Shiny New Supernova Spotted in Nearby Galaxy

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Literally an event of stellar proportions, a new Type Ia supernova has been identified in a spiral galaxy 25 million light-years away! Spotted by Caltech’s Palomar Transit Factory project, this supernova, categorized as PTF11kly, is located 58″.6 west and 270″.7 south of the center of M101. It was first seen yesterday, August 24, 2011.

According to AAVSO Special Notice #250 P. Nugent et al. reported in Astronomical Telegram #3581 that a possible Type-Ia supernova has been discovered by the Palomar Transient Factory shortly after eruption in the galaxy M101 and has been designated “PTF11kly”. The object is currently at a magnitude of 17.2, but may well rise by several magnitudes. The object is well placed within M101 for good photometry, and observations of this potential bright SNIa are strongly encouraged.

There are currently no comparison stars available in VSP for this field; please indicate clearly the comparison stars that you use for photometry when reporting observations to AAVSO. Please retain your images and/or photometry for recalibration when comparison star magnitudes are available.

Need coordinates? The (J2000) coordinates reported for the object are RA: 14:03:05.81 , Dec: +54:16:25.4. Messier 101 is located in the constellation of Ursa Major at RA: 14h 03m 12.6s Dec: +54 20′ 57″

Charts for PTF11kly may be plotted with AAVSO VSP. You should select the DSS option when plotting, as the galaxy will not appear on standard charts. This object has been assigned the name “PTF11kly” for use with AAVSO VSP and WebObs; please use this name when reporting observations until it is conclusively classified as a supernova and a proper SN name is assigned.

Image of M101 and PTF11kly by Joseph Brimacombe.

Type Ia supernovae are the result of a binary pair of mismatched stars, the smaller, denser one feeding on material drawn off its larger companion until it can no longer take in any more material. It then explodes in a catastrophic event that outshines the brightness of its entire galaxy! Astronomers believe that Type Ia supernovae occur in pretty much the same fashion every time and thus, being visible across vast distances, have become invaluable benchmarks for measuring distance in the Universe and gauging its rate of expansion.

The fact that this supernova was spotted literally within a day of its occurrence – visibly speaking, of course, since M101 is 25 million light-years away and thus 25 million years in our past – will be extremely handy for astronomers who will have the opportunity to study the event from beginning to end and learn more about some of the less-understood processes involved in Type Ia events.

“We caught this supernova earlier than we’ve ever discovered a supernova of this type. On Tuesday, it wasn’t there. Then, on Wednesday, boom! There it was – caught within hours of the explosion. As soon as I saw the discovery image I knew we were onto something big.”

– Andy Howell, staff scientist at Las Cumbres Observatory Global Telescope

It’s a big Universe and there are a lot of stars and therefore a lot of supernovae, but getting a chance to study one occurring so recently in a galaxy so relatively close to our own is something that is getting many astronomers very excited.

So, get those CCD camera out and best of luck!

Keep up with the latest news on PTF11kly on the rochesterastronomy.org site, and check out Phil Plait’s informative article on his BadAstronomy blog. Also read the press release from the University of California here.

Tammy Plotner also contributed to this article.

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Jason Major is a graphic designer, photo enthusiast and space blogger. Visit his website Lights in the Dark and follow him on Twitter @JPMajor and on Facebook for more astronomy news and images!

WISE Discovers Some Really “Cool” Stars!

[/caption]What would you say if I told you there are stars with a temperature close to that of a human body? Before you have me committed, there really is such a thing. These “cool” stars belong to the brown dwarf family and are termed Y dwarfs. For over ten years astronomers have been hunting for these dark little beasties with no success. Now infrared data from NASA’s Wide-field Infrared Survey Explorer (WISE) has turned up six of them – and they’re less than 40 light years away!

