| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Centaurus |
| Right ascension | 13 04 57.47645 |
| Declination | −52° 26′ 34.5284″ |
| Apparent magnitude (V) | 9.05 |
| Characteristics | |
| Spectral type | K9Vk: |
| B−V color index | 1.362±0.009 |
| Astrometry | |
| Radial velocity (Rv) | 39.23±0.012 km/s |
| Proper motion (μ) | RA: −786.038 mas/yr Dec.: −795.591 mas/yr |
| Parallax (π) | 61.3899 ± 0.0523 mas |
| Distance | 53.13 ± 0.05 ly (16.29 ± 0.01 pc) |
| Absolute magnitude (MV) | 8.03 |
| Details | |
| Mass | 0.585±0.05 M☉ |
| Radius | 0.53±0.02 R☉ |
| Luminosity | 0.127 L☉ |
| Surface gravity (log g) | 3.79±0.53 cgs |
| Temperature | 4,462±145 K |
| Metallicity | −0.24±0.06 dex |
| Age | 4.3±4.0 Gyr |
| Other designations | |
| CD−51 7244, GJ 496.1/9425, HD 113538, HIP 63833, LFT 966, LHS 344 | |
| Database references | |
| SIMBAD | data |
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. The distance to this star is 53 light years and it is drifting further away with a radial velocity of +39 km/s.
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. The star has 58.5% of the mass and 53% of the radius of the Sun. It is radiating just 12.7% of the luminosity of the Sun from its photosphere at an effective temperature of 4,462 K.
Planetary system
Radial velocity variation of HD 113538 was inferred from observations with the HARPS spectrograph. The star is active (Log R'HK −4.697, SMW 1.05), 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—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
- ^ 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.
- ^ 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.
- ^ 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", Astronomy & Astrophysics, vol. 527, pp. A63, arXiv:1012.3830, doi:10.1051/0004-6361/201015371, S2CID 118696125
