Special to CosmicTribune.com, March 24, 2025

Excerpts from weekly Sky&Telescope report.

MONDAY, MARCH 24

■ Many binocular observers check in on the 5th-magnitude open cluster M41 just 4° due south of Sirius. But how many then look the other way from Sirius for the open cluster M50? It’s 10° north-northeast from Sirius, dimmer, smaller and more subtle than M41.

Find it by sweeping from Sirius first to Theta Canis Majoris, the 4th-magnitude pointy nose of the Big Dog’s stick figure, then on again nearly as far in the same direction and just a touch to the left. M50 is not exactly easy, but it’s there. I can spot it without too much difficulty using 10×50 binoculars through moderate suburban light pollution. Use averted vision!

If you’re trying under difficult conditions, get more detailed guidance using the Pocket Sky Atlas, chart 27. The more exactly you know the spot to examine for a difficult deep-sky object, the more likely you are to be able to detect it. And take time. Keep at it.

M50 is about 2,900 light-years from us; M41 is about 2,300.

TUESDAY, MARCH 25

■ This is the time of year when Orion declines in the southwest through the evening, with his Belt turning roughly horizontal.

WEDNESDAY, MARCH 26

■ The Big Dipper glitters softly high in the northeast these evenings, standing on its handle and tipping leftward. You probably know that the two stars forming the front of the Dipper’s bowl (currently on top) are the Pointers; they point to Polaris, currently to their lower left.

And, you may know that if you follow the curve of the Dipper’s handle out and around by a little more than a Dipper length, you’ll arc to Arcturus, now climbing in the east.

But did you know that if you follow the Pointers backward the opposite way, you’ll land in Leo? Go four or five fists at arm’s length.

Draw a line diagonally across the Dipper’s bowl from where the handle is attached, continue far on, and you’ll go to Gemini (about four fists).

And look at the two stars forming the open top of the Dipper’s bowl. Follow this line past the bowl’s lip far across the sky, and you cruise to Capella (about five fists).

THURSDAY, MARCH 27

■ Now that it’s spring, have you met the Leo Triplet? Three fine spiral galaxies, magnitudes 9 to 10, fit into a 1° eyepiece view in the hind leg of Leo. Two are Messier objects for your life list. See Ken Hewett-White’s Suburban Stargazer article, finder chart, and pix in the March Sky & Telescope, page 55.

FRIDAY, MARCH 28

■ If you’re in the northeastern US or eastern Canada, find those old eclipse glasses, and/or mount a safe solar filter on the front of your scope, and set an alarm for tomorrow morning’s sunrise partial solar eclipse! See next entry.

A partial solar eclipse also happened for the East Coast at sunrise on June 10, 2021. Here the Sun and Moon top the Delaware Breakwater Lighthouse as seen from Lewes Beach, Delaware.
NASA/Aubrey Gemignani

SATURDAY, MARCH 29

■ A partial eclipse of the Sun happens for northeastern North America, Greenland, Iceland, and most of Europe. For most the northeastern US and the Canadian Maritimes, the eclipse will already be under way at sunrise. Use Xavier Jubier’s interactive map to find your own exact times, the maximum obscuration and magnitude of the eclipse at your location, the Sun’s altitude, and other circumstances. Times are given in Universal Time.

For instance: At New York City the eclipse is already diminishing when the Sun rises at 6:44 a.m. EDT, with 27% of its surface being obscured at that time. The last trace of the eclipse ends 21 minutes later when the Sun is still a mere 3° above the east horizon. So be on a high rooftop or a shoreline with a flat eastern view.

Boston has it better. The Sun is 57% obscured when it rises at 6:32 a.m. EDT, and it attains 6° altitude by the time the last of the partial eclipse slips away at 7:08 a.m.

At Halifax, maximum eclipse will happen 16 minutes after sunrise, when the Moon will cover 85% of the Sun’s surface — with the Sun just 2° up.

Also see Bob King’s article Sunrise Solar Eclipse on March 29th for Eastern North America, with timetable.

The big picture. The yellow lines show the percentage of the Sun’s surface that the Moon will cover at maximum obscuration. Interpolate between them.The green lines show when maximum eclipse will occur, where this happens with the Sun above the horizon. Times are in UTC, Coordinated Universal Time (a.k.a. UT). Eastern Daylight Time (EDT) is 4 hours behind UTC, so 10:30 UTC is 6:30 a.m. EDT.

The brown loops are sunrise and sunset lines. The western half of the loop crossing North America shows where the partial eclipse ends at sunrise; none of the eclipse can be seen there and farther west. The eastern half of the loop is where the eclipse begins at sunrise.

The blue line down the center of the brown loop is where maximum eclipse occurs at sunrise.
NASA Scientific Visualization Studio

SUNDAY, MARCH 30

■ The two biggest generally recognized open star clusters in the sky are the Hyades behind Aldebaran and the Coma Berenices Star Cluster, which is now wheeling up high in the eastern spring sky. The Coma Star Cluster appears about the size of a ping-pong ball held at arm’s length. But it’s very sparse and dim.

Do you know where to find it? Here’s the trick: Look 40% of the way from Denebola, the tail star of Leo, to Alkaid, the end of the Big Dipper’s handle and the tail of Ursa Major. Tail of the Lion to tail of the Bear.

In a really dark sky the Coma Star Cluster is a definite dim glow, with its brightest specks forming an upside-down Y. Through poorer skies, it just about fills a binocular’s view with somewhat more stars than usual.

  March 24-29: Partial solar eclipse, The Sky