AH Scorpii
| Observation data EpochJ2000EquinoxJ2000 | |
|---|---|
| Constellation | Scorpius |
| Right ascension | 17h11m17.01945s[1] |
| Declination | −32° 19′ 30.7140″[1] |
| Apparent magnitude(V) | 6.5 - 9.6[2] |
| Characteristics | |
| Spectral type | M4-5 Ia-Iab[3] |
| B−Vcolor index | +2.57[4] |
| Variable type | SRc[3] |
| Astrometry | |
| Radial velocity(Rv) | −13.40±2.4[5]km/s |
| Proper motion(μ) | RA:−2.322±0.115[1]mas/yr Dec.:−2.610±0.068[1]mas/yr |
| Parallax(π) | 0.5632 ± 0.0799mas[1] |
| Distance | 7,400±620ly (2,260±190[6]pc) |
| Absolute magnitude(MV) | −5.8[7] |
| Details | |
| Mass | 20[8]M☉ |
| Radius | 1,411±124[4]R☉ |
| Luminosity | 329,000±86,000[4]L☉ |
| Surface gravity(logg) | −0.5[4]cgs |
| Temperature | 3,682[4]K |
| Other designations | |
| Database references | |
| SIMBAD | data |
AH Scorpii(abbreviated toAH Sco) is ared supergiantvariable starlocated in the constellationScorpius.It is one of thelargest stars knownby radius and is alsoone of the most luminousred supergiant stars in theMilky Way.
Distance
[edit]The distance of AH Scorpii is considered to be uncertain.VLBImeasurements of the masers have provided an accurate distance of2,260 parsecsbased on observation of SiO, H2O, and OHmasersin its oxygen-rich circumstellar material. The masers were observed to be approaching the star at 13 km/s, indicating overall contraction at around phase 0.55 of the visual variations.[6]
Characteristics
[edit]
AH Scorpii is a dust-enshrouded red supergiant[10]and is classified as asemiregular variable starwith a main period of 714 days. The total visual magnitude range is 6.5 - 9.6.[2]No long secondary periods have been detected.[11]Modelling of AH Scorpii near maximum light has determined an effective temperature of3,682±190 Kand a luminosity of330,000±86,000L☉.A radius of1,411±124R☉was determined from anangular diameterof5.81±0.15masand the given distance of2.26±0.19 kpc.[4]Its angular diameter was re-measured at5.05±0.5 masin 2023.[12]
See also
[edit]Notes
[edit]References
[edit]- ^abcdeBrown, A. G. A.;et al. (Gaia collaboration) (2021)."GaiaEarly Data Release 3: Summary of the contents and survey properties ".Astronomy & Astrophysics.649:A1.arXiv:2012.01533.Bibcode:2021A&A...649A...1G.doi:10.1051/0004-6361/202039657.S2CID227254300.(Erratum:doi:10.1051/0004-6361/202039657e).Gaia EDR3 record for this sourceatVizieR.
- ^abKiss, L. L.; Szabó, Gy. M.;Bedding, T. R.(2006)."Variability in red supergiant stars: Pulsations, long secondary periods and convection noise".Monthly Notices of the Royal Astronomical Society.372(4): 1721–1734.arXiv:astro-ph/0608438.Bibcode:2006MNRAS.372.1721K.doi:10.1111/j.1365-2966.2006.10973.x.S2CID5203133.
- ^abSamus, N. N.; Durlevich, O. V.; et al. (2009). "VizieR Online Data Catalog: General Catalogue of Variable Stars (Samus+ 2007-2013)".VizieR On-line Data Catalog: B/GCVS. Originally Published in: 2009yCat....102025S.1.Bibcode:2009yCat....102025S.
- ^abcdefArroyo-Torres, B.; Wittkowski, M.; Marcaide, J. M.; Hauschildt, P. H. (2013). "The atmospheric structure and fundamental parameters of the red supergiants AH Scorpii, UY Scuti, and KW Sagittarii".Astronomy & Astrophysics.554:A76.arXiv:1305.6179.Bibcode:2013A&A...554A..76A.doi:10.1051/0004-6361/201220920.S2CID73575062.
- ^Gontcharov, G. A. (2006). "Pulkovo Compilation of Radial Velocities for 35 495 Hipparcos stars in a common system".Astronomy Letters.32(11): 759–771.arXiv:1606.08053.Bibcode:2006AstL...32..759G.doi:10.1134/S1063773706110065.S2CID119231169.
- ^abChen, Xi; Shen, Zhi-Qiang (2008). "VLBI Observations of SiO Masers around AH Scorpii".The Astrophysical Journal.681(2): 1574–1583.arXiv:0803.1690.Bibcode:2008ApJ...681.1574C.doi:10.1086/588186.S2CID7603031.
- ^Baudry, A.; Le Squeren, A. M.; Lepine, J. R. D. (1977). "The supergiant OH stars S Per and AH SCO - Conditions for OH emission in circumstellar envelopes".Astronomy and Astrophysics.54:593.Bibcode:1977A&A....54..593B.
- ^González-Torà, G.; Wittkowski, M.; Davies, B.; Plez, B. (2024-03-01). "The effect of winds on atmospheric layers of red supergiants II. Modelling VLTI/GRAVITY and MATISSE observations of AH Sco, KW Sgr, V602 Car, CK Car, and V460 Car".Astronomy and Astrophysics.683:A19.arXiv:2312.12521.Bibcode:2024A&A...683A..19G.doi:10.1051/0004-6361/202348047.ISSN0004-6361.
- ^"Download Data".aavso.org.AAVSO.Retrieved1 October2021.
- ^Van Loon, J. Th.; Cioni, M.-R. L.; Zijlstra, A. A.; Loup, C. (2005). "An empirical formula for the mass-loss rates of dust-enshrouded red supergiants and oxygen-rich Asymptotic Giant Branch stars".Astronomy and Astrophysics.438(1): 273–289.arXiv:astro-ph/0504379.Bibcode:2005A&A...438..273V.doi:10.1051/0004-6361:20042555.S2CID16724272.
- ^Percy, John R.; Sato, Hiromitsu (2009). "Long Secondary Periods in Pulsating Red Supergiant Stars".Journal of the Royal Astronomical Society of Canada.103(1): 11.Bibcode:2009JRASC.103...11P.
- ^González-Torà, G.; Wittkowski, M.; Davies, B.; Plez, B. (December 19, 2023). "The effect of winds on atmospheric layers of red supergiants II. Modelling VLTI/GRAVITY and MATISSE observations of AH Sco, KW Sgr, V602 Car, CK Car and V460 Car".Astronomy & Astrophysics.683:A19.arXiv:2312.12521.Bibcode:2024A&A...683A..19G.doi:10.1051/0004-6361/202348047.ISSN0004-6361.
