Skywatch Line for Friday, March 22, through Sunday, March 24, 2024 written by Sam Salem
This is Dudley Observatory’s Skywatch Line for Friday, March 22, through Sunday, March 24, written by Sam Salem.
On Friday, Sun rises at 6:54am and sets at 7:11pm; Moon sets at 6:07am and rises at 4:44pm.
On Friday evening, the waxing gibbous Moon will float near the bright star Regulus, the brightest star in Leo the Lion. They’ll be visible through dawn. The Moon will reach apogee, its farthest distance from Earth in its elliptical orbit around Earth on Saturday, when it’s 252,459 miles away. Full Moon at 3:00am Monday morning. It’ll be the second smallest, most distant, full Moon this year.
On Sunday, look for Mercury lower right of Jupiter as twilight fades. Jupiter is magnitude –2.1. Mercury is magnitude –0.1. Mercury is very low due west in evening twilight. The best time to look might be about 45 minutes after sunset, depending on the clarity of your air. Mercury is very far below Jupiter and a somewhat to the right. It’s brighter than it often is, but watch it fade in the next few nights from magnitude –1 to 0.
Jupiter, at magnitude –2.1 in the constellation of Aries, is the bright white “star” in the west in twilight, and lower later. In a telescope Jupiter has shrunk to only 35 arcseconds wide, and the seeing has also been getting worse as Jupiter moves lower every week. It’s almost as distant and small as we ever see it.
Arcturus, the “Spring Star,” now rises above the east-northeast horizon just around the time the stars come out. Once Arcturus is nicely up, look for the narrow Kite asterism of Boötes extending two fists to its left. The left end of the Kite is bent slightly up.
The fall-and-winter constellation Cassiopeia retreats down after dark. Look for it in the north-northwest. It’s standing roughly on end. For skywatchers at mid-northern latitudes and farther north, Cassiopeia is circumpolar, never going away completely. By 1 or 2 a.m. it will be at its lowest in the north, lying like a not quite horizontal W.
Recent observations, as of March 14, reported by the American Association of Variable Star Observers (AAVSO) indicate Betelgeuse has dimmed by about 0.5 magnitude since late January this year. Betelgeuse is a variable star, so a change in brightness isn’t unusual. However, it is currently dimmer than it has been in the last few years. Does that mean we are going to have another Great Dimming of Betelgeuse like we had in 2019-2020?