Posted on by Nancy Atkinson

Wild and Crazy Multi-Planetary System Surprises Astronomers

Epsilon Andromedae. Illustration Credit: NASA, ESA, and A. Feild (STScI) Science Credit: NASA, ESA, and B. McArthur, University of Texas at Austin, McDonald Observatory.

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Astronomers are finding that not only are there a wide range of different extrasolar planets, but there are different types of planetary systems, as well. “We’re not in Kansas anymore as far as solar systems go,” said Barbara McDonald from the University of Texas’ McDonald Observatory, at the American Astronomical Society meeting in Miami, Florida today. “The exciting thing is, we found another multi-planet system that is not at all like our own.”

A close look at the Upsilon Andromedae system with the Hubble Space Telescope, the Hobby-Eberly Telescope and other ground-based telescopes shows a whacky system where planets are out of tilt and have highly inclined orbits. The astronomers also found another planet, and also another star – this is likely a binary star system.

Even with Pluto’s inclined orbit, our solar system looks like an ocean of calm compared to Upsilon Andromedae.

Comparison of solar systems. Credit: HubbleSite

McDonald said these surprising findings will impact theories of how multi-planet systems evolve, and it shows that some violent events can happen to disrupt planets’ orbits after a planetary system forms.

“The findings mean that future studies of exoplanetary systems will be more complicated,” she said. “Astronomers can no longer assume all planets orbit their parent star in a single plane.” says Barbara McArthur of The University of Texas at Austin’s McDonald Observatory.

Similar to our Sun in its properties, Upsilon Andromedae lies about 44 light-years away. It’s a little younger, more massive, and brighter than the Sun. For just over a decade, astronomers have known that three Jupiter-type planets orbit the yellow-white star Upsilon Andromedae.

But after over a thousand combined observations, McDonald and her team uncovered hints that a fourth planet, e, orbits the star much farther out. They were also able to determine the exact masses of two of the three previously known planets, Upsilon Andromedae c and d. Much more startling, though, is that not all planets orbit this star in the same plane. The orbits of planets c and d are inclined by 30 degrees with respect to each other. This research marks the first time that the “mutual inclination” of two planets orbiting another star has been measured.

“Most probably Upsilon Andromedae had the same formation process as our own solar system, although there could have been differences in the late formation that seeded this divergent evolution,” McArthur said. “The premise of planetary evolution so far has been that planetary systems form in the disk and remain relatively co-planar, like our own system, but now we have measured a significant angle between these planets that indicates this isn’t always the case.”

Until now the conventional wisdom has been that a big cloud of gas collapses down to form a star, and planets are a natural byproduct of leftover material that forms a disk. In our solar system, there’s a fossil of that creation event because all of the eight major planets orbit in nearly the same plane. The outermost dwarf planets like Pluto are in inclined orbits, but these have been modified by Neptune’s gravity and are not embedded deep inside the Sun’s gravitational field.

So what knocked the Upsilon Andromedae system around?

“Possibilities include interactions occurring from the inward migration of planets, the ejection of other planets from the system through planet-planet scattering, or disruption from the parent star’s binary companion star, Upsilon Andromedae B,” McArthur said.

Or, the companion star – a red dwarf less massive and much dimmer than the Sun — could be the culprit. is.

“We don’t have any idea what its orbit is,” said team member Fritz Benedict. “It could be very eccentric. Maybe it comes in very close every once in a while. It may take 10,000 years.” Such a close pass by the secondary star could gravitationally perturb the orbits of the planets.”

The two different types of data combined in this research were astrometry from the Hubble Space Telescope and radial velocity from ground-based telescopes.

Astrometry is the measurement of the positions and motions of celestial bodies. McArthur’s group used one of the Fine Guidance Sensors (FGSs) on the Hubble telescope for the task. The FGSs are so precise that they can measure the width of a quarter in Denver from the vantage point of Miami. It was this precision that was used to trace the star’s motion on the sky caused by its surrounding — and unseen — planets.

Radial velocity makes measurements of the star’s motion on the sky toward and away from Earth. These measurements were made over a period of 14 years using ground-based telescopes, including two at McDonald Observatory and others at Lick, Haute-Provence, and Whipple Observatories. The radial velocity provides a long baseline of foundation observations, which enabled the shorter duration, but more precise and complete, Hubble observations to better define the orbital motions.

