HD 28527

HD 28527 is a star in the constellation Taurus, and a member of the Hyades open cluster.^[8] It is faintly visible to the naked eye with an apparent visual magnitude of 4.78.^[1] The distance to this star, as determined from its parallax shift of 22 mas, is 147 light years. It is moving away from the Earth with a heliocentric radial velocity of +38 km/s.^[1]

HD 28527

Observation data Epoch J2000      Equinox J2000
Constellation	Taurus[1]
Right ascension	04h 30m 33.633s[2]
Declination	+16° 11′ 38.45″[2]
Apparent magnitude (V)	4.78[1]
Characteristics
Spectral type	A6 IV[3] or A7 V[4]
B−V color index	+0.170±0.001[1]
Variable type	suspected δ Sct[5]
Astrometry
Radial velocity (Rv)	+38.1±0.8[1] km/s
Proper motion (μ)	RA: +104.889[2] mas/yr Dec.: −25.446[2] mas/yr
Parallax (π)	22.1875±0.1430 mas[2]
Distance	147.0 ± 0.9 ly (45.1 ± 0.3 pc)
Absolute magnitude (MV)	+1.58[6]
Details
Mass	1.75[7] M☉
Radius	2.209[8] R☉
Luminosity	19.03[1] L☉
Surface gravity (log g)	4.17±0.14[7] cgs
Temperature	8,274±281[7] K
Metallicity [Fe/H]	+0.30[9] dex
Rotation	1.278 d[8]
Rotational velocity (v sin i)	87.5[8] km/s
Age	307[7] Myr
Other designations
NSV 1627, BD+15°637, GJ 170.1, GJ 9157, HD 28527, HIP 21029, HR 1427, SAO 93975[10]
Database references
SIMBAD	data

Hyades cluster, with HD 28527 (marked with a green arrow) just NE of the θ Tauri pair

Based upon a stellar classification of A6 IV by Cowley et al. (1969),^[3] this is an A-type subgiant star that has consumed the hydrogen at its core and is evolving away from the main sequence. Older studies had it classed as an A-type main-sequence star with a class of A7 V.^[4] At the age of 307^[7] million years, it has a high rate of spin, revolving upon its axis once every 1.278 days.^[8] It is a Delta Scuti variable^[5] with 1.75^[7] times the mass of the Sun and 2.2^[8] times the Sun's radius. The star is radiating 19^[1] times the Sun's luminosity from its photosphere at an effective temperature of 8,274 K.^[7]

Due to its location near the ecliptic, this star is subject to lunar occultations. These events have provided occasional, but not definitive, evidence of a close secondary companion.^[11][12] Eggleton and Tokovinin (2008) catalogue this as a possible triple star system, having the inner pair being similar stars with an angular separation of 0.02″, and the outer component a magnitude 6.7 star of class F2 at a much wider separation of 250″.^[13] The wide companion is HD 28458, another member of the Hyades.^[10]

See also

• Taurus (Chinese astronomy)
• List of stars in Taurus