Star profile
Alpha Circinus
Variable starWhat is Alpha Circinus
Alpha Circini is the brightest star in the small constellation of the Compass, only 54 light-years away. It belongs to the rare roAp family — peculiar A-type stars with strong magnetic fields that pulse on scales of minutes, like a cosmic tuning fork. To the unaided eye it is a quiet white spark beside the foot of Centaurus, yet telescopes reveal unusual concentrations of heavy elements in its atmosphere, aligned by its magnetism, making it a well-studied curiosity of the southern sky.
Where it is and when to see it
Alpha Circinus 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 never rises above the horizon.
- From New York it never rises above the horizon.
- From Sydney it never sets and culminates about 59° up.
It can be seen from anywhere south of 25° N.
It is the brightest of the 21 stars of Circinus in our catalogue, which makes it the best starting point for finding your way around the constellation.
The light you see today left it about 54 years ago.
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A public signature from a real person. The chosen name is a symbolic denomination within Stelvia, with no official standing or IAU recognition: the sky is not for sale and belongs to no one.
Astronomical data for Alpha Circinus
- Constellation
- Circinus
- Apparent magnitude
- 3.18
- Distance
- 54.1 light years
- Coordinates (J2000)
- RA 220.627° · Dec -64.975°
- Catalogue
- HIP 71908 · HD 128898
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Other stars in Circinus
Circinus has 21 stars in Stelvia's catalogue. Here are a few of them.
- Beta Circinus4.07
- Gamma Circinus4.48
- Epsilon Circinus4.85
- Delta Circinus5.04
- Theta Circinus5.08
- Eta Circinus5.16
- HIP 730365.18
- HIP 721315.36