HIP 70849
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Lupus |
| Right ascension | 14h 29m 18.56436s[1] |
| Declination | −46° 27′ 49.7378″[1] |
| Apparent magnitude (V) | 10.36[2] |
| Characteristics | |
| Spectral type | K7Vk[3] |
| Apparent magnitude (B) | 11.787[2] |
| Apparent magnitude (J) | 7.639±0.023[2] |
| Apparent magnitude (H) | 7.006±0.061[2] |
| Apparent magnitude (K) | 6.790±0.027[2] |
| B−V color index | 1.427±0.019[2] |
| Variable type | 8.50[2] |
| Astrometry | |
| Radial velocity (Rv) | −0.134±0.0013[4] km/s |
| Proper motion (μ) | RA: −44.051±0.017 mas/yr[1] Dec.: −201.577±0.020 mas/yr[1] |
| Parallax (π) | 41.4618 ± 0.0175 mas[1] |
| Distance | 78.66 ± 0.03 ly (24.12 ± 0.01 pc) |
| Absolute magnitude (MV) | 8.5[2] |
| Details | |
| Mass | 0.63±0.03[5] 0.76±0.07[6] M☉ |
| Radius | 0.62±0.02[5] R☉ |
| Luminosity (bolometric) | 0.0892±0.0005[5] L☉ |
| Surface gravity (log g) | 3.70±0.09[6] cgs |
| Temperature | 4,103±25[6] K |
| Metallicity [Fe/H] | 0.00±0.03[6] dex |
| Rotation | 41.2 d[5] |
| Rotational velocity (v sin i) | 1.93 km/s[5] 0.30±0.30[6] km/s |
| Age | 3.6±0.15[5] Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
| Exoplanet Archive | data |
HIP 70849 is a star with two 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 78.7 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 was found in orbit around it.[8] Designated HIP 70849 b, it has 4.5 times the mass of Jupiter and takes more than 3000 days to orbit at a semimajor axis of 3.99 AU, with a high eccentricity.[9] There is also a T4.5 brown dwarf companion orbiting ~9000AU from HIP 70849.[10][11]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b | 4.5+0.4 −0.3 MJ |
3.99+0.06 −0.07 |
3649±18 | 0.65+0.02 −0.01 |
96±16° | — |
See also
[edit]References
[edit]- ^ a b c d e 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.
- ^ 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.
- ^ 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.
- ^ a b Philipot, F.; Lagrange, A.-M.; et al. (January 2023). "Updated characterization of long-period single companion by combining radial velocity, relative astrometry, and absolute astrometry". Astronomy & Astrophysics. 670: A65. arXiv:2301.01263. Bibcode:2023A&A...670A..65P. doi:10.1051/0004-6361/202245396. S2CID 255393653.
- ^ 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.
- ^ Šubjak, J.; Lodieu, N.; et al. (2023). "Search for planets around stars with wide brown dwarfs". Astronomy & Astrophysics. 671: A10. arXiv:2212.03757. Bibcode:2023A&A...671A..10S. doi:10.1051/0004-6361/202244238. S2CID 254366726.
