Regulus: Bright and Blue Heart of the Lion

Regulus, a bright blue and hot star of the spring and summer sky, makes its home in the constellation Leo. This beautiful star is the 21st-brightest star in the night. Before Copernicus gave the star its current name, ancient Babylonians referred to it as the “Kingly Star.” Meanwhile, ancient Arab stargazers looked upon this blue and referring to it by the name Qalb al-Asad, which means Heart of the Lion. As size and brightness goes, Regulus is 3.5 times the size of our sun and 140 time more luminous. It’s no wonder it burns bight in the night at a distance of 77 light years away.

Regulus has several star companions. Two of them (known as “a Leo B” and “a Leo C”) are bright enough to be viewed through small telescopes. a Leo B is an orange-red star, and provides a nice contrast to Regulus’ bright blue hue.

My Observations

On this night, the moon is washing out so much of the sky, so I know I’m missing fainter stars in this eyepiece field. However, Regulus’ companion Leo B comes through fine appearing like a small ruby laid down near a blue topaz.

Key Stats

Constellation	Leo
Best Viewing	Spring
Visual Magnitude	+1.4 | +8.2
Absolute Visual Magnitude	-.53
Distance from Earth	79 ly
Separation	177″ | 5000 AU
Orbital Period	130,000+ years
Milky Way Location	Orion Spur
My Viewing Grade	A

Sources and Notes

Banner shared under the Creative Commons Attribution-Share Alike 4.0 International license. Illustration by Pablo Carlos Budassi. Details here.

Sketch by Wayne McGraw

AKA: Alpha Leonis, SAO 98967, 32 Leo, Kalb