The fact that the team determined the orbital inclinations of planets c and d allowed them to calculate the exact masses of the two planets. The new information told us that our view as to which planet is heavier has to be changed. Previous minimum masses for the planets given by radial velocity studies put the minimum mass for planet c at 2 Jupiters and for planet d at 4 Jupiters. The new, exact masses, found by astrometry are 14 Jupiters for planet c and 10 Jupiters for planet d.

“The Hubble data show that radial velocity isn’t the whole story,” Benedict said. “The fact that the planets actually flipped in mass was really cute.”

The fourth planet is so far out, that its signal does not reveal the curvature of its orbit.

The 14 years of radial velocity information compiled by the team uncovered hints that a fourth, long-period planet may orbit beyond the three now known. There are only hints about that planet because it’s so far out that the signal it creates does not yet reveal the curvature of an orbit. Another missing piece of the puzzle is the inclination of the innermost planet, b, which would require precision astrometry 1,000 times greater than Hubble’s, a goal attainable by a future space mission optimized for interferometry.

Sources: HubbleSite, AAS Press conference

Posted on by Nancy Atkinson

Hubble Confirms Star is Devouring Hot Exoplanet

Artist's concept of the exoplanet WASP-12b -- a hot Jupiter being devoured by its parent star. Artwork Credit: NASA, ESA, and G. Bacon (STScI)
Artist's concept of the exoplanet WASP-12b -- a hot Jupiter being devoured by its parent star. Artwork Credit: NASA, ESA, and G. Bacon (STScI)

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We all like a hot meal, but this is really bizarre. Back in February, Jean wrote an article about WASP-12b, the hottest known planet in the Milky Way that is being ripped to shreds by its parent star. Shu-lin Li of the Department of Astronomy at the Peking University, Beijing, predicted that the star’s gravity would distort the planet’s surface and make the interior of the planet so hot that the atmosphere would expand out and co-mingle with the star. Shu-lin calculated the planet would one day be completely consumed. Now the Hubble Space Telescope has confirmed this prediction, and astronomers estimate the planet may only have another 10 million years left before it is completely devoured.

Using the Cosmic Origins Spectrograph (COS), and its sensitive ultraviolet instruments, astronomers saw that the star and the planet’s atmosphere share elements, passing them back and forth. “We see a huge cloud of material around the planet, which is escaping and will be captured by the star. We have identified chemical elements never before seen on planets outside our own solar system,” says team leader Carole Haswell of The Open University in Great Britain.

This effect of matter exchange between two stellar objects is commonly seen in close binary star systems, but this is the first time it has been seen so clearly for a planet.

The planet, called WASP-12b, is so close to its sunlike star that it completes an orbit in 1.1 days, and is heated to nearly 1,540 C (2,800 F) and stretched into a football shape by enormous tidal forces. The atmosphere has ballooned to nearly three times Jupiter’s radius and is spilling material onto the star. The planet is 40 percent more massive than Jupiter.

WASP-12 is a yellow dwarf star located approximately 600 light-years away in the winter constellation Auriga.

Haswell and her science team’s results were published in the May 10, 2010 issue of The Astrophysical Journal Letters.

Science Paper by: L Fossati et al.

Original article on Universe Today by Jean Tate
Original paper by Shu-Lin

Source: HubbleSite

Posted on by Nancy Atkinson

Runaway Star Needs Its Own Reality Docu-Drama

30 Dor #016. Illustration Credit: NASA, ESA, and Z. Levay (STScI) Science Credit: NASA, ESA, C. Evans (Royal Observatory Edinburgh), N. Walborn (STScI), and ESO

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In an astronomical version of “Biggest Loser” meets “Survivor,” a heavy weight star has been kicked out of its stellar nursery. This huge runaway star is rushing away from its birthplace at more than 402,336 kilometers per hour (250,000 miles an hour), and it likely was ejected by a group of even larger sibling stars. The future outlook for this tough-luck star seemingly doesn’t improve: Paul Crowther of the University of Sheffield, a member of the team who made the observations of 30 Dor #016, said the wayward star will continue to streak across space and will eventually end its life in a titanic supernova explosion, likely leaving behind a remnant black hole. There’s a new reality series in there somewhere!


