Binary star system in the constellation Gemini
38 Geminorum is a binary star system in the northern zodiac constellation of Gemini . It has the Bayer designation e Geminorum , while 38 Geminorum is the Flamsteed designation . This system is visible to the naked eye as a faint, white-hued point of light with an apparent visual magnitude of 4.71. The primary component is a magnitude 4.75 star, while the secondary is magnitude 7.80.[ 3] The system is located about 98 light years away from the Sun based on parallax , and is drifting further away with a radial velocity of +16 km/s.[ 15] It is a potential member of the Tucana–Horologium stellar kinematic group .[ 16]
This is a wide binary system with a projected separation of 184.3 AU .[ 11] Two sets of low quality orbital elements have been computed for this system, yielding periods of 1,943.8 years and 3,190 years, and eccentricities of 0.150 and 0.485, respectively.[ 17] As of 2018, the pair had an angular separation of 7.4″ along a position angle of 143°.[ 3]
Abt and Morrell (1995) classified the primary component as an A-type main-sequence star with a stellar classification of A8V.[ 4] It is a suspected chemically peculiar star of subtype CP1 (an Am star ),[ 14] which Slettebak (1955) classified as kA8mF0Vp.[ 18] This notation indicates the star displays the calcium K line of an A8 star and the metal lines of an F0V star . In 1949, J. Hopmann catalogued it as a suspected Delta Scuti variable .[ 7] The secondary is a G-type main-sequence star with a class of G6V.[ 5]
References
^ "MAST: Barbara A. Mikulski Archive for Space Telescopes" . Space Telescope Science Institute. Retrieved 11 September 2024 .
^ a b van Leeuwen, F. (2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics . 474 (2): 653– 664. arXiv :0708.1752 . Bibcode :2007A&A...474..653V . doi :10.1051/0004-6361:20078357 . S2CID 18759600 .
^ a b c Mason, B. D.; et al. (2014), "The Washington Visual Double Star Catalog", The Astronomical Journal , 122 (6): 3466, Bibcode :2001AJ....122.3466M , doi :10.1086/323920
^ a b Abt, Helmut A.; Morrell, Nidia I. (1995). "The Relation between Rotational Velocities and Spectral Peculiarities among A-Type Stars" . The Astrophysical Journal Supplement Series . 99 : 135. Bibcode :1995ApJS...99..135A . doi :10.1086/192182 .
^ a b Adams, Walter S.; et al. (1935). "The Spectroscopic Absolute Magnitudes and Parallaxes of 4179 Stars" . Astrophysical Journal . 81 : 187. Bibcode :1935ApJ....81..187A . doi :10.1086/143628 .
^ a b Johnson, H. L. (1966). "UBVRIJKL Photometry of the Bright Stars". Communications of the Lunar and Planetary Laboratory . 4 : 99. Bibcode :1966CoLPL...4...99J .
^ a b Starikova, G. A. (July 1979). "Absolute magnitudes and masses for three types of variable stars". Soviet Astronomy Letters . 5 : 188– 192. Bibcode :1979SvAL....5..188S .
^ a b Evans, D. S. (1967). "The Revision of the General Catalogue of Radial Velocities". Determination of Radial Velocities and Their Applications . 30 : 57. Bibcode :1967IAUS...30...57E .
^ a b c Brown, A. G. A. ; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties" . Astronomy & Astrophysics . 616 . A1. arXiv :1804.09365 . Bibcode :2018A&A...616A...1G . doi :10.1051/0004-6361/201833051 . Gaia DR2 record for this source at VizieR .
^ a b c d e f Brown, A. G. A. ; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties" . Astronomy & Astrophysics . 616 . A1. arXiv :1804.09365 . Bibcode :2018A&A...616A...1G . doi :10.1051/0004-6361/201833051 . Gaia DR2 record for this source at VizieR .
^ a b c Tokovinin, A.; Kiyaeva, O. (February 2016). "Eccentricity distribution of wide binaries" . Monthly Notices of the Royal Astronomical Society . 456 (2): 2070– 2079. arXiv :1512.00278 . Bibcode :2016MNRAS.456.2070T . doi :10.1093/mnras/stv2825 . S2CID 1615080 .
^ a b c David, Trevor J.; Hillenbrand, Lynne A. (2015). "The Ages of Early-Type Stars: Strömgren Photometric Methods Calibrated, Validated, Tested, and Applied to Hosts and Prospective Hosts of Directly Imaged Exoplanets". The Astrophysical Journal . 804 (2): 146. arXiv :1501.03154 . Bibcode :2015ApJ...804..146D . doi :10.1088/0004-637X/804/2/146 . S2CID 33401607 .
^ Gáspár, András; et al. (2016). "The Correlation between Metallicity and Debris Disk Mass" . The Astrophysical Journal . 826 (2): 171. arXiv :1604.07403 . Bibcode :2016ApJ...826..171G . doi :10.3847/0004-637X/826/2/171 . S2CID 119241004 .
^ a b Paunzen, E.; et al. (February 2013). "A photometric study of chemically peculiar stars with the STEREO satellites - II. Non-magnetic chemically peculiar stars" . Monthly Notices of the Royal Astronomical Society . 429 (1): 119– 125. arXiv :1211.1535 . Bibcode :2013MNRAS.429..119P . doi :10.1093/mnras/sts318 . S2CID 119231581 .
^ 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 . S2CID 119231169 .
^ Nakajima, Tadashi; Morino, Jun-Ichi (2012). "Potential Members of Stellar Kinematic Groups within 30 pc of the Sun" . The Astronomical Journal . 143 (1): 2. Bibcode :2012AJ....143....2N . doi :10.1088/0004-6256/143/1/2 .
^ Abt, Helmut A. (August 2005). "Observed Orbital Eccentricities" . The Astrophysical Journal . 629 (1): 507– 511. Bibcode :2005ApJ...629..507A . doi :10.1086/431207 .
^ Slettebak, Arne (May 1955). "The Spectra and Rotational Velocities of the Bright Stars of Draper Types A3-G0" . Astrophysical Journal . 121 : 653. Bibcode :1955ApJ...121..653S . doi :10.1086/146031 .