Tau Serpentis
Encyclopedia
The Bayer designation
Tau Serpentis (τ Ser / τ Serpentis) is shared by a collection of eight star
s, τ1 Serpentis through τ8 Serpentis, in the head of the constellation
Serpens
. They are distributed within a box of size 40 minutes in right ascension
by 3.5° in declination
. They are numbered by increasing right ascension:
Bayer designation
A Bayer designation is a stellar designation in which a specific star is identified by a Greek letter, followed by the genitive form of its parent constellation's Latin name...
Tau Serpentis (τ Ser / τ Serpentis) is shared by a collection of eight star
Star
A star is a massive, luminous sphere of plasma held together by gravity. At the end of its lifetime, a star can also contain a proportion of degenerate matter. The nearest star to Earth is the Sun, which is the source of most of the energy on Earth...
s, τ1 Serpentis through τ8 Serpentis, in the head of the constellation
Constellation
In modern astronomy, a constellation is an internationally defined area of the celestial sphere. These areas are grouped around asterisms, patterns formed by prominent stars within apparent proximity to one another on Earth's night sky....
Serpens
Serpens
Serpens is a constellation of the northern hemisphere. It was one of the 48 constellations listed by the 2nd century astronomer Ptolemy and it remains one of the 88 modern constellations defined by the International Astronomical Union....
. They are distributed within a box of size 40 minutes in right ascension
Right ascension
Right ascension is the astronomical term for one of the two coordinates of a point on the celestial sphere when using the equatorial coordinate system. The other coordinate is the declination.-Explanation:...
by 3.5° in declination
Declination
In astronomy, declination is one of the two coordinates of the equatorial coordinate system, the other being either right ascension or hour angle. Declination in astronomy is comparable to geographic latitude, but projected onto the celestial sphere. Declination is measured in degrees north and...
. They are numbered by increasing right ascension:
- Tau1 SerpentisTau¹ SerpentisTau1 Serpentis is an M-type giant star in the constellation of Serpens, approximately 900 light-years from Earth. It has an apparent visual magnitude which varies between 5.13 and 5.20....
, also designated 9 Serpentis or HD 137471. - Tau2 SerpentisTau² SerpentisTau2 Serpentis is a B-type main sequence star in the constellation of Serpens, approximately 430 light-years from Earth. It has an apparent visual magnitude of approximately 6.218....
, also designated 12 Serpentis or HD 138527. - Tau3 SerpentisTau³ SerpentisTau3 Serpentis is a G-type giant star in the constellation of Serpens. It is approximately 410 light-years from Earth. It has an apparent visual magnitude of approximately 6.108....
, also designated 15 Serpentis or HD 139074. - Tau4 SerpentisTau4 SerpentisTau4 Serpentis is a M-type bright giant star in the constellation of Serpens, approximately 520 light-years from the Earth. It is classified as a semiregular late-type variable star, and its magnitude varies between +5.89 and +7.07 with a period of approximately 100 days...
, also desiganted 17 Serpentis or HD 139216. - Tau5 SerpentisTau5 SerpentisTau5 Serpentis is a F-type main sequence star in the constellation of Serpens, approximately 160 light-years from Earth. It has an apparent visual magnitude of approximately 5.938....
, also desiganted 18 Serpentis or HD 139225. - Tau6 SerpentisTau6 SerpentisTau6 Serpentis is a G-type giant star in the constellation of Serpens, approximately 450 light-years from the Earth. It has an apparent visual magnitude of approximately 6.000, and is a member of the Ursa Major Stream....
, also desiganted 19 Serpentis or HD 140027. - Tau7 SerpentisTau7 SerpentisTau7 Serpentis is an A-type star in the constellation of Serpens, approximately 174 light-years from the Earth. It has an apparent visual magnitude of approximately 5.804....
, also desiganted 22 Serpentis or HD 140232. - Tau8 SerpentisTau8 SerpentisTau8 Serpentis is an A-type main sequence star in the constellation of Serpens, approximately 320 light-years from the Earth. It has an apparent visual magnitude of approximately 6.144...
, also desiganted 26 Serpentis or HD 140729.