HD 77887

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]

HD 77887

A light curve for HD 77887, plotted from Hipparcos data[1]
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]