Astronomy:41 Ophiuchi

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Short description: Binary star system in the constellation Ophiuchus
41 Ophiuchi
Ophiuchus constellation map.svg
Red circle.svg
Location of 41 Ophiuchi (circled)
Observation data
Equinox J2000.0]] (ICRS)
Constellation Ophiuchus
Right ascension  17h 16m 36.68653s[1]
Declination −00° 26′ 43.0915″[1]
Apparent magnitude (V) 4.72[2]
(4.92 + 7.51)[3]
Characteristics
Evolutionary stage horizontal branch[4]
Spectral type K2III[5]
U−B color index +1.11[6]
B−V color index +1.15[6]
Astrometry
Radial velocity (Rv)−0.16[7] km/s
Proper motion (μ) RA: −31.645[1] mas/yr
Dec.: −57.144[1] mas/yr
Parallax (π)16.1517 ± 0.2358[1] mas
Distance202 ± 3 ly
(61.9 ± 0.9 pc)
Absolute magnitude (MV)0.72[2]
Orbit[8]
Period (P)140.76±0.23 yr
Semi-major axis (a)0.959±0.008
Eccentricity (e)0.866±0.003
Inclination (i)65.1±0.0°
Longitude of the node (Ω)220.5±0.0°
Periastron epoch (T)1890.53±0.36 B
Argument of periastron (ω)
(secondary)
287.5±0.0°
Details
41 Oph A
Mass1.46[9] M
Radius11.80+0.27
−0.39
[1] R
Luminosity60.3±1.0[1] L
Surface gravity (log g)2.42[10] cgs
Temperature4,509±65[9] K
Metallicity [Fe/H]+0.06[2] dex
Rotational velocity (v sin i)2.6[7] km/s
Age3.73[9] Gyr
Other designations
41 Oph, BD−00°3255, GC 23320, HD 156266, HIP 84514, HR 6415, SAO 141586, CCDM J17166-0027AB, WDS J17166-0027[11]
Database references
SIMBADdata

41 Ophiuchi is a binary star[8] system in the zodiac constellation of Ophiuchus, and is positioned less than half a degree to the south of the celestial equator. It is visible to the naked eye as a faint, orange-hued point of light with a combined apparent visual magnitude of 4.72.[2] The distance to this system is approximately 202 light years based on parallax.[12]

This is a visual binary with an orbital period of 141 years and an eccentricity of 0.866.[8] The magnitude 4.92[3] primary, designated component A, is an aging K-type giant star with a stellar classification of K2III.[5] It is a red clump giant,[4] which indicates it is on the horizontal branch and is generating energy through helium fusion at its core. The star is 3.7[9] billion years old with 1.46[9] times the mass of the Sun and has expanded to nearly 12[1] times the Sun's radius. It is radiating 60[1] times the Sun's luminosity from its swollen photosphere at an effective temperature of 4,509 K.[9]

The secondary companion, component B, has a visual magnitude of 7.51 and an angular separation of 0.70 from the primary along a position angle of 22°, as of 2017.[3]

References

  1. 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 Brown, A. G. A. (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics 616: A1. doi:10.1051/0004-6361/201833051. Bibcode2018A&A...616A...1G.  Gaia DR2 record for this source at VizieR.
  2. 2.0 2.1 2.2 2.3 Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters 38 (5): 331. doi:10.1134/S1063773712050015. Bibcode2012AstL...38..331A.  Vizier catalog entry
  3. 3.0 3.1 3.2 Mason, Brian D.; Wycoff, Gary L.; Hartkopf, William I.; Douglass, Geoffrey G.; Worley, Charles E. (2001). "The 2001 US Naval Observatory Double Star CD-ROM. I. The Washington Double Star Catalog". The Astronomical Journal 122 (6): 3466. doi:10.1086/323920. Bibcode2001AJ....122.3466M.  Vizier catalog entry
  4. 4.0 4.1 Alves, David R. (August 2000). "K-Band Calibration of the Red Clump Luminosity". The Astrophysical Journal 539 (2): 732–741. doi:10.1086/309278. Bibcode2000ApJ...539..732A. 
  5. 5.0 5.1 Hoffleit, D.; Warren, W. H. (1995). "VizieR Online Data Catalog: Bright Star Catalogue, 5th Revised Ed. (Hoffleit+, 1991)". VizieR On-line Data Catalog: V/50. Originally Published in: 1964BS....C......0H 5050. Bibcode1995yCat.5050....0H. 
  6. 6.0 6.1 Mallama, A. (2014). "Sloan Magnitudes for the Brightest Stars". The Journal of the American Association of Variable Star Observers 42 (2): 443. Bibcode2014JAVSO..42..443M. Vizier catalog entry
  7. 7.0 7.1 Massarotti, Alessandro et al. (2008). "Rotational and Radial Velocities for a Sample of 761 Hipparcos Giants and the Role of Binarity". The Astronomical Journal 135 (1): 209–231. doi:10.1088/0004-6256/135/1/209. Bibcode2008AJ....135..209M. 
  8. 8.0 8.1 8.2 Tokovinin, Andrei et al. (August 2015). "Speckle Interferometry at SOAR in 2014". The Astronomical Journal 150 (2): 17. doi:10.1088/0004-6256/150/2/50. 50. Bibcode2015AJ....150...50T. 
  9. 9.0 9.1 9.2 9.3 9.4 9.5 Luck, R. Earle (2015), "Abundances in the Local Region. I. G and K Giants", Astronomical Journal 150 (3): 88, doi:10.1088/0004-6256/150/3/88, Bibcode2015AJ....150...88L. 
  10. Allende Prieto, C.; Lambert, D. L. (1999). "Fundamental parameters of nearby stars from the comparison with evolutionary calculations: Masses, radii and effective temperatures". Astronomy and Astrophysics 352: 555–562. Bibcode1999A&A...352..555A.  Vizier catalog entry
  11. "41 Oph". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=41+Oph. 
  12. Van Leeuwen, F. (2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics 474 (2): 653–664. doi:10.1051/0004-6361:20078357. Bibcode2007A&A...474..653V.  Vizier catalog entry