Location of α Indus (circled) |
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Observation data Epoch J2000 Equinox J2000 |
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Constellation | Indus |
Right ascension | 20h 37m 34.03201s[1] |
Declination | –47° 17′ 29.4026″[1] |
Apparent magnitude (V) | 3.11[2] |
Astrometry | |
Radial velocity (Rv) | -1.3[3] km/s |
Proper motion (μ) | RA: +49.24[1] mas/yr Dec.: +66.53[1] mas/yr |
Parallax (π) | 33.17 ± 0.18[1] mas |
Distance | 98.3 ± 0.5 ly (30.1 ± 0.2 pc) |
Absolute magnitude (MV) | 0.65[4] |
Characteristics | |
Spectral type | K0 III-IV[5] |
U−B color index | +0.79[2] |
B−V color index | +1.00[2] |
Details | |
Mass | 2.0[4] M☉ |
Radius | 12[6] R☉ |
Surface gravity (log g) | 3.00[7] |
Temperature | 4,893[7] K |
Metallicity [Fe/H] | +0.03[7] dex |
Age | 1[4] Gyr |
Other designations | |
Database references | |
SIMBAD | data |
Alpha Indi (α Ind, α Indi) is a third magnitude giant star in the constellation Indus, located about 98 light years from the Earth.[1] The stellar classification of this star is K0 III-IV,[5] so it has exhausted the hydrogen at its core and evolved away from the main sequence. It has about double the mass of the Sun and is an estimated billion years old.[4] As a giant star it has expanded to about 12 times the radius of the Sun.[6] The effective temperature of the photosphere is 4,893 K,[7] giving it the characteristic orange hue of a K-type star. It may have two nearby M-type companion stars, which are located at least 2,000 Astronomical Units from the primary.[9]
In China, this star is called Pe Sze where it also was known as the Persian, a title from the Jesuit missionaries.[10] The term Pe Sze is from the name of asterism 波斯 (Bō Sī, English: Persia). In Chinese astronomy, consequently, α Indi itself is known as 波斯二 (Bō Sī èr, English: the Second Star of Persia)[11]
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