This is the Dudley Observatory Skywatch Line for Wednesday, June 24th, and Thursday, June 25th, written by Louis Suarato.
The 17% illuminated, waxing crescent Moon sets at 11:34 p.m., Wednesday. Look for M44, the Beehive Cluster, to the Moon’s lower left. Thursday, the Moon moves into the constellation Leo, and will be about 6 degrees above its brightest star, Regulus. Over the eastern horizon, the asterism known as the Summer Triangle can be seen. The lowest star is Altair in Aquilla, to its upper left is Deneb in Cygnus, and completing the triangle is Vega in Lyra. Jupiter rises in the southeast, in the constellation Sagittarius, at 9:48 p.m., followed by Saturn 19 minutes later. Mars rises in Pisces 48 minutes after midnight. Venus is back in the pre-dawn sky. Look for Venus as it rises at 3:44 a.m. in Taurus.
To the upper left of the Moon, between Bootes’ brightest star, Arcturus, and Leo’s brightest star, Regulus, is a star cluster known as Melotte 111, in the constellation Coma Berenices. The 40 brightest stars within this cluster form a distinctive “V” shape. The Coma Star Cluster, as it is also known, covers 7.5 degrees, an area about twice the size of the Hyades Star Cluster. The stars within Melotte111 are approximately 350 million years old, and about 280 light-years away, making it the second nearest star cluster, after the Hyades. Coma Berenices was originally the tail of Leo before it became one of the 88 modern constellations. It was named for Ptolemy’s wife. Coma Berenices is not large, but it contains one galactic supercluster, two galactic clusters, one star cluster, and eight Messier objects, including several globular clusters. The Coma Cluster (Abel 1656) is one of the largest galaxy clusters, containing approximately 10,000 galaxies, mostly elliptical. Due to their distance. 230 to 300 million light-years away, most are only visible through large telescopes.