“WISE scanned the entire sky for these and other objects, and was able to spot their feeble light with its highly sensitive infrared vision,” said Jon Morse, Astrophysics Division director at NASA Headquarters in Washington. “They are 5,000 times brighter at the longer infrared wavelengths WISE observed from space than those observable from the ground.”

Often referred to as “failed stars”, the Y-class suns are simply too low mass to ignite the fusion process which makes other stars shine in visible light. As they age, they fade away – their only signature is what can be spotted in infrared. The brown dwarfs are of great interest to astronomers because we can gain a better understanding as to stellar natures and how planetary atmospheres form and evolve. Because they are alone in space, it’s much easier to study these Jupiter-like suns… without being blinded by a parent star.

“Brown dwarfs are like planets in some ways, but they are in isolation,” said astronomer Daniel Stern, co-author of the Spitzer paper at JPL. “This makes them exciting for astronomers — they are the perfect laboratories to study bodies with planetary masses.”

The WISE mission has been extremely productive – turning up more than 100 brown dwarf candidates. Scientists are hopeful that even more will emerge as huge amounts of data are processed from the most advanced survey of the sky at infrared wavelengths to date. Just imagine how much information was gathered from January 2010 to February 2011 as the telescope scanned the entire sky about 1.5 times! One of the Y dwarfs, called WISE 1828+2650, is the record holder for the coldest brown dwarf, with an estimated atmospheric temperature cooler than room temperature, or less than about 80 degrees Fahrenheit (25 degrees Celsius).

“The brown dwarfs we were turning up before this discovery were more like the temperature of your oven,” said Davy Kirkpatrick, a WISE science team member at the Infrared Processing and Analysis Center at the California Institute of Technology in Pasadena, Calif. “With the discovery of Y dwarfs, we’ve moved out of the kitchen and into the cooler parts of the house.”

Kirkpatrick is the lead author of a paper appearing in the Astrophysical Journal Supplement Series, describing the 100 confirmed brown dwarfs. Michael Cushing, a WISE team member at NASA’s Jet Propulsion Laboratory in Pasadena, California, is lead author of a paper describing the Y dwarfs in the Astrophysical Journal.

“Finding brown dwarfs near our Sun is like discovering there’s a hidden house on your block that you didn’t know about,” Cushing said. “It’s thrilling to me to know we’ve got neighbors out there yet to be discovered. With WISE, we may even find a brown dwarf closer to us than our closest known star.”

Given the nature of the Y-class stars, positively identifying these special brown dwarfs wasn’t an easy task. For that, the WISE team employed the aid of the Spitzer Space Telescope to refine the hunt. From there the team used the most powerful telescopes on Earth – NASA Infrared Telescope Facility atop Mauna Kea, Hawaii; Caltech’s Palomar Observatory near San Diego; the W.M. Keck Observatory atop Mauna Kea, Hawaii; and the Magellan Telescopes at Las Campanas Observatory, Chile, and others – to look for signs of methane, water and even ammonia. For the very coldest of the new Y dwarfs, the team used NASA’s Hubble Space Telescope. Their final answer came when changes in spectra indicated a low temperature atmosphere – and a Y-class signature.

“WISE is looking everywhere, so the coolest brown dwarfs are going to pop up all around us,” said Peter Eisenhardt, the WISE project scientist at NASA’s Jet Propulsion Laboratory, Pasadena, California, and lead author of a recent paper in the Astronomical Journal on the Spitzer discoveries. “We might even find a cool brown dwarf that is closer to us than Proxima Centauri, the closest known star.”

How cool is that?!

Original Story Source: JPL News Release.

Graphenes In Spaaaaaace!

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And just where have your buckyballs been lately? More technically known as fullerenes, this magnetic form of carbon shows some pretty interesting properties deduced from laboratory work here on Earth. But even more interesting is its cousin – graphene. And guess where it’s been found?!

