Gemini Planet Imager Exoplanet Survey – One Year into the Survey

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Gemini Planet Imager Exoplanet Survey – One Year into the Survey
SETI Institute | Gemini Observatory | 2015 Nov 12

Click to play embedded YouTube video.

What Is the Gemini Planet Imager (GPI)
Credit: F. Marchis, D. Futselaar, H. Marchis[hr][/hr]

The Gemini Planet Imager Exoplanet Survey (GPIES) is an ambitious three-year study dedicated to imaging young Jupiters and debris disks around nearby stars using the GPI instrument installed on the Gemini South telescope in Chile. On November 12, at the 47th annual meeting of the AAS’s Division for Planetary Sciences in Washington DC, Franck Marchis, Chair of the Exoplanet Research Thrust of the SETI Institute and a scientist involved in the project since 2004, will report on the status of the survey, emphasizing some discoveries made in its first year.

Led by Bruce Macintosh from Stanford University, the survey began a year ago and has already been highly successful, with several findings already published in peer-reviewed journals.

“This very large survey is observing 600 young stars to look for two things: giant planets orbiting them and debris disks. In our first year, we have already found what GPI was designed to discover — a young Jupiter in orbit around a nearby star,” said Marchis. This discovery was announced in an article published in Science on Oct. 28 2015 with an impressive list of eighty-eight co-authors from thirty-nine institutions located in North and South America. “This is modern astronomy at its best,” said Marchis. “These large projects gather energy and creativity from many groups of researchers at various institution, enabling them to consider different strategies to improve the on-sky efficiency of the instrument and its scientific output.”

The survey was officially launched in November 2014. Eight observing runs allowed the study of approximately 160 targets, or a quarter of the sample. Other parts of the survey are more frustrating, though. Due to the incipient El Nino, weather in Chile is worse than expected, with clouds, rain, snow, and atmospheric turbulence too severe even for GPI to fix. Since late June, out of the last 20 nights that team members have spent at the telescope, they’ve only gotten a few hours of good quality data. Despite this loss, over which the team of course had no control, they have already published ten peer-reviewed papers in the last year. ...

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Astronomers Spy a Nursery of Baby Exoplanets
Gemini Observatory | 2015 Dec 01

[imghover=http://www.gemini.edu/images/pio/News/2 ... b_gpi.jpeg]http://www.gemini.edu/images/pio/News/2 ... c_gpi.jpeg[/imghover][c]Image of HD 100546 obtained with the Gemini Planet Imager (GPI) at near-infrared
wavelengths (1.6 microns). The cross shows the position of the star, the green
hatched lines show the region interior to which GPI's coronagraph blocks our view
of the system. HD 100546 b appears as a bright point source sitting on a finger of
disk emission. The same image with a more relaxed color scale stretch reveals the
candidate HD 100546 c. (Credit: GPI, T. Currie et al.)[/c][hr][/hr]

Today, at the Extreme Solar Systems conference in Waikoloa, Hawai‘i, astronomers announced the discovery of at least one, probably two, baby Jupiter-like planets still actively forming and surrounded by their natal clouds of gas and dust. The Gemini Planet Imager, at the Gemini South telescope in Chile, provided the key data for this discovery. The system resembles an infant version of the first directly imaged planetary system, discovered using the Gemini North telescope on Maunakea.

Astronomers report that this system, surrounding a star known as HD 100546, is giving us a glimpse back in time to see what other, more developed exoplanet systems looked like in their adolescence. The star is remarkably similar to HR 8799, the first multiple planet system directly imaged and discovered in 2008, but HR 8799's planets are fully formed. "Now, seven years later, we can for the first time see what this planetary system may have looked like while the planets were just coming into existence," said principal investigator Thayne Currie, astronomer at the Subaru Observatory.

The team expects many more discoveries as they probe the environs of HD 100546 more deeply. According to University of Toronto graduate student Ryan Cloutier, systems like this one, containing multiple forming giant planets, have extensive spiral arms in their disks. "For HD 100546, its spiral arms may suggest the presence of additional planets," says Cloutier. "In fact, one of the observed protoplanets might instead be a hotspot within the disk or a signpost of an unseen protoplanet." ...

Resolving the HD 100546 Protoplanetary System with the Gemini Planet Imager:
Evidence for Multiple Forming, Accreting Planets - Thayne Currie et al

• Astrophysical Journal Letters 814(2):L27 (2015 Dec 01) DOI: 10.1088/2041-8205/814/2/L27
  arXiv.org > astro-ph > arXiv:1511.02526 > 08 Nov 2015 (v1), 10 Nov 2015 (v2)

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Exiled Exoplanet Possibly Kicked Out of Star's Local Neighborhood
University of California, Berkeley | 2015 Dec 01

[img3="A wide-angle view of the star HD 106906 taken by the Hubble Space Telescope and a close-up view from the Gemini Planet Imager reveal a dynamically disturbed system of comets, suggesting a link between this and the unusually distant planet (upper right), 11 times the mass of Jupiter. (Credit: Paul Kalas, UC Berkeley, HST, GPI)"]http://news.berkeley.edu/wp-content/upl ... arpix2.jpg[/img3][hr][/hr]

A planet discovered last year sitting at an unusually large distance from its star – 16 times farther than Pluto is from the sun – may have been kicked out of its birthplace close to the star in a process similar to what may have happened early in our own solar system’s history.

Images from the Gemini Planet Imager (GPI) in the Chilean Andes and the Hubble Space Telescope show that the star has a lopsided comet belt indicative of a very disturbed solar system, and hinting that the planet interactions that roiled the comets closer to the star might have sent the exoplanet into exile as well.

The planet may even have its own ring of debris that it dragged along with it.

“We think that the planet itself could have captured material from the comet belt, and that the planet is surrounded by a large dust ring or dust shroud,” said Paul Kalas, an adjunct professor of astronomy at the University of California, Berkeley. “We conducted three tests and found tentative evidence for a dust cloud, but the jury is still out.”

“The measurements we made on the planet suggest it may be dustier than comparison objects, and we are making follow-up observations to check if the planet is really encircled by a disk – an exciting possibility,” added Abhi Rajan, a graduate student at Arizona State University who analyzed the planet images.

Such planets are of interest because in its youth, our own solar system may have had planets that were kicked out of the local neighborhood and are no longer among of the eight planets we see today. ...

Direct imaging of an asymmetric debris disk in the HD 106906 planetary system - Paul G. Kalas et al

• Astrophysical Journal 814(1):32 (2015 Nov 20) DOI: 10.1088/0004-637X/814/1/32
  arXiv.org > astro-ph > arXiv:1510.02747 > 09 Oct 2015