KOI-74
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Cygnus[2] |
| Right ascension | 19h 53m 17.810s[3] |
| Declination | +42° 23′ 18.51″[3] |
| Apparent magnitude (V) | 10.715[4] |
| Characteristics | |
| Spectral type | A1V[1] |
| B−V color index | 0.154[4] |
| Astrometry | |
| Radial velocity (Rv) | −41.97±0.32[5] km/s |
| Proper motion (μ) | RA: +1.328[3] mas/yr Dec.: −41.497[3] mas/yr |
| Parallax (π) | 1.328±0.144 mas[3] |
| Distance | approx. 2,500 ly (approx. 750 pc) |
| Orbit[1] | |
| Period (P) | 5.18875 days |
| Eccentricity (e) | 0 |
| Inclination (i) | 88.8° |
| Semi-amplitude (K1) (primary) | 14.7 km/s |
| Details | |
| primary | |
| Mass | 2.22+0.10 −0.14[1] M☉ |
| Radius | 1.90+0.04 −0.05[1] R☉ |
| Luminosity | 25.6±2.4[1] L☉ |
| Temperature | 9,400±150[1] K |
| white dwarf | |
| Mass | 0.22±0.01[1] M☉ |
| Radius | 0.043±0.004[1] R☉ |
| Luminosity | 0.05±0.02[1] L☉ |
| Temperature | 13,000±1,000[1] K |
| Other designations | |
| KIC 6889235, 2MASS J19531781+4223185, GSC2.3 N2J3000844[6] | |
| Database references | |
| SIMBAD | data |
| KIC | data |
KOI-74 (KIC 6889235[7]) is an eclipsing binary star in the constellation of Cygnus. The primary star is an A-type main-sequence star with a temperature of 9,400 K (9,130 °C; 16,460 °F). It lies in the field of view of the Kepler Mission and was determined to have a companion object in orbit around it which is smaller and hotter than the main star.[8]
KOI-74b
[edit]KOI-74b is a hot compact object orbiting KOI-74. It was discovered in 2010 by the Kepler Mission and came to attention because of its small size (its radius is only 4.3% of the solar radius) and high temperature of 13,000 K (12,700 °C; 22,900 °F).[8] The orbit of KOI-74b around the main star takes 5.18875 days to complete. Analysis of relativistic boosting of light in the Kepler data indicates that it is likely to be a low mass white dwarf of approximately 0.22 solar masses, resulting from an earlier phase of mass transfer in a binary system when the object underwent its giant phase.[1]
See also
[edit]- KOI-81, a similar system also discovered by the Kepler Mission.
- Kepler Object of Interest, stars observed to have transits by the Kepler Mission
References
[edit]- ^ a b c d e f g h i j k l van Kerkwijk, Marten H.; Rappaport, Saul A.; Breton, René P.; Justham, Stephen; Podsiadlowski, Philipp; Han, Zhanwen (2010). "Observations of Doppler Boosting in Kepler Light Curves". The Astrophysical Journal. 715 (1): 51–58. arXiv:1001.4539. Bibcode:2010ApJ...715...51V. doi:10.1088/0004-637X/715/1/51. S2CID 15893663.
- ^ Roman, Nancy G. (1987). "Identification of a constellation from a position". Publications of the Astronomical Society of the Pacific. 99 (617): 695. Bibcode:1987PASP...99..695R. doi:10.1086/132034. Constellation record for this object at VizieR.
- ^ a b c d e Vallenari, A.; et al. (Gaia collaboration) (2023). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy and Astrophysics. 674: A1. arXiv:2208.00211. Bibcode:2023A&A...674A...1G. doi:10.1051/0004-6361/202243940. S2CID 244398875. Gaia DR3 record for this source at VizieR.
- ^ a b "GSC2.3 N2J3000844". Guide Star Catalog 2.3. 2008. Retrieved 2010-06-19.
- ^ Zhang, Li-yun; Su, Tianhao; Misra, Prabhakar; Han, Xianming L.; Meng, Gang; Pi, Qingfeng; Yang, Jiawei (2023). "Stellar Parameters and Spectroscopic Properties of TESS Objects Observed in the LAMOST Low- and Medium-resolution Spectral Survey". The Astrophysical Journal Supplement Series. 264 (1): 17. Bibcode:2023ApJS..264...17Z. doi:10.3847/1538-4365/ac9b28.
- ^ "KOI-74". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2010-06-19.
- ^ "6889235".
- ^ a b Rowe, Jason F.; Borucki, William J.; Koch, David; Howell, Steve B.; Basri, Gibor; Batalha, Natalie; Brown, Timothy M.; Caldwell, Douglas; Cochran, William D.; Dunham, Edward; Dupree, Andrea K.; Fortney, Jonathan J.; Gautier, Thomas N.; Gilliland, Ronald L.; Jenkins, Jon; Latham, David W.; Lissauer, Jack J.; Marcy, Geoff; Monet, David G.; Sasselov, Dimitar; Welsh, William F. (2010). "Kepler Observations of Transiting Hot Compact Objects". The Astrophysical Journal Letters. 713 (2): L150 – L154. arXiv:1001.3420. Bibcode:2010ApJ...713L.150R. doi:10.1088/2041-8205/713/2/L150. S2CID 118578253.
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