VisAO takes the first optical image of an exoplanet from the ground

Today the MagAO team, along with our collaborators from the NICI team, published a paper on the extrasolar planet beta Pictoris b. We used our CCD camera VisAO to take a picture of the planet, the first time such a camera has been used to image an extrasolar planet from the ground.

You can read more about this achievement at UA News, the NASA Exoplanet Science Institute, and PlanetQuest.

Here is our announcement:

A Small Step Toward Discovering Habitable Earths

University of Arizona researchers snapped images of a planet outside our solar system with an Earth-based telescope using essentially the same type of imaging sensor found in digital cameras instead of an infrared detector. Although the technology still has a very long way to go, the accomplishment takes astronomers a small step closer to what will be needed to image earth-like planets around other stars

An artist’s impression of a young, giant exoplanet orbiting its host star. (Image: NASA/JPL-Caltech)

“This is an important next step in the search for exoplanets because imaging in visible light instead of infrared is what we likely have to do if we want to detect planets that might be suitable for harboring life,” said Jared Males, a NASA Sagan Fellow in the UA’s Department of Astronomy and Steward Observatory and lead author on a report to be published in The Astrophysical Journal.

Even though the image was taken at a wavelength that is just shy of being visible to the human eye, the use of a digital camera-type imaging sensor – called a charge-coupled device or CCD – opens up the possibility of imaging planets in visible light, which has not been possible previously with Earth-based telescopes.

“This is exciting to astronomers because it means we now are a small step closer to being able to image planets outside our solar system in visible light,” said Laird Close, a professor in the Department of Astronomy, who co-authored the paper.

He explained that all the other Earth-based images taken of exoplanets close to their stars are infrared images, which detect the planets’ heat. This limits the technology to Gas Giants – massive, hot planets young enough to still shed heat. In contrast, older, possibly habitable planets that have cooled since their formation don’t show up in infrared images as readily, and to image them, astronomers will have to rely on cameras capable of detecting visible light.

“Our ultimate goal is to be able to image what we call pale blue dots,” Close said. “After all, the Earth is blue. And that’s where you want to look for other planets: in reflected blue light.”

The photographed planet, called Beta Pictoris b, orbits its star at only nine times the Earth-Sun distance, making its orbit smaller than Saturn’s. In the team’s CCD images, Beta Pictoris b appears about 100,000 times fainter than its host star, making it the faintest object imaged so far at such high contrast and at such relative proximity to its star. The new images of this planet helped confirm that its atmosphere is at a temperature of roughly 2600 degrees Fahrenheit (1700 Kelvin). The team estimates that Beta Pictoris b weighs in at about 12 times the mass of Jupiter.

An image of the exoplanet Beta Pictoris b made with the Magellan Adaptive Optics (MagAO) VisAO camera. This image was made using a CCD camera, which is essentially the same technology as a cell phone camera. The planet is nearly 100,000 times fainter than its star, and orbits its star at roughly the same distance as Saturn from our Sun.

“Because the Beta Pictoris system is 63.4 light years from Earth, the scenario is equivalent to imaging a dime next right next to a lighthouse beam from more than four miles away,” Males said. “Our image has the highest contrast ever achieved on an exoplanet that is so close to its star.”

The contrast in brightness between the bright star and the faint planet is similar to the height of a 4-inch molehill next to Mount Everest, Close explained.

In addition to the host star’s overwhelming brightness, the astronomers had to overcome the turbulence in Earth’s atmosphere, which causes stars to twinkle and telescope images to blur. The success reported here is mostly due to an adaptive optics system developed by Close and his team that eliminates much of the atmosphere’s effect. The Magellan Adaptive Optics technology is very good at removing this turbulence, or blurring, by means of a deformable mirror changing shape 1,000 times each second in real time.

The Magellan Telescope with MagAO’s Adaptive Secondary Mirror (ASM) mounted at the top looking down (some 9 meters) onto the 6.5m (21 foot) diameter Primary Mirror (not visible, inside blue mirror cell). Moonlight image, credit: Yuri Beletsky, Las Campanas Observatory.

Adaptive optics have been used for more than 20 years at observatories in Arizona, most recently at the Large Binocular Telescope, and the latest version has now been deployed in the high desert of Chile at the Magellan 6.5-meter telescope.

The team also imaged the planet with both of MagAO’s cameras, giving the scientists two completely independent simultaneous images of the same object in infrared as well as bluer light to compare and contrast.

