Leo: A Constellation of Spring

by Gary Madison [hakuna@pacific.net] 

Leo rising is a sure sign that spring is on it's way.  Though primarily a constellation full of dimmer spiral galaxies, Leo has some other objects to observe, even with a smaller telescope or binoculars.

STARS:

One of the most easily recognized asterisms in the night sky is the "sickle" of Leo. At the base of the handle is Regulus, alpha Leo. Regulus is a multiple star system with the primary pair easily split in a small scope (177" PA307). The 7.9 mag companion star provides a greater challenge, being only 2.6" away from its dimmer 13 mag partner.

Moving up the sickle, gamma Leo is a fine double for medium scopes with a 4.4" (PA 124) separation and similar magnitudes of 2.2 and 3.5.  

54 Leo is a beautiful pair with a separation of 6.5" (PA 110). At magnitudes 4.5 and 6.3 this is a great double for the medium to small scope. One star is white and the other blue.

WOLF 359 is fascinating, not only for being the location of a fictional grand battle against the Borg, but because it is the third closest star to our own solar system at 7.75 light years. With a magnitude of 13.5 and its large apparent motion, the challenge is to find this dim red dwarf.

R Leonis is a "Mira" type variable. This is a large red giant which varies in brightness over the course of approximately a year from about 5th magnitude to 10th . . . worth a look just for its color!

GALAXIES:

M65 and M66 are terrific galaxies for small scopes. I've managed to see them in dark skies with 8x24 binoculars--barely. In a telescope the nearby NGC 3628 is an excellent edge-on galaxy that completes this "Leo Triplet." One wonders how Messier missed it, with a similar magnitude as M65 (10.3), particularly with his later telescopes.

M95, M96, and M105 are bright galaxies in the same area of Leo. M95 and M96 are bright magnitude 11.0 and 10.2 galaxies. M105 itself is in a tight group with NGC 3384 and NGC 3389. If you can get to mag 12.2 then all three of the M105 group can be in the same field of view.

Other bright galaxies:

NGC 3626  (Caldwell 40) is mag 10.9
NGC 3521 is mag 10.2
NGC 2903 is mag 9.7

TOUGHER OBJECTS:

The "Gamma Group" is an excellent grouping of 4 or 5 galaxies near Gamma Leo. NGC 3193 is elliptical with spirals NGC 3187, NGC 3190, and NGC 3185 nearby. A bit further southwest one can find NGC 3177. These galaxies have magnitudes of 12.0, 13.6, 12.0, 12.7, and 12.8 respectively. 

For those of you with larger apertures there is a dim galaxy group that should give you a challenge. Copeland's Septet is made up of NGC 3745/46, 3748, 3750/51, and 3753/54. The magnitudes range from 13.6 to 15.2!