork of engineering, Cassini has returned thousands upon thousands of incredible images, showing amazing details in the rings.
On Dec. 25, 2012, from a distance of 1.1 million kilometers (680,000 miles), it took this phenomenal shot of Saturn’s outer rings:
^ Cassini spacecraft image of Saturn's A (upper left) and F rings. Image credit: NASA/JPL-Caltech/Space Science Institute
Saturn is off the frame to the upper left in this picture. Cassini was just over the plane of the rings, looking at them from a shallow angle. The Sun is shining down on them, so they look very bright.
The main A ring is to the upper left, and you can see the Keeler gap, a narrow (40 km/25 mile) empty region in the rings, where the ice particles that make up the rings have been swept clear by the gravity of the tiny moon Daphnis.
But the star of this show is the weird F ring (the rings were named in order of discovery, not distance from Saturn). To give you a sense of scale, the division between the A and F rings is about 3000 km (1800 miles), roughly the distance from New York City to Denver, Colorado.
The ring is narrow, and that’s no accident. Orbiting just inside and outside of it are two very small moons named Prometheus and Pandora, and they act as shepherds, constraining the ice particles into that narrow strand. Due to the vagaries of orbital mechanics, most of the particles that stray outward or inward from the ring are gently nudged back into it by the moons’ gravity.
Both moons have orbits that are slightly elliptical and slightly tipped with respect to the rings. That means, as they orbit, they move toward and away from the F ring, Prometheus more than Pandora. As it moves toward the ring, Prometheus’s gravity drags material away from it, creating those fans and kinks in the ring, as well as the faint spiral pattern of material inside the ring. Oddly, even though it does pull some of the material out of the ring, the overall effect of Prometheus is to keep the particles inside the ring. The interaction is complex and somewhat counterintuitive, but this video put out by NASA might help.
The F ring is constantly changing, sometimes on a scale of just hours. Saturn is a huge, fiendishly complex system, and we knew it would be weird when we got there, but I don’t think anyone suspected just how weird it would be. And we discovered all this because we sent a probe there that could stay there, orbiting the planet over and again, looking at as much as it can over as long a period of time as it can. Long-term visits are far, far better than a single fly-by (though they are critical as well!), because we learn how things behave over time. And everything changes over time. That’s why we need to make sure that when we visit other places, other worlds, we do so with the plans to go there and stay. It’s the only way we can learn over the long run.
Art will be the last bastion when all else fades away. ~ Timothy White (b 1952), American rock music journalist _________________
This post is a redesign of the original to make all things viewable. Thank You.
_________________ As seen on SpaceWeather dot com | 22FEB13
TWO COMETS AND THE SOUTHERN LIGHTS: Two comets are now visible in the skies of the southern hemisphere: "Comet Lemmon and Comet PanSTARRS got close enough together on the morning of Feb. 17th to fit into single image with a 35mm lens," reports Alex Cherney of Flinders, Victoria, Australia. "A brief but reasonably strong aurora was a welcome bonus." Click to set the scene in motion:
"Both comets were faint but visible to the naked eye, C/2011 L4 (PanSTARRS) slightly brighter than C/2012 F6 (Lemmon)," says Cherney. "I would guestimate the visual magnitude of Comet Lemmon at +5.5 and PanSTARRS at +5." Also visible in Cherney's images are the Small Magellanic Cloud and the 47 Tuc globular star cluster.
Comet Pan-STARRS is heading for a close encounter with the sun just inside the orbit of Mercury that could significantly boost its visibility in early March. At that time, the comet will be visible to northern-hemisphere observers as well. A video from NASA explores the possibilities.
[Allegro put the above mentioned NASA video right here.]
Art will be the last bastion when all else fades away. ~ Timothy White (b 1952), American rock music journalist _________________
by Allegro » Fri Feb 08, 2013 3:42 am 