“An important part of the signal processing is proving that the tiny dot of light is really the planet and not a speckle of noise,” said Katie Morzinski, who is also a Sagan Fellow and member of the MagAO team. “I obtained the second image in the infrared spectrum – at which the hot planet shines brightly – to serve as an unequivocal control that we are indeed looking at the planet. Taking the two images simultaneously helps to prove the planet image on the CCD is real and not just noise.”

Males added: “In our case, we were able to record the planet’s own glow because it is still young and hot enough so that its signal stood out against the noise introduced by atmospheric blurring.”

“But when you go yet another 100,000 times fainter to spot much cooler and truly earthlike planets,” Males said, “we reach a situation in which the residual blurring from the atmosphere is too large and we may have to resort to a specialized space telescope instead.”

Development of the MagAO system was made possible through the strong support of the National Science Foundation MRI, TSIP and ATI grant programs. The Magellan telescopes are operated by a partnership of the Carnegie institute, the University of Arizona, Harvard University, Massachusetts Institute of Technology and the University of Michigan. The work of NASA Sagan Fellows Jared Males and Katie Morzinski was performed in part under contract with the California Institute of Technology funded by NASA through the Sagan Fellowship Program executed by the NASA Exoplanet Science Institute.

MagAO Discovers a Planet

Today, Vanessa and the rest of the MagAO team announced the discovery of a new planet, named HD 106906 b. Read on for the exciting details.

You can find the original press release at UA News, and read more at: Discovery News, NBC News, Science Daily, Phys.org, ScienceBlog, Nature World News, CBS News, the LA Times, the Daily Mail, and many more (national and international).

Here is Universe Todays’ take, and more from The Monitor.

The Bad Astronomer has some thoughts about HD 106906 b too. A very nice retelling of the story.

In local news:  KOLD came for an interview. They were on campus for the unveiling of the latest Giant Magellan Telescope mirror segment, a major feat in and of itself. The Daily Star also posted a nice piece, as did the Daily Wildcat.

In an interesting twist, >100,000 people have signed a petition to the IAU and Vanessa to name this planet Gallifrey. Alas, we couldn’t give them good news.

From all that, we made the front pages at Wikipedia, Google News, Yahoo, and Slashdot.

 

Ok, enough hype, here’s the scoop:

Here is the Extrasolar Planet Encyclopedia entry for HD 106906 b.

UA Astronomers Discover Planet That Shouldn’t Be There

Artist’s conception of a young planet in a distant orbit around its host star. The star still harbors a debris disk, remnant material from star and planet formation, interior to the planet’s orbit (similar to the HD106906 system).
Image courtesy NASA/JPL-Caltech.

An international team of astronomers, led by a University of Arizona graduate student, has discovered the most distantly orbiting planet found to date around a single, sun-like star. It is the first exoplanet discovered at the UA.

Weighing in at 11 times Jupiter’s mass and orbiting its star at 650 times the average Earth-Sun distance, planet HD 106906 b is unlike anything in our own Solar System and throws a wrench in planet formation theories.

“This system is especially fascinating because no model of either planet or star formation fully explains what we see,” said Vanessa Bailey, a fifth-year graduate student in the UA’s department of astronomy, who led the research.

It is thought that planets close to their stars, like Earth, coalesce from small asteroid-like bodies born in the primordial disk of dust and gas that surrounds a forming star. However, this process acts too slowly to grow giant planets far from their star. Another mechanism proposes that giant planets can form from a fast, direct collapse of disk material. However, primordial disks rarely contain enough mass in their outer reaches to allow a planet like HD 106906 b to form. Several alternative hypotheses have been put forward including formation like a mini binary star system.

“A binary star system can be formed when two adjacent clumps of gas collapse more or less independently to form stars, and these stars are close enough to each other to exert a mutual gravitation attraction and bind them together in an orbit,” Bailey explained. “It is possible that in the case of the HD 106906 system the star and planet collapsed independently from clumps of gas, but for some reason the planet’s progenitor clump was starved for material and never grew large enough to ignite and become a star.”

According to Bailey, one problem with this scenario is that the mass ratio of the two stars in a binary system is typically no more than 10 to 1.

“In our case, the mass ratio is more than 100 to 1,” she explained. “This extreme mass ratio is not predicted from binary star formation theories – just like planet formation theory predicts that we cannot form planets so far from the host star.”

This system is also of particular interest because researchers can still detect the remnant “debris disk” of material left over from planet and star formation.

