Summary
HD 175541 is an 8th magnitude star with an exoplanetary companion in the constellation Serpens. It has the proper name Kaveh, which was selected by Iran during the NameExoWorlds campaign as part of the 100th anniversary of the IAU. Kaveh is one of the heroes of Shahnameh.[7][8] The apparent visual magnitude of 8.02[2] is too faint for this star to be visible in the naked eye. It is located at a distance of approximately 424 light years from the Sun based on parallax measurements, and is drifting further away with a radial velocity of +20 km/s.[1] Despite its distance, it was given the number 736 in the Gliese Catalogue of Nearby Stars.[6]
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Serpens |
| Right ascension | 18h 55m 40.8840s[1] |
| Declination | +04° 15′ 55.1623″[1] |
| Apparent magnitude (V) | 8.02[2] |
| Characteristics | |
| Spectral type | G6/8IV[3] |
| U−B color index | 0.56 |
| B−V color index | 0.869±0.024[2] |
| R−I color index | 0.33 |
| Astrometry | |
| Radial velocity (Rv) | 19.81±0.20[1] km/s |
| Proper motion (μ) | RA: −6.744±0.099[1] mas/yr Dec.: −90.226±0.084[1] mas/yr |
| Parallax (π) | 7.6877 ± 0.0595 mas[1] |
| Distance | 424 ± 3 ly (130 ± 1 pc) |
| Absolute magnitude (MV) | 2.54[2] |
| Details | |
| Mass | 1.45±0.03[4] M☉ |
| Radius | 4.07±0.05[4] R☉ |
| Luminosity | 10.0±0.1[4] L☉ |
| Surface gravity (log g) | 3.37±0.02[4] cgs |
| Temperature | 5,093±23[4] K |
| Metallicity [Fe/H] | −0.13±0.03[5] dex |
| Rotational velocity (v sin i) | 0.47±0.23[5] km/s |
| Age | 2.9±0.2[4] Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
| ARICNS | data |
This is an evolved G-type star with a stellar classification of G6/8IV.[3] The absolute magnitude of 2.54[2] places it 3.5 magnitudes above the comparable main sequence stars in the Sun's neighborhood, indicating that it is on the subgiant branch. When this intermediate-mass star was on the main-sequence, it was an A-type star.[9] It is around three[4] billion years old and is chromospherically inactive[9] with low a projected rotational velocity of 0.5 km/s.[5] The star has 1.45 times the mass and has expanded to 4.1 times the radius of the Sun. It is radiating ten times the luminosity of the Sun from its photosphere at an effective temperature of 5,093 K.[4]
In April 2007, a Jovian planet was found orbiting this star using the radial velocity method, from Lick and Keck Observatories in Mount Hamilton (California) and Mauna Kea (Hawai'i), United States.[9]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b / Kavian | ≥ 0.598±0.029 MJ | 0.975±0.087 | 298.43±0.45 | 0.110±0.049 | — | — |
See also edit
References edit
- ^ a b c d e f g 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 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 Houk, N.; Swift, C. (1999). "Michigan catalogue of two-dimensional spectral types for the HD Stars". Michigan Spectral Survey. 5. Bibcode:1999MSS...C05....0H.
- ^ a b c d e f g h Bonfanti, A.; Ortolani, S.; Nascimbeni, V. (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 Jofré, E.; Petrucci, R.; Saffe, C.; Saker, L.; Artur de la Villarmois, E.; Chavero, C.; Gómez, M.; Mauas, P. J. D. (2015). "Stellar parameters and chemical abundances of 223 evolved stars with and without planets". Astronomy & Astrophysics. 574: A50. arXiv:1410.6422. Bibcode:2015A&A...574A..50J. doi:10.1051/0004-6361/201424474. S2CID 53666931.
- ^ a b "HD 175541". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2019-09-11.
- ^ "Approved names". NameExoworlds. Retrieved 2020-01-02.
- ^ "International Astronomical Union | IAU". www.iau.org. Retrieved 2020-01-02.
- ^ a b c Johnson, John Asher; et al. (2007). "Retired A Stars and Their Companions: Exoplanets Orbiting Three Intermediate-Mass Subgiants". The Astrophysical Journal. 665 (1): 785–793. arXiv:0704.2455. Bibcode:2007ApJ...665..785J. doi:10.1086/519677.
- ^ Luhn, Jacob K.; et al. (2019). "Retired A Stars and Their Companions. VIII. 15 New Planetary Signals around Subgiants and Transit Parameters for California Planet Search Planets with Subgiant Hosts". The Astronomical Journal. 157 (4). 149. arXiv:1811.03043. Bibcode:2019AJ....157..149L. doi:10.3847/1538-3881/aaf5d0. S2CID 102486961.
- "GJ 736". webviz.u-strasbg.fr/.