New Exoplanet Discoveries

Today’s a big day for exoplanet discoveries and exoplanet naming. First, an announcement from NASA’s Kepler mission of the discovery of two new planetary systems that include three super-Earth-sized planets that are orbiting in the habitable zones of their respective stars.  Habitable zones are regions around stars where conditions are suitable for a planet to support liquid water on its surface. Liquid water could imply conditions where life could form and thrive, if it exists on the planet. If these new worlds are made of rock, with oceans and atmospheres, they could be capable of supporting life.

The first system has a star called Kepler-62. It’s a non-Sunlike star that is actually smaller than our star, and lies about 1,200 light-years from Earth. Its super-Earth planet is called Kepler-62f, it’s about 40 percent larger than Earth, and it orbits in its star’s habitable zone once every 267 days.

Kepler scientists point out this is the smallest known habitable zone planet found so far. Also in this system is Planet Kepler-62e, which is about 60 percent larger than Earth. It, too, orbits in the habitable zone, taking 122 days to do so.

The other system announced today is Kepler-69. It’s a Sun-like star, only slightly smaller than our star. It lies about 2,700 light-years away from Earth, and sports one planet in its habitable zone: Kepler-69c. This world is 70 percent larger than Earth, and it is the smallest planet found in the habitable zone of a Sun-like star.

Both the newly discovered planets are relatively close to us, in terms of the scale of the Galaxy, which is about 100,000 light-years in diameter.

Each of the two stars has several other planets outside their habitable zones, bringing the total count of new planets discovered around Kepler-62 and Kepler-69 to seven. These discoveries bring astronomers much closer to finding planets very similar to our own home world.

It’s only a matter of time before a true Earth analog (in size) is found, and before astronomers can determine whether or not conditions are right to support life on any of the Earth-sized and super-Earth planets they are finding.

The techniques for finding such life include detection and study of light from a planet’s star as it streams through the atmosphere of the planet. This occurs when the planet transits (that is, it passes between the star and Kepler).  The light is “imprinted” with fingerprints of the chemical compounds that exist in the planet’s blanket of air.

The Kepler mission is churning out discovery after discovery. John Grunsfeld, Associate Administrator of the Science Mission Directorate at NASA HQ, described the spacecraft’s achievements in glowing terms.

“The Kepler spacecraft has certainly turned out to be a rock star of science,” he said. “The discovery of these rocky planets in the habitable zone brings us a bit closer to finding a place like home. It is only a matter of time before we know if the galaxy is home to a multitude of planets like Earth, or if we are a rarity.”

Read more about these discoveries at the NASA Kepler page as well as NASA’s news page and a press announcement from the Carnegie Institution for Science.

Star andPlanet System Named after University of Georgia by NASA

The University of Georgia (UGA) and its Franklin College of Arts and Sciences have been honored for the work of one its alumni, Roger C. Hunter, by having the Kepler-37 star system officially nicknamed UGA-1785 by NASA. It’s the first such school to have a system named for it. Hunter, who attended UGA, became program manager for the Kepler mission in 2008, and began looking for ways to connect the public to the mission, and honor the school he attended.

In a story on the UGA Today web page, Dr. Hunter is quoted as saying he connected the discovery of Kepler-37 and its three planets to the date Franklin College was founded in 1801. “Knowing my UGA history, I knew that the light from this star began its journey toward the Kepler telescope in 1801, the same year that the Franklin College was founded and that classes began at UGA,” Hunter said, explaining the origins of UGA-1785.

Nicknaming it after the university allows people to connect better to the ongoing search for planets, according to Hunter. As he is quoted on the UGA Today site, “”I think the best science is when people take ownership of a mission and feel some sort of kindred spirit with it,” Hunter said. “It’s gratifying to know that the Bulldog nation now extends into interstellar space.”

The Kepler-37 system  was discovered by the Kepler telescope and confirmed in 2012. It has three planets, one of which is the smallest ever detected by the spacecraft, and they lie in or near the parent star’s habitable zone. The star in the system appears to be sun-like. Detecting a planet that small (Kepler 37b is about the size of our moon) is a significant achievement and the techniques used to find it and the planets discovered today should lead the discovery of even smaller planets around distant stars.