“Systems like this one, where we have additional information about the environment in which the planet resides, have the potential to help us disentangle the various formation models,” Bailey added. ” Future observations of the planet’s orbital motion and the primary star’s debris disk may help answer that question.”

At only 13 million years old, this young planet still glows from the residual heat of its formation. Because at 2,700 Fahrenheit (about 1,500 degrees Celsius) the planet is much cooler than its host star, it emits most of its energy as infrared rather than visible light.

Direct imaging observations require exquisitely sharp images, akin to those delivered by the Hubble Space Telescope. To reach this resolution from the ground requires a technology called Adaptive Optics, or AO. The team used the new Magellan Adaptive Optics (MagAO) system and Clio2 thermal infrared camera, both technologies developed at the UA, mounted on the 6.5 meter-diameter Magellan telescope in the Atacama Desert in Chile, to take the discovery image.

UA astronomy professor and MagAO Principal Investigator Laird Close said: “MagAO was able to utilize its special Adaptive Secondary Mirror, with 585 actuators, each moving 1000 times a second, to remove the blurring of the atmosphere. The atmospheric correction enabled the detection of the weak heat emitted from this exotic exoplanet without confusion from the hotter parent star.”

“Clio was optimized for thermal infrared wavelengths, where giant planets are brightest compared to their host stars, meaning planets are most easily imaged at these wavelengths,” explained UA astronomy professor and Clio Principal Investigator Philip Hinz, who directs the UA Center for Astronomical Adaptive Optics.

The team was able to confirm that planet is moving together with its host star by examining Hubble Space Telescope data taken eight years prior for another research program. Using the FIRE spectrograph, also installed at the Magellan telescope, the team confirmed the planetary nature of the companion. “Images tell us an object is there and some information about its properties but only a spectrum gives us detailed information about its nature and composition,” explained co-investigator Megan Reiter, a graduate student at the UA department of astronomy. “Such detailed information is rarely available for directly imaged exoplanets, making HD 106906 b a valuable target for future study.”

“Every new directly detected planet pushes our understanding of how and where planets can form,” said co-investigator Tiffany Meshkat, at graduate student at Leiden Observatory in the Netherlands. “This planet discovery is particularly exciting because it is in orbit so far from its parent star. This leads to many intriguing questions about its formation history and composition. Discoveries like HD 106906 b provide us with a deeper understanding of the diversity of other planetary systems.”

A paper describing the results, entitled, “HD 106906 b: A Planetary-mass Companion Outside a Massive Debris Disk,” has been accepted for publication in The Astrophysical Journal Letters and will appear in a future issue. A copy of the paper can be downloaded here. MagAO was funded by NSF MRI, TSIP, and ATI awards, and Vanessa Bailey was funded by the NSF Graduate Research Fellowship Program.
The members of the discovery team are Vanessa Bailey (University of Arizona [UA]), Tiffany Meshkat (Leiden Observatory [LO]), Megan Reiter (UA), Katie Morzinski (UA), Jared Males (UA), Kate Y. L. Su (UA), Philip M. Hinz (UA), Matthew Kenworthy (LO), Daniel Stark (UA), Eric Mamajek (University of Rochester), Runa Briguglio (Arcetri Observatory [AO]), Laird M. Close (UA), Katherine B. Follette (UA), Alfio Puglisi (AO), Timothy Rodigas (UA, Carnegie Institute of Washington [CIW]), Alycia J. Weinberger (CIW), and Marco Xompero (AO).

Scientists Make Highest Resolution Photos Ever of the Night Sky

Today the MagAO team is extremely happy to announce our first three refereed publications. Read on to find out about the exciting science we did in the Orion nebula.

The following press release can be downloaded as a pdf.

For a little more insight into the project see this Arizona Daily Star article. For Carnegie’s take go here. For the Italian version, check out INAF’s news. Nice work Simone.


Scientists Make Highest Resolution Photos Ever of the Night Sky

Astronomers at the University of Arizona, Arcetri Observatory in Italy, and at the Carnegie Observatory have developed a new type of camera that allows higher resolution (sharper) images to be taken than ever before. The team has been developing this technology for over 20 years at observatories in Arizona (most recently at the Large Binocular Telescope; LBT), and has now deployed the latest version of these cameras in the high desert of Chile at the Magellan 6.5m (21ft) telescope. “It was very exciting to see this new camera make the night sky look sharper than has ever before been possible” said University of Arizona professor Laird Close, the project’s principal scientist, “We can, for the first time, make deep images that resolve objects just 0.02 arcseconds across. That is a very small angle on the sky. It is like the width of a dime (1.7 cm) seen over 100 miles (160 km) away. It could also be compared to resolving a baseball diamond on the Moon”.

