The Pleiades (Chris Vaughan, Starry Night Education)

This Week’s Sky: January 11 to 17, 2021

With a new Moon in the sky this week, it’s the perfect time to look for some deep-sky objects

Wednesday, January 13 – New Moon (at 5:00 GMT)

New Moon (Chris Vaughan, Starry Night Education)

At 5:00 GMT on Wednesday, January 13, the Moon will officially reach its new Moon phase. When new, the Moon is travelling between Earth and the Sun. Since sunlight can only reach the far side of the Moon, and the Moon is in the same region of the sky as the Sun, the Moon becomes completely hidden from view for about a day.

Thursday, January 14 – Crescent Moon near Jupiter and Mercury (after sunset)

Crescent Moon near Jupiter and Mercury (Chris Vaughan, Starry Night Education)

Three evenings after Mercury passes close to bright Jupiter in the southwestern sky, a pretty young crescent Moon will join those two planets immediately after sunset on Thursday, January 14, setting up a lovely photo opportunity. The Moon will be positioned a fist’s diameter to the upper left (or 10 degrees to the celestial southeast) of Jupiter, with dimmer Mercury midway between them. You’ll need an unobstructed southwestern horizon to catch Jupiter before it sets at 6 p.m. in your local time zone. Mercury will become easier to see just before it sets at 6:18 p.m., and then the Moon will drop below the horizon at 6:35 p.m.

Thursday, January 14 – Uranus stands still (evening)

Uranus stands still (Chris Vaughan, Starry Night Education)

On Thursday, January 14, the distant, blue-green planet Uranus will temporarily cease its motion through the distant stars of southwestern Aries – completing a westward retrograde loop that began in mid-August (red path with labelled dates:times). After Thursday, the planet will begin to move eastward again. At magnitude +5.75, Uranus can be seen in binoculars (red circle) and backyard telescopes, and even with unaided eyes, under dark skies. Mars can help you find it. In mid-evening the bright red planet will be positioned three finger widths to the lower right (or 3.25 degrees to the celestial northwest) of Uranus.

Saturday, January 16 – The Pleiades (all night)

The Pleiades (Chris Vaughan, Starry Night Education)

At about 8:30 p.m. local time on mid-January evenings, the Pleiades open star cluster, also known as the “Seven Sisters” and Messier 45 is positioned high in the southern sky. The rest of its home constellation Taurus, the Bull sits below the cluster. Visually, the cluster is composed of medium-bright, hot blue stars named Asterope, Merope, Electra, Maia, Taygeta, Celaeno and Alcyone. In Greek mythology, those characters were the daughters of Atlas and half sisters of the Hyades. They are indeed related, recently born of the same primordial gas cloud. To the naked eye, only six of the sister stars are usually apparent; their parents Atlas and Pleione are huddled together at the east end of the grouping. Under magnification, hundreds of stars appear. Not surprisingly, many cultures, including Aztec, Maori, Sioux, Hindu and more, have noted this object and developed stories around it. In Japan, it is called Suburu, and forms the logo of the eponymous car maker. Due to its shape, the Pleiades are sometimes confused with the Little Dipper.

Chris Vaughan is a science writer, geophysicist, astronomer, planetary scientist and an “outreach RASCal.” He writes Astronomy Skylights, and you can follow him on Twitter at @astrogeoguy. He can also bring his Digital Starlab portable inflatable planetarium to your school or other daytime or evening event. Contact him through AstroGeo.ca to tour the universe together.