Theta Serpentis

Starbox short
name=θ Serpentis
epoch=J2000.0
constell=Serpens
ra=18^h 56^m 13.2^s
dec=+04° 12' 13"
spectral=A5V + A5Vn + G5
appmag_v="combined": +4.03
ABC: 4.62 + 4.98 + 6.71
dist_ly=132 ± 9
dist_pc=40 ± 3
names=Alya, 63 Serpentis,
HR 7142 + HR 7141,
HD 175639 + HD 175638
+ HD 175726, SAO 124070
+ SAO 124068, HIP 92951
+ HIP 92946 + HIP 92984,
ADS 11853, CCDM 18563+0413

Theta Serpentis (θ Ser / θ Serpentis) is a star system in the constellation Serpens. It is approximately 132 light years from Earth. Theta Serpentis also has the traditional name Alya, or Alga, which is derived from an Arabic term meaning "the fatty tail" of an Oriental breed of sheep.

Both Theta-1 Serpentis and Theta-2 Serpentis are white A-type main sequence dwarfs. θ¹ has an apparent magnitude of +4.62 while the slightly dimmer θ² has a magnitude of +4.98. These two stars are 22 arcseconds apart on the sky, putting them at least 900 Astronomical Units apart with an orbital period of at least 14,000 years. Both stars are similar to each other in all respects, having luminosities of 18 and 13 times solar respectively, radii of about twice solar and also masses of roughly 2 times that of our Sun. Both star have a surface temperature of 8,000 kelvins.

The third star in the system, Theta Serpentis C is a yellow G-type star with an apparent magnitude of +6.71. It is separated by 7 arcminutes from θ².

External links

* [http://www.astro.uiuc.edu/~kaler/sow/alya.html Alya]