Star profile

Brachium

Sigma Librae · Libra

Variable star

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

What is Brachium

Brachium, «the arm» in Latin, extends one of the pans of Libra. A red M-class giant 288 light years away, it is a late-stage star that has swollen its atmosphere after exhausting the hydrogen at its core. Slow pulsations make it a semiregular variable: a brightness that beats with the laziness of an ancient heart across almost three centuries of travel.

Where it is and when to see it

Brachium lies in the southern 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 13° above the horizon.
From New York it culminates about 24° above the horizon.
From Sydney it culminates about 81° above the horizon.

It can be seen from anywhere south of 65° N.

It ranks no. 3 in brightness among the 49 stars of Libra in our catalogue. To find it, start from Zubeneschamali, the brightest: it lies about 16° away (a fist at arm's length covers about 10°).

The light you see today left it about 290 years ago.

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Astronomical data for Brachium

Constellation: Libra
Apparent magnitude: 3.25
Distance: 288.4 light years
Coordinates (J2000): RA 226.018° · Dec -25.282°
Catalogue: HIP 73714 · HD 133216

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Other stars in Libra

Libra has 49 stars in Stelvia's catalogue. Here are a few of them.

See all 49 stars in Libra