Hamal

Hamal
	Location of α Arietis (circled)
Observation data; Epoch J2000.0 Equinox J2000.0 (ICRS)
Constellation	Aries
Right ascension	02h 07m 10.40570s
Declination	+23° 27′ 44.7032″
Apparent magnitude (V)	2.00
Characteristics
Evolutionary stage	Red giant branch
Spectral type	K1IIIb
U−B color index	+1.13
B−V color index	+1.15
V−R color index	+0.7
R−I color index	+0.62
Variable type	Suspected
Astrometry
Radial velocity (Rv)	−14.2 ± 0.9 km/s
Proper motion (μ)	RA: +188.55 mas/yr ; Dec.: −148.08 mas/yr
Parallax (π)	49.56 ± 0.25 mas
Distance	65.8 ± 0.3 ly ; (20.2 ± 0.1 pc)
Absolute magnitude (MV)	+0.47 ± 0.04
Details
Mass	1.5±0.2 M☉
Radius	15.19±0.1 R☉
Luminosity	76.2±0.8 L☉
Surface gravity (log g)	2.3 cgs
Temperature	4,411 K
Metallicity [Fe/H]	−0.214 dex
Rotational velocity (v sin i)	3.44 km/s
Age	3.4 ± 1.9 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
Database references
SIMBAD	data

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]

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^ ^a ^b ^c ^d Cite error: The named reference clpl4_99 was invoked but never defined (see the help page).
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^ ^a ^b ^c Cite error: The named reference bsc2 was invoked but never defined (see the help page).
^ Cite error: The named reference nsv1 was invoked but never defined (see the help page).
^ Cite error: The named reference rgcrv was invoked but never defined (see the help page).
^ Cite error: The named reference aj135_3_892 was invoked but never defined (see the help page).
^ ^a ^b ^c Cite error: The named reference aaa529_A134 was invoked but never defined (see the help page).
^ ^a ^b Cite error: The named reference npoi was invoked but never defined (see the help page).
^ ^a ^b ^c Cite error: The named reference gray2019 was invoked but never defined (see the help page).
^ Cite error: The named reference Bonfanti2015 was invoked but never defined (see the help page).
^ 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.
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[aaa474_2_653-1] ^ ^a ^b ^c ^d ^e ^f Cite error: The named reference aaa474_2_653 was invoked but never defined (see the help page).

[clpl4_99-2] Cite error: The named reference clpl4_99 was invoked but never defined (see the help page).

[sb0-3] Cite error: The named reference sb0 was invoked but never defined (see the help page).

[bsc2-4] Cite error: The named reference bsc2 was invoked but never defined (see the help page).

[nsv1-5] Cite error: The named reference nsv1 was invoked but never defined (see the help page).

[rgcrv-6] Cite error: The named reference rgcrv was invoked but never defined (see the help page).

[aj135_3_892-7] Cite error: The named reference aj135_3_892 was invoked but never defined (see the help page).

[aaa529_A134-8] Cite error: The named reference aaa529_A134 was invoked but never defined (see the help page).

[npoi-9] Cite error: The named reference npoi was invoked but never defined (see the help page).

[gray2019-10] Cite error: The named reference gray2019 was invoked but never defined (see the help page).

[Bonfanti2015-11] Cite error: The named reference Bonfanti2015 was invoked but never defined (see the help page).

[Kunitzsch-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.

[kaler-13] Cite error: The named reference kaler was invoked but never defined (see the help page).

[aaa323_L49-14] Cite error: The named reference aaa323_L49 was invoked but never defined (see the help page).

[GSM-15] Cite error: The named reference GSM was invoked but never defined (see the help page).

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Observation data Epoch J2000.0 Equinox J2000.0 (ICRS)
Location of α Arietis (circled)
Constellation	Aries
Right ascension	02^h 07^m 10.40570^s^[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 (R_v)	−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]
Distance	65.8 ± 0.3 ly (20.2 ± 0.1 pc)
Absolute magnitude (M_V)	+0.47 ± 0.04^[7]

Details

Mass	1.5±0.2^[8] `M`_☉
Radius	15.19±0.1^[9] `R`_☉
Luminosity	76.2±0.8^[9] `L`_☉
Surface gravity (log g)	2.3^[10] cgs
Temperature	4,411^[10] K
Metallicity [Fe/H]	−0.214^[10] dex
Rotational velocity (v sin i)	3.44^[8] km/s
Age	3.4 ± 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
SIMBAD	data