This is Dudley Observatory’s Skywatch Line for Friday, January 25 through Sunday, January 27, written by Sam Salem.
On Friday, the Sun rises at 7:17am and sets at 4:59pm; the waning gibbous Moon rises at 10:38pm and sets at 10:16am. The Moon reaches last quarter phase at 4:10pm on Sunday, however, it doesn’t rise until after 1am on Monday.
Mars, at magnitude 0.8, hovers in the south-southwest in the evening. The sole evening planet is still a conspicuous sight amid the faint stars of constellation Pisces. Mars sets around 11pm. Venus and Jupiter rise a few minutes after 4am. Venus has been steadily losing altitude while Jupiter has been gaining. The two planets pass in the dawn as the magnitude –4.4 Venus slowly slips by the magnitude –1.8 Jupiter. If you have an unobstructed east-southeast horizon, try to find Saturn using binoculars. It’s just now slowly emerging from its January 2nd. solar conjunction. Saturn shines at magnitude 0.5, and rises roughly one hour before the Sun.
Winter constellations are climbing higher in the early evening as the end of January nears. Evenings over the weekend are moon-free, allowing for some winter deep-sky hunting. One of the season’s most recognizable shapes is the distinct W of Cassiopeia, now high overhead. Cassiopeia is home to two Messier clusters, M52 and M103, as well as several rich NGC clusters. You can spend a rewarding hour or two with a small telescope exploring the stellar swarms located just between the stars Delta (δ) and Epsilon (ε) Cassiopeiae. Begin your hunt with M103, which is found just one degree northeast of 2.6-magnitude star Delta. M103 glows at magnitude 7.4. You can easily see it with binoculars. M103 is a tight knot of stars that features a few standout members brighter than magnitude 8. From M103, it’s a short hop northeast to NGC663, the region’s other bright open cluster. NGC 663, also known as Caldwell 10, is a young open cluster of about 400 stars in the Cassiopeia constellation. It spans about a quarter of a degree across the sky. It can reportedly be detected with the unaided eye. It looks conspicuous in binoculars as the brightest members of the cluster can be viewed.
M 52 is another bright open cluster located in constellation Cassiopeia. Messier 52 can easily be seen with binoculars. In 10×50 binoculars, it appears as a hazy, nebulous patch of light. 4-inch telescopes reveal a dense, compressed star cluster populated by many faint stars, with a shape resembling that of the letter V. More stars are visible in 6-inch and larger instruments. The cluster occupies an area just less than half of the size of the full Moon. M 52 is very easy to find as it lies near Cassiopeia‘s prominent W asterism. The cluster can be located by extending the line from the stars Schedar (Alpha Cassiopeiae) to Caph (Beta Cassiopeiae) to the northwest, about the same distance as that between the two stars. Messier 52 lies near another prominent deep sky object, the Bubble Nebula (NGC 7635). The nebula can be seen about 35 arc-minutes southwest of the cluster.