Three or four double stars in the constellation Leo

 The constellation Leo currently stands high in the sky during the late evening.  This constellation has several attractive double stars that are good targets for small telescopes.  

Three of the stars shown here are gravitationally-bound binary systems.  They are Algieba (Gamma Leonis), 54 Leonis, and 83 Leonis.  A fourth star, Tau Leonis, is classified as an optical double, but it forms a close pair with 83 Leonis, thus forming one half of a "double double".

 

Some double stars in Leo.  E-M1iii + Lumix 20mm f/1.7 + sparkle-6 filter.

credit: SkySafariAstronomy.com

Algieba, Gamma Leonis, is in the "shoulder" of the lion.  The two components have magnitudes of 2.4 and 3.6 and are separated by 4.6 arcsec.  They are easily seen with magnifications of 100x or 150x and form a golden pair of K and G-type stars.

Algieba.  Celestron C6 + E-M5iii.  ISO 200, 1/10 s. stack of three images.

 The double star 54 Leonis is situated on the back of the lion.  This pair of bluish A-type stars has magnitudes of 4.5 and 6.3, separated by 6.3 arcsec.

 

54 Leonis.  Celestron C6 + E-M5iii.  ISO 400, 1/4 s.  Stack of four.

83 Leonis and Tau Leonis form a "double double" in the southern part of Leo.  The 83 Leonis pair consists of magnitudes 6.6 and 7.5, separated by 28.6 arcsec.  The primary is a K-type star slightly larger than our sun.

Tau Leonis is nominally classified as an optical double.  The G-type main star has magnitude 5.1 and is separated from its magnitude-7.5 companion by 88 arcsec.  If the companion is at the same distance (560 ly), then the stars are separated by about 0.24 ly.  The gravitational connection would be tenuous at this distance.

83 Leonis and Tau Leonis.  Orion 80mm ED f/7.5. ISO 1600, 15 s.

 The Santa Fe sky was a slightly darker than average, sqml=19.84, when this image was taken.