Astronomy:K2-315b

From HandWiki
K2-315b
Size comparison of the planet K2-315b (artistic concept) with Earth
Discovery[1]
Discovered byKepler (K2)
Discovery date2020
Transit
Orbital characteristics[1]
0.02±0.00 astronomical unit|AU
Orbital period3.14±0.00 d
Inclination88.7°±0.2°
Physical characteristics
Mean radius0.95±0.06 R🜨[1]
Physics460 ± 5 K (368.33 ± 9.00 °F; 186.85 ± 5.00 °C)[1]


K2-315b is an exoplanet located 185.3 light years away from Earth in the southern zodiac constellation Libra.[2][3] It orbits the red dwarf K2-315.

Discovery

K2-315b was discovered in 2020 by astronomers in an observatory using the Kepler space telescope.[1] It is also nicknamed the "Pi Planet" or "Pi Earth" because it takes approximately 3.14 days to orbit the host star.[4][5][6]

Physical properties

The planet is thought to be a small rocky planet, even though composition is unknown.[4] Since it orbits very close to its star, it is too hot to host life, due to it having a scorching temperature of 450 K. Not much is known about it because it was just discovered, but it is similar to Earth, having a radius 95% that of Earth,[7] very similar to Venus.

Host star

K2-315
The location of K2-315 (circled in red)
The location of K2-315 (circled in red)
Observation data
Epoch J2000.0   Equinox (celestial coordinates)
Constellation Libra[8]
Right ascension  15h 12m 05.1944s[9]
Declination −20° 06′ 30.5428″[9]
Apparent magnitude (V) 17.67[10]
Characteristics
Evolutionary stage Red dwarf
Spectral type M3.5±0.5 V[11]
Astrometry
Radial velocity (Rv)6.25±0.17[11] km/s
Proper motion (μ) RA: −120.013[9] mas/yr
Dec.: +74.471[9] mas/yr
Parallax (π)17.6353 ± 0.0492[9] mas
Distance184.9 ± 0.5 ly
(56.7 ± 0.2 pc)
Details[11]
Mass0.174±0.004 M☉
Radius0.2±0.01 R☉
Luminosity0.398% L☉
Surface gravity (log g)5.094±0.006 cgs
Temperature3,300±30 K
Metallicity [Fe/H]−0.24±0.09 dex
Rotational velocity (v sin i)<5 km/s
Age>1 Gyr
Other designations
K2-315, EPIC 249631677
Database references
SIMBADdata

K2-315 is a star in the southern zodiac constellation Libra.[12] It has an apparent magnitude of 17.67,[10] requiring a powerful telescope to be seen. The star is relatively close at a distance of 185 light years[9] but is receding with a radial velocity of 6.25 km/s.[11]

K2-315 has a stellar classification of M3.5±0.5 V, indicating that it is a M-type main-sequence star (with 14% uncertainty).[11] It has 17.4% the mass of the Sun and 20% its radius.[11] Typical for red dwarves, it has a luminosity less than 1% of the Sun, which yields an effective temperature of 3,300 K.[11] Unlike most planetary hosts, K2-315 is metal-deficient, with an iron abundance only 57% that of the Sun.[11] It is estimated to be over a billion years old, and has a projected rotational velocity less than 5 km/s.[11]

References

  1. ↑ 1.0 1.1 1.2 1.3 1.4 Niraula, Prajwal; Julien de Wit; Rackham, Benjamin V.; Ducrot, Elsa; Burdanov, Artem; Crossfield, Ian J. M.; Valerie Van Grootel; Murray, Catriona et al. (2020). "Π Earth: A 3.14 day Earth-sized Planet from K2's Kitchen Served Warm by the SPECULOOS Team". The Astronomical Journal 160 (4): 172. doi:10.3847/1538-3881/aba95f. Bibcode: 2020AJ....160..172N. 
  2. ↑ "Exoplanet-catalog". NASA. https://exoplanets.nasa.gov/exoplanet-catalog/7666/k2-315-b/. 
  3. ↑ September 2020, Mike Wall 22 (22 September 2020). "'Pi planet' alien world takes 3.14 days to orbit its star". https://www.space.com/earth-size-exoplanet-pi-orbit. 
  4. ↑ 4.0 4.1 Starr, Michelle (22 September 2020). "Astronomers Discover "Pi Earth" Exoplanet Orbits Its Star Once Every 3.14 Days" (in en-gb). https://www.sciencealert.com/pi-earth-exoplanet-orbits-its-star-once-every-3-14-days. 
  5. ↑ Ciaccia, Chris (2020-09-29). "Mysterious ‘pi planet’ discovered in deep space" (in en-US). https://nypost.com/2020/09/29/mysterious-pi-planet-discovered-in-deep-space/. 
  6. ↑ Anderson, Paul Scott (2020-10-04). "Meet the Pi planet. It orbits its star every 3.14 days" (in en-US). https://earthsky.org/space/pi-exoplanet-k2-315b-has-3-14-day-orbit/. 
  7. ↑ "Exoplanet Archive". https://exoplanetarchive.ipac.caltech.edu/overview/K2-315. 
  8. ↑ "Find the constellation which contains given sky coordinates". http://djm.cc/constellation.html. 
  9. ↑ 9.0 9.1 9.2 9.3 9.4 Brown, A. G. A. (2021). "Gaia Early Data Release 3: Summary of the contents and survey properties". Astronomy & Astrophysics 649: A1. doi:10.1051/0004-6361/202039657. Bibcode: 2021A&A...649A...1G.  Gaia EDR3 record for this source at VizieR.
  10. ↑ 10.0 10.1 Muirhead, Philip S.; Dressing, Courtney D.; Mann, Andrew W.; Rojas-Ayala, Bárbara; Lépine, Sébastien; Paegert, Martin; De Lee, Nathan; Oelkers, Ryan (4 April 2018). "A Catalog of Cool Dwarf Targets for the Transiting Exoplanet Survey Satellite". The Astronomical Journal 155 (4): 180. doi:10.3847/1538-3881/aab710. Bibcode: 2018AJ....155..180M. 
  11. ↑ 11.0 11.1 11.2 11.3 11.4 11.5 11.6 11.7 11.8 Niraula, Prajwal et al. (21 September 2020). "π Earth: A 3.14 day Earth-sized Planet from K2's Kitchen Served Warm by the SPECULOOS Team". The Astronomical Journal 160 (4): 172. doi:10.3847/1538-3881/aba95f. ISSN 0004-6256. Bibcode: 2020AJ....160..172N. 
  12. ↑ "Odkryto "Ziemię Pi". Okrąża swoją gwiazdę raz na 3,14 dnia". https://www.national-geographic.pl/artykul/odkryto-ziemie-pi-jest-niemal-tej-wielkosci-co-nasza. 



Retrieved from "https://handwiki.org/wiki/index.php?title=Astronomy:K2-315b&oldid=3945772"