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K2-315b
Discovery [1]
Discovered by Kepler (K2)
Discovery date2020
Transit
Orbital characteristics [1]
0.02±0.00  AU
3.14±0.00  d
Inclination88.7 °±0.2 °
Physical characteristics
Mean radius
0.95±0.06  R🜨 [1]
Mass0.81  M🜨 [2]
Temperature460 ± 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. [3] [4] 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 Earth" because it takes approximately 3.14 days to orbit the host star. [5]

Physical properties

The planet is thought to be a small rocky planet, even though composition is unknown. [5] 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, [6] very similar to Venus, but has 81% Earth's mass. [2]

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 J2000.0 ( ICRS)
Constellation Libra [7]
Right ascension 15h 12m 05.1944s [8]
Declination −20° 06′ 30.5428″ [8]
Apparent magnitude (V) 17.67 [9]
Characteristics
Evolutionary stage Red dwarf
Spectral type M3.5±0.5 V [10]
Astrometry
Radial velocity (Rv)6.25±0.17 [10] km/s
Proper motion (μ) RA: −120.013  mas/ yr [8]
Dec.: +74.471  mas/ yr [8]
Parallax (π)17.6353 ± 0.0492  mas [8]
Distance184.9 ± 0.5  ly
(56.7 ± 0.2  pc)
Details [10]
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
SIMBAD data

K2-315 is a star in the southern zodiac constellation Libra. [11] It has an apparent magnitude of 17.67, [9] requiring a powerful telescope to be seen. The star is relatively close at a distance of 185 light years [8] but is receding with a radial velocity of 6.25  km/s. [10]

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). [10] It has 17.4% the mass of the Sun and 20% its radius. [10] Typical for red dwarves, it has a luminosity less than 1% of the Sun, which yields an effective temperature of 3,300 K. [10] Unlike most planetary hosts, K2-315 is metal-deficient, with an iron abundance only 57% that of the Sun. [10] It is estimated to be over a billion years old, and has a projected rotational velocity less than km/s. [10]

References

  1. ^ a b c d e Niraula, Prajwal; Julien de Wit; Rackham, Benjamin V.; Ducrot, Elsa; Burdanov, Artem; Crossfield, Ian J. M.; Valerie Van Grootel; Murray, Catriona; Garcia, Lionel J.; Alonso, Roi; Beard, Corey; Yilen Gomez Maqueo Chew; Delrez, Laetitia; Demory, Brice-Olivier; Fulton, Benjamin J.; Gillon, Michael; Gunther, Maximilian N.; Howard, Andrew W.; Issacson, Howard; Jehin, Emmanuel; Pedersen, Peter P.; Pozuelos, Francisco J.; Queloz, Didier; Rebolo-Lopez, Rafael; Sairam, Lalitha; Sebastian, Daniel; Thompson, Samantha; Triaud, Amaury H. M. J. (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. arXiv: 2006.07308. Bibcode: 2020AJ....160..172N. doi: 10.3847/1538-3881/aba95f. S2CID  219635862.
  2. ^ a b "Eyes On Exoplanets – Exoplanet Exploration: Planets Beyond our Solar System". exoplanets.nasa.gov. Retrieved 2021-08-08.
  3. ^ "Exoplanet-catalog". Exoplanet Exploration: Planets Beyond our Solar System. NASA. Retrieved 2020-10-22.
  4. ^ September 2020, Mike Wall 22 (22 September 2020). "'Pi planet' alien world takes 3.14 days to orbit its star". Space.com. Retrieved 2020-10-22.{{ cite web}}: CS1 maint: numeric names: authors list ( link)
  5. ^ a b Starr, Michelle (22 September 2020). "Astronomers Discover "Pi Earth" Exoplanet Orbits Its Star Once Every 3.14 Days". ScienceAlert. Retrieved 2020-10-21.
  6. ^ "Exoplanet Archive". exoplanetarchive.ipac.caltech.edu. Retrieved 2020-10-21.
  7. ^ "Find the constellation which contains given sky coordinates". djm.cc.
  8. ^ a b c d e Brown, A. G. A.; et al. (Gaia collaboration) (2021). "Gaia Early Data Release 3: Summary of the contents and survey properties". Astronomy & Astrophysics. 649: A1. arXiv: 2012.01533. Bibcode: 2021A&A...649A...1G. doi: 10.1051/0004-6361/202039657. S2CID  227254300. (Erratum:  doi: 10.1051/0004-6361/202039657e). Gaia EDR3 record for this source at VizieR.
  9. ^ a b 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. arXiv: 1710.00193. Bibcode: 2018AJ....155..180M. doi: 10.3847/1538-3881/aab710. eISSN  1538-3881.
  10. ^ a b c d e f g h i 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. arXiv: 2006.07308. Bibcode: 2020AJ....160..172N. doi: 10.3847/1538-3881/aba95f. eISSN  1538-3881. ISSN  0004-6256.
  11. ^ "Odkryto "Ziemię Pi". Okrąża swoją gwiazdę raz na 3,14 dnia". www.national-geographic.pl.