On Jan 17, NBA Hall of Famer, one of “50 Greatest Players in NBA History,” and iconic Deadhead Bill Walton came to town to be the color commentator for the UA-Oregon men’s basketball game. Whenever Walton is a commentator ESPN has a 2-minute feature called “Walton’s World.” In this episode, Bill visited the MagAO-X lab at Steward!
During our recent observing run we tested a new set of coronagraphs (devices for blocking star light so we can see planets!), which were developed by our friends Gilles Otten, Frans Snik, and Matt Kenworthy at Leiden University, in the Netherlands. Today Gilles gave a talk at the Spirit of Lyot Conference in Montreal, Canada. The new coronagraphs work spectacularly well! You can read about these results in Dutch, French, and in English.
Here is our announcement of this great news:
Astronomers develop breakthrough optical component for detecting exoplanets close to their host stars
Astronomers from Leiden University (the Netherlands) and the University of Arizona (USA) have successfully commissioned a new type of optic that can reveal the image of an exoplanet next to its parent star. The ‘vector Apodizing Phase Plate’ (vector-APP) coronagraph was installed at the 6.5-m Magellan Clay telescope in Chile in May 2015, and the first observations demonstrated an unprecedented contrast performance very close to the star, where planets are more likely to reside. These results will be presented by PhD student Gilles Otten (Leiden) this Monday to the scientific community at the “Spirit of Lyot” conference in Montreal.
Almost 2000 exoplanets have been detected to date, but only a handful of those have been imaged directly. Exoplanets are typically more than a million times fainter than and are lost in the glare of their parent star as seen from Earth. To directly image exoplanets and to characterize their atmospheres, astronomical instruments at the world’s largest telescopes use coronagraphs to suppress the overwhelming halo of light from the star.
The vector-APP coronagraph uses the wavelike nature of light to cancel out the starlight whilst allowing the planet’s light to shine through.
This manipulation is implemented through a complex phase pattern that can only be manufactured using advanced liquid crystal 3D patterning techniques . This technique creates two images of the star, for which dark D-shaped regions are located on opposite sides of each star image (see Figure 1). In this way, the whole region around the star can be scrutinized for planets. By combining several layers of liquid crystals, the device can be used over a wide range of wavelengths, including the infrared where the contrast between planet and star is more favorable.
On May 6, 2015 a vector-APP coronagraphic device saw first light (at 3.9 um wavelength, in the infrared range of the spectrum) at the MagAO instrument, attached to the 6.5-m diameter Magellan Clay telescope in Chile. The telescope’s integrated adaptive optics system provided the instrument with sharp images of stars, which were consequently split up and modified by the coronagraph to exhibit dark holes in which much fainter planets could be imaged than without the vector-APP coronagraph.
Frans Snik (Leiden University), who invented the principle behind the new vector-APP coronagraph, says: “It is fantastic to see that after all our design work and lab testing, this new approach works perfectly at the telescope on the very first night!” Gilles Otten adds: “We knew that we were in business as soon as we saw the first picture on the screen in the telescope control room.”
Jared Males (NASA Sagan Fellow, University of Arizona) is excited about the opportunities of the vector-APP: “With this new coronagraph we are now looking for planets around nearby stars. We have the capacity to directly detect, or rule out, planets smaller than Jupiter. ” Matthew Kenworthy (Leiden) concludes: “This new coronagraph technology is also excellent news for the extremely large telescopes currently under construction. With a vector-APP coronagraph in the next generation of telescopes, we can search for planets around nearby stars with unprecedented sensitivity.”
The advanced liquid crystal technology that the team adopted also permitted the production of extreme vector-APP designs that are not possible with more traditional manufacturing technologies. These new designs produce dark holes that cover the full 360 degrees around the target stars. The first data from an experimental device already shows the viability of this novel approach (see Figure 2).
Support from the William F. and Elizabeth Lucas Junior Faculty Astronomy Award and the NASA Origins of Solar Systems program made this exciting commissioning possible at the MagAO instrument in Chile. This work 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.
 For an introduction to the principles behind the vector-APP coronagraph, see Snik et al. (2012) and Otten el al. (2014). The name “vector-APP” stems from “Apodizing Phase Plate” based on polarization (vector) techniques. The original optical theory was developed by Johanan Codona at the University of Arizona.
 The vector-APP coronagraph devices for MagAO were developed in collaboration with the group of Dr. Michael Escuti at North Carolina State University, and were produced by ImagineOptix.
Welcome APOD and Sky and Telescope readers. This post was written while MagAO was mounted on the Clay 6.5 m telescope, and we post daily updates throughout the run on the main page. You can also find out about some of our scientific results using the In The News and Results pages.
You can also read about our eyepiece observations in a post by Tom Beal at the Arizona Daily Star.
On our first night on-sky in 2015A, our infrared camera Clio wasn’t quite ready to mount on the telescope. We also needed to test operating the AO system with a different camera, since there are several new instrument concepts in the works (Clio’s entrance window is the dichroic which sends light to the Pyramid and VisAO). The result of these fortunate circumstances is that we mounted the eyepiece for the very first time.
The night started out poorly. It was cloudy, a guider communications cable failed deep inside the telescope, and one of VisAO’s hard drives failed.
The telescope staff went to work on the cable, and Jared tore apart the VisAO electronics. Meanwhile, Laird was doing some last minute alignment checks on the eyepiece. At around midnight, all the problems were fixed and the sky magically began to clear.
Once we opened, we immediately pointed at alpha Centauri A which is a very bright star and so makes a good alignment target. Working out on the platform in near freezing temperatures, we moved the MagAO Pyramid wavefront sensor around until it was aligned to the star with the eyepiece dichroic.
Then, on the first try, we closed the loop at 1000 Hz controlling 300 modes.
At that point, we were observing the alpha Centauri system at the diffraction limit of a 6.5 meter telescope! Luckily the moon was out, giving Yuri Beletsky plenty of light to document the whole thing.
The eyepiece had a very red filter installed, passing wavelengths longer than 685 nm. This means the sharpest details in the image were as small as 22 milli-arcseconds. We’re pretty sure that this is the highest angular resolution image ever formed on a human retina. We compared what we saw to images recorded on the VisAO science camera at nearly the same wavelength, and it was very gratifying to see the similarities.
During the night, 9 people looked through the eyepiece. These astronomers are the inaugural members of an exclusive club: “L’Ordine degli Astronomi al Limite di Diffrazione” (The Order of Astronomers at the Limit of Diffraction). In this moonlit timelapse you can see most of them take their turn.
Special thanks to Yuri Beletsky for documenting this great night.
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.
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
“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.
“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.
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.
Here is the Extrasolar Planet Encyclopedia entry for HD 106906 b.
UA Astronomers Discover Planet That Shouldn’t Be There
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).