HD 113538 (Gliese 496.1) is a star with two planetary companions in the southern constellation of Centaurus. It is much too faint to be viewed with the naked eye at an apparent visual magnitude of 9.05.[2] The distance to this star is 53 light years and it is drifting further away with a radial velocity of +39 km/s.[4]
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Centaurus |
| Right ascension | 13h 04m 57.47645s[1] |
| Declination | −52° 26′ 34.5284″[1] |
| Apparent magnitude (V) | 9.05[2] |
| Characteristics | |
| Spectral type | K9Vk:[3] |
| B−V color index | 1.362±0.009[2] |
| Astrometry | |
| Radial velocity (Rv) | 39.23±0.012[4] km/s |
| Proper motion (μ) | RA: −786.038[1] mas/yr Dec.: −795.591[1] mas/yr |
| Parallax (π) | 61.3899 ± 0.0523 mas[1] |
| Distance | 53.13 ± 0.05 ly (16.29 ± 0.01 pc) |
| Absolute magnitude (MV) | 8.03[4] |
| Details[4] | |
| Mass | 0.585±0.05 M☉ |
| Radius | 0.53±0.02 R☉ |
| Luminosity | 0.127[1] L☉ |
| Surface gravity (log g) | 3.79±0.53 cgs |
| Temperature | 4,462±145 K |
| Metallicity [Fe/H] | −0.24±0.06 dex |
| Age | 4.3±4.0 Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
This is a K-type main-sequence star of a late spectral type, classified as K9Vk:. It displays chromospheric activity with a stellar cycle of at least four years and is metal poor.[4] The star has 58.5% of the mass and 53% of the radius of the Sun.[4] It is radiating just 12.7%[1] of the luminosity of the Sun from its photosphere at an effective temperature of 4,462 K.[4]
Planetary system
editRadial velocity variation of HD 113538 was inferred from observations with the HARPS spectrograph. The star is active (Log R'HK −4.697,[6] SMW 1.05[4]), but the RV variation is not correlated with activity, indicating that planets are responsible. The data is fitted well by a solution including two planets, with an eccentric Saturn-mass planet and a more massive planet on a longer-period orbit[7]—similar to the orbital architecture of the planetary system orbiting HD 163607, though with lower masses. Similar to HD 163607 b, the eccentricity and argument of periastron of HD 113538 b increases the planet's transit probability substantially more than it would be on a circular orbit.
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b | ≥ 0.36±0.04 MJ | 1.24±0.04 | 663.2+8.4 −7.4 |
0.14±0.08 | — | — |
| c | ≥ 0.93±0.06 MJ | 2.44±0.07 | 1,818+25 −22 |
0.20±0.04 | — | — |
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 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.
- ^ 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.
- ^ a b c d e f g h i Moutou, Claire; et al. (April 2015). "The HARPS search for southern extra-solar planets. XXXVII. Five new long-period giant planets and a system update". Astronomy & Astrophysics. 576: 14. arXiv:1412.6591. Bibcode:2015A&A...576A..48M. doi:10.1051/0004-6361/201424965. A48.
- ^ "HD 113538". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2021-10-03.
- ^ 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.
- ^ Moutou, Claire; Mayor, Michel; Lo Curto, Gaspare; Ségransan, Damien; Udry, Stéphane; Bouchy, François; Benz, Willy; Lovis, Christophe; Naef, Dominique; Pepe, Francesco; Queloz, Didier; Santos, Nuno C.; Sousa, Sérgio Gonçalves (2010), The HARPS search for southern extra-solar planets: XXVI: Seven new planetary systems, arXiv:1012.3830, doi:10.1051/0004-6361/201015371, S2CID 118696125