Astronomy:KOI-74
| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| Constellation | Cygnus |
| Right ascension | 19h 53m 17.811s[2] |
| Declination | +42° 23′ 18.52″[2] |
| Apparent magnitude (V) | 10.715[3] |
| Characteristics | |
| Spectral type | A1V[1] |
| B−V color index | 0.154[3] |
| Details | |
| 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 | 9400 ± 150[1] K |
| Other designations | |
KIC 6889235, 2MASS J19531781+4223185, GSC2.3 N2J3000844 | |
| Database references | |
| SIMBAD | data |
| KIC | data |
KOI-74 (KIC 6889235) 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.[4]
KOI-74b
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).[4] 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
- 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
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 1.6 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. doi:10.1088/0004-637X/715/1/51. Bibcode: 2010ApJ...715...51V.
- ↑ 2.0 2.1 "KOI-74". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=KOI-74.
- ↑ 3.0 3.1 "GSC2.3 N2J3000844". Guide Star Catalog 2.3. 2008. http://gsss.stsci.edu/webservices/GSC2/GSC2DataReturn.aspx?RAH=&RAM=&RAS=&DSN=+&DD=&DM=&DS=&EQ=2000&SIZE=&SRCH=Radius&FORMAT=HTML&CAT=GSC23&HSTID=N2J3000844&GSC1ID=&RA=&DEC=&R1=&R2=&M1=&M2=&N=&CL=.
- ↑ 4.0 4.1 Rowe, Jason F.; Borucki, William J.; Koch, David; Howell, Steve B.; Basri, Gibor; Batalha, Natalie; Brown, Timothy M.; Caldwell, Douglas et al. (2010). "Kepler Observations of Transiting Hot Compact Objects". The Astrophysical Journal Letters 713 (2): L150–L154. doi:10.1088/2041-8205/713/2/L150. Bibcode: 2010ApJ...713L.150R.
Coordinates: 
19h 53m 17.81s, +42° 23′ 18.5″
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