Special to CosmicTribune.com, February 10, 2025

Excerpts from weekly Sky&Telescope report.

MONDAY, FEBRUARY 10

■ After dinnertime Sirius the Dog Star blazes in the southeast, the brightest star of Canis Major. Look below Orion.

Every February, the Moon is full or nearly so when it crosses Gemini. This February Mars greets it there.

TUESDAY, FEBRUARY 11

■ Full Moon this evening and tomorrow evening. It’s exactly full at 8:53 a.m. February 12th EST, about halfway between the two evenings for the longitudes of the Americas.

This evening the Moon rises in the east-northeast about a half hour before sunset. Watch it emerge into view through the fading daylight.

Once the sky is fully dark, look for 1st-magnitude Regulus coming up about a fist at arm’s length below the Moon.

WEDNESDAY, FEBRUARY 12

■ Tonight the still-full Moon rises a little after sunset rather than a little before. Once the sky is dark, spot Regulus less than 2° to the Moon’s right. To reduce the Moon’s glare, cover it with two of your fingertips held out: one for each eye. Close one eye and position the fingertip you see, then do the same for the other.

THURSDAY, FEBRUARY 13

■ By 9 p.m. or so, the Big Dipper stands on its handle in the northeast. In the northwest, Cassiopeia also stands on end (its brighter end) at about the same height. Between them is Polaris.

FRIDAY, FEBRUARY 14

■ Orion stands at his highest in the south by about 8 p.m., looking smaller than you probably remember him appearing early in the winter when he was low. You’re seeing the “Moon illusion” effect. Constellations, not just the Moon, look bigger when they’re low.

■ With a telescope this evening, watch Jupiter’s moon Ganymede slowly fade from sight around 7:25 p.m. EST as it enters eclipse by Jupiter’s shadow. Ganymede will be the one about a Jupiter diameter to Jupiter’s celestial east-northeast.

Then watch Ganymede slowly reappear out of Jupiter’s shadow around 9:56 p.m. EST, farther to Jupiter’s east.

Jupiter’s shrunken Great Red Spot should cross the planet’s central meridian about a half hour later, around 10:27 p.m. EST.

SATURDAY, FEBRUARY 15

■ Right after night is completely dark this week, the W of Cassiopeia shines high in the northwest, standing almost on end. Near the zenith is Capella.

The brightest star about midway between Cassiopeia and Capella (and a little off to the side) is Alpha Persei, magnitude 1.8. It lies on the lower-right edge of the Alpha Persei Cluster: a large, elongated, very loose swarm of fainter stars about the size of your thumbtip at arm’s length. At least a dozen are 6th magnitude or brighter, bright enough to show very well in binoculars. Look fairly soon after dark before the Moon rises.

Alpha Per, a white supergiant, is a true member of the group and is its brightest light. It and the rest are about 580 light-years away.

■ Another deep-sky catch in the vicinity: Kemble’s Cascade, much fainter, awaits your binoculars very high in the north-northwest these evenings. This is a dim but rather famous asterism, a straight star chain 2¼° long named in 1980 for its noticer Fr. Lucian Kemble in Canada. But it’s located in dim, sprawling, shapeless Camelopardalis the Giraffe, which I find to be one of the most difficult constellations to navigate.

Here’s a shortcut. Draw a line from Algol through Alpha Persei. Extend the line farther on by exactly 1½ times that length. You’re now very close to the east end of the chain: a pair of stars magnitudes 6.8 and 6.2 a third of a degree apart (at the top of the image below).

Kemble’s Cascade is a long, straight star chain: an unusual random alignment of mostly unrelated stars at very different distances from us. Just off its southeast end (at top here) is the tight little cluster NGC 1502 — which is a real gathering, 3,500 light-years away.North is to the right. This field is 3° tall, roughly half the width of a typical binocular’s field of view. / Greg Parker and Noel Carbone

The Cascade currently hangs down from the southernmost of those two (the fainter of them) in early evening. Most of its 15 or so other members are 7th to 9th magnitude, so you’ll need a fairly dark sky. Averted vision helps, as always for faint sights.

Below (west of) its bottom end is a gentle arc of three brighter stars, mags 4.8 to 5.8.

Bonus for telescopes: That 6.2-mag star 1/3° to the right of the Cascade’s top is the brightest star of the sparse, very small open cluster NGC 1502, less than 0.1° wide. Its next-brightest dozen stars are all 9th and 10th magnitude.

And that 6.2-mag star near the center of NGC 1502 is a wide telescopic double. Its components are near-twins: mags 7.0 and 7.1, 17 arcseconds apart.

SUNDAY, FEBRUARY 16

■ A fast-creeping red dwarf. Have you ever seen a red dwarf star? These are the most common stars in space, but they’re so intrinsically dim that not one of them is among the 6,000 pinpoints visible to the naked eye on even the darkest nights. One of the nearest and brightest red dwarfs lies just 3° west of Procyon, nicely placed these winter evenings. It’s Luyten’s Star, also known as GJ 273, and at visual magnitude 9.9 it’s in range of small telescopes.

This humble object is very close to us as stars go, only 12.3 light-years away, so it is also a high proper motion star; it creeps across its celestial backdrop by 3.7 arcseconds per year. This means that a careful visual telescope user might detect its motion in as little as about 3 years, writes King, “depending on its proximity to field stars and the making and breaking of distinctive alignments with other stars.” He suggests, “Make an initial observation, note the position in a sketch, map or photo, and then return a couple years later. Hey, no hurry.”

  Feb. 10-16: How to view Kemble’s Cascade, The Sky