New Planet Imager Delivers First Science

JPL press release

A new device on the W.M. Keck Observatory in Hawaii has delivered its first images, showing a ring of planet-forming dust around a star, and separately, a cool, star-like body, called a brown dwarf, lying near its companion star.

Vortex Coronagraph
The vortex mask with a microscopic view shown on the right. Image Credit: University of Liège/Uppsala University
The device, called a vortex coronagraph, was recently installed inside NIRC2 (Near Infrared Camera 2), the workhorse infrared imaging camera at Keck. It has the potential to image planetary systems and brown dwarfs closer to their host stars than any other instrument in the world.

“The vortex coronagraph allows us to peer into the regions around stars where giant planets like Jupiter and Saturn supposedly form,” said Dmitri Mawet, research scientist at NASA’s Jet Propulsion Laboratory and Caltech, both in Pasadena. “Before now, we were only able to image gas giants that are born much farther out. With the vortex, we will be able to see planets orbiting as close to their stars as Jupiter is to our sun, or about two to three times closer than what was possible before.”

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Hot Jupiter-esque Discovery Hints at Planet Formation

W. M. Keck Observatory press release

A team of astronomers discovered a Jupiter-like planet within a young system that could serve as a decoder ring for understanding how planets formed around our sun. The W. M. Keck Observatory on Maunakea, Hawaii confirmed the discovery. The findings were headed by Bruce Macintosh, a professor of physics at Stanford University, and show the new planet, 51 Eridani b, is one million times fainter than its parent star and shows the strongest methane signature ever detected on an alien planet, which should yield additional clues as to how the planet formed. The results are published in the current issue of Science.

51Eri b
Image of 51 Eri b as seen by the NIRC2 instrument on Keck Observatory’s Keck II telescope. Credit: W. M. Keck Observatory, Christian Marois, NRC Canada
“This is the first exoplanet discovered with the Gemini Planet Imager, one of the new generation instruments designed specifically for discovering and analyzing faint, young planets orbiting bright stars,” said Franck Marchis, Senior Planetary Astronomer at the SETI Institute and member of the team that built the instrument and now conducts the survey.

While NASA’s Kepler space observatory has discovered thousands of planets, it does so indirectly by detecting a loss of starlight as a planet passes in front of its star, the Gemini Planet Imager was designed specifically for discovering and analyzing faint, young planets orbiting bright stars.

“To detect planets, Kepler sees their shadow,” said Macintosh, who is also a member of the Kavli Institute for Particle Astrophysics and Cosmology. “The Gemini Planet Imager instead sees their glow, which we refer to as direct imaging.”

Akin to trying to detect a firefly in front of a lighthouse, the team analyzed the light from the star, then blocked it out. The remaining incoming light was analyzed, with the brightest spots indicating a possible planet.

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Astronomers Thrilled by Extreme Storms on Uranus

W. M. Keck Observatory press release

The normally bland face of Uranus has become increasingly stormy, with enormous cloud systems so bright that for the first time ever, amateur astronomers are able to see details in the planet’s hazy blue-green atmosphere.

“The weather on Uranus is incredibly active,” said Imke de Pater, professor and chair of astronomy at the University of California, Berkeley, and leader of the team that first noticed the activity when observing the planet with adaptive optics on the W. M. Keck Observatory in Hawaii.

Uranus NIRC2
Infrared images of Uranus (1.6 and 2.2 microns) obtained on Aug. 6, 2014, with adaptive optics on the 10-meter Keck II telescope. Credit: Imke De Pater (UC Berkeley) & W. M. Keck Observatory
“This type of activity would have been expected in 2007, when Uranus’s once every 42-year equinox occurred and the sun shined directly on the equator,” noted co-investigator Heidi Hammel of the Association of Universities for Research in Astronomy. “But we predicted that such activity would have died down by now. Why we see these incredible storms now is beyond anybody’s guess.”