The star on the run is found 375 light-years from its suspected home, a giant star cluster called R136 in 30 Doradus, also called the Tarantula Nebula, about roughly 170,000 light-years from Earth. R136 contains several stars topping 100 solar masses each. 30 Dor #016 is 90 times more massive than our Sun.

Astronomers say runaway stars can be made in a couple of ways: a star may encounter one or two heavier siblings in a massive, dense cluster and get booted out through a stellar game of pinball. Or, a star may get a ‘kick’ from a supernova explosion in a binary system, with the more massive star exploding first.

“It is generally accepted, however, that R136 is sufficiently young, 1 million to 2 million years old, that the cluster’s most massive stars have not yet exploded as supernovae,” says COS team member Danny Lennon of the Space Telescope Science Institute. “This implies that the star must have been ejected through dynamical interaction.”

30 Dor with 30 Dor #16 in the inset. Image credits: : NASA, ESA, J. Walsh (ST-ECF), and ESO

The renegade star may not be the only runaway in the region. Two other extremely hot, massive stars have been spotted beyond the edges of 30 Doradus. Astronomers suspect that these stars, too, may have been ejected from their home. They plan to analyze the stars in detail to determine whether 30 Doradus might be unleashing a barrage of massive stellar runaways into the surrounding neighborhood.

The observations came from a team-effort using Hubble’s newly installed Cosmic Origins Spectrograph (COS) to take an image of the region in 2009, an optical image of the star taken by the Wide Field Planetary Camera 2 in 1995, and another spectroscopic study from the European Southern Observatory’s Very Large Telescope (VLT) at the Paranal Observatory. It was first observed in 2006 when a team led by Ian Howarth of University College London spotted it with the Anglo-Australian Telescope at Siding Spring Observatory.

COS’s ultraviolet spectroscopic observations showed that the wayward star is unleashing a fury of charged particles in one of the most powerful stellar winds known, a clear sign that it is extremely massive, perhaps as much as 90 times heavier than the Sun. The star, therefore, also must be very young, about 1 million to 2 million years old, because extremely massive stars live only a few million years.

The VLT observations revealed that the star’s velocity is constant and not a result of orbital motion in a binary system. Its velocity corresponds to an unusual motion relative to the star’s surroundings, evidence that it is a runaway star.

The study also confirmed that the light from the runaway is from a single massive star rather than the combined light of two lower-mass stars. In addition, the observation established that the star is about 10 times hotter than the Sun, a temperature that is consistent with a high-mass object.

“These results are of great interest because such dynamical processes in very dense, massive clusters have been predicted theoretically for some time, but this is the first direct observation of the process in such a region,” says Nolan Walborn of the Space Telescope Science Institute in Baltimore and a member of the COS team that observed the misfit star. “Less massive runaway stars from the much smaller Orion Nebula Cluster were first found over half a century ago, but this is the first potential confirmation of more recent predictions applying to the most massive young clusters.”

The research team, led by Chris Evans of the Royal Observatory Edinburgh, published the study’s results May 5 in the online edition of The Astrophysical Journal Letters.

Science paper by Evans, et al. 2010

Source: HubbleSite

Posted on by Nancy Atkinson

“Data” Narrates Hubble Documentary

The Hubble Space Telescope is one of the greatest technological achievements in our history, and for two decades has astonished us with dynamic images of our solar system and the world beyond. To celebrate this important twenty-year milestone, NASA looks back at the contributions of this extraordinary scientific tool, and the scientists who created it, in a documentary entitled “Hubble: Twenty Years of Discovery.” The movie is narrated by Brent Spiner, Data from Star Trek.

Posted on by Nancy Atkinson

Hubble Captures Distorted Beauty of M66

M 66. Image credit: NASA, ESA and the Hubble Heritage (STScI/AURA)-ESA/Hubble Collaboration. Acknowledgement: Davide De Martin and Robert Gendler

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This isn’t your basic spiral galaxy, but perhaps it used to be! Hubble’s Advanced Camera for Surveys has captured this beautiful view of the biggest child of the Leo Triplet, M66. Its asymmetric spiral arms and an apparently displaced core was mostly likely caused by the gravitational pull of the other two members of the trio. Talk about sibling rivalry!

