Xi Serpentis

ξ Serpentis

Observation data Epoch J2000.0      Equinox J2000.0
Constellation	Serpens
Right ascension	17h 37m 35.2s
Declination	-15° 23' 55"
Apparent magnitude (V)	+3.54
Distance	105 ± 4 ly (32 ± 1 pc)
Spectral type	F0IIIp
Other designations
55 Serpentis, HR 6561, HD 159876, SAO 160700, HIP 86263, CCDM 17376-1524

Xi Serpentis (ξ Ser, ξ Serpentis) is a triple star system in the constellation Serpens. The primary star, Xi Serpentis A, is a yellow-white F-type giant with an apparent magnitude of +3.54. It is a spectroscopic binary with an orbital period of 2.29 days. A 13th magnitude companion, Xi Serpentis B, is located 25 arcseconds from the primary pair. Xi Serpentis is approximately 105 light years from Earth.

Name

In Chinese, 天市左垣 (pinyin: Tiān Shì Zuǒ Yuán), meaning Left Wall of Heavenly Market Enclosure, refers to an asterism which is represent eleven old states (and region) in China which is marking the left borderline of the enclosure, consisting of ξ Serpentis, δ Herculis, λ Herculis, μ Herculis, ο Herculis, 112 Herculis, ζ Aquilae, η Serpentis, θ¹ Serpentis, ν Ophiuchi and η Ophiuchi. Consequently, ξ Serpentis itself is known as 天市左垣十 (Tiān Shì Zuǒ Yuán shí, English: the Tenth Star of Left Wall of Heavenly Market Enclosure), represent the region of Nanhai (南海, lit. meaning southern sea), possibly South China Sea.

References

• "HD 159876 -- Spectroscopic binary". SIMBAD Astronomical Database. http://simbad.u-strasbg.fr/sim-id.pl?protocol=html&Ident=xi+serpentis&NbIdent=1&Radius=10&Radius.unit=arcmin&CooFrame=FK5&CooEpoch=2000&CooEqui=2000&output.max=all&o.catall=on&output.mesdisp=N&Bibyear1=1983&Bibyear2=2005&Frame1=FK5&Frame2=FK4&Frame3=G&Equi1=2000.0&Equi2=1950.0&Equi3=2000.0&Epoch1=2000.0&Epoch2=1950.0&Epoch3=2000.0. Retrieved 2007-01-23.