Arcturus

|- bgcolor="#FFFAFA" | Note (category: variability): || H and K emission vary.

AI overview

I don't have enough context to write an accurate 2-sentence overview. The provided information only mentions that Arcturus shows variable H and K emission, which is a technical detail insufficient for a general reader to understand what Arcturus is or why it matters.

AI-generated from the Wikipedia summary — may contain errors.

Wikidata facts

Distance from Earth: 36.7
Radius: 25.4
Mass: 1.3
Image: Arcturus (optical).png

Show 17 more facts

Commons category: Arcturus
spectral class: K0III
catalog code: UBV M 20076
color index: 1.27
apparent magnitude: -2.911
absolute magnitude: -0.304
parallax: 0.12
metallicity: -0.52
radial velocity: -4.45165
right ascension: 213.915300295
declination: 19.182409162
effective temperature: 4291
stellar rotational velocity: 8
surface gravity: 20
right ascension component of proper motion: -1093
luminosity: 215
declination component of proper motion: -1998

Sources (5)

via Wikidata · CC0

~19 min read

Article

13 sections

Contents

Nomenclature
Observational history
Observation
Physical characteristics
Spectrum
Oscillations
Search for planets
Mythology
Cultural significance
In popular culture
References
Further reading
External links

|- bgcolor="#FFFAFA" | Note (category: variability): || H and K emission vary.

Arcturus is a red giant star in the northern constellation of Boötes, and the brightest star in the constellation. It has the Bayer designation α Boötis, which is Latinized to Alpha Boötis and abbreviated Alf Boo or α Boo. With an apparent visual magnitude of −0.05, it is the fourth-brightest star in the night sky and the brightest in the northern celestial hemisphere. Arcturus forms one corner of the Spring Triangle asterism.