Misplaced Pages

HD 27894 is a single star with a system of orbiting exoplanets, located in the southern constellation of Reticulum. It is too faint to be seen with the naked eye at an apparent visual magnitude of 9.36. This system lies at a distance of 142.5 light years from the Sun, as determined via parallax measurements, and is drifting further away with a radial velocity of 83 km/s.

The spectrum of HD 27894 presents as a K-type main-sequence star, an orange dwarf, with a stellar classification of K2 V. This is a quiescent solar-type star that displays no significant magnetic activity in its chromosphere and is spinning slowly with a rotation period of roughly 44 days. The abundance of iron in the star is much higher than in the Sun, an indicator that it is metal-rich. It has 83% of the mass of the Sun and 79% of the Sun's radius. The star is radiating 33% of the luminosity of the Sun from its photosphere at an effective temperature of 4,923 K.

Planetary system

In 2005, the Geneva Extrasolar Planet Search Team announced the discovery of an extrasolar planet orbiting the star. In 2017, the discovery of two additional exoplanets was announced. One is very close to the star like the one discovered earlier, while the other one orbits the star at a much larger distance. It is the first system where such a large gap between orbital distances has been found. In 2022, the inclination and true mass of HD 27894 d were measured via astrometry. The study only found strong evidence for planets b and d.

See also

• List of extrasolar planets

References

1. ^ Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters. 38 (5): 331. arXiv:1108.4971. Bibcode:2012AstL...38..331A. doi:10.1134/S1063773712050015. S2CID 119257644.
2. ^ Vallenari, A.; et al. (Gaia collaboration) (2023). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy and Astrophysics. 674: A1. arXiv:2208.00211. Bibcode:2023A&A...674A...1G. doi:10.1051/0004-6361/202243940. S2CID 244398875. Gaia DR3 record for this source at VizieR.
3. ^ Houk, Nancy (1979). Michigan catalogue of two-dimensional spectral types for the HD stars. Ann Arbor, Michigan: Dept. of Astronomy, University of Michigan. Bibcode:1978mcts.book.....H. LCCN 78010745.
4. ^ "HD 27894". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2024-01-14.
5. ^ Soubiran, C.; et al. (2018). "Gaia Data Release 2. The catalogue of radial velocity standard stars". Astronomy and Astrophysics. 616: A7. arXiv:1804.09370. Bibcode:2018A&A...616A...7S. doi:10.1051/0004-6361/201832795. S2CID 52952408.
6. ^ Moutou, C.; et al. (2005). "The HARPS search for southern extra-solar planets IV. Three close-in planets around HD 2638, HD 27894 and HD 63454". Astronomy and Astrophysics. 439 (1): 367–373. Bibcode:2005A&A...439..367M. doi:10.1051/0004-6361:20052826.
7. ^ Bonfanti, A.; et al. (2016). "Age consistency between exoplanet hosts and field stars". Astronomy & Astrophysics. 585: 14. arXiv:1511.01744. Bibcode:2016A&A...585A...5B. doi:10.1051/0004-6361/201527297. S2CID 53971692. A5.
8. Trevisan, M.; et al. (November 2011). "Analysis of old very metal rich stars in the solar neighbourhood". Astronomy & Astrophysics. 535: A42. arXiv:1109.6304. Bibcode:2011A&A...535A..42T. doi:10.1051/0004-6361/201016056. S2CID 49565866.. See table 13.
9. ^ Trifonov, T.; et al. (2017). "Three planets around HD 27894. A close-in pair with a 2:1 period ratio and an eccentric Jovian planet at 5.4 AU". Astronomy & Astrophysics. 602: L8. arXiv:1706.00509. Bibcode:2017A&A...602L...8T. doi:10.1051/0004-6361/201731044. S2CID 119105619.
10. Nowakowski, Tomasz (June 12, 2017). "Two new massive planets detected around the star HD 27894". Retrieved June 12, 2017.
11. ^ Feng, Fabo; Butler, R. Paul; et al. (August 2022). "3D Selection of 167 Substellar Companions to Nearby Stars". The Astrophysical Journal Supplement Series. 262 (21): 21. arXiv:2208.12720. Bibcode:2022ApJS..262...21F. doi:10.3847/1538-4365/ac7e57. S2CID 251864022.

v t e Constellation of Reticulum
List of stars in Reticulum Reticulum in Chinese astronomy
Stars	Bayer α β γ δ ε ζ ζ η θ ι κ Variable R YZ HR 1475 HD 21693 21749 23079 (Tupi) 23127 25171 27894 Other 2MASS J03480772−6022270 WISE 0350−5658 WISE 0359−5401
Exoplanets ε Reticuli b HD 23079 b HD 23127 b HD 27894 b
Galaxies	NGC 1313 1559
Astronomical events SN 1997D SN 2005df
Category

• K-type main-sequence stars
• Planetary systems with three confirmed planets
• Reticulum
• Durchmusterung objects
• Henry Draper Catalogue objects
• Hipparcos objects