HD 240210
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Cassiopeia |
| Right ascension | 23h 10m 29.22633s[1] |
| Declination | +57° 01′ 46.0277″[1] |
| Apparent magnitude (V) | 8.33[2] |
| Characteristics | |
| Evolutionary stage | giant[2] |
| Spectral type | K3III |
| B−V color index | 1.63 |
| Astrometry | |
| Radial velocity (Rv) | +8.57±0.05[1] km/s |
| Proper motion (μ) | RA: 18.492[1] mas/yr Dec.: 6.883[1] mas/yr |
| Parallax (π) | 2.6570 ± 0.0349 mas[1] |
| Distance | 1,230 ± 20 ly (376 ± 5 pc) |
| Absolute bolometric magnitude (Mbol) | +0.38[2] |
| Details | |
| Mass | 1.25±0.25[2] M☉ |
| Radius | 25.46+1.16 −0.75[1] R☉ |
| Luminosity | 152±3[1] L☉ |
| Surface gravity (log g) | 2.31±0.11[2] cgs |
| Temperature | 4,019+60 −90[1] K |
| Metallicity [Fe/H] | −0.18±0.12[2] dex |
| Rotation | > 654 days[2] |
| Rotational velocity (v sin i) | < 1.0[2] km/s |
| Age | 3.0+2.9 −1.5[3] Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
| Exoplanet Archive | data |
HD 240210 is a star in the northern constellation of Cassiopeia. It has an orange hue but is too faint to be viewed with the naked eye, having an apparent visual magnitude of 8.33.[2] Parallax measurements provide an estimate of its distance from the Sun as approximately 1,230 light years. It is drifting further away with a radial velocity of +8.6 km/s.[1]
This is an aging giant star with a class of K3,[2] which has exhausted the supply of hydrogen at its core and expanded to 25[1] times the radius of the Sun. It is around three[3] billion years old with 1.3[2] times the Sun's mass. The star is radiating 152 times the luminosity of the Sun from its enlarged photosphere at an effective temperature of 4,019 K.[1] It is spinning slowly, with each rotation taking at least 1.8 years.[2]
On June 10, 2009 a planet orbiting the star was discovered by Niedzielski et al. This exoplanet is a 6.9 or greater Jupiter mass planet. Evidence for additional planetary companions has been found.[5]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b | ≥ 6.90 MJ | 1.33 | 501.75±2.33 | 0.15±0.02 | — | — |
See also
References
- ^ a b c d e f g h i j k l 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 f g h i j k l m Niedzielski, A.; et al. (2009). "Substellar-mass Companions to the K-dwarf BD+14 4559 and the K-giants HD 240210 and BD+20 2457". The Astrophysical Journal. 707 (1): 768–777. arXiv:0906.1804. Bibcode:2009ApJ...707..768N. doi:10.1088/0004-637X/707/1/768. S2CID 16877069.
- ^ a b Adamczyk, M.; et al. (2016). "Masses and luminosities for 342 stars from the PennState-Toruń Centre for Astronomy Planet Search". Astronomy and Astrophysics. 587: A119. arXiv:1510.07495. Bibcode:2016A&A...587A.119A. doi:10.1051/0004-6361/201526628. S2CID 119299522.
- ^ "HD 240210". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2019-11-17.
- ^ Adamów, M.; et al. (July 2011). Martin, E.L.; Ge, J.; Lin, W. (eds.). A search for planets around intermediate Mass Stars with the Hobby-Eberly Telescope. Research, Science and Technology of Brown Dwarfs and Exoplanets: Proceedings of an International Conference held in Shangai on Occasion of a Total Eclipse of the Sun, Shangai, China. EPJ Web of Conferences. Vol. 16. Bibcode:2011EPJWC..1602005A. doi:10.1051/epjconf/20111602005. 02005.
