16 Serpentis

Binary star system in the constellation Serpens 16 Serpentis J2000.0 (ICRS) 15 36 29.57498 +10 00 36.5574 5.261 Serpens K0III: CN1 Ba0.7 Sr2 +0.937 +0.66 +2.94 0.13 41.881 −125.722 14.3226 0.1100 5324 19 commas days 0.345 0.024 44090 53 commas 358 4 3.86 0.09 16 Ser A 1.70 8 42.7 4946 51 commas −0.13 0.06 2.64 0.12 1.4 2.40 16 Ser +10°2884 3226 139195 76425 5802 101640 20981 16+Ser 16 Serpentis is a binary star system in the Serpens Caput portion of the equatorial constellation of Serpens, located 228 light years from the Sun. It is visible to the naked eye as a fain, orange-hued star with an apparent visual magnitude of 5.261. The system is moving further from the Earth with a heliocentric radial velocity of +3 km/s. The variable radial velocity of this star was discovered at Lick Observatory and was announced by J. H. Moore in 1924. It is a single-lined spectroscopic binary with an orbital period of 5324 days years out off and an eccentricity of 0.345. The visible component is an evolved giant star with a stellar classification of K0III: CN1 Ba0.7 Sr2. This is a mild barium star with the suffix notation above indicating associated abundance anomalies. The companion is a presumed white dwarf star that has already passed through its giant stage, during which time it enhanced the envelope of the companion with s-process elements. The pair form one of the widest barium star binaries known, which may account for the mildness of the barium anomaly. References 1165158832802119040 16 Ser 2019-03-22 Keenan Philip C. McNeil Raymond C. The Perkins catalog of revised MK types for the cooler stars Astrophysical Journal Supplement Series 71 245 1989 1989ApJS...71..245K 10.1086/191373 Tomkin J. Lambert D. L. Heavy-element abundances in the mild barium stars Omicron Virginis and 16 Serpentis The Astrophysical Journal 311 819 1986 1986ApJ...311..819T 10.1086/164821 free Spectroscopic binary orbits from photoelectric radial velocities. Paper 96: 16 Serpentis Griffin R. F. The Observatory 111 29–37 February 1991 1991Obs...111...29G Abundances in the Local Region. I. G and K Giants Luck R. Earle Astronomical Journal 150 3 88 2015 1507.01466 2015AJ....150...88L 10.1088/0004-6256/150/3/88 118505114 ] 1 Massarotti Alessandro Latham David W. Stefanik Robert P. Fogel Jeffrey Rotational and Radial Velocities for a Sample of 761 HIPPARCOS Giants and the Role of Binarity The Astronomical Journal 135 1 209–231 January 2008 10.1088/0004-6256/135/1/209 2008AJ....135..209M free Mermilliod J.-C. Compilation of Eggen's UBV data, transformed to UBV (unpublished) Catalogue of Eggen's UBV Data 1986 1986EgUBV........0M 1 Prugniel Ph. Vauglin I. Koleva M. The atmospheric parameters and spectral interpolator for the MILES stars Astronomy & Astrophysics 531 A165 July 2011 10.1051/0004-6361/201116769 free 2011A&A...531A.165P 1104.4952 54940439 Category:Barium stars Category:Spectroscopic binaries Category:Serpens Category:Durchmusterung objects Serpentis, 16 139195 076425 5802 Category:K0III stars