HD 27894
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.
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b | ≥0.665+0.009 −0.007 MJ |
0.125±0.0001 | 18.02+0.01 −0.02 |
0.047+0.012 −0.008 |
— | — |
| c | ≥0.162+0.011 −0.040 MJ |
0.198±0.001 | 36.07+0.26 −0.09 |
0.015+0.020 −0.002 |
— | — |
| d | 6.493+0.987 −0.353 MJ |
5.362+0.206 −0.223 |
5019.5+32.6 −31.1 |
0.343+0.031 −0.026 |
101.524+14.742 −31.503° |
— |
See also
References
- ^ 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.
- ^ 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.
- ^ 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.
- ^ "HD 27894". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2024-01-14.
- ^ 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.
- ^ 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.
- ^ 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.
- ^ 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.
- ^ 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.
- ^ Nowakowski, Tomasz (June 12, 2017). "Two new massive planets detected around the star HD 27894". Retrieved June 12, 2017.
- ^ 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.
