Special to CosmicTribune.com, April 20, 2025

Excerpts from weekly Sky&Telescope report.

SUNDAY, APRIL 20

■ Find Procyon high above brilliant Sirius in the southwest right after dark. Look upper left of Procyon by 15° (about a fist and a half at arm’s length) for the dim head of Hydra, the enormous Sea Serpent. His head is a group of 3rd- and 4th- magnitude stars about the size of your thumb at arm’s length.

■ Last-quarter Moon tonight (exact at 9:36 p.m. EDT). The half-lit “backward” Moon doesn’t rise until around 3 a.m. daylight-saving time. By the very beginning of dawn, roughly an hour and a half later, it’s still low in the southeast: in dim Capricornus, about two fists lower left of the Sagittarius Teapot.

MONDAY, APRIL 21

■ The Lyrid meteor shower should be at its most active late tonight. It’s usually fairly weak, with 15 or 20 meteors visible per hour even under ideal conditions. Your best time for a meteor watch will be from midnight or 1 a.m. until the Moon (a day past last quarter) rises around 3 or 3:30 a.m. daylight-saving time.

TUESDAY, APRIL 22

■ Bright Arcturus is climbing high in the east these evenings. Equally bright Capella is descending high in the northwest. They stand at exactly the same height above your horizon sometime between 8:30 and 10 p.m. daylight-saving time, depending mostly on how far east or west you live in your time zone.

How accurately can you time this moment for your location? Like everything constellation-related, it happens 4 minutes earlier each night (or to be more exact, 3 minutes 56 seconds earlier). This is the sort of measurement for which sextants were invented.

WEDNESDAY, APRIL 23

■ Capella is the brightest star high in the west-northwest during and after dusk. Its pale-yellow color matches that of the Sun, meaning they’re both about the same temperature. But otherwise Capella is very different. It consists of two yellow giant stars orbiting each other every 104 days.

That part is common knowledge among starwatchers. But did you know that, for telescope users, Capella is accompanied by a distant, tight pair of red dwarfs? They’re Capella H and L, magnitudes 10 and 13.

THURSDAY, APRIL 24

■ High above the Big Dipper late these evenings, nearly crossing the zenith, are three pairs of dim naked-eye stars, all 3rd or 4th magnitude, marking the Great Bear’s feet. They’re also known as the Three Springs (or Leaps) of the Gazelle, from early Arab lore. They form an east-west line that lies roughly midway between the Bowl of the Big Dipper and the Sickle of Leo. The line is 30° (three fists) long. See the evening constellation chart in the center of the April or May Sky & Telescope.

■ If you know a spot with an open view of the east horizon, be there about 40 or 30 minutes before sunrise Friday morning to catch Venus over the thin crescent Moon, as shown in the second illustration below. Bring binoculars to try for much more difficult Saturn and Mercury. And know that a fourth planet lurks invisibly faint in their background: 8th-magnitude Neptune.

FRIDAY, APRIL 25

■ This is the time of year when, as the last of twilight fades away, the dim Little Dipper extends to the right from Polaris and slightly up. High above the Little Dipper’s bowl, you’ll find the Big Dipper’s bowl.

SATURDAY, APRIL 26

■ As night descends, look high in the west for Pollux and Castor, the heads of the Gemini twins, lined up almost horizontally (depending on your latitude). Mars is off to their left.

Pollux and Castor form the top of the enormous Arch of Spring. To their lower left spot Procyon, the left end of the Arch. Farther to their lower right is the other end, formed by Menkalinan (Beta Aurigae) and then brilliant Capella. The whole thing sinks in the west through the evening.

SUNDAY, APRIL 27

■ Arcturus is the brightest star high in the east these evenings. Spica shines lower right of it by about three fists at arm’s length. To the right of Spica by half that distance is the distinctive four-star constellation Corvus, the springtime Crow.

■ Vega, the Summer Star, the zero-magnitude equal of Arcturus, is now twinkling low in the northeast at nightfall. . . depending on your latitude. The farther north you are the higher Vega will be. If you’re in the latitudes of the southern US, you’ll have to wait until a bit later for it to appear.

■ New Moon (exact at 3:31 p.m. EDT).

  April 20-27: Arcturus is brightest star, high in the East, The Sky