Posted on by Jean Tate

Stunning Science Using Nature’s Telescope

3Star-birth in SMM J2135-0102 (Credit: M. Swinbank et al./Nature, ESO, APEX; NASA, ESA, SMA)

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Einstein started it all, back in 1915.

Eddington picked up the ball and ran with it, in 1919.

And in the last decade or so astronomers have used a MACHO to OLGE CASTLES … yes, I’m talking about gravitational lensing.

Now LABOCA and SABOCA are getting into the act, using Einstein’s theory of general relativity to cast a beady eye upon star birth most fecund, in a galaxy far, far away (and long, long ago).

APEX at Chajnantor (Andreas Lundgren)

How galaxies evolved is one of the most perplexing, challenging, and fascinating topics in astrophysics today. And among the central questions – as yet unanswered – are how quickly stars formed in galaxies far, far away (and so long, long ago), and how such star formation differed from that which we can study, up close and personal, in our own galaxy (and our neighbors). There are lots of clues to suggest that star formation happened very much faster long ago, but because far-away galaxies are both dim and small, and because Nature drapes veils of opaque dust over star birth, there’s not much hard data to put the numerous hypotheses to the test.

Until last year that is.

“One of the brightest sub-mm galaxies discovered so far,” say a multi-national, multi-institution team of astronomers, was “first identified with the LABOCA instrument on APEX in May 2009” (you’d think they’d give it a name like, I don’t know, “LABOCA’s Stunner” or “APEX 1”, but no, dubbed “the Cosmic Eyelash”; formally it’s called SMMJ2135-0102). “This galaxy lies at [a redshift of] 2.32 and its brightness of 106 mJy at 870 μm is due to the gravitational magnification caused by a massive intervening galaxy cluster,” and “high resolution follow-up with the sub-mm array resolves the star-forming regions on scales of just 100 parsecs. These results allow study of galaxy formation and evolution at a level of detail never before possible and provide a glimpse of the exciting possibilities for future studies of galaxies at these early times, particularly with ALMA.” Nature’s telescope giving astronomers ALMA-like abilities, for free.

OK, so what did Mark Swinbank and his colleagues find? “The star-forming regions within SMMJ2135-0102 are ~100 parsecs across, which is 100 times larger than dense giant molecular cloud (GMC) cores, but their luminosities are approximately 100 times higher than expected for typical star-forming regions. Indeed, the luminosity densities of the star-forming regions within SMMJ2135-0102 are comparable to dense GMC cores, but with luminosities ten million times larger. Thus, it is likely that each of the star-forming regions in SMMJ2135-0102 comprises ~ten million dense GMC cores.” That’s pretty mind-blowing; imagine the Orion Nebula (M42, approximately 400 parsecs distant) as one of these star-forming regions!

James Dunlop of the University of Edinburgh suggests that such galaxies as SMMJ2135-0102 formed stars so abundantly because the galaxies still had plenty of gas – the raw material for making stars – and the gravity of the galaxies had had enough time to pull the gas together into cold, compact regions. Before about 10 billion years ago, gravity hadn’t yet drawn enough clumps of gas together, while at later times most galaxies had already run out of gas, he suggests.

But I’m saving the best for last: “the energetics of the star-forming regions within SMMJ2135-0102 are unlike anything found in the present day Universe,” Swinbank et al. write (now there’s an understatement if ever I’ve heard one!), “yet the relations between size and luminosity are similar to local, dense GMC cores, suggesting that the underlying physics of the star-forming processes is similar. Overall, these results suggest that the recipes developed to understand star-forming processes in the Milky Way and local galaxies can be used to model the star formation processes in these high-redshift galaxies.” It’s always good to get confirmation that our understanding of the physics at work so long ago is consistent and sound.

Einstein would have been delighted, and Eddington too.

Sources: “Intense star formation within resolved compact regions in a galaxy at z = 2.3” (Nature), “The Properties of Star-forming Regions within a Galaxy at Redshift 2” (ESO Messenger No. 139), Science News, SciTech, ESO. My thanks to debreuck (ESO’s Carlos De Breuck?) for setting the record straight re the name.

