Astronomy:Alpha Indi
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| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| 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] cgs |
| Temperature | 4,893[7] K |
| Metallicity [Fe/H] | +0.03[7] dex |
| Age | 1[4] Gyr |
| Other designations | |
HD 196171, HR 7869, SAO 230300, FK5 769, CD −47 13477, HIP 101772.[8] | |
| 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.[9] It may have two nearby M-type companion stars, which are located at least 2,000 AU from the primary.[10]
In China, this star is called Pe Sze where it also was known as the Persian, a title from the Jesuit missionaries.[11] 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)[12]
References
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 van Leeuwen, F. (November 2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics 474 (2): 653–664. doi:10.1051/0004-6361:20078357. Bibcode: 2007A&A...474..653V.
- ↑ 2.0 2.1 2.2 Johnson, H. L. et al. (1966), "UBVRIJKL photometry of the bright stars", Communications of the Lunar and Planetary Laboratory 4 (99): 99, Bibcode: 1966CoLPL...4...99J
- ↑ Evans, D. S. (June 20–24, 1966), "The revision of the general catalogue of radial velocities", in Batten, Alan Henry; Heard, John Frederick, Determination of Radial Velocities and their Applications, Proceedings from IAU Symposium no. 30, 30, University of Toronto: International Astronomical Union, pp. 57, Bibcode: 1967IAUS...30...57E
- ↑ 4.0 4.1 4.2 4.3 Thorén, P.; Edvardsson, B.; Gustafsson, B. (October 2004), "Subgiants as probes of galactic chemical evolution", Astronomy and Astrophysics 425: 187–206, doi:10.1051/0004-6361:20040421, Bibcode: 2004A&A...425..187T
- ↑ 5.0 5.1 Gray, R. O. et al. (July 2006), "Contributions to the Nearby Stars (NStars) Project: Spectroscopy of Stars Earlier than M0 within 40 parsecs: The Northern Sample I", The Astronomical Journal 132 (1): 161–170, doi:10.1086/504637, Bibcode: 2006AJ....132..161G
- ↑ 6.0 6.1 Pasinetti Fracassini, L. E. et al. (February 2001), "Catalogue of Apparent Diameters and Absolute Radii of Stars (CADARS) - Third edition - Comments and statistics", Astronomy and Astrophysics 367 (2): 521–524, doi:10.1051/0004-6361:20000451, Bibcode: 2001A&A...367..521P
- ↑ 7.0 7.1 7.2 7.3 Gratton, R. G.; Ortolani, S. (November 1986), "The forbidden O/Fe ratio in metal-poor late-type stars", Astronomy and Astrophysics 169 (1–2): 201–207, Bibcode: 1986A&A...169..201G
- ↑ "alf Ind -- Star in double system", SIMBAD (Centre de Données astronomiques de Strasbourg), http://simbad.u-strasbg.fr/simbad/sim-id?Ident=Alpha+Indi, retrieved 2011-12-12
- ↑ "The Colour of Stars", Australia Telescope, Outreach and Education (Commonwealth Scientific and Industrial Research Organisation), December 21, 2004, archived from the original on March 18, 2012, https://web.archive.org/web/20120318151427/http://outreach.atnf.csiro.au/education/senior/astrophysics/photometry_colour.html, retrieved 2012-01-16
- ↑ Kaler, James B., "THE PERSIAN (Alpha Indi)", Stars (University of Illinois), http://stars.astro.illinois.edu/sow/persian.html, retrieved 2011-12-23
- ↑ Star Name - R.H.Allen p. 246
- ↑ (in Chinese) AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 7 月 30 日)
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