Skywatch Line for Friday, January 10, through Sunday, January 12, written by Sam Salem
This is Dudley Observatory’s Skywatch Line for Friday, January 10, through Sunday, January 12, written by Sam Salem.
On Friday, Sun rises at 7:25am and sets at 4:41pm; Moon sets at 4:27am and rises at 1:14pm.
On Friday evening, the Moon shines in line with Jupiter and Aldebaran. Watch the straightness of the line change hour by hour. Every hour, the Moon moves by nearly its own diameter eastward against the stars.
On Saturday, the Moon, two days from full, forms a triangle with Beta and fainter Zeta Tauri, the Bull’s horn-tip stars.
Mars is nearest to Earth on Sunday night. It appears 14.6 arcseconds wide and magnitude –1.4. That’s as bright as Sirius, which sparkles whitely about four fists to Mars’s lower right in early evening. Sirius lies directly below Mars when they’re highest around midnight. Lesser Procyon shines roughly midway between them and a bit to the right.
Mercury, magnitude –0.4, is sinking away into the glow of sunrise. Early in the week, look for it low in the southeast about 40 or 50 minutes before sunup. Binoculars may help.
Venus, magnitude –4.6 in Aquarius, shines very high and bright as the “Evening Star” in the southwest during twilight, and lower in the west-southwest later in the evening. It doesn’t set until about 2½ hours after dark. As darkness deepens, spot Saturn, much fainter, upper left or left of Venus and closing in on it day by day. Use a telescope to watch Venus as it appears very nearly half-lit, at or just past dichotomy. Venus is enlarging week by week as it swings toward Earth, while waning in phase as it swings closer to our line of sight to the Sun.
Saturn, magnitude +1.1 in the constellation of Aquarius, glows in the southwest after dark, upper left of Venus and closing in on it fast. Saturn is 7° from Venus on Friday. They’ll pass each other by 2.2° at conjunction on January 18th.
Jupiter shines at a bright magnitude –2.7 in the constellation of Taurus. It dominates the high east to south during evening, with fainter orange Aldebaran, fainter bluish white Beta Tauri, and the Pleiades nearby. Jupiter is still a good 45 arcseconds wide.
The Winter Circle, or Hexagon, is a large circular pattern, made of some of the brightest stars in the Northern Hemisphere’s winter sky. It’s an asterism, or prominent group of stars that form a noticeable pattern. he Winter Circle has a smaller asterism inside it, called the Winter Triangle.
This year, the planet Jupiter lies inside the Winter Circle and Mars is nearby. Watch this circular pattern of 1st-magnitude stars from six different constellations. Rigel in Orion the Hunter, Aldebaran in Taurus the Bull, Capella in Auriga the Charioteer, Pollux and Castor in Gemini the Twins, Procyon in Canis Minor the Lesser Dog, and Sirius in Canis
Major the Greater Dog. An additional 1st-magnitude star, Betelgeuse in Orion the Hunter, lies toward the center of the Circle.