α Leonis

Alpha Leonis is now called Regulus, as named by Copernicus. Previously it was known as Sharru, "King", and before that it went by the auspicious name of 'Guardian of the Heavens'. The Romans called it Cor Leonis, the Lion's Heart.

Regulus is easily found, as it is one of the brighter stars of the early spring.

The blue-white star has a deep yellow companion -- a dwarf : 1.4, 8.2; 307, 175.2".

Large telescopes will show that this dwarf has its own companion, a very faint thirteenth-magnitude dwarf.

Since Regulus is found so close to the ecliptic, it is one of the few bright stars occasionally occulted (briefly blocked out) by the moon.


West of alpha Leonis one and a half binocular fields is omicron Leonis as well as several interesting neighbours:
      7 Leonis is a binocular binary: 6.3, 9.4; 90, 41.0".
      R Leonis is a Mira-type variable which achieves naked-eye visibility (around 4.4) every 310 days. Click on R on the map for more details.

Moving back to alpha, now move one and a half binocular fields north of alpha to find eta, which is half way between alpha and gamma Leonis.

In this same field is the binary Struve 1399, a yellow-whitish primary with a bluish-white companion: 7.7, 8.4; 175, 30.6".

Back to alpha and this time move eastward two binocular fields. This region, between 52 and 53 Leonis has a number of galaxies which go under the collective name The M96 Group. We only indicate the three Messier objects here; there are about a dozen galaxies here for large telescopes.

Click on M96 for more details.

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1999-2014 by Richard Dibon-Smith.