Epoch J2000.0 Equinox J2000.0 (ICRS)
|Right ascension||18h 37m 35.9613s|
|Declination||−00° 18′ 34.100″|
|Apparent magnitude (V)||5.74 to 5.86|
|Spectral type||A1V / A1V
|U−B color index||+0.06|
|B−V color index||+0.07|
|R−I color index||+0.04|
|Radial velocity (Rv)||11.4 km/s|
|Proper motion (μ)||RA: 11.74 mas/yr
Dec.: −19.83 mas/yr
|Parallax (π)||5.06 ± 0.93 mas|
|Distance||approx. 600 ly
(approx. 200 pc)
|Absolute magnitude (MV)||−0.7|
The star HD 171978 is a spectroscopic binary in the constellation of Serpens. It consists of two A-type main sequence stars orbiting each other with a period of approximately 14.7 days. The overall apparent visual magnitude of the system varies between 5.74 and 5.86.
- NSV 11122 -- Spectroscopic binary, database entry, SIMBAD. Accessed on line October 3, 2008.
- NSV 11122, database entry, New Catalogue of Suspected Variable Stars, the improved version, Sternberg Astronomical Institute, Moscow, Russia. Accessed on line October 3, 2008.
- HR 6993, database entry, The Bright Star Catalogue, 5th Revised Ed. (Preliminary Version), D. Hoffleit and W. H. Warren, Jr., CDS ID V/50. Accessed on line October 3, 2008.
- Figure is for the barycenter of the spectroscopic binary system.
- From apparent magnitude and parallax.
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