Spitzer Reveals Earth’s Hot New Neighbour.
Located about 33 light years away from Earth and catalogued as exoplanet UCF 1.01, this hot little body comes in at about two-thirds our size. We call these things a ‘Super Earth.
It completes an orbit around its parent star in less than a day and half. Its gravity is lower and surface temperatures are surmised to exceed 1000 degrees Fahrenheit. It has no atmosphere and it’s quite probably a molten, volcanic mess. However, for astronomers at the University of Central Florida, it’s the most exciting thing that could possibly happen… their first planet find.
“We have found strong evidence for a very small, very hot and very close-by planet with the help of the Spitzer Space Telescope,” said Kevin Stevenson, a recent Ph.D. graduate from the UCF and lead author of the paper, which appears online tomorrow in The Astrophysical Journal. “This discovery is a significant accomplishment for UCF.”
While studying a hot-Neptune exoplanet, designated GJ 436b, the team noticed little dips in the light curves emanating from the parent red-dwarf star GJ 436. When Stevenson and his group reviewed the Spitzer data, they noticed these “dips” were periodic – signfying that something was blocking the infrared light as seen from Earth. A something that just might be another planet!
“I could see these faint dips in the starlight and I wanted to determine their source. I knew that if these signals were periodic, they could be from an unknown planet,” said Stevenson, who is now a postdoctoral scholar at the University of Chicago. So he, UCF planetary sciences professor Joseph Harrington and UCF graduate student Nate Lust began looking at the data. They sifted through hundreds of hours of observations collected from Spitzer, the Deep Impact spacecraft, the ground-based Very Large Telescope in Chile and the Canada-France-Hawaii Telescope near the summit of Mauna Kea in Hawaii.
With only a handful of smaller-than-Earth planets discovered, the Spitzer Space Telescope may play a new role in exoplanet research. While Spitzer has aided in transit studies, the revelation of UCF-1.01 is a first for this telescope. “We have found strong evidence for a very small, very hot and very near planet with the help of the Spitzer Space Telescope,” said Dr. Stevenson. “Identifying nearby small planets such as UCF-1.01 may one day lead to their characterization using future instruments.”
In addition to UCF-1.01, Stevenson and his colleagues obtained data that indicated there may even be a third planet, known as UCF-1.02, orbiting GJ 436. Spitzer has observed the evidence of these two new exoplanets several times, but even incredibly sensitive instruments are hard put to measure masses as small as one-third the size of the Earth. Because knowing the mass is a requirement for confirming a discovery, the paper’s authors are referring to them as “candidates” for now.
“I hope future observations will confirm these exciting results, which show Spitzer may be able to discover exoplanets as small as Mars,” said Michael Werner, Spitzer Project Scientist at NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, Calif. “Even after almost nine years in space, Spitzer’s observations continue to take us in new and important scientific directions.”
Others who contributed to the study include: Nikole Lewis (University of Arizona), Guillaume Montagnier (European Organisation for Astronomical Research in the Southern Hemisphere), Julianne Moses (Space Science Institute), Channon Visscher (Southwest Research Institute) and UCF students Jasmina Blecic, Ryan Hardy, Patricio Cubillos and Christopher Campo.
Original Story Source: University of Central Florida News Release.