16 Sagittarii

Star in the constellation Sagittarius 16 Sagittarii J2000 Sagittarius 18 15 12.96915 -20 23 16.7021 6.02 O9.5 III 0.02 −11.0 1.3 +1.60 −1.51 4,600 1,400 12.76123 0.00022 commas days 0.181 0.060 54005.3 ± 0.7 156 19 22.1 2.8 16 Sgr Aa 50 12.5 0.5 3.3449 0.0270 0.0247 21691 149 159 commas 0.0123 0.0189 0.0100 51 16 Sgr Ab 3.72 16 Sgr -20° 5055 167263 89440 6823 186544 J18152-2023A 16+Sgr 16 Sagittarii is a multiple star system in the southern zodiac constellation of Sagittarius. It is near the lower limit of brightness for stars that can be seen with the naked eye, having an apparent visual magnitude of 6.02. The estimated distance to this system is about 4,600 light years. It is a member of the Sgr OB7 cluster. Along with the O-type star 15 Sgr, it is ionizing an H II region along the western edge of the molecular cloud L291. Mason et al. (1998) found this to be a member of a speckle binary with an estimated orbital period of roughly 130 years and a magnitude difference of 0.4. Both components show indications of a variable radial velocity, suggesting that they are spectroscopic binaries – making it a candidate quadruple star system. However, Tokovinin (2008) considers it a triple star system. Orbital elements for the main spectroscopic binary, components Aa and Ab, were published by Mayer et al. (2014), giving an orbital period of 12.76 days and an eccentricity of 0.18. This system displays a merged stellar classification of O9.5 III, matching a blue-hued O-type giant star. It shows a longitudinal magnetic field strength of −74 44 G and a projected rotational velocity of 51 km/s. Tokovinin (2008) gives an estimated mass of 50 times the mass of the Sun for the primary, and 3.72 for the secondary. The tertiary member, component B, has 2.54 times the Sun's mass. References 16 Sgr 2018-03-16 4094031138050641408 Validation of the new Hipparcos reduction van Leeuwen F. . Astronomy and Astrophysics 474 2 653–664 2007 0708.1752 2007A&A...474..653V 10.1051/0004-6361:20078357 18759600 XHIP: An extended hipparcos compilation Anderson E. Francis Ch. Astronomy Letters 38 5 331 2012 2012AstL...38..331A 10.1134/S1063773712050015 1108.4971 119257644 . HH 80-81: A Highly Collimated Herbig-Haro Complex Powered by a Massive Young Star 1 Marti J. Rodriguez L. F. Reipurth B. Astrophysical Journal 416 208 October 1993 10.1086/173227 1993ApJ...416..208M free Tokovinin A. Comparative statistics and origin of triple and quadruple stars Monthly Notices of the Royal Astronomical Society 389 2 925–938 September 2008 10.1111/j.1365-2966.2008.13613.x free 2008MNRAS.389..925T 0806.3263 16452670 The MiMeS survey of Magnetism in Massive Stars: magnetic analysis of the O-type stars Grunhut J. H. Wade G. A. Neiner C. Oksala M. E. Petit V. Alecian E. Bohlender D. A. Bouret J. -C. Henrichs H. F. Hussain G. A. J. Kochukhov O. MiMeS Collaboration Monthly Notices of the Royal Astronomical Society 465 2 2432–2470 February 2017 10.1093/mnras/stw2743 free 2017MNRAS.465.2432G 1610.07895 The Multiplicity of Massive Stars: a High Angular Resolution Survey With the Guidance Sensor Aldoretta E. J. Caballero-Nieves S. M. Gies D. R. Nelan E. P. Wallace D. J. Hartkopf W. I. Henry T. J. Jao W. -C. Maíz Apellániz J. Mason B. D. Moffat A. F. J. Norris R. P. Richardson N. D. Williams S. J. The Astronomical Journal 1 149 1 26 14 January 2015 10.1088/0004-6256/149/1/26 2015AJ....149...26A 1410.0021 58911264 New and revised parameters for several southern OB binaries Mayer Pavel Drechsel Horst Irrgang Andreas Astronomy & Astrophysics 565 A86 9 May 2014 10.1051/0004-6361/201423455 free 2014A&A...565A..86M 1404.1686 119254200 The Galactic O-Star Spectroscopic Survey (GOSSS). II. Bright Southern Stars The Astrophysical Journal Supplement 211 10 2014 Sota A. Maíz Apellániz J. Morrell N. I. Nidia Morrell Barbá R. H. Walborn N. R. Gamen R. C. Arias J. I. Alfaro E. J. 1 2014ApJS..211...10S 10.1088/0067-0049/211/1/10 1312.6222 118847528 VizieR Online Data Catalog: Catalogue of Stellar Photometry in Johnson's 11-color system CDS/ADC Collection of Electronic Catalogues Ducati J. R. 2237 2002 2002yCat.2237....0D Category:O-type giants Category:Spectroscopic binaries Category:Triple star systems Category:Sagittarius (constellation) Category:Durchmusterung objects Sagittarii, 16 167263 089440