Novel camera set to produce first direct images of extrasolar planets

June 22, 2004

A University of Arizona astronomer and his collaborators are using a novel camera to hunt for extrasolar planets.

Their camera has already made stunning images of Saturn's moon, Titan, and discovered an object just 27 times the mass of Jupiter. They hope the camera will be the first to directly photograph faint gas-giants similar to Jupiter in solar systems beyond our own.

The project is being funded over the next five years by a $545,000 National Science Foundation award. NSF awarded the highly competitive Faculty Early Career Development (CAREER) award to Associate Professor Laird M. Close. The CAREER program is a foundation-wide activity that offers the NSF's most prestigious awards for new faculty members. The program recognizes and supports the early career-development activities of those teacher-scholars who are most likely to become the academic leaders of the 21st century.

Close and his graduate students, Beth Biller and Eric Nielsen, will use Close's custom SDI (Simultaneous Differential Imager) cameras on two big telescopes in Arizona and Chile to hunt for planets orbiting other stars.

Astronomers have indirectly detected more than 100 planets circling stars in other solar systems, but none have yet been directly imaged.

Close plans to solve the problem of detecting faint planets near their billion-times-brighter stars by using a unique, high-contrast, SDI camera. The camera uses adaptive optics, which remove the blurring effects of the Earth's atmosphere and produce extremely sharp images.

The SDI camera splits light from a single object into four identical images, then passes the resulting beams through four slightly different methane-sensitive filters. When the filtered light beams hit the detector array, astronomers can subtract the images so the bright star disappears, revealing the massive, methane-rich planet.

Close and his collaborators will use SDI to examine 100 young northern- and southern-hemisphere stars that are near Earth. They will hunt for planets as small as 3 Jupiter masses (three times the mass of Jupiter) that are as close as 5 AU from their stars. This is about the distance between Jupiter and the sun. One "AU," or astronomical unit, is the distance between Earth and the sun.

The northern SDI camera will be used on the 6.5-meter, UA/Smithsonian, MMT telescope on Mount Hopkins, Ariz, in collaboration with Steward Observatory astronomer Donald McCarthy. The southern SDI camera has been installed at the European Southern Observatory's (ESO) 8.2-meter Very Large Telescope (VLT) in Chile. Astronomers Rainer Lenzen and Wolfgang Brandner of the Max-Planck-Institut für Astronomie (MPIA), Heidelberg, Germany, and Markus Hartung of ESO collaborate on this project.

"Our imaging technique should be about 100 times more sensitive than current imaging technologies," Close said. "This will allow us to directly detect sub-stellar companions to nearby stars. It also will allow us to look for planets in regions where we have not been able to search before but that are likely to be rich with massive planets," he added. "If we find such planets, they can help tell us if those stars have Earth-like planets."

In collaboration with Mark McCaughrean of the Astrophysical Institute Potsdam, Close and his German colleagues discovered a 27 Jupiter mass object named Epsilon Indi Bb the first night they used the camera. They reported the finding the Journal Astronomy & Astrophysics.

Epsilon Indi Bb is a methane-rich object a mere 12 light years from the sun and just 2.6 AU away from a 43 Jupiter-mass object. Epsilon Indi Ba, that McCaughrean and others reported in another paper in 2003.

"Although a bit too massive to be a true planet, Epsilon Indi Bb is just slightly hotter than a convection oven," Close said. "It is the coolest, closest binary 'brown dwarf' ever imaged."

Brown dwarfs are too small to shine like a star but too big to be called planets.

"This discovery will play an important role in understanding the nature and physics of brown dwarfs," Close said.

Last February, during commissioning of the SDI camera in Chile, Hartung, Close and their European colleagues produced the sharpest images ever taken of Saturn's largest moon, Titan.

One of the super-sharp images shows red surface features and dark surface areas on the moon, which is ringed with a haze of Titan's methane-rich atmosphere, shown as blue.

The image has a 360 kilometer resolution at the distance of Saturn, then at about 8.5 AU from Earth. That is, the SDI camera resolves a 200-mile distance on Titan from about 800 million miles away.

"The 'red' features may be the icy surface of Titan," Close said. "The dark areas may be liquid methane and ethane lakes."

Hartung has also made a movie of Titan rotating, based on SDI data. It is online at SDI Titan movie

The Journal Astronomy & Astrophysics will publish a 2004 paper by Hartung, Tom Herbst of MPIA, and the rest of the SDI team on these Titan images.
-end-
Titan SDI Images Press Release
http://eso.org/outreach/press-rel/pr-2004/pr-09-04.html

SDI Camera Page
http://exoplanet.as.arizona.edu/~lclose/talks/ins/SDI_NACO.html

Titan movie made from SDI images
http://www.eso.org/outreach/press-rel/pr-2004/video/vid-06-04.avi

Laird Close's home page
http://athene.as.arizona.edu/~lclose/

University of Arizona

Related Planets Articles from Brightsurf:

Stars and planets grow up together as siblings
ALMA shows rings around the still-growing proto-star IRS 63

Two planets around a red dwarf
The 'SAINT-EX' Observatory, led by scientists from the National Centre of Competence in Research NCCR PlanetS of the University of Bern and the University of Geneva, has detected two exoplanets orbiting the star TOI-1266.

Some planets may be better for life than Earth
Researchers have identified two dozen planets outside our solar system that may have conditions more suitable for life than our own.

Fifty new planets confirmed in machine learning first
Fifty potential planets have had their existence confirmed by a new machine learning algorithm developed by University of Warwick scientists.

Rogue planets could outnumber the stars
An upcoming NASA mission could find that there are more rogue planets - planets that float in space without orbiting a sun - than there are stars in the Milky Way, a new study theorizes.

Could mini-Neptunes be irradiated ocean planets?
Many exoplanets known today are ''super-Earths'', with a radius 1.3 times that of Earth, and ''mini-Neptunes'', with 2.4 Earth radii.

As many as six billion Earth-like planets in our galaxy, according to new estimates
There may be as many as one Earth-like planet for every five Sun-like stars in the Milky way Galaxy, according to new estimates by University of British Columbia astronomers using data from NASA's Kepler mission.

How planets may form after dust sticks together
Scientists may have figured out how dust particles can stick together to form planets, according to a Rutgers co-authored study that may also help to improve industrial processes.

Planets around a black hole?
Theoreticians in two different fields defied the common knowledge that planets orbit stars like the Sun.

The rare molecule weighing in on the birth of planets
Astronomers using one of the most advanced radio telescopes have discovered a rare molecule in the dust and gas disc around a young star -- and it may provide an answer to one of the conundrums facing astronomers.

Read More: Planets News and Planets Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.