New Planet Imager Delivers First Science | WPN World People News

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.

The vortex mask shown at left is made out of synthetic diamond. Viewed with an scanning electron microscope, right, the "vortex" microstructure of the mask is revealed.

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."

The new vortex results are presented in two papers, both published in the January 2017 issue of The Astronomical Journal. One study, led by Gene Serabyn of JPL, the overall lead of the Keck vortex project, presents the first direct image of the brown dwarf called HIP79124 B. This brown dwarf is located 23 astronomical units from a star (an astronomical unit is the distance between our sun and Earth) in a nearby star-forming region called Scorpius-Centaurus.

"The ability to see very close to stars also allows us to search for planets around more distant stars, where the planets and stars would appear closer together. Having the ability to survey distant stars for planets is important for catching planets still forming," said Serabyn. He also led a team that tested a predecessor of the vortex device on the Hale Telescope at Caltech's Palomar Observatory, near San Diego. In 2010, the team secured high-contrast images of three planets orbiting in the distant reaches of the star system called HR8799.

The second vortex study, led by Mawet, presents an image of the innermost of three rings of dusty, planet-forming material around the young star called HD141569A. The results, when combined with infrared data from NASA's Spitzer and WISE missions, and the European Space Agency's Herschel mission, reveal that the star's planet-forming material is made up of pebble-size grains of olivine, one of the most abundant silicates in Earth's mantle. The data also show that the temperature of the innermost ring imaged by the vortex is about minus 280 degrees Fahrenheit (100 Kelvin, or minus 173 degrees Celsius), a bit warmer than our asteroid belt.

"The three rings around this young star are nested like Russian dolls and undergoing dramatic changes reminiscent of planetary formation," said Mawet. "We have shown that silicate grains have agglomerated into pebbles, which are the building blocks of planet embryos."

Source: Jet Propulsion Laboratory