Removing the “twinkle” From the Stars in Visible Light

The reason for the factor of 2 improvement over past efforts is that, for the first time, a large 6.5m telescope is being used for digital photography at its theoretical resolution limit in wavelengths of visible light. “As you move from infrared to visible light, your image sharpness improves”, said Dr. Jared Males, a NASA Sagan Fellow at the University of Arizona , “Up until now, large telescopes could make the theoretically sharpest photos only in infrared (long wavelength) light, but our new camera can work in the visible and make photos twice as sharp”. These images are also at least twice as sharp as what the Hubble Space Telescope (HST) can make because the 6.5m Magellan telescope is much larger than the 2.4m HST. HST has always produced the best available visible light images, since until now even large ground-based telescope with complex adaptive optics imaging cameras could only make blurry images in light that the eye can see (visible light). To obtain the excellent correction of atmospheric turbulence required for “visible light AO”, the team developed a very powerful adaptive optics system that floats a thin (1/16 inch (1.6 mm) thick) curved glass mirror (2.7 feet (85 cm) across) on a magnetic field 30 feet (9.2m) above the large 21 foot (6.5m) primary mirror of the telescope (see figure 1). This so-called “Adaptive Secondary Mirror” (ASM) can change its shape at 585 points on its surface 1000 times a second. In this manner the “blurring” effects of the atmosphere can be removed, and thanks to the high density of actuators on the mirror, astronomers can see the visible sky more clearly than ever before, almost like having a 6.5m telescope in space.

Magellan Clay with MagAO
Figure 1: The Magellan Telescope with MagAO’s Adaptive Secondary Mirror (ASM) mounted at the top looking down (some 9 meters) onto the 6.5m (21 foot) diameter Primary Mirror (not visible, inside blue mirror cell). Moonlight image, credit: Yuri Beletsky, Las Campanas Observatory.

New Science Results From MagAO: Insights into How Stars and Planets Form

The new adaptive optics system, called MagAO, has already made some important scientific discoveries. As the system was being tested (so called “First Light”) the team tried to resolve the famous star that gives the Great Orion Nebulae (M42) most of its UV light. This young (~1 million year old) star is called Theta 1 Ori C and it was previously known to be two stars (a binary star pair; called C1 and C2). However, the separation is so small that this famous pair has never been resolved into 2 stars in a direct telescope photo. Once MagAO and its visible science camera (VisAO; see figure 2) were pointed towards Theta Ori 1 C, the results were exciting and immediate (see figure 3). “I have been imaging Theta 1 Ori C for over 20 years and never could I directly see that it was in fact 2 stars”, said Dr. Close, “But as soon as we turned on the MagAO system it was beautifully split into 2 stars just 0.032 arcseconds apart”. MagAO was then used to map out all the positions of the brightest nearby Orion Trapezium cluster stars and was able to detect very small motions compared to older LBT data, a result of the stars slowly revolving around each other. Indeed, a small group of stars called Theta 1 Ori B1-B4 was proved to be likely a bound “mini-cluster” of stars that will likely eject the lowest mass star in the near future (see figure 4). This result has just been published in the Astrophysical Journal (preprint).

MagAO on the Clay telescope.
Figure 2: The VisAO camera and MagAO wavefront sensors at the focus of the 6.5m Magellan telescope (all optics inside dark ring) that were used to make the visible wavelength images. Dr. Jared Males (VisAO instrument scientist/NASA Sagan Fellow) and Professor Laird Close (MagAO project scientist) are shown for scale from left to right. Photo credit Dr. Katie Morzinski, NASA Sagan Fellow at the University of Arizona.
Theta 1 Ori C resolved with VisAO
Figure 3: The power of visible light adaptive optics. Here we show (on the left) a “normal” photo of the theta 1 Ori C binary star in red light (in the r’ filter, 630 nm). It just looks an unresolved star. Then the middle image shows how if we remove (in real time) the blurring of the atmosphere with MagAO’s adaptive optics’ the resulting photo becomes ~17 times sharper (corrected resolutions range from 0.019-0.029 arcseconds on theta 1 Ori C). Both photos are 60 seconds long, and no post-detection image enhancement has been applied. These are the highest resolution photos taken by a telescope. Photo credit Laird Close, University of Arizona.

