112 Herculis

Binary star system in the constellation Hercules Hercules constellation map.svg center 280 right Red circle.svg 10 112 Herculis 90 712 Location of 112 Herculis (circled) J2000 Hercules 18 52 16.428 +21 25 30.51 5.43 B9p Hg (B6.5V + A2V) −0.0680.008 −19.80.9 −7.526 −10.231 7.8558 0.0728 −0.04 6.36246 0.00002 days commas 0.110.03 2452540.11 0.03 JD commas 1982 17.00.6 352 Primary ~5.0 2.888 12853 89 commas 203 4 3 4.1 20 12.419 days Secondary ~2.5 4.2 112 Her +21°3582 25895 174933 92614 7113 86521 J18523+2126 112+Her 112 Herculis is a binary star system in the northern constellation of Hercules. It is dimly visible to the naked eye with a combined apparent visual magnitude of 5.43. The secondary component is about two magnitudes fainter than the primary star. The distance to this system is approximately 415 light years based on parallax measurements. It is drifting closer to the Sun with a radial velocity of −20 km/s. The binary character of this system was discovered by W. F. Meyer in 1926. By measuring the variation in velocity of the primary component, he determined an orbital period of 6.3624 days. K. Osawa in 1959 found a stellar classification of A4 III for the pair. W. P. Bidelman observed that the primary has unusually strong lines of ionized phosphorus, and it was assigned to the class of peculiar manganese stars by W. L. W. Sargent and L. Searle in 1962, with a resulting spectral type of B9. No evidence was found for a strong magnetic field by P. S. Conti in 1970. thumb|left|A light curve for 112 Herculis, plotted from TESS data In 1969, A. Cowley and associates found a stellar class of B9p Hg for this system, indicating a peculiar star with an abundance anomaly of mercury. C. E. Seligman in 1970 determined a mass ratio of 2.060.17 for the pair, which supported individual stellar classes of B7V and A3V for main sequence components. The sharpness of the spectral lines suggested that at least the primary is rotating synchronously with its orbital period. A more detailed analysis by Seligman and L. H. Allen later in 1970 refined the classifications to B6.5V and A2V. The elemental abundances for both stars appeared similar, although the secondary abundances were more uncertain. In 1975, the primary was classified as a mercury-manganese star by C. R. Cowley and G. C. L. Aikman. T. A. Ryabchikova and associates in 1996 refined the mass ratio to 1.980.03. The primary showed significant deficiencies of helium and mercury, but a large overabundance of iron. The secondary component displayed abundances similar to an Am star. This is a double-lined spectroscopic binary system with an orbital period of 6.36246 days and an eccentricity (ovalness) of 0.11. As of 2021, measurements by the TESS space telescope show a rotation period of 12.4 days for the primary, suggesting that it is not rotating synchronously with its orbit. Some variability in flux was recorded by TESS, but this is due to orbital motion – the stars themselves do not appear to be variable. References 112 Her 2022-10-24 4531234550775627136 XHIP: An extended hipparcos compilation Anderson E. Francis Ch. Astronomy Letters . 38 5 331 2012 2012AstL...38..331A 1108.4971 10.1134/S1063773712050015 119257644 . MAST: Barbara A. Mikulski Archive for Space Telescopes https://mast.stsci.edu/portal/Mashup/Clients/Mast/Portal.html Space Telescope Science Institute 27 October 2022 . Orbital solutions for SB2 systems with a HgMn component Catanzaro G. Leto P. Astronomy and Astrophysics 416 661–668 March 2004 2 10.1051/0004-6361:20034445 62892090 2004A&A...416..661C free . The orbit of the spectroscopic binary 112 Herculis Meyer William Ferdinand Lick Observatory Bulletin 381 165–167 1926 Berkeley University of California Press 10.5479/ADS/bib/1926LicOB.12.165M 1926LicOB..12..165M . Spectral Classification of 533 B8-A2 Stars and the Mean Absolute Magnitude of A0 V Stars Osawa Kiyoteru Astrophysical Journal 130 159 July 1959 10.1086/146706 1959ApJ...130..159O free . Studies of the Peculiar A Stars. I. The Oxygen-Abundance Anomaly Sargent Wallace L. W. Searle Leonard Astrophysical Journal 136 408 September 1962 10.1086/147393 1962ApJ...136..408S . Zeeman Measures of Four Double-Lined Peculiar A Stars Conti Peter S. Astrophysical Journal 160 1077 June 1970 10.1086/150495 1970ApJ...160.1077C . Wilson Ralph Elmer 1953 General catalogue of stellar radial velocities Washington 0 Carnegie Institution of Washington 1953GCRV..C......0W . TESS survey of rotational and pulsational variability of mercury-manganese stars 1 Kochukhov O. Khalack V. Kobzar O. Neiner C. Paunzen E. Labadie-Bartz J. David-Uraz A. Monthly Notices of the Royal Astronomical Society 506 4 5328–5344 October 2021 10.1093/mnras/stab2107 free 2107.09096 2021MNRAS.506.5328K . A Mass Ratio for 112 Herculis Seligman Courtney E. Publications of the Astronomical Society of the Pacific 82 484 128 February 1970 10.1086/128894 121129664 1970PASP...82..128S . A Model Atmosphere Analysis of the Binary 112 Herculis Seligman Courtney E. Aller L. H. Astrophysics and Space Science 9 3 461–481 December 1970 10.1007/BF00649584 122876855 1970Ap&SS...9..461S . A study of the bright A stars. I. A catalogue of spectral classifications Cowley A. Cowley C. Jaschek M. Jaschek C. 1 Astronomical Journal 74 375–406 April 1969 10.1086/110819 1969AJ.....74..375C . A study of the lambda 3984 feature in the mercury-manganese stars Cowley C. R. Aikman G. C. L. Publications of the Astronomical Society of the Pacific 87 513–521 August 1975 10.1086/129801 121306556 1975PASP...87..513C free . Elemental abundance analyses with DAO spectrograms - XIV. The double-lined spectroscopic binary 112 Herculis 1 Ryabchikova T. A. Zakharova L. A. Adelman S. J. Monthly Notices of the Royal Astronomical Society 283 4 1115–1132 December 1996 10.1093/mnras/283.4.1115 free 1996MNRAS.283.1115R . Rotational Velocities of B Stars 1 Abt Helmut A. Levato Hugo Grosso Monica The Astrophysical Journal 573 1 359–365 July 2002 10.1086/340590 2002ApJ...573..359A free . The Behavior of HgMn Stars in the Far UV—Paper 16: HD 174933 Richard Monier Research Notes of the AAS 6 10 October 2022 218 10.3847/2515-5172/ac9afe 2022RNAAS...6..218M 253018177 free Category:Mercury-manganese stars Category:Am stars Category:Spectroscopic binaries Category:Hercules (constellation) 7113 Category:Durchmusterung objects Herculis, 112 174933 92614