The Sky This Week from April 2 to 9

Friday, April 2
The constellation Leo is already high in the eastern sky at sunset. About an hour later, begin looking for R Leonis, the Lion’s first identified variable star and April’s AAVSO featured variable star of the month. You’ll find it about 5.1° west-southwest of bright (magnitude 1.4) Regulus or 2.2° northeast of magnitude 3.5 Subra. With binoculars or a telescope, R Leonis will appear as the ruby-colored tip of a triangle, with two yellow stars (magnitude 9 and 10) to its southwest, forming the base.

R Leonis is a cool red giant star nearing the end of its life. It is characterized as a long-period variable, much like the more famous Mira in Cetus. Its magnitude fluctuates between 5 and 10.5 over the course of about 312 days, so the star may be difficult to see if it’s near its minimum magnitude. But keep watching — over time, you’ll see this crimson star “reappear” in the sky as it brightens once more.

Sunrise: 6:42 A.M.
Sunset: 7:26 P.M.
Moonrise: 12:31 A.M.
Moonset: 10:04 A.M.
Moon Phase: Waning gibbous (69%)
*Times for sunrise, sunset, moonrise, and moonset are given in local time from 40° N 90° W. The Moon’s illumination is given at 12 P.M. local time from the same location.

Saturday, April 3

Magnitude 5.7 M5 is the brightest globular cluster in the Northern Hemisphere. You can find it in the constellation Serpens after it clears the horizon around 9:30 P.M. local time and climbs higher as the night progresses. Fortunately, there’s no Moon yet.

Look 11.5° due north of magnitude 2.6 Zubenesch (Beta [β] Librae) to find M5, which actually sits 24,500 light-years away. If you’re in a dark location, you may spot a fuzzy patch without optical aid. Binoculars or a telescope will definitely make this ancient grouping of stars easier to locate. Through even a small instrument, you’ll see the cluster’s “grainy” nature. And the larger your scope, the more cluster stars you’ll see. (In fact, William Herschel was the first to resolve M5 into stars in 1791, although it had been discovered earlier that same century.)

Sunrise: 6:40 A.M.
Sunset: 7:27 P.M.
Moonrise: 1:42 A.M.
Moonset: 10:57 A.M.
Moon Phase: Waning gibbous (58%)

Sunday, April 4
Last Quarter Moon occurs today at 6:02 A.M. EDT. Two hours later, asteroid 9 Metis reaches opposition at 8 A.M. EDT in the constellation Virgo. Early risers can find the magnitude 10 asteroid about 3.4° southeast of Auva (Delta [δ] Virginis).

For those who celebrate Easter, there’s an Easter Rabbit waiting in the sky for you tonight. After sunset, look southwest to spot the stars of the constellation Lepus the Hare, who sits at the feet of Orion the Hunter. The Hare contains about a dozen easily visible stars scattered over 290 square degrees, or 0.7 percent of the sky. Its brightest stars are magnitude 2.6 Arneb and magnitude 2.9 Nihal.

To find Lepus, locate magnitude –1.4 Sirius, the Northern Hemisphere’s brightest star. Lepus lies due west of this star and due south of a line connecting Orion’s knees (Rigel and Saiph). The Hare contains one Messier object: magnitude 7.7 globular cluster M79, easily visible with binoculars or a small scope. You’ll find it 3.5° south-southwest of Nihal.

Sunrise: 6:39 A.M.
Sunset: 7:28 P.M.
Moonrise: 2:43 A.M.
Moonset: 11:57 A.M.
Moon Phase: Last Quarter

Monday, April 5
Saturn’s largest and brightest moon, Titan, passes due south of the ringed planet today, although the event occurs during daylight hours in North America. Two hours before sunrise, Saturn is already nearly 6° high and rising in Capricornus the Sea Goat. The Moon, now roughly 40 percent lit, lies nearly 14° to its southwest, just over the border in Sagittarius. Our satellite will pass close to Saturn tomorrow morning.

Magnitude 8.8 Titan currently sits about 54″ southeast of the planet. Over the next several hours, it will progress west until it passes due south of the planet. Smaller moons Rhea, Tethys, and Dione may also be easily visible, closer to Saturn’s rings. Mimas and Enceladus also float nearby, while Iapetus lies a considerable 5.5′ to the planet’s west.

Sunrise: 6:37 A.M.
Sunset: 7:29 P.M.
Moonrise: 3:36 A.M.
Moonset: 1:01 P.M.
Moon Phase: Waning crescent (36%)