Monday, April 24
Asteroid 4 Vesta, the second-most massive body in the main belt, reaches conjunction with the Sun at 5 A.M. EDT. While this means it’s not visible, the No. 1 body in the belt, 1 Ceres, is readily visible this evening near the tail of Leo the Lion.
After dark, look south for the Sickle of Leo, a pattern of six stars that starts with the Lion’s brightest star, Regulus, at the bottom of the handle and ends with 3rd-magnitude Epsilon (ϵ) Leonis at the tip of the hook. Many observers think of it as a backwards question mark on the sky. Once you’ve found it, look left (east) down the Lion’s body for the tip of his tail: This is 1st-magnitude Denebola. Ceres lies 3.5° east-northeast of this star, in a region relatively devoid of bright background stars. The magnitude 7.5 dwarf planet should be relatively easy to identify with binoculars or a telescope — you can use the chart in April’s Sky This Month to guide you.
Next, move back to the Sickle for a bonus target: The galaxy NGC 2903 lies some 4° west-southwest of Epsilon (ϵ) Leonis. This 9th-magnitude galaxy can be challenging in some binoculars, but its oval-shaped glow should show up in larger pairs or through a more powerful telescope.
Sunrise: 6:09 A.M.
Sunset: 7:48 P.M.
Moonrise: 8:55 A.M.
Moonset: 12:01 A.M.
Moon Phase: Waxing crescent (21%)
Tuesday, April 25
The Moon continues along the ecliptic, passing 3° north of Mars at 10 P.M. EDT. The two are in roughly that position by sunset and an hour after the Sun disappears, they remain some 50° high in the west, hanging below 1st-magnitude Castor and Pollux.
Also setting in the west this evening is one of the largest asterisms in the sky. Now that spring has sprung, the wintertime constellations are disappearing as darkness falls, including the Winter Hexagon. It is anchored by six bright stars, all still visible above the horizon for an hour or two after. Start above the Moon and Mars at Pollux, the leftmost (eastern) Twin’s head. From there, move clockwise to Capella in Auriga, Aldebaran in Taurus, Rigel in Orion, Sirius in Canis Major, and Procyon in Canis Minor, finally closing the loop back at Pollux.
The Winter Hexagon encloses a huge area of sky that contains many rich treasures, including several bright nebulae and clusters. Soon, these stars will set at the same time or even before the Sun and the summertime constellations will fully rule the sky from dusk ‘till dawn.
Sunrise: 6:08 A.M.
Sunset: 7:49 P.M.
Moonrise: 9:48 A.M.
Moonset: 12:58 A.M.
Moon Phase: Waxing crescent (30%)