HD 77887
Star in the constellation Volans
From Wikipedia, the free encyclopedia
HD 77887 (HR 3610) is a solitary star located in the southern circumpolar constellation Volans. It has an apparent magnitude of 5.87,[3] making it faintly visible to the naked eye if viewed under ideal conditions. The star is situated at a distance of about 760 light years[2] but is receding with a heliocentric radial velocity of 12.6 km/s.[8]
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Volans |
| Right ascension | 09h 01m 08.5140s[2] |
| Declination | −68° 41′ 02.1096″[2] |
| Apparent magnitude (V) | 5.87±0.01[3] |
| Characteristics | |
| Evolutionary stage | AGB[4] |
| Spectral type | M1 III[5] |
| U−B color index | +1.96[6] |
| B−V color index | +1.63[6] |
| Variable type | Lb[7] |
| Astrometry | |
| Radial velocity (Rv) | 12.6±0.4[8] km/s |
| Proper motion (μ) | RA: +16.413[2] mas/yr Dec.: −0.069[2] mas/yr |
| Parallax (π) | 4.2938±0.051 mas[2] |
| Distance | 760 ± 9 ly (233 ± 3 pc) |
| Absolute magnitude (MV) | −0.78[9] |
| Details[10] | |
| Mass | 1.12[11] M☉ |
| Radius | 56.73 R☉ |
| Luminosity | 598 L☉ |
| Surface gravity (log g) | 0.9 cgs |
| Temperature | 3,820 K |
| Other designations | |
| 45 G. Volantis, NSV 18118, CPD−68°879, GC 12510, HD 77887, HIP 44283, HR 3610, SAO 250421 | |
| Database references | |
| SIMBAD | data |
HD 77887 is an ageing M-type giant[5] that is currently on the asymptotic giant branch.[4] At present it has 1.12 times the mass of the Sun[11] but has expanded to 56.73 times its girth.[10] It shines at 598 L☉ from its enlarged photosphere at an effective temperature of 3,820 K,[10] which gives it a red glow. HD 77887 is suspected to be a slow irregular variable[7] whose brightness fluctuates at a tenth of a magnitude.[12] Koen and Eyer examined the Hipparcos data for the star, and found that it varied periodically, with an amplitude of 0.012 magnitudes, and a period of 4.4649 days.[13]