HD 45652 is a star with an exoplanetary companion in the equatorial constellation of Monoceros. It was officially named Lusitânia on 17 December 2019, after the IAU100 press conference in Paris by the IAU (International Astronomical Union).[8] This star has an apparent visual magnitude of 8.10,[2] making it an 8th magnitude star that is too dim to be visible to the naked eye. The system is located at a distance of 114 light-years from the Sun based on parallax measurements,[1] but is drifting closer with a radial velocity of −5 km/s.[5] It shows a high proper motion, traversing the celestial sphere at an angular rate of 0.188 arcsec yr−1.[9]
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Monoceros |
| Right ascension | 06h 29m 13.1919s[1] |
| Declination | +10° 56′ 02.0061″[1] |
| Apparent magnitude (V) | 8.10[2] |
| Characteristics | |
| Spectral type | G8-K0[3] |
| B−V color index | 0.846±0.020[2] |
| V−R color index | 0.5[4] |
| R−I color index | 0.4[4] |
| Astrometry | |
| Radial velocity (Rv) | −5.040±0.0008[5] km/s |
| Proper motion (μ) | RA: 206.328±0.106[1] mas/yr Dec.: −62.573±0.089[1] mas/yr |
| Parallax (π) | 28.6622 ± 0.0551 mas[1] |
| Distance | 113.8 ± 0.2 ly (34.89 ± 0.07 pc) |
| Absolute magnitude (MV) | 5.42[2] |
| Details | |
| Mass | 0.83±0.05 M☉[3] 0.94±0.02 M☉[6] 0.91±0.03[7] M☉ |
| Radius | 0.91±0.02[6] R☉ |
| Luminosity | 0.61±0.01[6] L☉ |
| Surface gravity (log g) | 4.49±0.03[6] cgs |
| Temperature | 5,342±31[6] K |
| Metallicity [Fe/H] | 0.286±0.032[7] dex |
| Rotational velocity (v sin i) | 3.5[7] km/s |
| Age | 5.4±2.7[6] Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
The measured atmospheric properties match a metal-rich late G- or early K-type dwarf star.[3] It is a middle-aged main sequence star, about five billion years old,[6] and is chromospherically inactive.[3] The star is smaller and less massive than the Sun.[6] It is radiating 61%[6] of the Sun's luminosity from its photosphere at an effective temperature of 5,342 K.[6] HD 45652 is spinning with a projected rotational velocity of 3.5 km/s.[7]
Planetary system
editIn May 2008, the discovery of an extrasolar planet, HD 45652 b, orbiting the star was announced. The planet was detected by the radial velocity method, using observations made from 2005 to 2007.[3] It has been assigned the name Viriato by the IAU Division C Working Group on Star Names.[10]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b / Viriato | ≥0.433±0.076 MJ | 0.237±0.011 | 44.073±0.0048 | 0.607±0.026 | — | — |
References
edit- ^ a b c d e f 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 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 c d e Santos, N. C.; et al. (2008). "ELODIE metallicity-biased search for transiting Hot Jupiters. V. An intermediate-period Jovian planet orbiting HD 45652". Astronomy and Astrophysics. 487 (1): 369–372. arXiv:0805.1019. Bibcode:2008A&A...487..369S. doi:10.1051/0004-6361:200809402. S2CID 14178114.
- ^ a b c "HD 45652". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2021-10-21.
- ^ a b 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 i j 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.
- ^ a b c d Gonzalez, G.; et al. (2010). "Parent stars of extrasolar planets - X. Lithium abundances and v sini revisited". Monthly Notices of the Royal Astronomical Society. 403 (3): 1368. arXiv:0912.1621. Bibcode:2010MNRAS.403.1368G. doi:10.1111/j.1365-2966.2009.16195.x. S2CID 118520284.
- ^ "112 sets of exoplanets and host stars named in the IAU100". International Astronomical Union. Retrieved 2019-12-18.
- ^ Luyten, W. J. (June 1995). "NLTT Catalogue". Vizier Online Data Catalog. Bibcode:1995yCat.1098....0L.
- ^ "2015 NameExoWorlds Names and Themes" (PDF). 2019 Annual Report. IAU Division C Working Group on Star Names. Retrieved 2021-10-22.
- ^ Ment, Kristo; et al. (2018). "Radial Velocities from the N2K Project: Six New Cold Gas Giant Planets Orbiting HD 55696, HD 98736, HD 148164, HD 203473, and HD 211810". The Astronomical Journal. 156 (5). 213. arXiv:1809.01228. Bibcode:2018AJ....156..213M. doi:10.3847/1538-3881/aae1f5. S2CID 119243619.
External links
edit- "Notes for star HD 45652". Extrasolar Planets Encyclopaedia. Archived from the original on August 3, 2008.
- "NLTT 16570 -- High proper-motion Star". SIMBAD.