M66, is located at a distance of about 35 million light-years in the constellation of Leo. Together with Messier 65 and NGC 3628, Messier 66 is one third of the Leo Triplet, a trio of interacting spiral galaxies, part of the larger Messier 66 group. While M66 is the biggest — it is about 100,000 light-years across — the gravitational influence from the two neighboring galaxies have distorted the one orderly spiral arms, making them appear to rise above the central core.

The striking dust lanes and bright star clusters along the spiral arm — pictured in the blue and pinkish regions of the image — are key tools for astronomers since they are used as indicators of how the parent galaxies assembled over time.

Messier 66 boasts a remarkable record of supernovae explosions. The spiral galaxy has hosted three supernovae since 1989, the latest one occurring in 2009. A supernova is a stellar explosion that may momentarily outshine its entire host galaxy. It then fades away over a period lasting several weeks or months. During its very short life the supernova radiates as much energy as the Sun would radiate over a period of about 10 billion years.

Source: European Hubble Space Telescope webpage

Posted on by Nancy Atkinson

Astronomers Begin Observing Hanny’s Voorwerp with the Hubble Space Telescope

The green "blob" is Hanny's Voorwerp. Credit: Dan Herbert, Peter Smith, Matt Jarvis, Galaxy Zoo Team, Isaac Newton Telescope

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The green “blob” is Hanny’s Voorwerp. Credit: Dan Herbert, Peter Smith, Matt Jarvis, Galaxy Zoo Team, Isaac Newton Telescope

A storybook astronomy mystery is now part of the most famous telescope in history. A team of astronomers secured time on the Hubble Space Telescope to observe Hanny’s Voorwerp, the unusual object found by Dutch teacher Hanny Van Arkel while she was scanning through images for the Galaxy Zoo project. Hubble will be trained on the Voorwerp during three separate observing sessions, the first of which occurred on April 4, 2010. “The WFC3 (Wide Field Camera 3) images were obtained (Sunday),” said Principal Investigator Bill Keel from the University of Alabama in an email to Universe Today “and I was able to pull the calibrated files over last night for a quick look. Combining pairs of offset images to reject cosmic rays optimally will take some further work, but we’re happy to start working with the data and see what emerges at each step.”


The Voorwerp (also known by the much less endearing name of SDSS J094103.80+344334.2) created a sensation among amateur, armchair and professional astronomers alike, almost immediately after Van Arkel saw the object in 2007 and posted a question on the Galaxy Zoo forum, asking “What is this?” All this took place just a month after the Galaxy Zoo project opened up their online citizen science shop, and the rest is history. But in case you haven’t heard the story yet, a quick rundown is that ‘voorwerp’ means ‘object’ in Dutch – and as of yet, no one has determined exactly what Hanny’s Voorwerp is.

The working hypothesis, according to the Galaxy Zoo team, is that Hanny’s Voorwerp might be a “light echo” of an event that occurred millions of years ago. The object itself consists of dust and gas which perhaps was illuminated by a quasar outburst within the nearby galaxy IC 2497 (see the images). The outburst has faded within the last 100,000 years but the light reached the dust and gas in time for our telescopes to see the effect.

Hanny's Voorwerp. Credit: Matt Jarvis, William Herschel Telescope.

The Galaxy Zoo images come from observations done by the Sloan Digital Sky Survey. In evidence of the interest in this object, since 2007 Hanny’s Voorwerp has also been imaged by the Swift gamma-ray satellite, the Suzaku X-ray telescope, the Westerbork Synthesis Radio Telescope (WSRT), the Issac Newton Telescope and the William Herschel Telescope, to name a few.

But now, the most famous telescope of all – with its new and updated instruments – will take a gander to see if the mysteries of the Voorwerp can be solved.

The team – which includes Keel, and fellow Galaxy “Zookeepers” Chris Lintott, Kevin Schawinski, Vardha Nicola Bennert, Daniel Thomas, and Hanny Van Arkel herself – submitted a proposal to the Space Telescope Science Institute back in 2008 and were among the proud and few from close to 1000 proposals submitted to be granted observing time on Hubble.

During the three observing sessions, three different Hubble instruments will be used.

“The observations use three instruments and would naturally be broken into three target visits,” said Keel, “some constrained to be at different times because of the required orientations on the sky –for example, to have both Hanny’s Voorwerp and IC 2497 in the narrow field of view of ACS (Advanced Camera for Surveys) with the monochromatic ramp filters.”

