Special to CosmicTribune.com, December 3, 2024

Excerpts from weekly Sky&Telescope report.

MONDAY, DECEMBER 2

■ Two faint fuzzies naked-eye. The Andromeda Galaxy (M31) and the Perseus Double Cluster are two of the most famous deep-sky objects. They’re both cataloged as 4th magnitude, and in a moderately good sky you can see each with the unaided eye. Binoculars make them easier. Did you know they’re only 22° apart? They’re very high toward the east early these evenings — to the right of Cassiopeia and closer below Cassiopeia, respectively. They’re nearly overhead later.

TUESDAY, DECEMBER 3

■ As twilight fades, spot the crescent Moon, just under three days old for North America, about a fist at arm’s length lower right of Venus — as shown under December 4 below.

■ The Double Cluster may be Perseus’s most famous deep-sky object, but it’s neither the biggest nor the brightest! That distinction goes to the big Alpha Persei Association. Binoculars are the perfect instrument for this swarm of stars born in the same area around the same time. It’s called an “association” rather than a “cluster” because it’s not gravitationally bound; its stars will simply drift apart.

The Alpha Per Association appears about 3° long, the size of your thumbprint at arm’s length. That’s roughly half the width of a typical binocular’s field of view. Find it running toward celestial south-southeast from Perseus’s brightest star.

WEDNESDAY, DECEMBER 4

■ Catch the Moon paired with Venus during twilight and for an hour or so after dark, as shown below. When seen from the Americas they’ll be just 2° or 3° apart.

Think photo opportunity. Zoom way in and frame the Moon and Venus with interesting foreground. Prop your phone up on something solid, or mount your camera on a tripod, to prevent wiggles during what may be a relatively long exposure.

First the waxing Moon passes Venus on the evening of the 4th . . .

THURSDAY, DECEMBER 5

■ Now the thickening crescent Moon hangs about 12° upper left of Venus, as shown above.

FRIDAY, DECEMBER 6

■ Orion comes into good view low in the east-southeast after dinnertime now. And that means Gemini is also coming up to its left (for the world’s mid-northern latitudes). The head stars of the Gemini twins, Castor and Pollux, are at the left end of the Gemini constellation — one over the other, with Castor on top. The stick figures of the Twins are lying on their sides, with their feet toward Orion.

■ This is also the time of year when M31, the Andromeda Galaxy, passes your zenith after dinnertime (if you live in the mid-northern latitudes). The exact time depends on your longitude. Binoculars will show M31 just off the knee of the Andromeda constellation’s stick figure.

SATURDAY, DECEMBER 7

■ Saturn shines about 5° upper left of the Moon this evening, as shown below for North America. Although they may look like companions, Saturn is currently 3,900 times farther away. The Moon and Saturn are the nearest and farthest solar-system objects that are easily visible to the naked eye.

. . . Then the Moon hops past Saturn between the North American evenings of the 7th and 8th.That star near the Moon on the 6th is Delta Capricorni, magnitude 2.8. (The Moon’s actual apparent position against its background will always depend a bit on your location.)

■ Jupiter is at opposition.

■ Earliest sunset of the year (if you’re near latitude 40° north). By the time of the solstice and longest night on December 21st, the Sun sets 3 minutes later than it does now. The latest sunrise doesn’t come until January 4th. These slight discrepancies arise from the tilt of Earth’s axis and the ellipticity of Earth’s orbit.

SUNDAY, DECEMBER 8

■ First-quarter Moon (exact at 10:27 a.m. EST on this date). The Moon shines upper left of Saturn this evening, as shown above.

■ After darkness is complete, can you make out the dim Circlet of Pisces less than a fist-width above the Moon? Its stars are only 4th and 5th magnitude. Cover the glary Moon with your finger to help them show.

Still too much light pollution? Try binoculars. The Circlet is 7° wide and 5° tall, slightly overspilling the field of view of typical binoculars. Sweep around just a little bit to pick up all seven of the Circlet’s stars.

The Circlet’s easternmost (leftmost) star is the carbon star TX Piscium. It’s strikingly redder than ordinary “red” stars, which look more like orange or yellow-orange. We see carbon-rich stars through C₂ vapor in their atmospheres, which acts as a red filter.

■ By midnight the Dipper stands straight up on its handle in fine view in the northeast, while Cassiopeia has wheeled down to the northwest to stand nearly upright on the bright end of its W shape.

  Dec. 2-8, featuring M31, the Andromeda Galaxy, The Sky