When you picture a fullerene, you conjure up a mental image of carbon atoms arranged in a three-dimensional configuration with two structures: C60 which patterns out similar to a soccer ball and C70 which more closely resembles a rugby ball. Both of these types of “buckyballs” have been detected in space, but the real kicker is graphene. Its technical name is planar C24 and instead of being geodesic, it’s the thinnest substance known. Just one atom thick, this flat sheet of carbon is a portrait in extraordinary strength, conductivity and elasticity. Graphene was first synthesized in the lab in 2004 and now planar C24 may have been detected in space.

Through the use of the Spitzer Space Telescope, a team of astronomers led by Domingo Aníbal García-Hernández of the Instituto de Astrofísica de Canarias in Spain have not only picked up a C70 fullerene molecule, but may have also detected graphene as well. “If confirmed with laboratory spectroscopy – something that is almost impossible with the present techniques – this would be the first detection of graphene in space” said García-Hernández.

Letizia Stanghellini and Richard Shaw, members of the team at the National Optical Astronomy Observatory in Tucson, Arizona suspect collisional shocks generated in stellar winds of planetary nebulae could be responsible for the presence of fullerenes and graphenes through the destruction of hydrogenated amorphous carbon grains (HACs). “What is particularly surprising is that the existence of these molecules does not depend on the stellar temperature, but on the strength of the wind shocks” says Stanghellini.

So where has this discovery taken place? Try the Magellanic Clouds. In this case, using a planetary nebula “closer to home” is not part of the equation because science needs to be certain the material they are looking at is indeed the by-product of a planetary nebula and not a mix. Fortunately the SMG is known to be metal-poor, which enhances the chances of spotting complex carbon molecules. Right now the challenge has been to pinpoint the evidence for graphene from Spitzer data.

“The Spitzer Space Telescope has been amazingly important for studying complex organic molecules in stellar environments” says Stanghellini. “We are now at the stage of not only detecting fullerenes and other molecules, but starting to understand how they form and evolve in stars.” Shaw adds “We are planning ground-based follow up through the NOAO system of telescopes. We hope to find other molecules in planetary nebulae where fullerene has been detected to test some physical processes that might help us understand the biochemistry of life.”

Original News Source: National Optical Astronomy Observatory News Release.

Do Planets Rob Their Stars of Metals?

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It has been known for several years that stars hosting planets are generally more rich in elements heavier than hydrogen and helium, known in astronomy as “metals”. These heavy elements help to form the cores of the forming planets and accelerate the formation process. However, a new study has helped to suggest that the opposite may also be true: Planets may make their host stars less metal rich than they should otherwise be.

The new research is led by Ivan Ramirez at the Carnegie Institution for Science. In it, the team analyzed the unusual exo-planetary system 16Cygni. The star system itself is a triple star system composed of two stars similar to the sun (A and B) as well as a red dwarf (C). The solar A star and the red dwarf form a tight binary system with the sun-like B star in a wider orbit of nearly 900 AU. 16CygniB was discovered to be host to a Jovian planet in 1996 making it one of the first systems known to contain an extrasolar planet.

The study analyzed the spectra of the two solar type stars and found that the one around which the planet orbits was notably lower in metals than the one in the binary orbit with the red dwarf. Because both stars should have formed from the same molecular cloud astronomers assume their initial compositions should be identical. Since both are similar masses, they should also have evolved similarly in their main-sequence life which should rule out divergence in their chemical fingerprints.

Similar properties have been noted in a 2009 paper by astronomers at the university of Porto in Portugal. In that study, the team compared our own Sun to other stars of similar composition and age. They discovered that the Sun had an odd feature: It was notably depleted in elements known as refractory metals when compared to volatile elements with low melting and boiling temperatures. The team suggested that those missing elements may have been stolen by forming planets. The newer study makes the same proposition.

