For other stars with this Bayer designation

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...

, see Tau Serpentis

Tau Serpentis

The Bayer designation Tau Serpentis is shared by a collection of eight stars, 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...

.

Tau⁴ Serpentis (Tau⁴ Ser, τ⁴ Serpentis, τ⁴ Ser) is a M-type bright giant

Bright giant

The luminosity class II in the Yerkes spectral classification is given to bright giants. These are stars which straddle the boundary between giants and supergiants, and the classification is in general given to giant stars with exceptionally high luminosity, but which are not sufficiently bright...

 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...

 in 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....

 of Serpens, approximately 520 light-years from the Earth

Earth

Earth is the third planet from the Sun, and the densest and fifth-largest of the eight planets in the Solar System. It is also the largest of the Solar System's four terrestrial planets...

. It is classified as a semiregular late-type variable star

Variable star

A star is classified as variable if its apparent magnitude as seen from Earth changes over time, whether the changes are due to variations in the star's actual luminosity, or to variations in the amount of the star's light that is blocked from reaching Earth...

, and its magnitude varies between +5.89 and +7.07 with a period of approximately 100 days. τ⁴ is unique among the stars with the Bayer designation τ Serpentis as being the only one with no HR catalog number.