Hamal

This article is about the star. For other uses, see Hamal (disambiguation).
Hamal
Location of α Arietis (circled)
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Aries
Right ascension 02h 07m 10.40570s[1]
Declination +23° 27′ 44.7032″[1]
Apparent magnitude (V) 2.00[2]
Characteristics
Evolutionary stage Red giant branch
Spectral type K1IIIb
U−B color index +1.13[2]
B−V color index +1.15[2]
V−R color index +0.7[3]
R−I color index +0.62[4]
Variable type Suspected[5]
Astrometry
Radial velocity (Rv)−14.2 ± 0.9[6] km/s
Proper motion (μ) RA: +188.55[1] mas/yr
Dec.: −148.08[1] mas/yr
Parallax (π)49.56 ± 0.25 mas[1]
Distance65.8 ± 0.3 ly
(20.2 ± 0.1 pc)
Absolute magnitude (MV)+0.47 ± 0.04[7]
Details
Mass1.5±0.2[8] M☉
Radius15.19±0.1[9] R☉
Luminosity76.2±0.8[9] L☉
Surface gravity (log g)2.3[10] cgs
Temperature4,553±15[8] K
Metallicity [Fe/H]−0.214[10] dex
Rotational velocity (v sin i)3.44[8] km/s
Age3.4 ± 1.9[11] Gyr
Other designations
Hemal, Hamal, Ras Hammel, El Nath, Arietis, α Ari, Alpha Arietis, Alpha Ari, 13 Arietis, 13 Ari, BD+22 306, FK5 74, GC 2538, GJ 84.3, GJ 9072, HD 12929, HIP 9884, HR 617, LTT 10711, NLTT 7032, PPM 91373, SAO 75151[3][4]
Database references
SIMBADdata

Hamal /ˈhæməl/,[12] designated Alpha Arietis (α Arietis, abbreviated Alpha Ari, α Ari), is the brightest star in the northern zodiacal constellation of Aries.[4][13]

With an apparent visual magnitude of 2.0,[2] it is the mean 50th-brightest star in the night sky. Based upon parallax measurements made with the Hipparcos astrometry satellite,[14][15] Hamal is about 65.8 light-years (20.2 parsecs) from Earth.[1] It is a giant star that may host an orbiting planet with a mass greater than Jupiter.[8]

  1. ^ a b c d e f Cite error: The named reference aaa474_2_653 was invoked but never defined (see the help page).
  2. ^ a b c d Cite error: The named reference clpl4_99 was invoked but never defined (see the help page).
  3. ^ a b Cite error: The named reference sb0 was invoked but never defined (see the help page).
  4. ^ a b c Cite error: The named reference bsc2 was invoked but never defined (see the help page).
  5. ^ Cite error: The named reference nsv1 was invoked but never defined (see the help page).
  6. ^ Cite error: The named reference rgcrv was invoked but never defined (see the help page).
  7. ^ Cite error: The named reference aj135_3_892 was invoked but never defined (see the help page).
  8. ^ a b c d Cite error: The named reference aaa529_A134 was invoked but never defined (see the help page).
  9. ^ a b Cite error: The named reference npoi was invoked but never defined (see the help page).
  10. ^ a b Cite error: The named reference gray2019 was invoked but never defined (see the help page).
  11. ^ Cite error: The named reference Bonfanti2015 was invoked but never defined (see the help page).
  12. ^ Kunitzsch, Paul; Smart, Tim (2006). A Dictionary of Modern star Names: A Short Guide to 254 Star Names and Their Derivations (2nd rev. ed.). Cambridge, Massachusetts: Sky Pub. ISBN 978-1-931559-44-7.
  13. ^ Cite error: The named reference kaler was invoked but never defined (see the help page).
  14. ^ Cite error: The named reference aaa323_L49 was invoked but never defined (see the help page).
  15. ^ Cite error: The named reference GSM was invoked but never defined (see the help page).