“The next observations will probably be the most visually striking,” Keel continued. “Two orbits’ worth of ACS images in narrow bands including [O III] an H-alpha emission, and are scheduled for April 12. The final visit in the program has 2 orbits of STIS (Space Telescope Imaging Spectrograph) spectroscopy around the nucleus of IC2497, and should be coming up by mid-June.”

The April 4 observations included three orbits of data from the WFC3.

So, even though the first images have now been seen, the team won’t be able to share their findings until all the observations have occurred and the data has been analyzed.

Hanny Van Arkel. Image courtesy of Hanny.

“I indeed can’t say much more than that we got the first data in our mailboxes,” Van Arkel said in an email to Universe Today. “The team is still working on it and until they’ve worked it out, I won’t even understand enough of it myself to explain anything on the matter. It is exciting however that the investigations have started and it’s nice to see how many curious people are sending me messages about it and ‘retweeting’ my quotes on Twitter. After almost two years, I’m very much looking forward to the outcome of all of this!”

Van Arkel isn’t the only one excited.

“Through a combination of geometry and weather,” Keel shared,”I saw HST sail by to our south less than two orbits after it finished this first data set. So I waved in what was probably a most unprofessional manner.”

And the rest of us will be waiting – and waving – until Hubble can tell us more about Hanny’s Voorwerp.

For more information:

Hanny Van Arkel’s website

A post on the Galaxy Zoo blog by Bill Keel explaining in greater detail the Hubble observing sessions.

Galaxy Zoo

For other citizen science projects, visit the Zooniverse

Posted on by Nancy Atkinson

Mystery Object Found Orbiting Brown Dwarf

This Hubble Space Telescope image of young brown dwarf 2M J044144 show it has a companion object at the 8 o'clock position that is estimated to be 5-10 times the mass of Jupiter.Credit: NASA, ESA, and K. Todorov and K. Luhman (Penn State University)

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Big planet or companion brown dwarf? Using the Hubble Space Telescope and the Gemini Observatory, astronomers have discovered an unusual object orbiting a brown dwarf, and its discovery could fuel additional debate about what exactly constitutes a planet. The object circles a nearby brown dwarf in the Taurus star-forming region with an orbit approximately 3.6 billion kilometers (2.25 billion miles) out, about the same as Saturn from our sun. The astronomers say it is the right size for a planet, but they believe the object formed in less than 1 million years — the approximate age of the brown dwarf — and much faster than the predicted time it takes to build planets according to conventional theories.

Kamen Todorov of Penn State University and his team conducted a survey of 32 young brown dwarfs in the Taurus region.

The object orbits the brown dwarf 2M J044144 and is about 5-10 times the mass of Jupiter. Brown dwarfs are objects that typically are tens of times the mass of Jupiter and are too small to sustain nuclear fusion to shine as stars do.

Artist's conception of the binary system 2M J044144. Science Credit: NASA, ESA, and K. Todorov and K. Luman (Penn State University) Artwork Credit: Gemini Observatory, courtesy of L. Cook

While there has been a lot of discussion in the context of the Pluto debate over how small an object can be and still be called a planet, this new observation addresses the question at the other end of the size spectrum: How small can an object be and still be a brown dwarf rather than a planet? This new companion is within the range of masses observed for planets around stars, but again, the astronomers aren’t sure if it is a planet or a companion brown dwarf star.

The answer is strongly connected to the mechanism by which the companion most likely formed.

The Hubble new release offers these three possible scenarios for how the object may have formed:

Dust in a circumstellar disk slowly agglomerates to form a rocky planet 10 times larger than Earth, which then accumulates a large gaseous envelope; a lump of gas in the disk quickly collapses to form an object the size of a gas giant planet; or, rather than forming in a disk, a companion forms directly from the collapse of the vast cloud of gas and dust in the same manner as a star (or brown dwarf).

If the last scenario is correct, then this discovery demonstrates that planetary-mass bodies can be made through the same mechanism that builds stars. This is the likely solution because the companion is too young to have formed by the first scenario, which is very slow. The second mechanism occurs rapidly, but the disk around the central brown dwarf probably did not contain enough material to make an object with a mass of 5-10 Jupiter masses.

