47 Ophiuchi

47 Ophiuchi
Observation data
Epoch J2000      Equinox J2000
Constellation Ophiuchus[1]
Right ascension 17h 26m 37.88094s[2]
Declination −05° 05′ 11.7500″[2]
Apparent magnitude (V) 4.54[3] (4.93 / 5.83)[4]
Characteristics
Spectral type F3V[5]
U−B color index -0.03[6]
B−V color index +0.39[6]
Astrometry
Radial velocity (Rv)1.67 ± 0.13[4] km/s
Proper motion (μ) RA: -92.50[2] mas/yr
Dec.: -43.29[2] mas/yr
Parallax (π)33.25 ± 0.25 mas[2]
Distance98.1 ± 0.7 ly
(30.1 ± 0.2 pc)
Orbit[4]
Period (P)26.27565 ± 0.00004 d
Semi-major axis (a)7.99 ± 0.10 mas
Eccentricity (e)0.481 ± 0.002
Inclination (i)59.5 ± 1.3°
Longitude of the node (Ω)121.8 ± 1.0°
Periastron epoch (T)JD 2448103.380 ± 0.026
Argument of periastron (ω)
(secondary)		27.04 ± 0.54°
Semi-amplitude (K1)
(primary)		46.92 ± 0.40 km/s
Semi-amplitude (K2)
(secondary)		52.80 ± 0.39 km/s
Details[4]
47 Oph A
Mass1.50 ± 0.06 M☉
Radius2.06 ± 0.07 R☉
Luminosity7.80 ± 0.36 L☉
47 Oph B
Mass1.34 ± 0.06 M☉
Radius1.36 ± 0.06 R☉
Luminosity3.41 ± 0.25 L☉
Other designations
BD−04° 4275, FK5 647, HD 157950, HIP 85365, HR 6493, SAO 141665
Database references
SIMBADdata

47 Ophiuchi (47 Oph) is a binary star in the constellation Ophiuchus. The combined apparent magnitude of the system is 4.54.[3] The system is located about 98.1 light-years, or 30.1 parsecs away, based on its parallax as measured by Hipparcos.[2]

47 Ophiuchi is a spectroscopic binary: that is, the two stars move fast enough that periodic Doppler shifts in the stars' spectra can be detected. In this case, the two stars have also been resolved using interferometry.[4] The primary star is an F-type main-sequence star,[5] that is 1.5 times the mass of the Sun and around twice as wide.[4] Its companion star is 1.34 times the mass of the Sun, and 1.36 times the radius of the Sun.[4] The two stars orbit each other every 26.3 days, and its orbital eccentricity is 0.481.[4]

The designation 47 Ophiuchi was originally used for the star HR 6496.[7] However, when constellation borders were redrawn, the star fell into the constellation Serpens, and the designation became used for this star, HR 6493, instead.[8]

In 2014 it was discovered that a brown dwarf orbits this binary with a separation of 294.1 arcseconds or 8850 astronomical units. The object is also called 2MASS J17262235-0502110 and has a spectral type of L5.5.[9] This object has a mass of 69.66 ±0.88 MJ.[10]

  1. ^ "Finding the constellation which contains given sky coordinates". djm.cc. 2 August 2008. Archived from the original on 15 August 2019. Retrieved 23 May 2024.
  2. ^ a b c d e f van Leeuwen, F.; et al. (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.
  3. ^ a b Ducati, J. R. (2002). "VizieR Online Data Catalog: Catalogue of Stellar Photometry in Johnson's 11-color system". CDS/ADC Collection of Electronic Catalogues. 2237. Bibcode:2002yCat.2237....0D.
  4. ^ a b c d e f g h Wang, Xiaoli; Hummel, Christian A.; Ren, Shulin; Fu, Yanning (2015). "The Three-Dimensional Orbit and Physical Parameters of 47 Oph". The Astronomical Journal. 149 (3): 110. Bibcode:2015AJ....149..110W. doi:10.1088/0004-6256/149/3/110. S2CID 54767546.
  5. ^ a b Abt, H. A. (2009). "MK Classifications of Spectroscopic Binaries". The Astrophysical Journal Supplement Series. 180 (1): 117–118. Bibcode:2009ApJS..180..117A. doi:10.1088/0067-0049/180/1/117. S2CID 122811461.
  6. ^ a b Mermilliod, J.-C. (1986). "Compilation of Eggen's UBV data, transformed to UBV (unpublished)". Catalogue of Eggen's UBV Data. Bibcode:1986EgUBV........0M.
  7. ^ Wagman, M. (August 1987). "Flamsteed's Missing Stars". Journal for the History of Astronomy. 18 (3): 212. Bibcode:1987JHA....18..209W. doi:10.1177/002182868701800305. S2CID 118445625.
  8. ^ 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. Bibcode:1995yCat.5050....0H.
  9. ^ Cite error: The named reference Deacon2014 was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference Sanghi2023 was invoked but never defined (see the help page).