α Andromedae

Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Andromeda
Right ascension 00
Declination +29° 05′ 25.555″
Apparent magnitude (V) 2.22 4.21
Characteristics
Spectral type B8IVpMnHg A3V
U-B color index −0.46
B-V color index −0.11
R-I color index −0.10
Astrometry
Radial velocity (Rv) −10.6 ± 0.3km/s
Proper motion:  
RA α cos δ) 135.68 mas/yr
Dec. δ) −162.95 mas/yr
Parallax (π) 33.60 ± 0.73mas
Distance 97 ± 2 ly
(29.8 ± 0.6 pc)
Absolute magnitude (MV) −0.19 ± 0.30 2.00 ± 0.30
Details
Mass 3.60 ± 0.20 M 1.78 ± 0.08 M
Radius 2.7 ± 0.4 R 1.65 ± 0.3 R
Surface gravity (log g) 4.15 ± 0.16 4.28 ± 0.20
Luminosity (bolometric) 240 ± 90 L 13 ± 7 L
Temperature 13800 ± 125 K 8500 ± 250 K
Metallicity [M/H] = 0.2 [M/H] = 0.2
Rotation 2.38195 d
Rotational velocity (v sin i) 52km/s 110 ± 5km/s
Orbit
Period (P) 96.7015 ± 0.0044 days
Semimajor axis (a) 24.0 ± 0.13 mas
Eccentricity (e) 0.535 ± 0.0046
Inclination (i) 105.6 ± 0.23°
Longitude of node (Ω) 284.4 ± 0.21°
Periastron epoch (T) MJD 47374.563 ± 0.095
Argument of periastron (ω)
(secondary)
257.4 ± 0.31°
Database references
SIMBAD data
Other designations
Alpheratz, Sirrah, Sirah, α And, Alpha Andromedae, Alpha And, δ Pegasi, δ Peg, Delta Pegasi, Delta Peg, 21 Andromedae, 21 And, H 5 32A, MKT 11, ADS 94 A, BD+28°4, CCDM J00083+2905A, FK5 1, GC 127, HD 358, HIP 677, HR 15, IDS 00032+2832 A, LTT 10039, NLTT 346, PPM 89441, SAO 73765, WDS 00084+2905A/Aa.

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Alpheratz, which is released under the Creative Commons Attribution-Share-Alike License 3.0