Kepler-62b
Discovery | |
---|---|
Discovered by | Borucki et al. |
Discovery site | Kepler Space Observatory |
Discovery date | 18 April 2013[1] |
Transit (Kepler Mission)[1] | |
Orbital characteristics | |
0.0553 ± 0.0005[1] | |
Eccentricity | ~0[1] |
5.714932 ± 0.000009[1] d | |
Inclination | 89.2 ± 0.4[1] |
Star | Kepler-62 (KOI-701) |
Physical characteristics | |
1.31 ± 0.04[1] R🜨 | |
Mass | <9[1] ME |
Temperature | Teq: 750 K (477 °C; 890 °F) |
Kepler-62b (also known by its Kepler Object of Interest designation KOI-701.02) is the innermost and the second smallest discovered exoplanet orbiting the star Kepler-62, with a diameter roughly 30% larger than Earth. It was found using the transit method, in which the dimming effect that a planet causes as it crosses in front of its star is measured. It is likely to have an equilibrium temperature slightly higher than the surface temperature of Venus (around 750 K (477 °C; 890 °F)), high enough to melt some types of metal.[1] Its stellar flux is 70 ± 9 times Earth's.[1]
Physical characteristics
[edit]Mass, radius and temperature
[edit]Kepler-62b is a super-Earth, an exoplanet with a radius and mass bigger than Earth but smaller than that of the ice giants Neptune and Uranus. It has an equilibrium temperature of 750 K (477 °C; 890 °F). This is hot enough to melt some types of metal. It has a radius of 1.3 R🜨,[1] placing it below the estimated radius of ≤1.6 R🜨 where it would otherwise be a mini-Neptune with a volatile composition, with no solid surface.[2] However, the mass is currently not known, estimates place an upper limit of <9 ME, the actual mass is expected to be significantly lower than this.[1]
Host star
[edit]The planet orbits a (K-type) star named Kepler-62, orbited by a total of five planets, of which Kepler-62f has the lengthiest orbital period.[1] The star has a mass of 0.69 M☉ and a radius of 0.64 R☉. It has a temperature of 4925 K and is 7 billion years old.[1] In comparison, the Sun is 4.6 billion years old[3] and has a surface temperature of 5778 K.[4]
The star's apparent magnitude, or how bright it appears from Earth's perspective, is 13.65. Therefore, it is too dim to be seen with the naked eye.
Orbit
[edit]Kepler-62b orbits its host star with an orbital period of 5 days at a distance of about 0.05
Discovery
[edit]In 2009, NASA's Kepler spacecraft was completing observing stars on its photometer, the instrument it uses to detect transit events, in which a planet crosses in front of and dims its host star for a brief and roughly regular period of time. In this last test, Kepler observed 50000 stars in the Kepler Input Catalog, including Kepler-62; the preliminary light curves were sent to the Kepler science team for analysis, who chose obvious planetary companions from the bunch for follow-up at observatories. Observations for the potential exoplanet candidates took place between 13 May 2009 and 17 March 2012. After observing the respective transits, which for Kepler-62b occurred roughly every 5 days (its orbital period), it was eventually concluded that a planetary body was responsible for the periodic 5-day transits. The discovery, along with the planetary system of the star Kepler-69 were announced on April 18, 2013.[1]
References
[edit]- ^ a b c d e f g h i j k l m n o p Borucki, William J.; et al. (18 April 2013). "Kepler-62: A Five-Planet System with Planets of 1.4 and 1.6 Earth Radii in the Habitable Zone". Science Express. 340 (6132): 587–90. arXiv:1304.7387. Bibcode:2013Sci...340..587B. doi:10.1126/science.1234702. hdl:1721.1/89668. PMID 23599262. S2CID 21029755.
- ^ Angus, Ruth (31 July 2014). "Most 1.6 Earth-radius planets are not rocky". Astrobites.
- ^ Fraser Cain (16 September 2008). "How Old is the Sun?". Universe Today. Retrieved 19 February 2011.
- ^ Fraser Cain (15 September 2008). "Temperature of the Sun". Universe Today. Retrieved 19 February 2011.