Visibility
Arcturus has a visual magnitude of −0.04, making it the brightest star north of the celestial equator, and the fourth brightest star in the night sky. However, Alpha Centauri is a bright binary star, whose unresolved components to the naked eye are both fainter than Arcturus. This makes Arcturus the third brightest individual star, just ahead of Alpha Centauri A (α Cen A), whose visual magnitude is −0.01.
Arcturus is visible from both hemispheres in the sky, as it is located less than 20 degrees north of the celestial equator. The star culminates at midnight on 27 April, and at 9PM on June 10 being visible during the late northern spring or the southern autumn. From the northern hemisphere, an easy way to find Arcturus is to follow the arc of the handle of the Big Dipper. By continuing in this path, one can find Spica, "Arc to Arcturus, then spike to Spica." The star is also a member of the Local Interstellar Cloud.
Eta Bootis, or Muphrid, is only 3.3 light years distant from Arcturus, and would have a visual magnitude -2½, whereas an observer on the former system would find Arcturus as bright as Venus as seen from Earth.
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