Featured Research

from universities, journals, and other organizations

NASA's Kepler mission discovers tiny planet system: Smallest planet yet found around a star similar to our sun

Date:
February 20, 2013
Source:
NASA/Jet Propulsion Laboratory
Summary:
NASA's Kepler mission scientists have discovered a new planetary system that is home to the smallest planet yet found around a star similar to our sun. The planets are located in a system called Kepler-37, about 210 light-years from Earth in the constellation Lyra. The smallest planet, Kepler-37b, is slightly larger than our moon, measuring about one-third the size of Earth. It is smaller than Mercury, which made its detection a challenge.

NASA's Kepler mission has discovered a new planetary system that is home to the smallest planet yet found around a star like our sun, approximately 210 light-years away in the constellation Lyra.
Credit: NASA/Ames/JPL-Caltech

NASA's Kepler mission scientists have discovered a new planetary system that is home to the smallest planet yet found around a star similar to our sun.

Related Articles


The planets are located in a system called Kepler-37, about 210 light-years from Earth in the constellation Lyra. The smallest planet, Kepler-37b, is slightly larger than our moon, measuring about one-third the size of Earth. It is smaller than Mercury, which made its detection a challenge.

The moon-size planet and its two companion planets were found by scientists with NASA's Kepler mission, which is designed to find Earth-sized planets in or near the "habitable zone," the region in a planetary system where liquid water might exist on the surface of an orbiting planet. However, while the star in Kepler-37 may be similar to our sun, the system appears quite unlike the solar system in which we live.

Astronomers think Kepler-37b does not have an atmosphere and cannot support life as we know it. The tiny planet almost certainly is rocky in composition. Kepler-37c, the closer neighboring planet, is slightly smaller than Venus, measuring almost three-quarters the size of Earth. Kepler-37d, the farther planet, is twice the size of Earth.

The first exoplanets found to orbit a normal star were giants. As technologies have advanced, smaller and smaller planets have been found, and Kepler has shown that even Earth-size exoplanets are common.

"Even Kepler can only detect such a tiny world around the brightest stars it observes," said Jack Lissauer, a planetary scientist at NASA's Ames Research Center in Moffett Field, Calif. "The fact we've discovered tiny Kepler-37b suggests such little planets are common, and more planetary wonders await as we continue to gather and analyze additional data."

Kepler-37's host star belongs to the same class as our sun, although it is slightly cooler and smaller. All three planets orbit the star at less than the distance Mercury is to the sun, suggesting they are very hot, inhospitable worlds. Kepler-37b orbits every 13 days at less than one-third Mercury's distance from the sun. The estimated surface temperature of this smoldering planet, at more than 800 degrees Fahrenheit (700 degrees Kelvin), would be hot enough to melt the zinc in a penny. Kepler-37c and Kepler-37d, orbit every 21 days and 40 days, respectively.

"We uncovered a planet smaller than any in our solar system orbiting one of the few stars that is both bright and quiet, where signal detection was possible," said Thomas Barclay, Kepler scientist at the Bay Area Environmental Research Institute in Sonoma, Calif., and lead author of the new study published in the journal Nature. "This discovery shows close-in planets can be smaller, as well as much larger, than planets orbiting our sun."

The research team used data from NASA's Kepler space telescope, which simultaneously and continuously measures the brightness of more than 150,000 stars every 30 minutes. When a planet candidate transits, or passes, in front of the star from the spacecraft's vantage point, a percentage of light from the star is blocked. This causes a dip in the brightness of the starlight that reveals the transiting planet's size relative to its star.

The size of the star must be known in order to measure the planet's size accurately. To learn more about the properties of the star Kepler-37, scientists examined sound waves generated by the boiling motion beneath the surface of the star. They probed the interior structure of Kepler-37's star just as geologists use seismic waves generated by earthquakes to probe the interior structure of Earth. The science is called asteroseismology.

The sound waves travel into the star and bring information back up to the surface. The waves cause oscillations that Kepler observes as a rapid flickering of the star's brightness. Like bells in a steeple, small stars ring at high tones while larger stars boom in lower tones. The barely discernible, high-frequency oscillations in the brightness of small stars are the most difficult to measure. This is why most objects previously subjected to asteroseismic analysis are larger than the sun.

