Saturday, April 2
Mercury reaches superior conjunction with the Sun at 7 P.M. EDT. But don’t worry — in just a few short weeks, the speedy planet will achieve its best evening appearance of the year, so stay tuned for details on how to see it later this month.
Meanwhile, let’s take a look at the American Association of Variable Star Observers’ featured variable of the month: R Leonis. This star resides, as its name might imply, within Leo the Lion, who is already climbing the sky in the southeast after sunset. R Leonis is located near the great cat’s front paw, 2.2° northeast of magnitude 3.5 Subra and just over 5° west of mighty magnitude 1.4 Regulus, the Lion’s heart.
R Leonis itself is a red giant star in the latter stages of its life. It is a long-period Mira-type variable, whose magnitude ranges from 4.4 — visible with the naked eye — to 11.3, invisible without binoculars or a telescope. Fortunately for us, it recently hit a maximum just over a week ago in late March, meaning you’ll be able to spot it without any optical aid at all under good observing conditions. As its period is about 312 days, or nearly a year, R Leonis will take several months to fade to its minimum before brightening again. This spring and summer will be an excellent time to return to this star over and over again, comparing it with its nearby neighbors and watching it vanish from (naked-eye) sight. The star’s next maximum will come at the end of January 2023.
Sunrise: 6:42 A.M.
Sunset: 7:26 P.M.
Moonrise: 7:35 A.M.
Moonset: 9:06 P.M.
Moon Phase: Waxing crescent (2%)
Sunday, April 3
The delicate crescent Moon passes 0.6° south of Uranus at 1 P.M. EDT. By an hour after sunset this evening, they are just over 3° apart in Aries the Ram, setting slowly in the west.
Uranus, at magnitude 5.9, is an easy binocular object, sitting west-southwest of the Moon,’s Cheshire grin. Both float picturesquely below the stunning Pleiades open cluster, also cataloged as M45, which lies in Taurus the Bull. This young grouping of stars resembles a tiny dipper in the sky, sometimes mistaken for the much larger Little Dipper in the north. It is best enjoyed with the naked eye or low-power binoculars or a small scope, as its stars are scattered across about 110′ on the sky and won’t all fit into a high-powered field of view.
Astrophotography can bring out the delicate wisps of interstellar dust and gas surrounding the Pleiades, although this material is not, as is commonly thought, left over from the stars’ formation. Instead, it is an unrelated molecular cloud that the stars just happen to be traveling through at the current epoch in time.
Sunrise: 6:40 A.M.
Sunset: 7:27 P.M.
Moonrise: 7:59 A.M.
Moonset: 10:10 P.M.
Moon Phase: Waxing crescent (6%)
Monday, April 4
We’re gearing up for a big show: Mars passes 0.6° south of Saturn at 6 P.M. EDT. Although both planets are below the horizon at that time, they will grow even closer in the subsequent hours. Check back tomorrow for the best early-morning view as these two planets make a close (apparent, of course) pass.
Since you’ll want to be up early tomorrow morning, tonight’s observing can be done right after sunset, when the Rosette Nebula in Monoceros is some 50° high in the southwestern sky. This gorgeous deep-sky object is one of the most famous diffuse nebulae in the sky, and actually comprises both nebulae and a young open star cluster, NGC 2244. You’ll find your target just 2.2° northeast of 4th-magnitude Epsilon (ϵ) Monocerotis.
Even a small scope will capture some two dozen stars. Bump up your aperture and even more will appear. If you want to spot the nebulosity that surrounds them, consider switching back to low power and swapping in a nebula filter to reduce the stars’ glare and bring out the surrounding clouds of dust and gas instead. This object is a favorite of astrophotographers, so if you’re so inclined, give it a go!
Sunrise: 6:39 A.M.
Sunset: 7:28 P.M.
Moonrise: 8:26 A.M.
Moonset: 11:13 P.M.
Moon Phase: Waxing crescent (12%)
