The sky, Jan. 27-Feb. 2: Moon, Saturn and Venus put on a show

Special to CosmicTribune.com, January 27, 2025

Excerpts from weekly Sky&Telescope report.

MONDAY, JANUARY 27

■ While the evenings are still dark and moonless, use big binoculars or a telescope to hunt down the 8th-magnitude globular cluster M79 in Lepus below the feet of Orion. Summer is the season for most globular clusters, but here we have a rare winter one. It’s below the two brightest stars of Lepus, Alpha and Beta Leporis: the back and front of the Hare’s neck. Continue the line that they make downward by that same distance and you’re just about there.

Also check out the binocular double star Gamma Leporis nearby on the chart. It’s a yellow-white F6 dwarf a little larger, hotter, and brighter than the Sun, with a dimmer orange K2 dwarf travelling through space with it about 96 arcseconds to its north-northwest (directly above it in the evening). They’re magnitudes 3.6 and 6.3. It helps a lot to brace your binoculars firmly against something to eliminate the jiggles.

The orange dwarf is very slightly variable due to large starspots on its surface; the star rotates with a 21-day period, so the spots come and go. The pair is just 29 light-years away.

■ Algol high overhead should be in mid-eclipse, magnitude 3.4 instead of its usual 2.1, for about two hours centered on 10:17 p.m. EST; 7:17 p.m. PST. Algol takes several additional hours to fade and to rebrighten.

TUESDAY, JANUARY 28

■ After dark now the Great Square of Pegasus sinks low in the west, tipped onto one corner. Meanwhile the Big Dipper is creeping up in the north-northeast, tipped up on its handle.

WEDNESDAY, JANUARY 29

■ The Pleiades and Hyades are the most famous star clusters in Taurus, which is now high overhead and hosting Jupiter. But awaiting your telescope in Taurus on these moonless evenings are also big, scattered NGC 1746 and NGC 1647, and the smaller, sparse cluster pair NGC 1807 and NGC 1817, which look almost like two little parallel lines.

■ New Moon (exact at 7:36 a.m. EST).

THURSDAY, JANUARY 30

■ Is your sky dark enough for you to trace the winter Milky Way? After dinnertime now, it runs vertically from Canis Major low in the southeast, up between Orion and Gemini, through Auriga and Perseus almost straight overhead, and down through Cassiopeia, Cepheus, and Cygnus to the northwest horizon.

■ Algol should be in mid-eclipse for about two hours centered on 7:06 p.m. EST.

FRIDAY, JANUARY 31

■ The waxing crescent Moon shines under 1.1-magnitude Saturn this evening, as shown below. Venus, more than 200 times brighter than Saturn at magnitude –4.8, looks on expectantly from above.

Like it did a month ago, the waxing crescent Moon lines up with Saturn and Venus on consecutive evenings. But this time Saturn comes first, and the Moon-planet separations are closer. Like it did a month ago, the waxing crescent Moon lines up with Saturn and Venus on consecutive evenings. But this time Saturn comes first, and both of the Moon-planet separations are closer. On January 31st the Moon and Saturn are 3° apart, then on February 1st the brilliant Moon-Venus pair are just 2½° apart (for the Americas). Many millions of people will be struck by the sight and wonder what’s up. You will know.

SATURDAY, FEBRUARY 1

■ Now it’s Venus’s turn to host the lunar guest, as shown above. They are not as paired as they look. Venus, currently 4 light-minutes away, is about 200 times farther from us than the Moon’s current distance of 1.2 light-seconds.

■ Jupiter’s moon Io enters onto Jupiter’s face at 6:41 p.m. EST coming from the east, then it exits from Jupiter’s western limb at 8:53 p.m. EST. Following behind Io across the planet’s face, from 7:50 to 10:02 p.m. EST, will be Io’s tiny black dot of a shadow.

SUNDAY, FEBRUARY 2

■ The biggest well-known asterism (informal star pattern) is the Winter Hexagon. It fills the sky toward the east and south these evenings.

Start with brilliant Sirius at its bottom. Going clockwise from there, march up through Procyon, Pollux and Castor, Menkalinan and Capella on high, down to Aldebaran, then to Rigel in Orion’s foot, and back to Sirius. Betelgeuse shines inside the Hexagon, way off center.

The Hexagon is somewhat distended. But if you draw a line through its middle from Capella down to Sirius, the “Hexagon” is fairly symmetric with respect to that long axis.

Take the line from Aldebaran to Capella, turn it to go from Aldebaran to Betelgeuse instead, and the Winter Hexagon becomes the Heavenly G.

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