Both teams note that the effect is not conclusive. They consider that 16CygA may have been polluted by heavy elements, possibly by the accretion of a planet or similar material. However, they note that if this was the case, they should also expect to see an additional amount of lithium. Yet the lithium abundance for the two stars match. The 2009 paper considers similar cases. They consider that the solar nebula may have been seeded by a nearby supernova that would enhance the abundances, but the enhanced elements do not seem to match the expected productions for any type of supernova. Still, with such a small number of systems for which this effect has been discovered, such cases of special pleading are still within the realm of statistical possibility. Future work will undoubtedly search for similar effects in other planetary systems. If confirmed, such elemental oddities could be considered as a sign of planetary formation.

Forever Blowing Bubbles…

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Thanks to ESO’s Hidden Treasures 2010 astrophotography competition, Manu Mejias, from Argentina compiled the data to give us a view of a cosmic superbubble that staggers the imagination with its size. Spanning around around 325 by 250 light-years across, we’d never realize the true nature of this phenomenon if it wasn’t so far away.

Officially designated as LHA 120–N 44, this sprawling complex of hot gases makes its home in the Large Magellanic Cloud. Skirting its edge is young star cluster, NGC 1929, whose intense ultra-violet radiation paints the visible portrait of stellar winds in action. To give you a good idea of just how big this super-bubble really is, take a look at this awesome map from Atlas Of The Universe.

This map is a plot of the 1500 most luminous stars within 250 light years. All of these stars are much more luminous than the Sun and most of them can be seen with the naked eye. About one third of the stars visible with the naked eye lie within 250 light years, even though this is only a tiny part of our galaxy. Credit: Richard Powell

Can you conceive of a nebula so large that it stretched from Cassiopeia to Vela in one direction and far further than Ursa Major to Phoenix in the other? Like a bracelet around the arm of the Milky Way, it would be so huge we probably wouldn’t even be aware it was there. Now that’s a super superbubble!

Picture a soapy mixture being stretched to the breaking point… the massive stars embedded in the nearby clusters going supernova – creating shockwaves and expelled gases. Like the child blowing the bubble, the stellar winds continued to expel, clearing the center of material. At the perimeters, new stars are continuing to form where the gases are compressed. It’s the nature of the beast… cosmic recycling in action.

Many thanks go to Manu Mejias for taking a look at a really BIG picture!

Original Story Source: ESO Photo Release. And thanks to Richard Powell of Atlas Of The Universe.

New Kids On The Block – The Brown Dwarfs

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When it comes to being close to “home”, there are not a lot of stars out there in our general neighborhood. Proxima Centauri is 4.2 light years away and Rigil Kentaurus is 4.3. There’s Barnard’s Star, Wolf 359, Lalande 21185, Luyten 726-8A and B and big, bright Sirius A and B. But what about a celestial neighbor that’s not quite so prominent? Try a pair of newly discovered brown dwarfs.

Scientists from the Leibniz Institute for Astrophysics Potsdam (AIP) using the NASA satellite WISE (Wide-field Infrared Survey Explorer) have discovered this unlikely duo just 15 and 18 light years from our solar system. “We have used the preliminary data release from WISE, selected bright candidates with colours typical of late-T dwarfs, tried to match them with faint 2MASS and SDSS objects, to determine their proper motions, and to follow-up them spectroscopically.” says RD Scholz, et al.

Named WISE J0254+0223 and WISE J1741+2553, the pair drew attention to themselves by their very disparity – one very bright in infrared and the other very faint in optical light. Even more attractive was the speed at which they’re moving – the proper motion changing drastically between observations. “The very large proper motions are a first hint that these objects should be very close to the Sun. Both objects are only detected in the SDSS z-band which is typical of nearby late-T dwarfs.” says Scholz.

Because the pair were optically visible at the time of the discovery, the team employed the Large Binocular Telescope (LBT) in Arizona to determine their spectral type and home in more accurately on their distance. They wanted to know more about the coolest representatives of T-type brown dwarf – the ultra-cool ones. Better known as failed stars because they lacked the mass to ignite nuclear fusion, the duo required study because their magnitude decreases sharply with time. Because they fade so quickly, there’s a strong possibility of a brown dwarf being much closer than we realize.