In all, de Pater, Hammel and their team detected eight large storms on Uranus’s northern hemisphere when observing the planet with the Keck Observatory on August 5 and 6. One was the brightest storm ever seen on Uranus at 2.2 microns, a wavelength that senses clouds just below the tropopause, where the pressure ranges from about 300 to 500 mbar, or half the pressure at Earth’s surface. The storm accounted for 30 percent of all light reflected by the rest of the planet at this wavelength.

When amateur astronomers heard about the activity, they turned their telescopes on the planet and were amazed to see a bright blotch on the surface of a normally boring blue dot.

‘I got it!’

French amateur astronomer Marc Delcroix processed the amateur images and confirmed the discovery of a bright spot on an image by French amateur Régis De-Bénedictis, then in others taken by fellow amateurs in September and October. He had his own chance on Oct. 3 and 4 to photograph it with the Pic du Midi one-meter telescope, where on the second night, “I caught the feature when it was transiting, and I thought, ‘Yes, I got it!’” said Delcroix.

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Planet Found with an 80,000-Year Orbit

W. M. Keck Observatory Press Release

A team of researchers has discovered and photographed a gas giant only 155 light years from our solar system, adding to the short list of exoplanets discovered through direct imaging. It is located around GU Psc, a star with one-third the mass of the Sun and located in the constellation Pisces. See the article in The Astrophysical Journal.

GU Psc b
Artist’s view of the planet GU Psc b and its star GU Psc. Credit: Lucas Granito
The international research team, led by Marie-Ève Naud, a PhD student in the Department of Physics at the Université de Montréal, was able to find this planet by combining observations from the the Gemini Observatory, the Observatoire Mont-Mégantic (OMM), the Canada-France-Hawaii Telescope (CFHT) and the W. M. Keck Observatory.

A distant planet that can be studied in detail

The object was discovered using Gemini-South and followed-up with Gemini-North spectroscopy and CFHT photometry. Once Naud’s team had the entire spectrum, they realized the object had a very low temperature, with properties similar to substellar objects like brown dwarfs or planets.

One possibility was that the object had a peculiar spectrum simply from its youth, and that this had nothing to do with it being a binary, but the other tantalizing possibility was it was a binary planet, with one component being slightly warmer than the team derived from their analysis and the other component slightly cooler.

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Mega-galaxy is Missing Link in History of Cosmos

W. M. Keck Observatory press release

Two hungry young galaxies that collided 11 billion years ago are rapidly forming a massive galaxy about 10 times the size of the Milky Way, according to UC Irvine-led research conducted on the W. M. Keck Observatory and other research facilities around the world. The results will be published today in the journal Nature.

Merging Galaxies
The image at right shows a close-up of the colliding galaxies in red and green. The red data show dust-enshrouded regions of star formation. The green data show gas in the merging galaxies. The blue spots are visible-light observations of galaxies located much closer to us. Credit: JPL-Caltech/UC Irvine/Keck Observatory/STScI/NRAO/SAO/ESA/NASA
Capturing the creation of this type of large, short-lived star body is extremely rare – the equivalent of discovering a missing link between winged dinosaurs and early birds, said the scientists, who relied primarily on data from Keck Observatory’s NIRC2 fitted with the laser guide star adaptive optics (LGSAO) system. The new mega-galaxy, dubbed HXMM01, is the brightest, most luminous and most gas-rich submillimeter-bright galaxy merger known.

HXMM01 is fading away as fast as it forms, a victim of its own cataclysmic birth. As the two parent galaxies smashed together, they gobbled up huge amounts of hydrogen, emptying that corner of the universe of the star-making gas.

“These galaxies entered a feeding frenzy that would quickly exhaust the food supply in the following hundreds of million years and lead to the new galaxy’s slow starvation for the rest of its life,” said lead author Hai Fu, a UC Irvine postdoctoral scholar.

The discovery solves a riddle in understanding how giant elliptical galaxies developed quickly in the early universe and why they stopped producing stars soon after. Other astronomers have theorized that giant black holes in the heart of the galaxies blew strong winds that expelled the gas. But cosmologist Asantha Cooray, the UC Irvine team’s leader, said that they and colleagues across the globe found definitive proof that cosmic mergers and the resulting highly efficient consumption of gas for stars are causing the quick burnout.

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