K2-315b

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K2-315b
K2-315 b.jpg
Size comparison of the planet K2-315b (artistic concept) with Earth
Discovery [1]
Discovered by Kepler (K2)
Discovery date2020
Transit
Orbital characteristics [1]
0.02±0.00  AU
3.14±0.00  d
Inclination 88.7° ±0.2°
Physical characteristics
0.95±0.06  R🜨 [1]
Temperature 460 ± 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.

    Contents

    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
    K2-315Location.png
    The location of K2-315 (circled in red)
    Observation data
    Epoch J2000.0        Equinox J2000.0 (ICRS)
    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 mas/yr [9]
    Dec.: +74.471 mas/yr [9]
    Parallax (π)17.6353±0.0492  mas [9]
    Distance 184.9 ± 0.5  ly
    (56.7 ± 0.2  pc)
    Details [11]
    Mass 0.174±0.004  M
    Radius 0.2±0.01  R
    Luminosity 0.398%  L
    Surface gravity (log g)5.094±0.006  cgs
    Temperature 3,300±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. [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 2 3 4 5 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. "Exoplanet-catalog". Exoplanet Exploration: Planets Beyond our Solar System. NASA . Retrieved 2020-10-22.
    3. 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)
    4. 1 2 Starr, Michelle (22 September 2020). "Astronomers Discover "Pi Earth" Exoplanet Orbits Its Star Once Every 3.14 Days". ScienceAlert. Retrieved 2020-10-21.
    5. Ciaccia, Chris (2020-09-29). "Mysterious 'pi planet' discovered in deep space" . Retrieved 2025-05-06.
    6. Anderson, Paul Scott (2020-10-04). "Meet the Pi planet. It orbits its star every 3.14 days". earthsky.org. Retrieved 2025-05-06.
    7. "Exoplanet Archive". exoplanetarchive.ipac.caltech.edu. Retrieved 2020-10-21.
    8. "Find the constellation which contains given sky coordinates". djm.cc.
    9. 1 2 3 4 5 6 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.
    10. 1 2 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.
    11. 1 2 3 4 5 6 7 8 9 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.
    12. "Odkryto "Ziemię Pi". Okrąża swoją gwiazdę raz na 3,14 dnia". www.national-geographic.pl.