Alpha Mensae, a yellow main-sequence star in Mensa
Alpha Mensae is a yellow main-sequence star in the constellation Mensa. At 33 light years away, it shines at an apparent visual magnitude of 5.08.
Alpha Mensae (HIP 29271)
Alpha Mensae is a yellow main-sequence star in the constellation Mensa. At 33 light years away, it shines at an apparent visual magnitude of 5.08. Alpha Mensae is a component of a multiple-star system. The star's age is estimated to be 5.8 billion years but is certainly no greater than 11 billion years. The iron abundance of Alpha Mensae is +0.1 (125.9% of the Sun). It is moving through the Galaxy at a speed of 38.9 km/s relative to the Sun.
Sky position: RA 6h 10.2m, Dec -74° 45'
Common designations: Alpha Mensae, HIP 29271, HD 43834, Gliese 231
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Brightest stars in Mensa:
(list all)
1
| 5.08
) Alpha Mensae
| Rank | Mag. | Star |
| 2 | 5.18 | Gamma Mensae |
| 3 | 5.30 | Beta Mensae |
| 4 | 5.45 | Theta Mensae |
| 5 | 5.46 | Kappa Mensae |
| 6 | 5.47 | Eta Mensae |
| 7 | 5.53 | Mu Mensae |
| 8 | 5.54 | Epsilon Mensae |
| 9 | 5.61 | Zeta Mensae |
| 10 | 5.65 | Pi Mensae |
| 11 | 5.67 | Delta Mensae |
| 12 | 5.68 | HR 1109 |
| 13 | 5.78 | Nu Mensae |
| 14 | 5.79 | HD 37993 |
| 15 | 5.84 | Xi Mensae |
| 16 | 6.04 | Iota Mensae |
| 17 | 6.05 | HR 1531 |
Galactic Orbit of Alpha Mensae
(compared to the Sun)
E
ccentricity: 21.2% vs. 16.0%Angle φ : 136.7°vs. 26.0°
Semi-major axis : 6,550 pc vs. 8,686 pc
Semi-minor axis: 6,401 pc vs. 8,574 pc
Focus-to-center
: 1,390 pcvs. 1,388 pcSemilatus rectum : 6,255 pc vs. 8,464 pc
Perigalacticon: 5,160 pc vs. 7,297 pc
Apogalacticon
: 7,941 pcvs. 10,074 pcSome Tabulated XHIP Data for Alpha Mensae
(see also: SIMBAD)
Astrometry
2007A&A...474..653V
| Position | Proper Motion | |
| Right Ascension: | 92.55918066° ±0.13 mas | 121.81 ±0.14 mas/yr. |
| Declination: | -74.75252786° ±0.14 mas | -212.36 ±0.16 mas/yr. |
| Galactic Longitude: | 285.75763338° | 207.53 mas/yr. |
| Galactic Latitude: | -28.80196512° | 129.86 mas/yr. |
Parallax: 98.06 ± 0.14 mas
Spectrography
Spectral Type: G7V 2006AJ....132..161G.
Radial Velocity: 37.10 ±1.04 km/s [A rating] 2005ApJS..159..141V.
Iron Abundance [Fe/H]:
0.10 ±0.01 dex
2011A&A...530A.138C, 2007A&A...465..271R, 2006MNRAS.370..163B, 2005ApJS..161..444T, 2005ApJS..159..141V, 2004A&A...420..183A, 2004A&A...415.1153S, 2003A&A...410..527B, 2001A&A...373.1019S, 1994A&A...287..191P.
Photometry
| band | magnitude | Abs. Mag. |
| U | ||
| B | 5.79 | 5.75 |
| V | 5.08 | 5.04 |
| R | ||
| I | 4.40 | 4.36 |
| J | 3.95 | 3.91 |
| H | 3.51 | 3.47 |
| K | 3.45 | 3.40 |
B-V: +0.71 V-I: +0.68
Derivations
Heliocentric distance: 10.20 pc (0.1% margin of error)
Galactocentric distance: 7,398 pc
Transverse velocity: 11.8 km/s
3D heliocentric position and motion:
|
toward: |
Galactic center | Galactic rotation | North Galactic Pole |
| Position ( X, Y, Z) | 2.4 pc | -8.6 pc | -4.9 pc |
| Velocity (U, V, W) | 19.3 km/s | -31.5 km/s | -12.4 km/s |