102 Herculis

Star in the constellation Hercules Hercules constellation map.svg center 280 right Red circle.svg 10 102 Herculis 310 750 Location of 102 Herculis (circled in red) J2000 Hercules 18 08 45.49142 +20 48 52.4079 4.37 B2 IV or B2 V −0.164 0.013 −14.9 0.6 −1.92 −5.89 3.56 0.19 −2.87 9.7 0.2 22420 1440 commas 3,631.92 3.54 41 20.0 1.4 Ramus 102 Her +20°3674 3443 166182 88886 6787 85769 J18088+2049 102+Her 102 Herculis, also named Ramus, is a single star in the northern constellation of Hercules. It is visible to the naked eye as a faint, blue-white hued star with an apparent visual magnitude of 4.37. Based upon parallax measurements, it is located around 920 light years away from the Sun. The star is moving closer to the Earth with a heliocentric radial velocity of −15 km/s. The stellar classification of this object matches a massive, early B-type star with a luminosity class of IV or V, corresponding to a subgiant or main sequence star, respectively. It is 20 million years old with nearly ten times the mass of the Sun and is spinning with a projected rotational velocity of 41 km/s. The strength of the stellar magnetic field has been measured at 209.5 135.4 -4 T. The star is radiating 3,632 times the Sun's luminosity from its photosphere at an effective temperature of 22,420 K. Etymology In Chinese, zh 帛度 (zh-Latn Bó Dù), meaning Textile Ruler, refers to an asterism consisting of 102 Herculis and 95 Herculis. Consequently, 102 Herculis itself is known as zh 帛度二 (zh-Latn Bó Dù èr, en the Second Star of Textile Ruler.) This star, together with 93 Herculis, 95 Herculis, and 109 Herculis, formed the now obsolete constellation of Cerberus, which was sometimes combined with Ramus, the apple branch.Ian Ridpath's Star Tales - Cerberus The IAU Working Group on Star Names approved the name Ramus for 102 Herculis on 17 June 2025 and it is now so entered in the IAU Catalog of Star Names. The WGSN avoided using the name Cerberus since it was already in use for the asteroid 1865 Cerberus. References 102 Her 2019-06-17 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 1108.4971 10.1134/S1063773712050015 119257644 Eggleton P. P. Tokovinin A. A. A catalogue of multiplicity among bright stellar systems Monthly Notices of the Royal Astronomical Society 389 2 869–879 September 2008 10.1111/j.1365-2966.2008.13596.x free 2008MNRAS.389..869E 0806.2878 14878976 . Lesh Janet Rountree . The Kinematics of the Gould Belt: an Expanding Group? Astrophysical Journal Supplement 17 371 December 1968 10.1086/190179 1968ApJS...17..371L free 1 Tetzlaff N. Neuhäuser R. Hohle M. M. A catalogue of young runaway Hipparcos stars within 3 kpc from the Sun Monthly Notices of the Royal Astronomical Society 410 1 190–200 January 2011 10.1111/j.1365-2966.2010.17434.x free . 2011MNRAS.410..190T 1007.4883 118629873 1 Zorec J. Cidale L. Arias M. L. Frémat Y. Muratore M. F. Torres A. F. Martayan C. Fundamental parameters of B supergiants from the BCD system. I. Calibration of the (λ_1, D) parameters into Teff Astronomy and Astrophysics 501 1 297–320 July 2009 10.1051/0004-6361/200811147 . 2009A&A...501..297Z 0903.5134 14969137 Simón-Díaz S. Godart M. Castro N. Herrero A. Aerts C. Puls J. Telting J. Grassitelli L. The IACOB project . III. New observational clues to understand macroturbulent broadening in massive O- and B-type stars 1 Astronomy and Astrophysics 597 A22 2017 2017A&A...597A..22S 1608.05508 10.1051/0004-6361/201628541 3478126 . 1 Lyubimkov L. S. Rostopchin S. I. Lambert D. L. Surface abundances of light elements for a large sample of early B-type stars - III. An analysis of helium lines in spectra of 102 stars Monthly Notices of the Royal Astronomical Society 351 2 745–767 June 2004 10.1111/j.1365-2966.2004.07825.x 2004MNRAS.351..745L . free 1 Bychkov V. D. Bychkova L. V. Madej J. Catalogue of averaged stellar effective magnetic fields. I. Chemically peculiar A and B type stars Astronomy and Astrophysics 407 2 631–642 August 2003 10.1051/0004-6361:20030741 . 2003A&A...407..631B astro-ph/0307356 14184105 Space motions and distribution of the apparently bright B-type stars Eggen Olin J. . Royal Observatory Bulletins 41 245–287 1961 1961RGOB...41..245E IAU Catalog of Star Names https://exopla.net/star-names/modern-iau-star-names/ 17 June 2025 Bodu (帛度) https://ase.exopla.net/index.php/Bodu All Skies Encyclopaedia IAU Working Group on Star Names 17 June 2025 Ramus https://ase.exopla.net/index.php/Ramus All Skies Encyclopaedia IAU Working Group on Star Names 17 June 2025 Category:B-type subgiants Category:B-type main-sequence stars Category:Hercules (constellation) BD+20 3674 Herculis, 102 166182 088886 6787 Ramus