The sky this week from April 1 to 8
saturday april 2
Mercury reaches superior conjunction with the Sun at 7:00 p.m. EDT. But don’t worry – in just a few short weeks, the speedy planet will be making its best party appearance of the year, so stay tuned for details on how to see it later this month.
In the meantime, 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 suggests, in Leo the Lion, which already climbs the sky in the southeast after sunset. R Leonis is located near the big cat’s forelimb, 2.2° northeast of magnitude 3.5 Subra and just over 5° west of mighty magnitude 1.4 Regulus, the heart of Leo.
R Leonis itself is a red giant star in the later stages of its life. It is a long-period Mira-like variable, ranging in magnitude from 4.4 – visible to the naked eye – to 11.3, invisible without binoculars or a telescope. Luckily for us, it recently peaked just over a week ago at the end of March, meaning you’ll be able to spot it without any optical aids in good viewing conditions. Since her period is around 312 days, or nearly a year, R Leonis will take several months to fade to its minimum before it clears again. This spring and summer will be a great time to revisit this star again and again, compare it with its close neighbors, and watch it disappear from view (with the naked eye). The next maximum of the star will arrive at the end of January 2023.
Sunset: 7:26 p.m.
Moonrise: 7:35 am
Moon setting: 9:06 p.m.
Moon phase: Wax Crescent (2%)
Sunday April 3
The delicate crescent Moon passes 0.6° south of Uranus at 1:00 p.m. EDT. An hour after sunset tonight, they are just over 3° apart in Aries the Aries, slowly setting to the west.
Uranus, at magnitude 5.9, is an easy binocular object, sitting west-southwest of the Moon, according to the Cheshire Smile. Both float picturesquely beneath the magnificent open cluster Pleiades, also cataloged as M45, which is found in Taurus Taurus. This young cluster of stars looks like a small dipper in the sky, sometimes confused with the much larger dipper in the north. It is best appreciated with the naked eye or with low-powered binoculars or a small telescope, as its stars are scattered about 110 feet across the sky and not all of them fit within the high-powered field of view.
Astrophotography can bring out the delicate streaks of interstellar dust and gas surrounding the Pleiades, though this material is not, as is commonly thought, a leftover from star formation. Instead, it’s an unrelated molecular cloud that stars pass through in the present day.
Sunrise: 6:40 a.m.
Sunset: 7:27 p.m.
Moon setting: 10:10 p.m.
Moon phase: Wax Crescent (6%)
Monday april 4th
We’re gearing up for a big show: Mars passes 0.6° south of Saturn at 6:00 p.m. EDT. Although the two planets are below the horizon at this time, they will approach even closer in the following 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 get up early tomorrow morning, tonight’s observation can be made just after sunset, when the Rosetta Nebula in Monoceros is about 50° high in the southwestern sky. This beautiful deep sky object is one of the most famous diffuse nebulae in the sky and actually includes both nebulae and a young open star cluster, NGC 2244. You’ll find your target just 2.2° down. northeast of 4th magnitude (ϵ) Epsilon Monocerotis.
Even a small telescope will capture about two dozen stars. Increase your openness and even more will appear. If you want to spot the nebulosity around them, consider switching back to low power and swapping out a nebula filter to reduce star glare and bring out surrounding clouds of dust and gas instead. This object is one of the favorites of astrophotographers, so if you feel like it, give it a try!
Sunset: 7:28 p.m.
Moon setting: 11:13 p.m.
Moon phase: Wax Crescent (12%)