![cover image](https://wikiwandv2-19431.kxcdn.com/_next/image?url=https://upload.wikimedia.org/wikipedia/commons/thumb/8/86/Hydra_constellation_map.svg/640px-Hydra_constellation_map.svg.png&w=640&q=50)
Alphard
Star in the constellation Hydra / From Wikipedia, the free encyclopedia
Dear Wikiwand AI, let's keep it short by simply answering these key questions:
Can you list the top facts and stats about Alpha Hydrae?
Summarize this article for a 10 year old
SHOW ALL QUESTIONS
This article is about the star. For the programming language, see Alphard (programming language). For the vehicle, see Toyota Alphard.
Alphard /ˈælfɑːrd/,[10] designated Alpha Hydrae (α Hydrae, abbreviated Alpha Hya, α Hya), is the brightest star in the constellation of Hydra. It is a single giant star, cooler than the Sun but larger and more luminous. It is about 177 light-years away.
Quick Facts Observation data Epoch J2000 Equinox J2000, Constellation ...
Observation data Epoch J2000 Equinox J2000 | |
---|---|
Constellation | Hydra |
Right ascension | 09h 27m 35.2433s[1] |
Declination | −08° 39′ 30.969″[1] |
Apparent magnitude (V) | +2.00[2] |
Characteristics | |
Evolutionary stage | Giant star |
Spectral type | K3IIIa[3] |
U−B color index | +1.73[4] |
B−V color index | +1.45[3] |
Astrometry | |
Radial velocity (Rv) | −4.3[5] km/s |
Proper motion (μ) | RA: −14.49[1] mas/yr Dec.: 33.25[1] mas/yr |
Parallax (π) | 18.40 ± 0.78 mas[1] |
Distance | 177 ± 8 ly (54 ± 2 pc) |
Absolute magnitude (MV) | −1.743±0.032[3] |
Details | |
Mass | 3.2±0.32[3] M☉ |
Radius | 55.9±2.4[6] R☉ |
Luminosity | 971±21[3] L☉ |
Luminosity (visual, LV) | 426[3][lower-alpha 1] L☉ |
Surface gravity (log g) | 1.77[6] cgs |
Temperature | 4117±18[3] K |
Metallicity [Fe/H] | −0.12[6] dex |
Rotation | 2,991 days[7] |
Rotational velocity (v sin i) | 1.1[7] km/s |
Age | 420±160[8] Myr |
Other designations | |
Database references | |
SIMBAD | data |
Close