Leo - under construction

The constellation Leo lies between 40 and 60° above the horizon just E of due S at 22:00 UT around the middle of March.  It will clearly lie elsewhere at other times of the year.

Its most distinctive feature is the “backwards question-mark” shape of six bright stars that represents the Leo’s mane, sometimes called “The Sickle”.

The bottom star of the Sickle is Regulus, at magnitude +1.34 the brightest star in Leo and its immediate area, and the 21st brightest star in all the sky.  Binoculars show that Regulus is a double star whose companion is also a double.

The second star up , eta Leo, is of magnitude +3.46, and the third star, Algieba, magnitude +2.00, is another double star. The second star of the double is just about visible with the naked eye, and a telescope shows that both stars are a yellow/orange colour.

The fourth star, Adhafera (magnitude +3.40), has been incorrectly allocated to the constellation Leo. Its name translates to "lock of hair", and really belongs to the nearby constellation Coma Berenices (Berenice's Hair).  It is yet another double with a 6th magnitude companion, but the two stars are not gravitationally connected - its purely a line of sight effect.

Rasalas (magnitude +4.1) is reddish-orange in coiour, and the final star of the Sickle, epsilon Leo, also known as Ras Elased Australis, is a yellow star of magnitude +2.96.