Posted on by Tammy Plotner

Planet Dance…

Have you been watching the conjunction of Venus and Mercury? Right now the inner planets are putting on quite a show just after sunset…

If you missed Mercury at its closest to Venus and brightest this weekend, don’t worry. The pair will still be mixing it up in the twilight sky through April 12. What will really be fun is watching the orbital path over the next week. Thanks to Sky & Telescope Magazine, you’ve got a wonderful diagram to help you see visualize the orientation. Don’t give up if you don’t spot Mercury right away, because even the slightest amount of sky haze can conceal it. Instead, try using binoculars to assist you… and use a telescope to pick out the phases of both planets!

And don’t forget… There is more than one planetary pair dancing right now, too! As the skies darken, be sure to look higher overhead as Mars and Saturn take their posts at either end of Leo the Lion. It’s a spectacular evening showing that doesn’t even require a telescope!

Enjoy….

Many thanks to Mike Romine for the conjunction photo and to Sky and Telescope for the planetary diagram.

Posted on by Nancy Atkinson

Amazing Pic: ISS Flys Through Aurora

"Fly through Aurora at 28,000kmh. Happy 1,000 tweets :-)" Tweeted astronaut Soich Noguchi.

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What an amazing pic of the International Space Station “flying through” an aurora at orbital speeds of 28,000 kmh (17,500 mph)! Super-space-photographer and Tweeter Soichi Noguchi captured this spectacular image earlier today, taking advantage of some rare solar activity. “Fly through Aurora at 28,000kmh. Happy 1,000 tweets” Noguichi wrote on Twitter. NOAA’s Space Weather Prediction Center sent out a notice early this morning saying : “A geomagnetic storm began at 05:55 AM EST Monday, April 5, 2010. Space weather storm levels reached Strong (G3) levels on the Geomagnetic Storms Space Weather Scale.”

And indeed, that solar activity created a picturesque backdrop to the ISS today! Wow!


Noguchi, a.k.a. Astro_Soichi on Twitter is setting a new standard for Twittering and Twitpics from space — and photography, too. He and his Expedition 22 crewmates recently broke the record for the amount of images taken by an ISS crew. They snapped over 100,000 images of space and Earth during their accumulated six-month Expedition, bringing the number of pictures taken from the space station to a grand total of almost 639,000 images. With the new crew arriving at the ISS this past weekend, Expedition 23 is now officially underway.

Check out more of Astro_Soichi’s Twitter pictures on his TwitPic page.
. And here are more amazing space pictures.

Sources: Twitter, NOAA, Yahoo News

Posted on by Ken Kremer

Discovery Dazzles with Two Dawns in One Day

Predawn Liftoff of Space Shuttle Discovery this morning (April 5) at 6:21 AM EDT at the Kennedy Space Center. Credit: Alan Walters for Universe Today. See awaltersphoto.com

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(Editor’s Note: Ken Kremer and Alan Walters are at the Kennedy Space Center for Universe Today covering the flight of Discovery)

Space Shuttle Discovery blasted to orbit this morning (April 5) precisely on time at 6:21 AM EDT in the predawn skies at the Kennedy Space Center. Hints of sunlight cracking through the horizon were discernible in the last minutes before liftoff.

The rumbling thunder from the spectacular liftoff was felt for miles around. Folks in the surrounding counties of Florida reported experiencing shockwaves.

Personally, I can say it was the loudest and most magnificent Shuttle liftoff I have witnessed from the Press Site at KSC which is located about 3 miles away from the launch pad. Many members of the media and NASA officials I spoke with said it was one of the best ever.

Liftoff of Space Shuttle Discovery on April 5 at 6:21 AM EDT for the 8 ½ minute climb to orbit. Credit: Alan Walters for Universe Today. See awaltersphoto.com

The blazing fire from 7 million pounds of thrust created by the twin shuttle solid rocket boosters (SRB’s) and three main engines turned night into day for the days first dawn. Eventually our sun rose about 45 minutes later just as expected, for this days second incredible dawn and thus exposing clear blue skies. I clearly saw the SRB’s being jettisoned after burnout about 2 minutes into the flight.

Fifteen minutes before blast off, everyone was treated to fabulously bright overhead view of the ISS that coincidentally passed directly in front of the moon in a north easterly pass that lasted over 3 minutes

Bill Gerstenmaier, NASAs Associate Administrator for Space Operations, hailed the launch of Discovery on the STS 131 mission as a “Great success and a great start to a great mission” and was a tribute to the team at Kennedy that got the vehicle ready to fly. This is the second of the final five planned flights until the space shuttle program is retired at the end of 2010. Only 3 more launches remain on the manifest.

