Astronomy:HD 222237
| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| Constellation | Tucana[1] |
| Right ascension | 23h 39m 37.38737s[2] |
| Declination | −72° 43′ 19.7554″[2] |
| Apparent magnitude (V) | 7.09[3] |
| Characteristics | |
| Evolutionary stage | main sequence |
| Spectral type | K3+V[4] |
| U−B color index | 0.824[3] |
| B−V color index | 1.001[3] |
| V−R color index | 0.585[3] |
| Astrometry | |
| Radial velocity (Rv) | 69.62±0.13[2] km/s |
| Proper motion (μ) | RA: 143.736[2] mas/yr Dec.: −736.907[2] mas/yr |
| Parallax (π) | 87.3724 ± 0.0187[2] mas |
| Distance | 37.329 ± 0.008 ly (11.445 ± 0.002 pc) |
| Absolute magnitude (MV) | 6.80[3] |
| Details | |
| Mass | 0.76±0.09[5] M☉ |
| Radius | 0.71±0.06[5] R☉ |
| Luminosity | 0.22[6] L☉ |
| Surface gravity (log g) | 4.61±0.10[5] cgs |
| Temperature | 4751±139[5] K |
| Metallicity [Fe/H] | −0.32±0.02[5] dex |
| Rotational velocity (v sin i) | 2.4[6] km/s |
| Age | 8.8+5.3 −8.1[6] Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
| Exoplanet Archive | data |
HD 222237 is a K-type main-sequence star located 37.3 light-years (11.4 parsecs) away in the constellation Tucana. With an apparent magnitude of 7.1, it is too faint to be visible to the naked eye. It is somewhat smaller, fainter, and cooler than the Sun, with about 76% of the Sun's mass, 71% of its radius, and just 22% of its luminosity, with an effective temperature of 4,750 Kelvin. It is a low metallicity star, meaning the abundance of elements heavier than helium is lower than in the Sun.[5] No infrared excess has been detected that would otherwise indicate the presence of a circumstellar disk around this star.[8]
The star hosts one known exoplanet, the super-Jupiter HD 222237 b. This planet was discovered in 2024 using radial velocity as well as astrometry from the Hipparcos and Gaia space telescopes. It has about 5 times the mass of Jupiter, and has an eccentric orbit around its star with a period of about 40 years at a distance of about 11 AU, around the distance of Saturn from the Sun.[5] Direct imaging of the planet with the James Webb Space Telescope is planned.[9]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (years) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b | 5.19±0.58 MJ | 10.8+1.1 −1.0 |
40.8+5.8 −4.5 |
0.56±0.03 | 49.9+3.4 −2.8° |
— |
See also
References
- ↑ "Finding the constellation which contains given sky coordinates". 2 August 2008. http://djm.cc/constellation.html.
- ↑ 2.0 2.1 2.2 2.3 2.4 Vallenari, A. et al. (2022). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy & Astrophysics. doi:10.1051/0004-6361/202243940 Gaia DR3 record for this source at VizieR.
- ↑ 3.0 3.1 3.2 3.3 3.4 Koen, C. et al. (April 2010). "UBV(RI)C JHK observations of Hipparcos-selected nearby stars". Monthly Notices of the Royal Astronomical Society 403 (4): 1949-1968. doi:10.1111/j.1365-2966.2009.16182.x. Bibcode: 2010MNRAS.403.1949K.
- ↑ 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. doi:10.1086/504637. Bibcode: 2006AJ....132..161G.
- ↑ 5.0 5.1 5.2 5.3 5.4 5.5 5.6 5.7 Xiao, Guang-Yao et al. (November 2024). "HD 222237 b: a long-period super-Jupiter around a nearby star revealed by radial-velocity and Hipparcos-Gaia astrometry". Monthly Notices of the Royal Astronomical Society 534 (3): 2858-2874. doi:10.1093/mnras/stae2151. Bibcode: 2024MNRAS.534.2858X.
- ↑ 6.0 6.1 6.2 Valenti, Jeff A.; Fischer, Debra A. (July 2005). "Spectroscopic Properties of Cool Stars (SPOCS). I. 1040 F, G, and K Dwarfs from Keck, Lick, and AAT Planet Search Programs". The Astrophysical Journal Supplement Series 159 (1): 141-166. doi:10.1086/430500. Bibcode: 2005ApJS..159..141V.
- ↑ "HD 222237". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=HD+222237.
- ↑ Lawler, S. M. et al. (November 2009). "Explorations Beyond the Snow Line: Spitzer/IRS Spectra of Debris Disks Around Solar-type Stars". The Astrophysical Journal 705 (1): 89-111. doi:10.1088/0004-637X/705/1/89. Bibcode: 2009ApJ...705...89L.
- ↑ "Direct Detection and Characterization of a Nearby Temperate Giant Planet". STScI. https://www.stsci.edu/jwst/science-execution/program-information?id=6915. "We propose to image HD 222237 b, a nearby, temperate, eccentric giant planet prime for characterization by JWST."
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