Like maybe next door…

Original News Source: Leibniz Institute for Astrophysics Potsdam News. For further reading: Cornell University Library – Two very nearby (d ~ 5 pc) ultracool brown dwarfs detected by their large proper motions from WISE, 2MASS, and SDSS data.

Neutron Star Burps Up Stellar Gas

This animated sequence of images illustrates the partial ingestion of a clump of matter by the neutron star hosted in the Supergiant Fast X-Ray Transient, IGR J18410-0535. The ingestion of the clump material produced a dramatic increase in the X-rays released by the neutron star, which was detected with XMM-Newton. The peak in the X-ray luminosity corresponds to the period when the accretion rate was at its maximum. Credits: ESA/AOES Medialab

During a routine twelve and a half hour observation of star system IGR J18410-0535, the XMM-Newton caught an event that would make Emily Post proud… a not-so-discreet burp from a neutron star. Continue reading “Neutron Star Burps Up Stellar Gas”

Betelgeuse: A Claim To Flame

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If it were at home in the center of our solar system, this red supergiant’s girth would extend out almost to the orbit of Jupiter. It’s about a thousand times larger than Sol and shines a hundred thousand times brighter. What’s more, the amount of mass it sheds every ten thousand years could create another sun. It’s nearing the end of its life and when it goes supernova, we’ll be able to see it here on Earth – even in broad daylight. So what’s surrounding Betelgeuse that looks like the conflagration generation? Read on…

Using the VISIR instrument on ESO’s Very Large Telescope (VLT), researchers have been able to take a more detailed look than ever at the nebula surrounding Betelgeuse. These infrared diffraction-limited images hold clues to the stellar aging process, since much of this structure cannot be seen in visible light. Filled with knots and pockets, this mysterious ether makes for prime study.

“Mass-loss occurring in red supergiants (RSGs) is a major contributor to the enrichment of the interstellar medium in dust and molecules. The physical mechanism of this mass loss is however relatively poorly known. Betelgeuse is the nearest RSG, and as such a prime object for high angular resolution observations of its surface (by interferometry) and close circumstellar environment.” says P. Kervella, et al. “The goal of our program is to understand how the material expelled from Betelgeuse is transported from its surface to the interstellar medium, and how it evolves chemically in this process.”

With branches extending up to six times the diameter of the star, Betelguese isn’t showing any uniformity in its surface shedding process. Picture, if you will, heating a pot of spaghetti sauce on a hot stove. When the temperature fires up below, it creates a rising bubble. When this surfaces, it pops – blowing spaghetti sauce all over the top of your stove and walls – and releasing steam. While this is a loose analogy, it’s fairly representative of what’s going on with this red supergiant. Large-scale gas motions inside the star are popping out O-rich dust, such as silicates or alumina and expelling gases in jets.

“The circumstellar envelope around Betelgeuse extends at least up to several tens of stellar radii. Its relatively high degree of clumpiness indicates an inhomogeneous spatial distribution of the material lost by the star.” says P. Kervella, et al. “Its extension corresponds to an important intermediate scale, where most of the dust is probably formed, between the hot and compact gaseous envelope observed previously in the near infrared and the interstellar medium.”

For now, there’s still many questions to be answered, such as how the dust is created and how it can be found as such great distances from the star itself. We’re just now beginning to understand RSG convection properties and their mechanisms for mass loss. For now, the team will continue their studies using these new techniques. “The knots and filamentary extensions of the nebula observed at larger distances from Betelgeuse appear to correspond to inhomogeneities in the mass lost by the star in the recent past, probably within the last few centuries. Further observations are expected to clarify the nature and composition of the nebular features identified in our images, using spatially resolved spectroscopy of the CSE.”

And the marshmallow for this campfire might just be a companion star…

Original Story Source: ESO Press Release.