With the very high precision of the Kepler instrument, astronomers have reached a new milestone. The star Kepler-37, with a radius just three-quarters of the sun, now is the smallest bell in the asteroseismology steeple. The radius of the star is known to three percent accuracy, which translates to exceptional accuracy in the planet's size.


Story Source:

The above story is based on materials provided by NASA/Jet Propulsion Laboratory. Note: Materials may be edited for content and length.


Journal Reference:

  1. Thomas Barclay, Jason F. Rowe, Jack J. Lissauer, Daniel Huber, Fran็ois Fressin, Steve B. Howell, Stephen T. Bryson, William J. Chaplin, Jean-Michel D้sert, Eric D. Lopez, Geoffrey W. Marcy, Fergal Mullally, Darin Ragozzine, Guillermo Torres, Elisabeth R. Adams, Eric Agol, David Barrado, Sarbani Basu, Timothy R. Bedding, Lars A. Buchhave, David Charbonneau, Jessie L. Christiansen, J๘rgen Christensen-Dalsgaard, David Ciardi, William D. Cochran, Andrea K. Dupree, Yvonne Elsworth, Mark Everett, Debra A. Fischer, Eric B. Ford, Jonathan J. Fortney, John C. Geary, Michael R. Haas, Rasmus Handberg, Saskia Hekker, Christopher E. Henze, Elliott Horch, Andrew W. Howard, Roger C. Hunter, Howard Isaacson, Jon M. Jenkins, Christoffer Karoff, Steven D. Kawaler, Hans Kjeldsen, Todd C. Klaus, David W. Latham, Jie Li, Jorge Lillo-Box, Mikkel N. Lund, Mia Lundkvist, Travis S. Metcalfe, Andrea Miglio, Robert L. Morris, Elisa V. Quintana, Dennis Stello, Jeffrey C. Smith, Martin Still, Susan E. Thompson. A sub-Mercury-sized exoplanet. Nature, 2013; DOI: 10.1038/nature11914

Cite This Page:

NASA/Jet Propulsion Laboratory. "NASA's Kepler mission discovers tiny planet system: Smallest planet yet found around a star similar to our sun." ScienceDaily. ScienceDaily, 20 February 2013. <www.sciencedaily.com/releases/2013/02/130220133551.htm>.
NASA/Jet Propulsion Laboratory. (2013, February 20). NASA's Kepler mission discovers tiny planet system: Smallest planet yet found around a star similar to our sun. ScienceDaily. Retrieved December 18, 2014 from www.sciencedaily.com/releases/2013/02/130220133551.htm
NASA/Jet Propulsion Laboratory. "NASA's Kepler mission discovers tiny planet system: Smallest planet yet found around a star similar to our sun." ScienceDaily. www.sciencedaily.com/releases/2013/02/130220133551.htm (accessed December 18, 2014).

Share This


More From ScienceDaily



More Space & Time News

Thursday, December 18, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Rover Finds More Clues About Possible Life On Mars

Rover Finds More Clues About Possible Life On Mars

Newsy (Dec. 17, 2014) — NASA's Curiosity rover detected methane on Mars and organic compounds on the surface, but it doesn't quite prove there was life ... yet. Video provided by Newsy
Powered by NewsLook.com
Evidence of Life on Mars? NASA Rover Finds Methane, Organic Chemicals

Evidence of Life on Mars? NASA Rover Finds Methane, Organic Chemicals

Reuters - US Online Video (Dec. 16, 2014) — NASA's Mars Curiosity rover finds methane in the Martian atmosphere and organic chemicals in the planet's soil, the latest hint that Mars was once suitable for microbial life. Linda So reports. Video provided by Reuters
Powered by NewsLook.com
Geminids Meteor Shower Lights Up Skies in China

Geminids Meteor Shower Lights Up Skies in China

AFP (Dec. 16, 2014) — The Geminids meteor shower lights up the skies over the Changbai Mountains in northeast China. Duration: 01:03 Video provided by AFP
Powered by NewsLook.com
Raw: Defense Satellite Launches from California

Raw: Defense Satellite Launches from California

AP (Dec. 13, 2014) — A U.S. defense satellite launched from California's central coast on Friday after weather delays caused by a major storm that drenched the state. (Dec. 13) Video provided by AP
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:

Strange & Offbeat Stories

 

Space & Time

Matter & Energy

Computers & Math

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