Special to CosmicTribune.com, December 26, 2023, 2023

Excerpts from weekly Sky&Telescope report.

TUESDAY, DECEMBER 26

■ Full Moon tonight (exact at 7:33 p.m. EST). Now shining above the feet of Gemini in the evening, the Moon forms a deeper triangle with Capella and Aldebaran than it did last night.

WEDNESDAY, DECEMBER 27

■ As the stars come out, face due north and look high. Cassiopeia is now a flattened M shape canted at about a 45° angle (depending on where you live). Hardly more than an hour later, the M has turned horizontal! Constellations passing near the zenith appear to rotate rapidly with respect to your direction “up.”

THURSDAY, DECEMBER 28

■ Orion strides upward in the east-southeast after dinnertime. Above it shines orange Aldebaran, 1st magnitude, with the large, loose Hyades cluster in its background. Binoculars are the ideal instrument for this cluster given its size: its brightest stars (4th and 5th magnitude) span an area about 4° wide. Higher above, the Pleiades are hardly more than 1° across if you count just the brightest stars.

FRIDAY, DECEMBER 29

■ This is the time of year when M31, the Andromeda Galaxy, passes your zenith soon after dark (if you live in the mid-northern latitudes). The exact time depends on your longitude. Binoculars will show M31 as a small, dim gray elongated glow just off the knee of the Andromeda constellation’s stick figure.

Venus still shines brightly at dawn. As dawn swells, use binoculars or a wide-field telescope to try for much more difficult Antares and Mercury, and maybe even fainter, lower little Mars. For a sense of scale, Antares is 11° below Venus this morning and Mars is 5° below Mercury.

SATURDAY, DECEMBER 30

■ The brightest asteroid in the sky, 4 Vesta, is just past opposition and creeping toward Zeta Tauri, the dimmer horntip of Taurus near the top of Orion’s club. Binoculars will show Vesta easily at magnitude 6.5.

Vesta will pass 0.2° from Zeta Tau on the nights of January 7th and 8th. Then it will cruise about ½° south of the dim Crab Nebula, M1, on January 11th, 12th, and 13th.

SUNDAY, DECEMBER 31 – MONDAY, JANUARY 1

■ After the noise and celebration at the turning of midnight tonight, step outside into the silent, cold dark. The waning gibbous Moon will be shining high in the east, with the Sickle of Leo floating about a fist at arm’s length above it.

In the south Sirius will be shining at its highest, with the other bright stars of Canis Major to its right and below it.

Sirius is the bottom star of the bright, equilateral Winter Triangle. The others are Betelgeuse in Orion’s shoulder to Sirius’s upper right, and Procyon the same distance to Sirius’s upper left. The Triangle now stands upright on Sirius, just about in balance.

And look west of the zenith for Perseus now heading down. If you’re in the Mountain or Pacific time zones, you’ll find Algol, the prototype eclipsing variable star, near its minimum brightness of magnitude 3.4 instead of its usual 2.1. Algol takes several additional hours to fade and to rebrighten.

PLANETS

Mercury emerges into dawn view late this week. Starting around December 29th, look for it about three fists at arm’s length lower left of Venus. On that morning Mercury is still only a difficult magnitude +1.3, but it’s brightening and climbing daily.

Venus, magnitude –4.0 in Libra, shines as the bright “Morning Star” in the southeast before and during dawn. It’s less high every week now. Closing in toward it from below is sparkly orange Antares, magnitude +1.0.

Mars is barely peeking over the eastern horizon in bright dawn, probably out of reach even with a telescope. It will very slowly get a little higher for the next five months!

Jupiter, magnitude –2.6 in Aries, is the bright white dot dominating the high southeast to south these evenings. It stands at its highest around 7 or 8 p.m. It has shrunk a little since opposition, but it’s still a good 45 arcseconds wide in a telescope.

  a bright ‘morning star’ at -4.0 magnitude, The sky: December 26 – January 1; Venus