Tau⁸ Serpentis

Tau⁸ Serpentis, Latinized from τ⁸ Serpentis, is an A-type main sequence star in the constellation of Serpens, approximately 320 light-years from the Earth.[1] It has an apparent visual magnitude of approximately 6.144.[1] Although it was observed to be binary by speckle interferometry in 1985, subsequent observations show no sign of binarity, and the detection appears to have been spurious.[5]

τ⁸ Serpentis

Observation data Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation	Serpens
Right ascension	15^h 44^m 42.1323^s[1]
Declination	+17° 15′ 51.197″[1]
Apparent magnitude (V)	6.144[1]
Characteristics
Spectral type	A0V[1]
U−B color index	−0.03[2]
B−V color index	0.00[2]
Astrometry
Radial velocity (Rv)	−5.2 ± 5[1] km/s
Proper motion (μ)	RA: −30.44[1] mas/yr Dec.: 6.59[1] mas/yr
Parallax (π)	10.16 ± 0.79[1] mas
Distance	320 ± 20 ly (98 ± 8 pc)
Absolute magnitude (MV)	0.88[3]
Details
Radius	2.0[4] R☉
Rotational velocity (v sin i)	76[2] km/s
Other designations
τ^8 Ser, 26 Serpentis, BD+17° 2906, GC 21164, HD 140729, HIP 77111, HR 5858, SAO 101712, PPM 131656[1] τ^8 Ser, Tau^8 Serpentis, Tau^8 Ser, 26 Serpentis, 26 Ser, BD+17 2906, GC 21164, HD 140729, HIP 77111, HR 5858, PPM 131656, SAO 101712.
Database references
SIMBAD	data

References

1. * 26 Ser -- Star, database entry, SIMBAD. Accessed on line September 19, 2008.
2. HR 5858, 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 September 19, 2008.
3. Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters, 38 (5): 331, arXiv:1108.4971, Bibcode:2012AstL...38..331A, doi:10.1134/S1063773712050015, S2CID 119257644.
4. HD 140729, database entry, Catalog of Apparent Diameters and Absolute Radii of Stars (CADARS), 3rd edition, L. E. Pasinetti-Fracassini, L. Pastori, S. Covino, and A. Pozzi, CDS ID II/224. Accessed on line September 19, 2008.
5. ICCD speckle observations of binary stars. X - A further survey for duplicity among the bright stars, Harold A. McAlister, Brian D. Mason, William I. Hartkopf, and Michael M. Shara, Astronomical Journal 106, #4 (October 1993), pp. 1639–1655, doi:10.1086/116753, Bibcode:1993AJ....106.1639M.