Featured Research

from universities, journals, and other organizations

Exoplanet Atmospheres Detected From Earth

Date:
January 15, 2009
Source:
Carnegie Institution
Summary:
Two independent groups have simultaneously made the first-ever ground-based detection of extrasolar planets thermal emissions. Until now, virtually everything known about atmospheres of planets orbiting other stars in the Milky Way has come from space-based observations. These two independent results are very interesting for astronomers and planetary scientists because they allow a direct probe of the temperature of these planetary atmospheres, and because they show that such measurements can be made from ground-based observatories, and not only when using space telescopes.

This artist's impression shows the star OGLE-TR-56 and its planet, as it passes behind the star.
Credit: Copyright D. Sing (IAP) / A&A

Two independent groups have simultaneously made the first-ever ground-based detection of extrasolar planets thermal emissions. Until now, virtually everything known about atmospheres of planets orbiting other stars in the Milky Way has come from space-based observations.

These new results open a new frontier to studying these alien worlds and are especially critical because the major space-based workhorse to these studies, the Spitzer telescope, will soon run out of cryogens, highly limiting its capabilities.

One team of scientists observed a planet named OGLE-TR-56b, which is a "hot Jupiter." Hot Jupiters are massive planets that orbit very close to their stars, whipping around them in 2 to 3 days. Since they are so close to their stars, they are believed to be hot enough to emit radiation in the optical and near-infrared wavelengths and be detectable from Earth. The orbit of OGLE-TR-56b carries it behind its host star from the perspective of an observer on Earth, but a challenge to observing is that the planet is faint and in a crowded field, located in the direction of the center of our galaxy, about 5,000 light years away.

"Others have tried to detect planetary atmospheres from Earth, but to no avail," remarked co-author Mercedes López-Morales at the Carnegie Institution's Department of Terrestrial Magnetism. "We hit it right two nights last summer. The successful recipe is a planet that emits a lot of heat and has little to no wind in its atmosphere. Plus it has to be a clear, calm night on Earth to measure accurately the differences in thermal emissions when the planet is eclipsed as it goes behind the star. Only about one of every 3,000 photons from the star comes from the planet. This eclipse allows us to separate the emissions of the planet from those of the star. The magic moments came on July 2nd at the European Southern Observatory's Very Large Telescope (VLT) and on August 3rd on Carnegie's Magellan-Baade telescope in Chile." López-Morales and colleague Sara Seager had earlier predicted that the ideal candidate for such a detection would be a planet with the characteristics of OGLE-TR-56b.

The scientists obtained over 600 images from both telescopes. "Because that part of the galaxy is so crowded and the planet so faint we needed these large telescopes," explained lead author David Sing from Institut d'Astrophysique de Paris. "The planet is glowing red-hot like a kitchen stove burner, but we had to know precisely when the eclipse was going to happen and measure the stellar flux very accurately so it could be removed to reveal the planet's thermal emission."

In the other study, published in the same issue of the journal, astronomers in the Netherlands detected thermal emission in the near-infrared from another exoplanet named TrES-3b, also from the ground. Information about atmospheres of hot Jupiters from Spitzer studies has helped both sets of scientists. The hot Jupiters Spitzer has observed have similar atmospheric properties, in particular thermal inversions, in which a warm layer holds a cooler layer underneath. "OGLE-TR-56b is hotter than any that Spitzer has seen so far," said López-Morales. "At over 4400° F it's the hottest atmosphere yet measured. It is way too hot for silicon or iron clouds to form, which would keep it dark—typical of the hot Jupiters that Spitzer had found. It's comforting to know that when Spitzer goes out of service, studies like these two will be able to keep the field alive."


Story Source:

The above story is based on materials provided by Carnegie Institution. Note: Materials may be edited for content and length.


Journal References:

  1. de Mooij et al. Ground-based K-band detection of thermal emission from the exoplanet TrES-3b. Astronomy and Astrophysics, 2009; 493 (2): L35 DOI: 10.1051/0004-6361:200811239
  2. Sing et al. Ground-based secondary eclipse detection of the very-hot Jupiter OGLE-TR-56b. Astronomy and Astrophysics, 2009; 493 (2): L31 DOI: 10.1051/0004-6361:200811268

Cite This Page:

Carnegie Institution. "Exoplanet Atmospheres Detected From Earth." ScienceDaily. ScienceDaily, 15 January 2009. <www.sciencedaily.com/releases/2009/01/090114160540.htm>.
Carnegie Institution. (2009, January 15). Exoplanet Atmospheres Detected From Earth. ScienceDaily. Retrieved September 1, 2014 from www.sciencedaily.com/releases/2009/01/090114160540.htm
Carnegie Institution. "Exoplanet Atmospheres Detected From Earth." ScienceDaily. www.sciencedaily.com/releases/2009/01/090114160540.htm (accessed September 1, 2014).

Share This




More Space & Time News

Monday, September 1, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Raw: NASA Captures Solar Flare

Raw: NASA Captures Solar Flare

AP (Sep. 1, 2014) — NASA reported the sun emitted a mid-level solar flare, on August 24th. NASA's Solar Dynamics Observatory captured the images of the flare, which erupted on the left side of the sun. (Sept. 1) Video provided by AP
Powered by NewsLook.com
Space Shuttle Discovery's Legacy, 30 Years Later

Space Shuttle Discovery's Legacy, 30 Years Later

Newsy (Aug. 30, 2014) — The space shuttle Discovery launched for the very first time 30 years ago. Here's a look back at its legacy. Video provided by Newsy
Powered by NewsLook.com
Experiment Tests Whether Universe Is Actually A Hologram

Experiment Tests Whether Universe Is Actually A Hologram

Newsy (Aug. 27, 2014) — Researchers at Fermilab are using a device called "The Holometer" to test whether our universe is actually a 2-D hologram that just seems 3-D. Video provided by Newsy
Powered by NewsLook.com
SpaceX’s Falcon 9 Rocket Explodes After Liftoff

SpaceX’s Falcon 9 Rocket Explodes After Liftoff

Newsy (Aug. 23, 2014) — The private spaceflight company says it is preparing a thorough investigation into Friday's mishap. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins