Arcturus - α Boötis (alpha Boötis)
Arcturus, also designated as α Boötis (alpha Boötis), is a variable giant star in the constellation of Boötes.
Arcturus visual magnitude is -0.04, making it the third brightest star in the sky. Thanks to its high brightness, Arcturus is clearly visible when observed from locations with dark skyes, and should be also quite easily visible from light polluted areas.
The proper motion of Arcturus is -1.093 arcsec per year in Right Ascension and -1.998 arcsec per year in Declination and the associated displacement for the next 100 years is represented with the red arrow.
Key facts about Arcturus
Celestial coordinates and finder chart of Arcturus
Arcturus is situated close to the celestial equator, as such, it is at least partly visible from both hemispheres in certain times of the year. Celestial coordinates for the J2000 equinox as well as galactic coordinates of Arcturus are provided in the following table:
The simplified sky map below shows the position of Arcturus in the sky:
Visibility of Arcturus from your location
Today's Arcturus - α Boötis (alpha Boötis) rise, transit and set times from Greenwich, United Kingdom are the following (all times relative to the local timezone Europe/London):
Distance of Arcturus from the Sun and relative movement
Arcturus is distant 36.69 light years from the Sun and it is moving towards the Sun at the speed of 5 kilometers per second.
Spectral properties of Arcturus
Arcturus belongs to spectral class K1 and has a luminosity class of III corresponding to a giant star.
The red dot in the diagram below shows where Arcturus is situated in the Hertzsprung–Russell diagram.