CY Boötis
Star in the constellation Boötes
From Wikipedia, the free encyclopedia
CY Boötis (Flamsteed: 101 Virginis) is a red giant variable star in the Boötes constellation, currently on the asymptotic giant branch.[4] Its apparent magnitude ranges from 5.74 to 5.9, making it faintly visible to the naked eye under good observing conditions. It was originally catalogued as 101 Virginis by Flamsteed due to an error in the position.[9][10] John R. Percy found it to be "marginally variable" in 1993.[11] When it was confirmed as a variable star, it was actually within the border of the constellation Boötes and given its name.[12]
 | |
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Boötes[1] |
| Right ascension | 14h 17m 28.4519s[2] |
| Declination | +15° 15′ 48.167″[2] |
| Apparent magnitude (V) | 5.74 - 5.90[3] |
| Characteristics | |
| Evolutionary stage | AGB[4] |
| Spectral type | M3IIIa[1] |
| B−V color index | 1.678[1] |
| Variable type | SRb[3] |
| Astrometry | |
| Radial velocity (Rv) | −11.30[5] km/s |
| Proper motion (μ) | RA: 14.27[2] mas/yr Dec.: 8.80[2] mas/yr |
| Parallax (π) | 3.3735±0.1766 mas[6] |
| Distance | 970 ± 50 ly (300 ± 20 pc) |
| Absolute magnitude (MV) | −0.98[1] |
| Details | |
| Mass | 1.2[7] M☉ |
| Radius | 76.78[6] R☉ |
| Luminosity | 1,078[8] L☉ |
| Surface gravity (log g) | 1.35[7] cgs |
| Temperature | 3,682[8] K |
| Metallicity | −0.31[7] |
| Other designations | |
| 101 Vir, CY Boötis, NSV 6613, AG+15°1445, BD+15°2690, GC 19284, HD 125180, HIP 69829, HR 5352, SAO 100956, PPM 130465, TYC 1469-1456-1, GCRV 8358, GSC 01469-01456, IRAS 14150+1529, 2MASS J14172843+1515478 | |
| Database references | |
| SIMBAD | data |
| Data sources: | |
| Hipparcos Catalogue, Bright Star Catalogue (5th rev. ed.) | |
The variability is not strongly defined but a primary period of 23 days and a secondary period of 340 days have been reported.[13]
CY Boo is listed in the Hipparcos catalogue as a "problem binary", a star which was suspected of being multiple but for which the Hipparcos observations did not give a satisfactory solution. Further observations have always shown it to be single.[14]