The crew of seven astronauts aboard are in for the ride of a lifetime on the 13 day flight to the International Space Station which will include three spacewalks. Discoveries cargo bay is packed with the Leonardo resupply module that is loaded with numerous science experiments and instrument racks, spare parts, food and sleeping quarters.

Discovery is set to dock to the orbiting outpost at 3:44 a.m. on Wednesday, April 7 after a two day pursuit.

Earlier STS 131 articles by Ken Kremer:

Discovery Unveiled on Easter Sunday to the Heavens Above

Countdown Clock Ticking for Discovery Blast off on April 5

Credit: Alan Walters for Universe Today. See awaltersphoto.com
Credit: Alan Walters for Universe Today. See awaltersphoto.com
Credit: Alan Walters for Universe Today. See awaltersphoto.com
STS-131 crew heads out to the launchpad. Image: Alan Walters (awaltersphoto.com) for Universe Today.
Posted on by Jean Tate

Universe Puzzle No. 8

As with last week’s Universe Puzzle, something that cannot be answered by five minutes spent googling, a puzzle that requires you to cudgel your brains a bit, and do some lateral thinking. This is a puzzle on a “Universal” topic – astronomy and astronomers; space, satellites, missions, and astronauts; planets, moons, telescopes, and so on.

This puzzle is actually from Universe Today reader, Vino; thanks Vino!

What comes next in the sequence?

0.789, 0.854, 0.941

UPDATE: Answer has been posted below.

1.091

These are the periods, in days, of the transiting extrasolar planets so far discovered, in ascending order (source): WASP-19b, CoRoT-7b, WASP-18b, and WASP-12b.

Check back next week for another Universe Puzzle!

Posted on by Ken Kremer

Discovery Unveiled on Easter Sunday to the Heavens Above

At NASA’s Kennedy Space Center in Florida, the rotating service structure, or RSS, rolled back Sunday morning revealing space shuttle Discovery ready for launch. The rollback is in final preparation for Discovery’s scheduled 6:21 a.m. EDT liftoff Monday, Apr. 5 on the STS-131 mission.

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(Editor’s Note: Ken Kremer is at the Kennedy Space Center for Universe Today covering the launch of Discovery)

It was a glorious Easter Sunday morning here at the Kennedy Space Center as Space Shuttle Discovery was unveiled to the clear blue skies of the heavens above. The Rotating Service Structure (RSS) was rolled back this Sunday morning at 9:30 AM to reveal Discovery in anticipation of launch on Monday morning, Apr. 5 at 6:21 AM EDT The rollback of the giant cocoon like structure takes about 25 minutes.

This evening the Shuttle Mission management team gave the “GO” to begin the fueling of the cryogenic propellants. Over a half million pounds of liquid oxygen and liquid hydrogen is being loaded into the shuttle’s huge orange colored External Tank as of 9:28 PM tonight !

The loading of fuel takes about three hours.

Final preparations are underway for the STS 131 mission which is scheduled to last 13 days and includes 3 spacewalks. The crew of 7 astronauts will deliver the Leonardo re-supply module loaded with tons of food, spare parts and science equipment.

Live launch coverage will kick off on NASA TV and on NASA’s Launch Blog at 1:15 a.m. Monday. The Launch Blog can be found at www.nasa.gov/launch and NASA TV at www.nasa.gov/ntv.

Credit: Alan Walters for Universe Today. See awaltersphoto.com
Credit: Alan Walters for Universe Today. See awaltersphoto.com
Lone bird stands guard protecting Discovery from the media horde of a few hundred photo journalists today at Launch Pad 39 A at KSC. Credit: Ken Kremer
Ken Kremer and Shuttle Discovery on April 4 at the Kennedy Space Center. Credit: Alan Walters for Universe Today. See awaltersphoto.com
Alan Walters and Shuttle Discovery on April 4 at the Kennedy Space Center. Credit: Alan Walters for Universe Today. See awaltersphoto.com
Posted on by Jean Tate

Andromeda’s Double Nucleus – Explained at Last?

M31's nucleus (Credit: WF/PC, Hubble Space Telescope)


In 1993, the Hubble Space Telescope snapped a close-up of the nucleus of the Andromeda galaxy, M31, and found that it is double.

