Pi Mensae

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Pi Mensae
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Mensa
Right ascension 05h 37m 09.89s [1]
Declination –80° 28′ 08.8″ [1]
Apparent magnitude (V) +5.67
Characteristics
Spectral type G1IV
U−B color index 0.11
B−V color index 0.60
V−R color index 0.31
R−I color index 0.29
Variable type none
Astrometry
Radial velocity (Rv) +9.4 km/s
Proper motion (μ) RA: 312.01 ± 0.24 [1] mas/yr
Dec.: 1050.38 ± 0.26 [1] mas/yr
Parallax (π) 54.60 ± 0.21[1] mas
Distance 59.7 ± 0.2 ly
(18.32 ± 0.07 pc)
Absolute magnitude (MV) +4.37
Details
Mass 1.1 M
Radius 2.1 ± 0.6 R
Luminosity 4.73 L
Surface gravity (log g) 3.33 cgs
Temperature 5888 K
Metallicity 0.09 (123%)
Rotation ?
Age 3.83 × 109 years
Other designations
CD-80°195, CP(D)-80°161, LTT 2359, LFT 429, LHS 208, HR 2022, HD 39091, HIP 26394, SAO 258421, GJ 9189.

Pi Mensae (π Men) is a yellow subgiant star in the constellation of Mensa. This star has a high proper motion. The apparent magnitude is 5.67, which can be visible to the naked eye in exceptionally dark, clear skies. It is nearly 60 ly away. The star dwarfs the Sun in terms of mass, size, luminosity, temperature, and metallicity and is about 730 million years younger. It ranks 100th on the list of top 100 target stars for the planned Terrestrial Planet Finder mission to search for Earth-like planets.

Planetary system[edit]

On October 15, 2001, an extrasolar planet was found orbiting the star.[2] It is one of the most massive planets ever discovered. It has a very eccentric orbit that takes approximately 2151 days (5.89 years). Because of its eccentricity, and being a massive superjovian that passes through the habitable zone, it would have disrupted the orbits of any Earth-like planets, and possibly thrown them into the star, or out into the interstellar medium.

The Pi Mensae planetary system[3]
Companion
(in order from star)
Mass Semimajor axis
(AU)
Orbital period
(days)
Eccentricity Inclination Radius
b ≥10.27 ± 0.84 MJ 3.38 ± 0.22 2151 ± 85 0.6405 ± 0.0072

See also[edit]

References[edit]

External links[edit]

Coordinates: Sky map 05h 37m 09.89s, −80° 28′ 08.84″