Evening sky with Milky Way over tree silhouettes

Minnesota Skies: November 2020

Your local guide to observing celestial objects and events

Published10/26/2020 , by Thaddeus LaCoursiere and Deane Morrison

Despite the recent (and ongoing) (and upcoming) snow, it’s still fall and as you shake off your sugar rush from the Halloween (physically distanced) festivities. In celebration of the season’s snow (and to try to distract from it), head out and take a look at some of these deep sky objects.

Across the sky from the east to west, the Milky Way Galaxy arches over our heads. Observing it on cold fall nights is always a delight, try to head out when there’s a new Moon, or early in the evening during the waning crescent Moon. Without the distracting moonlight, the gaseous clouds and millions of stars are that much easier to see.

The Milky Way isn’t the only galaxy you can spot this time of year with the unaided eye. Positioned almost perfectly at the zenith is Messier 31, the Andromeda Galaxy, appearing as a faint smudge under dark skies. Named after the constellation it appears near, this the closest major galaxy to our own. Keep a close eye on M31, though—at a little over 70 miles per second, it’s moving closer and closer to the Milky Way, and we’re due for a collision in about five billion years.

That’s a lot of time to go before the fireworks start, so skip over to the other side of the band of the Milky Way, near the bright star Alderamin in Cepheus, the King. Just three finger widths the west of the star is the Fireworks Galaxy, or Caldwell 12. An extraordinary 10 supernovae have been observed in the galaxy’s spiral arms since 1917! Despite all this activity, you’ll still need a telescope to observe it. It’s only about a third of the size of the Milky Way, and 25 million light years away (10 times farther than M31!).

Five billion years is also a lot of time for our own Sun. It’s about that age now and has about that long to go before the end of its life. When the Sun starts to die, it will expand outward and become a red giant, filling up our solar system almost to the orbit of Mars! This is a short part of the Sun’s life, lasting probably just a few million years at most. With such a short time spent in this stage, there are only a few red giant stars we can see: Betelgeuse, in the shoulder of Orion, the Hunter, is one of the best known. There’s also Aldebaran, the eye of Taurus, the Bull; Hamal in Aries, the Ram; and Herschel’s Garnet Star, or Mu Cephei in Cepheus.

With a long night of observing drawing to an end, you might be ready to pack it up and head to warmer quarters, but don’t leave quite yet. Just like a star, stick around for a little while longer (just a few tens of thousands of years) and observe some planetary nebula: the last remains of a small star’s life. One striking example this time of year takes you back toward M31, where, one and a half fist lengths higher in the sky, you can observe the Blue Snowball Nebula, or NGC 7662. Formally a part of Andromeda, the Princess, it can be easier to find if you look for the Great Square of Pegasus (the Winged Horse). The two stars making the top line of the Square—Alpheratz and Scheat—also form the bottom of a triangle if you connect them to the Blue Snowball, again, about one and a half fist lengths up from those two stars. This nebula gets its name from the oxygen present in the outer layers of the star atmosphere. The oxygen is being heated by the remains of the star, which has collapsed down into a white dwarf.

A blue snowball and a white dwarf are a fitting conclusion to stargazing in an almost wintery wonderland, so as you take your last look for the night, remember to stay warm and stay safe as we head into the even colder months.

As dawn prepares to break on November 1, Venus and a bright round Moon face each other across an expanse of sky sparkling with the stars of the winter constellations.

Venus holds its ground as the Moon works its way eastward toward the shimmering planet. As it goes, the Moon wanes to a thin crescent that hangs above Venus on November 12. On November 13, the Moon and Venus form a triangle with Spica, Virgo’s brightest star. With sharp eyes, you may see Mercury very low beneath the Moon that morning.

Spica also begins the month below Venus, but glides past the planet between November 17 and 19. By month’s end, Spica and Venus will be far apart and Arcturus, the brightest star in Bootes, the herdsman, will shine high to the left of Venus.

Meanwhile, the winter constellations are making their grand entrance into the evening sky. They appear one by one, earlier every night. When the hourglass form of Orion, the hunter, climbs over the eastern horizon, you’ll know that Sirius, the night sky’s brightest star, won’t be far behind.

Mars, still fairly bright, is well up in the east to southeast at nightfall. Over the night of the November 25–16, a bright gibbous Moon rises and sets with the red planet. Brilliant Jupiter and dimmer Saturn come out in the south to southwest. Watch as they drift farther westward, drawing closer to each other all the while. Both are moving eastward against the background of stars, but Jupiter moves faster and gains steadily on the ringed planet. Go out close to nightfall on November 18 and 19 to see a crescent Moon shining near them. In December, Jupiter sweeps by Saturn in a very close encounter.

The Leonid meteor shower peaks after midnight the morning of November 17. Meteors radiate from the Sickle—the backward question mark of stars outlining the head of Leo, the lion. No Moon will interfere, and you may see 10 to 15 meteors per hour.

November’s full Moon reaches perfect fullness at 3:30 a.m. on the 30th. It rises the evening of the 29th, between Aldebaran, the eye of Taurus, the bull, below; and the Pleiades star cluster above.