“The most interesting implication of this result is that it shows that the process that makes binary stars extends all the way down to planetary masses. So it appears that nature is able to make planetary-mass companions through two very different mechanisms,” said team member Kevin Luhman of the Center for Exoplanets and Habitable Worlds at Penn State University.

If the mystery companion formed through cloud collapse and fragmentation, as stellar binary systems do, then it is not a planet by definition because planets build up inside disks.

The mass of the companion is estimated by comparing its brightness to the luminosities predicted by theoretical evolutionary models for objects at various masses for an age of 1 million years.

Further supporting evidence comes from the presence of a very nearby binary system that contains a small red star and a brown dwarf. Luhman thinks that all four objects may have formed in the same cloud collapse, making this in actuality a quadruple system.

“The configuration closely resembles quadruple star systems, suggesting that all of its components formed like stars,” he said.

The team’s research is being published in an upcoming issue of The Astrophysical Journal.

The team’s paper: Discovery of a Planetary-Mass Companion to a Brown Dwarf in Taurus

Source: HubbleSite

Posted on by Nancy Atkinson

Hubble Confirms Cosmic Acceleration with Weak Lensing

This image shows a smoothed reconstruction of the total (mostly dark) matter distribution in the COSMOS field, created from data taken by the NASA/ESA Hubble Space Telescope and ground-based telescopes.Credit: NASA, ESA, P. Simon (University of Bonn) and T. Schrabback (Leiden Observatory)

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Need more evidence that the expansion of the Universe is accelerating? Just look to the Hubble Space Telescope. An international team of astronomers has indeed confirmed that the expansion of the universe is accelerating. The team, led by Tim Schrabback of the Leiden Observatory, conducted an intensive study of over 446,000 galaxies within the COSMOS (Cosmological Evolution Survey) field, the result of the largest survey ever conducted with Hubble. In making the COSMOS survey, Hubble photographed 575 slightly overlapping views of the same part of the Universe using the Advanced Camera for Surveys (ACS) onboard the orbiting telescope. It took nearly 1,000 hours of observations.

In addition to the Hubble data, researchers used redshift data from ground-based telescopes to assign distances to 194,000 of the galaxies surveyed (out to a redshift of 5). “The sheer number of galaxies included in this type of analysis is unprecedented, but more important is the wealth of information we could obtain about the invisible structures in the Universe from this exceptional dataset,” said co-author Patrick Simon from Edinburgh University.

In particular, the astronomers could “weigh” the large-scale matter distribution in space over large distances. To do this, they made use of the fact that this information is encoded in the distorted shapes of distant galaxies, a phenomenon referred to as weak gravitational lensing. Using complex algorithms, the team led by Schrabback has improved the standard method and obtained galaxy shape measurements to an unprecedented precision. The results of the study will be published in an upcoming issue of Astronomy and Astrophysics.

The meticulousness and scale of this study enables an independent confirmation that the expansion of the Universe is accelerated by an additional, mysterious component named dark energy. A handful of other such independent confirmations exist. Scientists need to know how the formation of clumps of matter evolved in the history of the Universe to determine how the gravitational force, which holds matter together, and dark energy, which pulls it apart by accelerating the expansion of the Universe, have affected them. “Dark energy affects our measurements for two reasons. First, when it is present, galaxy clusters grow more slowly, and secondly, it changes the way the Universe expands, leading to more distant — and more efficiently lensed — galaxies. Our analysis is sensitive to both effects,” says co-author Benjamin Joachimi from the University of Bonn. “Our study also provides an additional confirmation for Einstein’s theory of general relativity, which predicts how the lensing signal depends on redshift,” adds co-investigator Martin Kilbinger from the Institut d’Astrophysique de Paris and the Excellence Cluster Universe.

The large number of galaxies included in this study, along with information on their redshifts is leading to a clearer map of how, exactly, part of the Universe is laid out; it helps us see its galactic inhabitants and how they are distributed. “With more accurate information about the distances to the galaxies, we can measure the distribution of the matter between them and us more accurately,” notes co-investigator Jan Hartlap from the University of Bonn. “Before, most of the studies were done in 2D, like taking a chest X-ray. Our study is more like a 3D reconstruction of the skeleton from a CT scan. On top of that, we are able to watch the skeleton of dark matter mature from the Universe’s youth to the present,” comments William High from Harvard University, another co-author.

