Kepler-22b
Kepler-22b is an exoplanet located in a habitable zone , which orbits the sun-like star Kepler-22 , which is about 600 light-years away from Earth .
discovery
The planet was discovered with the help of the Kepler space telescope. This telescope records brightness fluctuations that occur when a planet, viewed from Earth, passes exactly in front of its central star (see transit method ). A transit was observed for the first time in 2009, three days after Kepler was reported operational, and the third inspection required for confirmation took place in 2010. Its discovery was published on December 5, 2011 after further observations of the central star with earth-based instruments, with which other causes of the transit light curves (such as an eclipsing star in the line of sight) could be excluded with a probability of about 1: 600.
properties
The star orbited by Kepler-22b belongs to the spectral class G5. The extrasolar planet needs about 290 days for one orbit. It is about 2.4 times the diameter of the earth, or about 30,500 km, and is therefore possibly a super-earth . The planet is located in the habitable zone, which in principle enables temperatures similar to the earth and the existence of water in liquid form. The average temperature on the surface is around 22 ° C.
The mass of Kepler-22b is currently difficult to estimate. The research group led by William J. Borucki calculated upper limits of 36 M ⊕ in December 2011 , assuming a circular orbit upper limits of 27 M ⊕ within the standard deviation . Since it is significantly larger than the earth, its composition is also completely unclear. It could be a rock planet , but also an ocean planet or a gas planet . Nothing is known about a possibly existing atmosphere of the planet either. It is hoped to be able to carry out spectroscopic measurements during the next transits .
Web links
- Kepler-22b in the Extrasolar Planets Encyclopaedia (accessed December 6, 2011)
- Kepler-22b kepler.nasa.gov, (accessed December 7, 2011)
- Habitable Exoplanets Catalog
Individual evidence
- ↑ Kepler-22b: Facts About Exoplanet in Habitable Zone
- ↑ NASA's Kepler confirms its first planet in habitable zone of sun-like star
- ↑ a b William J. Borucki et al .: Kepler-22b: A 2.4 Earth-radius Planet in the Habitable Zone of a Sun-like Star . December 7, 2011, arxiv : 1112.1640 (English).
- ↑ Kepler-22 exoplanet.eu, accessed on May 23, 2016
- ↑ spiegel.de , accessed on December 6, 2011.
- ↑ sueddeutsche.de. Retrieved December 6, 2011 .
- ↑ www.nasa.gov. Retrieved December 5, 2011 .
- ↑ www.thecosmopolite.org. Retrieved August 30, 2018 .