Minnesota Starwatch - February 2021

Deane Morrison, University of Minnesota

February evenings offer some of the best conditions for viewing the famous winter constellations. This year they approach Mars from the east, ending the month with the Pleiades star cluster closing in on the red planet. Meanwhile, the rising of Scorpius brings a hint of summer to the morning sky.

February Starwatch

The brightest stars in the winter constellations form the corners of the Winter Hexagon. To see it, start at the top with Capella, in Auriga the charioteer, and move counterclockwise through the other corners: Pollux, the brighter Gemini twin; Procyon, in Canis Minor, the little dog; Sirius, in Canis Major, the big dog; Rigel, in Orion; and Aldebaran, in Taurus, the bull. If you start instead at Aldebaran, you can trace a “G” by turning when you get to Rigel and finishing at Betelgeuse, Orion’s right shoulder.

While viewing Orion, aim your binoculars at his sword—a line of stars that seem suspended below the three stars of his belt. On a clear moonless night you can see, even with the naked eye, a colorful, hazy “star” about halfway down the sword. This is the Orion Nebula, a chaotic cauldron of starlit gas and dust whipped by interstellar winds. At 1,300 light-years away, it is the closest large stellar nursery, where new stars—and potential planetary systems—are being born.

Orion is also home to another famous nebula: the Horsehead. Shaped like its namesake, the Horsehead Nebula is silhouetted against a glowing cloud of gas below Alnitak, the farthest left of the three stars in Orion’s belt. It is best seen in images online. 

In the predawn sky, the sinuous form of the summer constellation Scorpius rears up over the southeastern horizon. On the 6th, a hefty waning crescent moon hangs near Antares, the red heart of the scorpion. 

Groundhog Day also carries the promise of summer. It began as the astronomically based Celtic holiday Imbolc, which heralded the start of lambing season. Imbolc was one of four “cross-quarter” days falling midway between a solstice and an equinox. 

A waxing moon shines close to Mars the evening of the 18th. On the night of the 26th-27th, February’s full moon crosses the sky with the spring constellation Leo, the lion.   

The University of Minnesota’s public viewings of the night sky at its Duluth and Twin Cities campuses have been curtailed due to the COVIC-19 pandemic.