The astronomers specifically chose the COSMOS survey because it is thought to be a representative sample of the Universe. With thorough studies such as the one led by Schrabback, astronomers will one day be able to apply their technique to wider areas of the sky, forming a clearer picture of what is truly out there.

Source: EurekAlert

Paper: Schrabback et al., ‘Evidence for the accelerated expansion of the Universe from weak lensing tomography with COSMOS’, Astronomy and Astrophysics, March 2010,

Posted on by Nancy Atkinson

Review: Hubble 3-D IMAX

Hubble 3-D IMAX movie poster.

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I have seen the new Hubble 3-D IMAX movie twice now, and both times I was overcome with tears by the end of the film. It wasn’t that the story of Hubble itself was overwhelming; no, that story I already knew by heart. It wasn’t that the account of the servicing mission to save Hubble was especially dramatic; actually, I think watching the five EVAs live on NASA TV in May 2009 was more heart-pounding. And it wasn’t that the cinematography was overly stunning or that there were non-stop 3-D effects.

What this film does is portray the immensity and gloriousness of our universe, and that we are currently, serendipitously, living during an amazing era of discovery, one that humanity has never known before. Some of these discoveries we are only able to make because of this marvelous telescope and the people who laid their lives on the line to fix it and make it better. It also shows — almost subtly – that we are inexorably connected to the Universe around us, joined like the intertwining web of 3-D galaxies shown near the movie’s final scenes. We are witnessing – and are a part of – history.

The movie chronicles the 20-year life of Hubble, and focuses on the STS-125 servicing mission, the final mission to Hubble. There ARE wonderful 3-D views of Hubble itself, anchored to shuttle Atlantis’ payload bay, where the telescope appears to come out into the audience and into your lap. This includes stunning views of planet Earth spinning overhead. “This is a gift we astronauts have been given,” astronaut Mike Massimino says of the vistas that can only be seen from space.

And viewers get to experience not one, but two shuttle launches captured in the so-close-up-you-can-feel-it shots which can only be experienced in IMAX. But much of the footage from on-orbit detailing the EVAs and action inside the shuttle were shot with the regular, albeit high-tech cameras that normally NASA flies on missions, including the small “lipstick” cameras on the helmets of the spacewalkers, and some was able to be rendered in grainy, but effective 3-D. The only genuine IMAX 3-D camera on board the mission was bolted to the shuttle’s cargo bay and it carried only 5,400 feet of film – which translates into just 8 minutes of IMAX 3-D footage. Here’s an article about a 3 D Solar System

Endearing are the behind-the-scenes looks at the STS-125 mission. Astronauts joking with each other on orbit – Commander Scott Altman sticking gum under the shuttle’s “dashboard,” Massimino describing how suiting up for an EVA is like putting on a snowsuit as a child. “You need your Mom,” he says.

In both showings I attended, the scene that got the most audible reaction from the audience was Drew Feustal making a chicken salad tortilla wrap. But, hey, we all have to eat, and for those who have never seen food preparation or astronauts eating in space before, it holds a certain level of fundamental fascination.

Additionally we get to hear what is going through the minds of the astronauts on launch day. Mike Good recalls how his grandfather opened up the Universe by showing him views through a telescope. Megan McArthur glows with excitement. John Grunsfeld meticulously goes through in his mind all the tasks that lie before him and the crew.

The film quickly moves through the EVAs, highlighting anxious moments of the mission — stuck bolts, the handrail that Massimino had to rip off of Hubble, the tension of undertaking the meticulous repairs on a one-of-a-kind iconic telescope, all while wearing a bulky spacesuit. But within a 43 minute film, these situations are dealt with quickly, — and honestly, — the movie doesn’t give real justice to how tense some of these situations really were.

A vast canyon of dust and gas in the Orion Nebula from a 3-D computer model based on observations by NASA's Hubble Space Telescope. Credit: NASA, G. Bacon, L. Frattare, Z. Levay, and F. Summers (STScI/AURA)

But most mesmerizing in the film are 3-D visualizations of actual Hubble data. For this film, regular 2-D Hubble images were converted into 3-D environments, giving the audience the impression they are traveling through space and time.

Viewers get to experience an exhilarating ride through the Orion Nebula, swooping through a giant canyon of gas and dust, and witness star-forming regions that include dusty tadpole-shaped objects that are fledgling solar systems, likely a vision of how our own solar system once looked.

