mountain profile Institute for Astronomy University of Hawaii

Newly Discovered Planet May Have Water on Its Surface

Maintained by LG

For immediate release
September 29, 2010

Contacts:

Dr. Nader Haghighipour
Institute for Astronomy
University of Hawaii at Manoa
808-956-6098
nader@ifa.hawaii.edu


Dr. Gareth Wynn-Williams
Institute for Astronomy
University of Hawaii at Manoa
Honolulu, Hawaii 96822
1-808-956-8807
wynnwill@ifa.hawaii.edu

Ms. Louise Good
Publications Editor
Institute for Astronomy
University of Hawaii at Manoa
1-808-956-9403
good@ifa.hawaii.edu

High-Resolution Photos:

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Artist's conception of Gliese 581g and its star
This artist's conception shows the inner four planets of the Gliese 581 system and their host star, a red dwarf star only 20 light-years away from Earth. The large planet in the foreground is the newly discovered GJ 581g, an Earth-size planet that orbits in the star's habitable zone. Artwork by Lynette Cook.

A team of astronomers that includes the University of Hawaii’s Nader Haghighipour has announced the discovery of a planet that could have liquid water on its surface.

The planet, which is probably 30 percent larger than Earth, was discovered using one of the telescopes of the W. M. Keck Observatory on Mauna Kea. It orbits a relatively small star, Gliese 581, that is 20 light-years from Earth in the constellation Libra.

“By determining the orbit of this planet, we can deduce that its surface temperature is similar to that of Earth,” said Haghighipour. This means that at least some of any water on the surface of the planet and in its atmosphere will be in liquid form rather than ice or vapor. The discovery of liquid water in space is an important step in the search for extraterrestrial life.

The team estimates that the new planet, called Gliese 581g, has a mass three to four times that of Earth, and orbits its star in just under 37 Earth days. Its mass indicates that it is probably a rocky planet with enough gravity to hold on to its atmosphere. It is one of six known planets orbiting the star.

To discover the planet, the team looked for the tiny changes in the star’s velocity that arise from the gravitational tugs of its planets. They used 238 separate observations of Gliese 581 taken over a period of 11 years.

Haghighipour said that the team is keeping tabs on many nearby stars using the Keck Observatory. “As we collect more and more data about how these stars are moving, we expect to find many more planets with potentially Earth-like conditions,” he said. He noted that to learn more about the conditions on these planets would take even bigger telescopes, such at the Thirty Meter Telescope planned for Mauna Kea.

The team that made the discovery is led by Steven Vogt of the University of California, Santa Cruz (UCSC) and Paul Butler of the Carnegie Institution of Washington. Other team members include UCSC associate research scientist Eugenio Rivera, and Gregory Henry and Michael Williamson of Tennessee State University.

This research was supported by grants from the National Science Foundation, NASA, and the NASA Astrobiology Institute.

For a related press release, see http://news.ucsc.edu/2010/09/planet.html.


PICTURE CAPTIONS

Figure 1: This artist's conception shows the inner four planets of the Gliese 581 system and their host star, a red dwarf star only 20 light-years away from Earth. The large planet in the foreground is the newly discovered GJ 581g, an Earth-size planet that orbits in the star's habitable zone. Artwork by Lynette Cook.

Figure 2: Orbital diagrams comparing the Gliese 581 system to our own solar system. Image by Zina Deretsky, NSF.


Founded in 1967, the Institute for Astronomy at the University of Hawaii at Manoa conducts research into galaxies, cosmology, stars, planets, and the sun. Its faculty and staff are also involved in astronomy education, deep space missions, and in the development and management of the observatories on Haleakala and Mauna Kea.

Established in 1907 and fully accredited by the Western Association of Schools and Colleges, the University of Hawaii is the state's sole public system of higher education. The UH System provides an array of undergraduate, graduate, and professional degrees and community programs on 10 campuses and through educational, training, and research centers across the state. UH enrolls more than 50,000 students from Hawaii, the U.S. mainland, and around the world.