A mystery about how planets form is: how are the disks of dust and gas affected by the strong ionizing light/wind coming from a massive star like Theta 1 Ori C (some 44 times the mass of the Sun)? The team used MagAO and VisAO to look for red light (at 656 nm, or hydrogen alpha) from ionized hydrogen gas to trace out how the strong UV flux and stellar wind from Theta 1 Ori C affects the disks around its neighboring stars. MagAO’s photo shows that the envelope of gas and dust around a pair of stars (called LV1) just 6.5 arcseconds away from Theta 1 Ori C are heavily distorted into “teardrop” shapes as the strong UV light and wind create shock fronts and drag gas downwind of the pair (see bottom insert in figure 4). “We were surprised to find that the mass of the pair of young stars was very low, making this a very rare example of a low mass pair of young disks (called proplyds).” Said Arizona graduate student Ya-Lin Wu (who led the Astrophysical Journal paper on this result (preprint).

Trapezium
Figure 4: The Orion Trapezium is a cluster of young stars still in the process of forming. The top inset image shows MagAO’s photo of the “mini-cluster” of young stars in the Theta 1 Ori B group (B1-B4; Top Inset image). There is now clear evidence of relative motion of these stars around B1. The lowest mass member (B4) will likely be ejected in the future. The middle inset photo shows the highest resolution astronomical photo of the Theta 1 Ori C1 C2 pair, and the bottom insert shows the LV 1 binary young star pair shaped by the wind from Theta 1 Ori C (in the visible light of hydrogen gas (at 656 nm). Photo Credit: Laird Close and Ya-Lin Wu, University of Arizona. The Background image is a previous HST Orion Trapezium Cluster visible image (NASA, C.R. O’Dell and S.K. Wong, Rice University).

The distribution of gas and dust in young planetary systems is another unsolved problem in planet formation. The team used VisAO’s simultaneous/spectral differential Imager (SDI) to image in and out of the bright 656 nm hydrogen alpha emission line. This allowed the team to trace the absorption (hence mass) of one of the rare “silhouette” disks in Orion. The disk lies in front of the bright Orion nebula, so we see the dark shadow cast as the dust in the disk absorbs background light from the nebula (see figure 5). The more material lies in the foreground disk, the greater the degree of absorption of background light from the nebula. The SDI camera allowed the light from the star to be removed at a very high level—leaving, for the first time, a clear look at the inner regions of the silhouette. “We were surprised to find that the amount of attenuated light from the nebula increased gradually, rather than sharply, toward the star”, noted Arizona graduate student (and lead author of the Astrophysical Journal letter – preprint) Kate Follette. “It seems as though the outer parts of this large disk have less dust than we would have expected”. As can been seen from Figure 5, there is clear evidence that MagAO with its SDI camera can make visible images of even very faint stars such as Orion 218-354.

H alpha silhouette disk with VisAO.
Figure 5: A MagAO image of Orion 218-354 silhouette after removal of light from the central star. The left-hand image shows the silhouette (shadow) of the disk against the bright background hydrogen alpha emission of the Orion nebula. The right-hand image is the same, but with contours denoting levels of increasing attenuation of the background nebular light toward the central star. The percentages denote the amount of nebular light passing through the disk. The degree of attenuation probes the amount of dust in the disk at each location. Photo credit Kate Follette, University of Arizona.

These results are just highlights of the first three science papers from the MagAO system. More exciting results will soon follow. Development of the MagAO system could not have been possible without the strong support of the National Science Foundation MRI, TSIP and ATI grant programs. The ASM itself was produced by Microgate and ADS of Italy, with the University of Arizona, Steward Observatory Mirror Lab. The MagAO pyramid wavefront sensor was developed at the Arcetri Observatory, Italy. The success of the system could not have been possible without the great support of the Magellan Telescope staff that helped us use their powerful telescope. The Magellan telescopes are run by a partnership of the Carnegie institute, University of Arizona, Harvard University, MIT, and the University of Michigan. The work of NASA Sagan Fellows Jared Males and Katie Morzinski was performed in part under contract with the California Institute of Technology (Caltech) funded by NASA through the Sagan Fellowship Program executed by the NASA Exoplanet Science Institute. The work of Kate Follette was funded in part by the NSF Graduate Research Fellowship program.

For more information about the Magellan Adaptive Optics System (MagAO) see /

Other places you can read about these results: UA News, the NSF, Space.com, Science Daily, National Geographic Society, slashdot, reddit, Gawker.