Later we travel to the distant Virgo Cluster and emerge on the other side of a black hole, and then travel back in time to witness early misshapen galaxies. Returning to more recent views that include new images from the Wide Field Camera 3 that was installed on STS-125, we see an ocean of stars in multiple wavelengths. Upon pulling away from the stars, we see 3-D galaxies interwoven like a web.

It’s these mind-numbing visions that produce a child-like sense of awe and wonder – and in my case, tears. The film is a testament to how Hubble has allowed us to see the wonders of our Universe.

I asked for reactions from the members of the audience following the premier showing of Hubble 3-D at the Kennedy Space Center IMAX, and while many commented on the amazing graphics, they also observed how small they felt in comparison to the rest of the Universe, but yet, incredibly an integral part of all that is.

The graphics were created by image processing specialists at Hubble’s Space Telescope Science Institute,– familiar names to those of us that follow Hubble : Frank Summers, Zolt Levay, Lisa Frattare, and Greg Bacon. They worked with the National Center for Supercomputing Applications at the University of Illinois at Urbana-Champaign (more about them in a subsequent, upcoming article on Universe Today), and the Spitzer Science Center at the California Institute of Technology.

Hubble 3-D was directed by Toni Myers, who has been at the helm of all the space-themed IMAX movies, and narrated by Leonardo DiCaprio.

Go see the movie if you have the chance, and bring anyone who may not normally follow space exploration or astronomy. Their view of the Universe will never be the same.

For more info see the official Hubble 3-D IMAX website. Official trailer below.

Posted on by Nancy Atkinson

Hubble Captures Double Aurorae Light Show on Saturn

Hubble's view of Saturn with a double view of its fluttering aurorae. Credit: NASA, ESA and Jonathan Nichols (University of Leicester)


In January and March 2009, researchers using Hubble took advantage of a rare opportunity to record Saturn when its rings are edge-on, resulting in a unique look featuring both of the giant planet’s poles. And Saturn cooperated by providing an incredible double light show with Saturn’s own northern and southern lights. Since Saturn is only in this position every 15 years or so, this favorable orientation has allowed a sustained study of the two beautiful and dynamic aurorae.

Since it takes Saturn almost thirty years to orbit the Sun, the opportunity to image both of its poles occurs only twice in that period. Hubble has been snapping pictures of the planet at different angles since the beginning of the mission in 1990, but 2009 brought a unique chance for Hubble to image Saturn with the rings edge-on and both poles in view. At the same time Saturn was approaching its equinox so both poles were equally illuminated by the Sun’s rays.

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These recent observations go well beyond just a still image and have allowed researchers to monitor the behavior of both Saturn’s poles in the same shot over a sustained period of time. The movie they created from the data, collected over several days during January and March 2009, has aided astronomers studying both Saturn’s northern and southern aurorae. Given the rarity of such an event, this new footage will likely be the last and best equinox movie that Hubble captures of our planetary neighbor.

Despite its remoteness, the Sun’s influence is still felt by Saturn. The Sun constantly emits particles that reach all the planets of the Solar System as the solar wind. When this electrically charged stream gets close to a planet with a magnetic field, like Saturn or the Earth, the field traps the particles, bouncing them back and forth between its two poles. A natural consequence of the shape of the planet’s magnetic field, a series of invisible “traffic lanes” exist between the two poles along which the electrically charged particles are confined as they oscillate between the poles. The magnetic field is stronger at the poles and the particles tend to concentrate there, where they interact with atoms in the upper layers of the atmosphere, creating aurorae, the familiar glow that the inhabitants of the Earth’s polar regions know as the northern and southern lights.

At first glance the light show of Saturn’s aurorae appears symmetric at the two poles. However, analysing the new data in greater detail, astronomers have discovered some subtle differences between the northern and southern aurorae, which reveal important information about Saturn’s magnetic field. The northern auroral oval is slightly smaller and more intense than the southern one, implying that Saturn’s magnetic field is not equally distributed across the planet; it is slightly uneven and stronger in the north than the south. As a result, the electrically charged particles in the north are accelerated to higher energies as they are fired toward the atmosphere than those in the south. This confirms a previous result obtained by the space probe Cassini, in orbit around the ringed planet since 2004.

Source: ESA