In the 15+ years since, dozens of papers have been written about it, with titles like The stellar population of the decoupled nucleus in M 31, Accretion Processes in the Nucleus of M31, and The Origin of the Young Stars in the Nucleus of M31.

And now there’s a paper which seems, at last, to explain the observations; the cause is, apparently, a complex interplay of gravity, angular motion, and star formation.

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It is now reasonably well-understood how supermassive black holes (SMBHs), found in the nuclei of all normal galaxies, can snack on stars, gas, and dust which comes within about a third of a light-year (magnetic fields do a great job of shedding the angular momentum of this ordinary, baryonic matter).

Also, disturbances from collisions with other galaxies and the gravitational interactions of matter within the galaxy can easily bring gas to distances of about 10 to 100 parsecs (30 to 300 light years) from a SMBH.

However, how does the SMBH snare baryonic matter that’s between a tenth of a parsec and ~10 parsecs away? Why doesn’t matter just form more-or-less stable orbits at these distances? After all, the local magnetic fields are too weak to make changes (except over very long timescales), and collisions and close encounters too rare (these certainly work over timescales of ~billions of years, as evidenced by the distributions of stars in globular clusters).

That’s where new simulations by Philip Hopkins and Eliot Quataert, both of the University of California, Berkeley, come into play. Their computer models show that at these intermediate distances, gas and stars form separate, lopsided disks that are off-center with respect to the black hole. The two disks are tilted with respect to one another, allowing the stars to exert a drag on the gas that slows its swirling motion and brings it closer to the black hole.

The new work is theoretical; however, Hopkins and Quataert note that several galaxies seem to have lopsided disks of elderly stars, lopsided with respect to the SMBH. And the best-studied of these is in M31.

Hopkins and Quataert now suggest that these old, off-center disks are the fossils of the stellar disks generated by their models. In their youth, such disks helped drive gas into black holes, they say.

The new study “is interesting in that it may explain such oddball [stellar disks] by a common mechanism which has larger implications, such as fueling supermassive black holes,” says Tod Lauer of the National Optical Astronomy Observatory in Tucson. “The fun part of their work,” he adds, is that it unifies “the very large-scale black hole energetics and fueling with the small scale.” Off-center stellar disks are difficult to observe because they lie relatively close to the brilliant fireworks generated by supermassive black holes. But searching for such disks could become a new strategy for hunting supermassive black holes in galaxies not known to house them, Hopkins says.

Sources: ScienceNews, “The Nuclear Stellar Disk in Andromeda: A Fossil from the Era of Black Hole Growth”, Hopkins, Quataert, to be published in MNRAS (arXiv preprint), AGN Fueling: Movies.

Posted on by Ken Kremer

Countdown Clock Ticking for Discovery Blast off on April 5

In an extremely rare media photo opportunity with Discovery poised at the top of Pad 39 A, the massive Rotating Service Structure (RSS, at left) had been retracted the day before my visit on March 19. I stood in absolute awe right beneath Discovery and the RSS and the just delivered payload canister. The enormous canister containing ‘Leonardo’ resupply module had just been hoisted by crane and attached to the RSS. Credit: Ken Kremer

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(Editor’s Note: Ken Kremer is at the Kennedy Space Center for Universe Today covering the flight of Discovery)
At the Kennedy Space Center (KSC) in Florida, the countdown clock is ticking towards blast off for the STS 131 assembly mission of Space Shuttle Discovery to the International Space Station. Discovery is slated to lift off on Monday, April 5 at 6:21 AM.

Mike Moses, chairman of NASA’s Mission Management Team at KSC announced a “Unanimous Go for Launch” at the KSC pre-launch news briefing today, April 3. “This is one of the most heavily packed shuttle missions with science equipment and will position the ISS very well for science in the future”

The weather forecast is 80 % Favorable.

The international crew of seven astronauts arrived at the Shuttle landing strip at KSC on a Gulfstream II jet at 7 AM on Thursday morning (April 1). They were greeted by KSC Director Bob Cabana and the media including myself.

“The crew’s ready to go and we’re looking forward to our mission to the International Space Station. It’s a complex 13-day mission. It’s main mission is resupply. We also have three very challenging EVAs,” said Shuttle Commander Alan Poindexter.

