HD 79498 is a double star in the northern constellation of Cancer. The primary component of this pair has an orbiting exoplanet companion. This star is too faint to be viewed with the naked eye, having an apparent visual magnitude of 8.05.[2] The system is located at a distance of 159 light years based on parallax measurements,[1] and is drifting further away with a heliocentric radial velocity of 20 km/s.[1] It has a relatively high proper motion, traversing the celestial sphere at an angular rate of 0.2″·yr−1.[11]
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Cancer |
| Right ascension | 09h 15m 09.4020s[1] |
| Declination | +23° 22′ 31.979″[1] |
| Apparent magnitude (V) | 8.05[2] |
| Characteristics | |
| Evolutionary stage | main sequence |
| Spectral type | G5 V[3] + M0 V[4] |
| Variable type | None[5] |
| Astrometry | |
| Radial velocity (Rv) | 19.94±0.14[1] km/s |
| Proper motion (μ) | RA: −127.013[1] mas/yr Dec.: −155.703[1] mas/yr |
| Parallax (π) | 20.5658 ± 0.0198 mas[1] |
| Distance | 158.6 ± 0.2 ly (48.62 ± 0.05 pc) |
| Absolute magnitude (MV) | 4.62[6] |
| Details | |
| Primary (A) | |
| Mass | 1.08[7] M☉ |
| Radius | 1.05[2] R☉ |
| Luminosity | 1.07[2] L☉ |
| Surface gravity (log g) | 4.43[3] cgs |
| Temperature | 5,800[3] K |
| Metallicity [Fe/H] | +0.21[3] dex |
| Rotational velocity (v sin i) | 2.0[8] km/s |
| Age | 2.8[7] Gyr |
| Secondary (B) | |
| Temperature | 3,881[9] K |
| Metallicity [Fe/H] | 0.18[9] dex |
| Other designations | |
| Database references | |
| SIMBAD | data |
The primary, designated component A, is a G-type main-sequence star with a stellar classification of G5 V.[3] It has 8%[7] greater mass compared to the Sun and a 5% larger girth.[2] The star is estimated to be 2.8[7] billion years old and appears to be spinning slowly with a projected rotational velocity of 2.0 km/s.[8] It has a higher than solar abundance of elements other than hydrogen and helium; what astronomers term a metal-rich star.[12] The star is radiating 7% more luminosity than the Sun from its photosphere at an effective temperature of 5,800 K.[3] There appears to be only a low level of magnetic activity in the star's chromosphere.[5]
The secondary member, component B, is located at a projected separation of 2,900 AU from the primary.[5] It is a small red dwarf of spectral class M0 V.[4]
Planetary system
editThe McDonald Observatory planet search program discovered an exoplanet orbiting the primary in 2011 using the radial velocity method.[5]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| Ab | ≥1.34 ± 0.07 MJ | 3.13 ± 0.08 | 1966 ± 41 | 0.59 ± 0.02 | — | — |
See also
editReferences
edit- ^ a b c d e f g h 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 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.
- ^ a b c d e f Montes, D.; et al. (September 2018). "Calibrating the metallicity of M dwarfs in wide physical binaries with F-, G-, and K-primaries - I: High-resolution spectroscopy with HERMES: stellar parameters, abundances, and kinematics". Monthly Notices of the Royal Astronomical Society. 479 (1): 1332–1382. arXiv:1805.05394. Bibcode:2018MNRAS.479.1332M. doi:10.1093/mnras/sty1295. S2CID 119260219.
- ^ a b Alonso-Floriano, F. J.; et al. (May 2015). "CARMENES input catalogue of M dwarfs. I. Low-resolution spectroscopy with CAFOS". Astronomy & Astrophysics. 577: 19. arXiv:1502.07580. Bibcode:2015A&A...577A.128A. doi:10.1051/0004-6361/201525803. S2CID 53135130. A128.
- ^ a b c d e Robertson, Paul; et al. (April 2012). "The McDonald Observatory Planet Search: New Long-period Giant Planets and Two Interacting Jupiters in the HD 155358 System". The Astrophysical Journal. 749 (1): 39. arXiv:1202.0265. Bibcode:2012ApJ...749...39R. doi:10.1088/0004-637X/749/1/39. S2CID 59273311.
- ^ Boro Saikia, S.; et al. (2018). "Chromospheric activity catalogue of 4454 cool stars. Questioning the active branch of stellar activity cycles". Astronomy and Astrophysics. 616: 616. arXiv:1803.11123. Bibcode:2018A&A...616A.108B. doi:10.1051/0004-6361/201629518. S2CID 118915212.
- ^ a b c d Aguilera-Gómez, Claudia; Ramírez, Iván; Chanamé, Julio (2018). "Lithium abundance patterns of late-F stars: An in-depth analysis of the lithium desert". Astronomy and Astrophysics. 614: A55. arXiv:1803.05922. Bibcode:2018A&A...614A..55A. doi:10.1051/0004-6361/201732209. S2CID 62799777.
- ^ a b Llorente de Andrés, F.; et al. (October 2021). "The evolution of lithium in FGK dwarf stars. The lithium-rotation connection and the Li desert". Astronomy and Astrophysics. 654: A137. arXiv:2108.05852. Bibcode:2021A&A...654A.137L. doi:10.1051/0004-6361/202141339. ISSN 0004-6361.
- ^ a b Veyette, Mark J.; et al. (December 2017). "A Physically Motivated and Empirically Calibrated Method to Measure the Effective Temperature, Metallicity, and Ti Abundance of M Dwarfs". The Astrophysical Journal. 851 (1): 26. arXiv:1710.10259. Bibcode:2017ApJ...851...26V. doi:10.3847/1538-4357/aa96aa. 26.
- ^ "HD 79498". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 15 August 2012.
- ^ Lépine, Sébastien; Shara, Michael M. (March 2005). "A Catalog of Northern Stars with Annual Proper Motions Larger than 0.15" (LSPM-NORTH Catalog)". The Astronomical Journal. 129 (3): 1483–1522. arXiv:astro-ph/0412070. Bibcode:2005AJ....129.1483L. doi:10.1086/427854. S2CID 2603568.
- ^ Schneider, Jean (1995). "Planet HD 79498 b". Extrasolar Planets Encyclopaedia. Retrieved 2012-08-22.