Star profile

Tau 1 Serpens

Cool red star

3D likeness based on its real data · class M · ~3,200 K

What is Tau 1 Serpens

Tau-1 Serpentis burns with a deep red in the head of the Serpent, that constellation split into two halves and held between the hands of Ophiuchus. It is a red M-type giant, a star well advanced in its evolution, swollen to colossal dimensions and cooled at the surface to barely three thousand degrees. Its light has been crossing space for nearly seven centuries: what we see tonight set out while all of Europe was dying under the Black Death of the fourteenth century.

Where it is and when to see it

Tau 1 Serpens lies in the northern celestial hemisphere. It is visible to the naked eye under a dark sky. Its best month of the year is May, when it culminates around midnight.

From London it culminates about 54° above the horizon.
From New York it culminates about 65° above the horizon.
From Sydney it culminates about 41° above the horizon.

It can be seen from anywhere north of 75° S.

It ranks no. 23 in brightness among the 65 stars of Serpens in our catalogue. To find it, start from Unukalhai, the brightest: it lies about 10° away (a fist at arm's length covers about 10°).

The light you see today left it about 690 years ago.

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Astronomical data for Tau 1 Serpens

Constellation: Serpens
Apparent magnitude: 5.16
Distance: 689.6 light years
Coordinates (J2000): RA 231.447° · Dec 15.428°
Catalogue: HIP 75530 · HD 137471

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Other stars in Serpens

Serpens has 65 stars in Stelvia's catalogue. Here are a few of them.

See all 65 stars in Serpens