White Dwarf Stars Predict Our Solar System’s Demise

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With no more volume than could be contained within a teaspoon, the material that makes up a white dwarf star weighs tons. Smaller than the diameter of Earth, and a direct family member of stars like our own Sol, these stellar gnomes could predict our eventual fate.

Using data from the Hubble Space Telescope, Nathan Dickinson, a postgraduate student in the University’s Department of Physics and Astronomy, is hard at work analyzing chemical compositions of white dwarf stars for his PhD. Unlike many students interested in “heavy metal”, Dickinson is more interested in “heavy elements”. The older, more cool models could contain elements such as oxygen, nitrogen, silicon… while the hot youngsters show heavy elements like calcium and magnesium. These weighty basics occur at extreme heat and sometimes, even to excess. The cremation generation?

“Understanding whether the extra material in hot white dwarfs comes from torn up planets is important,” emphasizes Dickinson. “It can give us an idea of how these ancient planetary systems evolve as the star ages, so we get a fuller picture of how solar systems die. However, they sometimes exhibit more of this material than is expected, which raises the question of whether this extra material also came from planets or whether it originated elsewhere, perhaps in clouds around the star.”

Past research has shown that anywhere from 1 to 3% of white dwarf stars can be contaminated by an influx of materials from closely orbiting dust clouds. What makes up these clouds? It could be rocky debris like asteroids. Held within the Roche Limit, these planetoids are mulched by gravitational tides – just like Saturn’s ring system.

“Working at the forefront of this scientific area is extremely exciting,” says Dickinson. “I find being one of a relatively small community of people in the world to work on this particular area amazing. This work is helping to shape our understanding of how most stars end their lives, how solar systems die, how the environment around these ancient stars behaves and what will ultimately happen to the vast majority of stars in the galaxy.”

And really close to home…

Original Story Source: Science Daily.

Sleeping Beauties: A Galactic Fairye Tale

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It’s a well known fact that galaxies come in two types – either actively forming stars or not. In simplistic terms, that means they are either awake or asleep. But now scientists are looking back twelve billion light years across time to find the same holds just as true then as it does now. As a matter of fact, galaxies may have been behaving this way for around 85% of the history of the Universe.

“The fact that we see such young galaxies in the distant universe that have already shut off is remarkable,” said Kate Whitaker, a Yale University graduate student and lead author of the paper, which is published in the June 20 online edition of the Astrophysical Journal.

So, without poking the sleeping dragon, just how did the astronomers make their determinations? Try with the use of a 4-meter Kitt Peak telescope in Arizona and a special set of filters developed by Whitaker and her team. Just like all astronomy filters, this new breed is selective to certain bandpasses, or wavelengths, of light. These new filter sets were then used on 40,000 galaxies over a 75 night period and the data collected and examined. The end product was the deepest and most comprehensive of its kind so far. Active, awake galaxies appear more blue, while the sleepy-heads appear red. Believe it or not, when it comes to the cosmic bedroom there’s more activity than previously thought.

“We don’t see many galaxies in the in-between state,” said Pieter van Dokkum, a Yale astronomer and another author of the paper. “This discovery shows how quickly galaxies go from one state to the other, from actively forming stars to shutting off.”

Whether the dozing galaxies have completely shut down remains an open question, Whitaker said. However, the new study suggests the active galaxies are forming stars at rates about 50 times greater than their somnambulistic counterparts. “Next, we hope to determine whether galaxies go back and forth between waking and sleeping or whether they fall asleep and never wake up again,” van Dokkum said. “We’re also interested in how long it takes galaxies to fall asleep, and whether we can catch one in the act of dozing off.”

Pass the Red Bull… and sing the blues! “Are you sleeping? Can you hear me? Do you know if I am by your side? Does it matter? If you hear me? When the mornin’ comes I’ll be there by your side… There was a time, we had a time. There was a time we had time…”

Original Story Source: Yale Daily Bulletin.