HIP 70849
HIP 70849 is a star with one or more non-stellar companions in the southern constellation Lupus. It is a 10th magnitude star, making it too faint to be visible to the naked eye.[2] The system is located at a distance of 78.5 light-years from the Sun based on parallax measurements.[1]
This is a K-type main-sequence star with a stellar classification of K7Vk,[3] where the 'k' indicates interstellar absorption features in the spectrum. The star is magnetically active with a 10.1±1.4 yr starspot cycle. It appears about 3.6 billion years old and the light emission shows a 41.2 day periodicity, which is likely the rotation period.[5] This star, which resembles a brighter red dwarf, is smaller and less massive than the Sun. It is radiating just 9%[5] of the luminosity of the Sun from its photosphere at an effective temperature of 4,103 K.[6]
In 2009, a gas giant planet/brown dwarf was found in orbit around it. Designated HIP 70849 b it has more than five times the mass of Jupiter and takes more than 3000 days to orbit at a semimajor axis of more than 3.5 AU.[8] There is also a potential T4.5 brown dwarf companion orbiting ~9000AU from HIP 70849.[9]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b | >5 MJ | >3.5 | >3000 | ? | — | — |
See also
References
- ^ a b c d e Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051. Gaia DR2 record for this source at VizieR.
- ^ a b c d e f g h i 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.
- ^ a b Gray, R. O.; et al. (July 2006). "Contributions to the Nearby Stars (NStars) Project: spectroscopy of stars earlier than M0 within 40 pc-The Southern Sample". The Astronomical Journal. 132 (1): 161–170. arXiv:astro-ph/0603770. Bibcode:2006AJ....132..161G. doi:10.1086/504637. S2CID 119476992.
- ^ 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.
- ^ a b c d e f g h Zurlo, A.; et al. (October 2018). "Imaging radial velocity planets with SPHERE". Monthly Notices of the Royal Astronomical Society. 480 (1): 35–48. arXiv:1807.01324. Bibcode:2018MNRAS.480...35Z. doi:10.1093/mnras/sty1809.
- ^ a b c d e f Sousa, S. G.; et al. (November 2018). "SWEET-Cat updated. New homogenous spectroscopic parameters". Astronomy & Astrophysics. 620: 13. arXiv:1810.08108. Bibcode:2018A&A...620A..58S. doi:10.1051/0004-6361/201833350. S2CID 119374557. A58.
- ^ "CD-45 9206". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2021-11-11.
- ^ a b Ségransan, D.; et al. (2011). "The HARPS search for southern extra-solar planets. XXIX. Four new planets in orbit around the moderately active dwarfs HD 63765, HD 104067, HD 125595, and HIP 70849". Astronomy and Astrophysics. 535. A54. arXiv:1107.0339. Bibcode:2011A&A...535A..54S. doi:10.1051/0004-6361/200913580. S2CID 119197766.
- ^ Lodieu, N.; et al. (2014). "Binary frequency of planet-host stars at wide separations. A new brown dwarf companion to a planet-host star". Astronomy and Astrophysics. 569. A120. arXiv:1408.1208. Bibcode:2014A&A...569A.120L. doi:10.1051/0004-6361/201424210. S2CID 118516214.
