Mu2 Scorpii
Mu² Scorpii (μ² Scorpii, abbreviated Mu² Sco, μ² Sco), also named Pipirima /pɪˈpɪrɪmə/,[11] is a star in the zodiac constellation of Scorpius. It has an apparent visual magnitude of +3.56,[2] which is bright enough to be seen with the naked eye. Its distance from the Sun is about 474 light-years, as determined by parallax measurements.[1] It is a member of the Upper Centaurus-Lupus subgroup of the Scorpius–Centaurus Association.[12]
Observation data Epoch J2000 Equinox J2000 | |
---|---|
Constellation | Scorpius |
Right ascension | 16h 52m 20.14532s[1] |
Declination | −38° 01′ 03.1258″[1] |
Apparent magnitude (V) | +3.56[2] |
Characteristics | |
Spectral type | B2 IV[3] |
U−B color index | −0.878[2] |
B−V color index | −0.219[2] |
Astrometry | |
Radial velocity (Rv) | +1.4[4] km/s |
Proper motion (μ) | RA: −11.09[1] mas/yr Dec.: −23.32[1] mas/yr |
Parallax (π) | 6.88 ± 0.12[1] mas |
Distance | 474 ± 8 ly (145 ± 3 pc) |
Absolute magnitude (MV) | −2.25[5] |
Details | |
Mass | 8.7±0.2[6] M☉ |
Radius | 7.0[7] R☉ |
Luminosity | 2,385[8] L☉ |
Temperature | 23,113[7] K |
Rotational velocity (v sin i) | 58[9] km/s |
Age | 18.5±3.2[6] Myr |
Other designations | |
Database references | |
SIMBAD | data |
Properties
This is a blue-white, B-type subgiant star with a stellar classification of B2 IV.[3] It has an estimated 7 times the radius of the Sun, almost 9 times the Sun's mass,[6] and shines with 2,385 times the Sun's luminosity.[8] The outer atmosphere has an effective temperature of 23,113 K.[7] It is some 18.5[6] million years old and is spinning with a projected rotational velocity of 58 km/s.[9]
Nomenclature
μ² Scorpii (Latinised to Mu² Scorpii) is the star's Bayer designation.
In Tahiti, a traditional story is told of a brother and sister, named Pipiri and Rehua, who flee their parents into the sky and become stars. Their parents call them Pipiri ma while chasing them into the sky: ma "with, and" is used after names to mean "et al."[13][14] In one account, the children become Shaula and Lesath in the tip of the tail of Scorpio,[13] and in another they become Mu² and Mu¹ Scorpii. (In a similar version of the story told in the Cook Islands, they become Omega¹ and Omega² Scorpii).[13]
In 2016, the IAU organized a Working Group on Star Names (WGSN)[15] to catalog and standardize proper names for stars. The WGSN approved the name Pipirima for this star on 5 September 2017 (along with Xamidimura for its partner) and it is now so included in the List of IAU-approved Star Names.[11]
In Chinese astronomy, Mu² Scorpii is called 尾宿增二.[16]
References
- van Leeuwen, F. (November 2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics, 474 (2): 653–664, arXiv:0708.1752, Bibcode:2007A&A...474..653V, doi:10.1051/0004-6361:20078357.
- Gutierrez-Moreno, Adelina; Moreno, Hugo (June 1968), "A photometric investigation of the Scorpio-Centaurus association", Astrophysical Journal Supplement, 15: 459, Bibcode:1968ApJS...15..459G, doi:10.1086/190168.
- Hiltner, W. A.; et al. (July 1969), "MK Spectral Types for Bright Southern OB Stars", The Astrophysical Journal, 157: 313, Bibcode:1969ApJ...157..313H, doi:10.1086/150069.
- Evans, D. S. (June 20–24, 1966), Batten, Alan Henry; Heard, John Frederick (eds.), "The Revision of the General Catalogue of Radial Velocities", Determination of Radial Velocities and their Applications, Proceedings from IAU Symposium no. 30, University of Toronto: International Astronomical Union, Bibcode:1967IAUS...30...57E.
- Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters, 38 (5): 331, arXiv:1108.4971, Bibcode:2012AstL...38..331A, doi:10.1134/S1063773712050015.
- Tetzlaff, N.; et al. (2011), "A catalogue of young runaway Hipparcos stars within 3 kpc from the Sun", Monthly Notices of the Royal Astronomical Society, 410: 190–200, arXiv:1007.4883, Bibcode:2011MNRAS.410..190T, doi:10.1111/j.1365-2966.2010.17434.x.
- Underhill, A. B.; et al. (November 1979), "Effective temperatures, angular diameters, distances and linear radii for 160 O and B stars", Monthly Notices of the Royal Astronomical Society, 189: 601–605, Bibcode:1979MNRAS.189..601U, doi:10.1093/mnras/189.3.601.
- McDonald, I.; et al. (2012), "Fundamental Parameters and Infrared Excesses of Hipparcos Stars", Monthly Notices of the Royal Astronomical Society, 427 (1): 343–57, arXiv:1208.2037, Bibcode:2012MNRAS.427..343M, doi:10.1111/j.1365-2966.2012.21873.x.
- Uesugi, Akira; Fukuda, Ichiro (1970), "Catalogue of rotational velocities of the stars", Contributions from the Institute of Astrophysics and Kwasan Observatory, University of Kyoto, Bibcode:1970crvs.book.....U.
- "mu.02 Sco". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2016-09-20.
- "Naming Stars". IAU.org. Retrieved 16 December 2017.
- Bobylev, V. V.; Bajkova, A. T. (September 2007), "Kinematics of the Scorpius-Centaurus OB association", Astronomy Letters, 33 (9): 571–583, arXiv:0708.0943, Bibcode:2007AstL...33..571B, doi:10.1134/S1063773707090010.
- Johannes Carl Andersen (1931) Myths and Legends of the Polynesians. 1995 Dover reprint, p.400ff.
- Herbert John Davies, A Tahitian and English dictionary, with introductory remarks on the Polynesian language, and a short grammar of the Tahitian dialect. London Missionary Society, 1851.
- "IAU Working Group on Star Names (WGSN)". Retrieved 22 May 2016.
- (in Chinese) AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 5 月 10 日
External links
- The beautiful maidens from the Once, Upon a Reef, on: Facebook, Cook Islands Dance Video's