In the Sky This Month

Gamma Cassiopeia is the middle point of the letter M or W formed by the stars of Cassiopeia, which is in the north-northwest at nightfall. Gamma Cas is the most distant member of that pattern, at 550 light-years.

The glorious stars of winter are dropping from the evening sky this month. Most prominent among them are the stars of Taurus, the bull; Orion the hunter; and Canis Major, the big dog, all of which are in the west and southwest at nightfall.

The Moon reaches last quarter at 11:51 p.m. CDT. At first and last quarter, the Moon looks as though it were sliced through from top to bottom like a ripe melon. Half of the side facing Earth is in sunlight, while the other half is in shadow.

Comet C/2025 R3 PanStarrs will zip across the Great Square of Pegasus next week. It will pass closest to the Sun on April 20, and closest to Earth a week later. The comet is low in the east before and during dawn now, and may be visible through binoculars.

The most recent known supernova in the Milky Way Galaxy flared to life in 1604. Today, the remnants of the star form a rapidly expanding cloud known as a nebula. It’s at the southern edge of Ophiuchus. At dawn tomorrow, it appears to the upper right of the Moon.

NGC 2467, a nebula in the constellation Puppis, is well to the left of Sirius, the brightest star in the night sky, in early evening. It’s visible through binoculars. It’s actually several stellar nurseries that line up in the same direction.

The bright star Antares, the heart of the scorpion, climbs into good view by 1 or 1:30 a.m. tonight. It stands close to the lower left of the Moon as they rise, with the Moon inching closer to the star before dawn.

The star Beta Monocerotis is a highlight of Monoceros, the unicorn. The constellation is high in the southwest in early evening, between Orion and the “little dog” star Procyon. A telescope shows that it consists of three stars, all with a fetching blue-white color.

The faint constellation Draco, the dragon, is in the northeast at nightfall and slithers high across the north later on. One of its treasures is the Cat’s Eye Nebula, which represents the glowing remains of a dying star.

Spica, the brightest star of Virgo, rises just above the Moon early this evening. Spica consists of two big, heavy stars. The primary star is about 10 times the mass of the Sun, while the other is about seven times the Sun’s mass.