Discovery crew arrives at the Shuttle Landing Strip at the Kennedy Space Center on April 1. The 7 person crew is led by Commander Alan Poindexter (at right). Jim Dutton (at mic) will serve as the pilot. Mission Specialists (from left) are Clay Anderson, Naoko Yamazaki of the Japan Aerospace Exploration Agency, Stephanie Wilson, Dorothy Metcalf-Lindenburger and Rick Mastracchio. Credit: Ken Kremer

Pre-launch operations have been on-going for several months. I had the opportunity to participate in media tours to inspect her primary cargo, the Leonardo resupply module, inside the Space Station Processing Facility at KSC and take a quite rare and absolutely thrilling visit to witness Discovery close up from directly on top of Launch Pad 39A as her giant payload canister was delivered to the massive pad structure on March 19, 2010.

Nestled inside Discovery’s cargo bay is the ‘Leonardo’ Multi-purpose logistics module (MPLM) and a 3800 lb Ammonia cooling tank. Leonardo weighs over 27,000 pounds and is jam packed with16 science and stowage racks including the 3rd MELFI low temperature science freezer, the 4th crew personal quarters and the WORF space science imagery experiment which features Klingon inscriptions for future visitors.

STS-131 will be the 33rd shuttle mission to the station and the 131st shuttle mission overall. This will be the penultimate voyage for Discovery.

Posted on by Steve Nerlich

Astronomy Without A Telescope – Is An Anomalous Anomaly A Normality?

The lack of any flyby anomaly effect when the Rosetta spacecraft passed Earth in November 2009 is what, an anomaly? No. Anomalies arise when there is a mismatch between a predicted and an observed value. When it happens our first thought shouldn’t be that OMG there’s something wrong with physics! We should probably start by reviewing whether we really got the math right.

The flyby anomaly story starts with the Galileo spacecraft‘s flyby of Earth in December 1990 – where it was measured to have gained a speed increase (at least, an increase over the predicted value) of 2.5 millimeters per second at perigee. In its second pass in December 1992, the predicted value was the same as the observed value, although it has been suggested that atmospheric drag effects confound any analysis of this particular flyby.

The next, and biggest anomaly so far detected, was the NEAR spacecraft‘s flyby in 1998 (a whopping 7.2 millimeters per second at perigee increase over the predicted value). After that you have Rosetta showing an anomaly on its first flyby in 2005. Then a quantitative formula which aimed to model the various flybys to date was developed by Anderson et al in 2007 – predicting a small but detectable speed increase would be found in Rosetta’s second fly-by of 13 November 2007. However (or should I say anomalously), no such increase was detected in this, or in Rosetta’s third (2009), pass.

So, on balance, our spacecraft (and often the same spacecraft) are more likely to behave as predicted than to behave anomalously. This reduces (though not negates) the likelihood of the anomaly being anything of substance. One might sagely state that the intermittent absence of an anomaly is not in itself anomalous.

More recently, Mbelek in 2009 has proposed that the anomalous flyby data (including Anderson et al’s formula) can be explained by a more rigorous application of special relativity principles, concluding that ‘spacecraft flybys of heavenly bodies may be viewed as a new test of SR which has proven to be successful near the Earth’. If such recalculated predicted values match observed values in future flybys, that would seem to be that.

Pioneer 10 - launched in 1972 and now making its way out towards the star Aldebaran, which it should pass in about 2 million years. Credit: NASA

Then there’s the Pioneer anomaly. This has no obvious connection with the flyby anomaly, apart from a common use of the word anomaly, which gives us another epistemological maxim – two unrelated anomalies do not one bigger anomaly make.

Between around 20 and 70 AU out from Earth, Pioneer 10 and 11 both showed tiny but unexpected decelerations of around 0.8 nanometers per second2 – although again we are just talking about an observed value that differed from a predicted value.

Some key variables not considered in calculating the original predicted value are radiation pressure from sunlight-heated surfaces, as well as internal radiation generated from the spacecrafts’ own (RTG) power source. A Planetary Society update of an ongoing review of the Pioneer data indicated that revised predicted values now show less discrepancy from the observed values. Again, this doesn’t yet negate the anomaly – but given the trend for more scrutiny equals less discrepancy, it’s fair to say that this anomaly is also becoming less substantial.

Don’t get me wrong, this is all very useful science, teaching us more about how our spacecraft operate out there in the field. I am just suggesting that when faced with a data anomaly perhaps our first reaction should be Doh! rather than OMG!