The Pleiades (or the Seven Sisters) open cluster of stars in the constellation Taurus.
Night’s window is opening. It’s Last Quarter Moon tonight, which means our natural satellite is half-lit from our point of view and rising after midnight. Better still, it will rise even later tomorrow night and for the next week until a crescent Moon disappears into the Sun’s glare—and causes a dramatic total solar eclipse in the southern hemisphere on April 20, 2023.
Cue April 2023’s dark sky window, the best time of the month for stargazers, amateur astronomers and astrophotographers to experience moonless night skies. It’s no coincidence that it’s International Dark Sky Week (April 15–22), a celebration of the night and a reminder that we desperately need better, more efficient outdoor lighting to reduce dangerous light pollution.
Here are seven incredible sights in the night sky that will look their best in April’s darkest night skies—and from both the northern and southern hemispheres:
The Pleiades, an open cluster of stars visible to the naked eye.
1. The Pleiades
The closest to us and the most beautiful open cluster of stars in the night sky, the Pleiades are now only visible for a short time after sunset in the west, though from both hemispheres. You can’t miss this bright, fuzzy patch of diffuse light—though be quick!
Also called the “Seven Sisters,” the Pleiades (pronounced either “player-deez” or “plee-er-deez”) are seven bright—and about 100 dimmer—stars 440 light-years away. Look to the side of the Pleiades and you’ll better appreciate their brightness in the corner of your eyes.
The constellation Ursa Major is much larger than the Big Dipper, which merely represents the … [+]
2. The Great Bear
Can you find the Big Dipper? Of course you can (if you’re in the northern hemisphere). Everyone knows that constellation, right? Actually, it’s not a constellation. It’s an asterism—a shape—within a much larger constellation called Ursa Major—the “Great Bear.” In fact, the Big Dipper is but the rear-end and the tail. See if you can pick out the others stars that create the much larger body of the bear, though note that it’s “upside down” at this time of year from the northern hemisphere. Hint: its feet are wide double stars.
Alpha and Beta Centauri, taken from Atacama Lodge, Chile, March 2010, with Canon 5D MkII (modified) … [+]
3. Alpha Centauri
At a mere 4.37 light-years away, Alpha Centauri is the closest bright star to us and the third brightest in the night sky. It’s highest in the night sky from March to September in the southern hemisphere, though it can be seen north of the equator just above the southern horizon from about 29°N latitudes (Texas and northern Florida), though not until May. Alpha Centauri is next to Beta Centauri, usually called the “pointer stars” because they point directly to …
The two “pointer stars”—Alpha Centauri and Beta Centauri—lead the way to the Southern Cross.
4. Crux, The Southern Cross
An asterism within the Crux constellation that’s only visible in the southern hemisphere, the Southern Cross is easy to find—when you know how. Go from Alpha Centauri to Beta Centauri, three times that distance to a star called Gacrux at the tip of the Southern Cross. It’s best between March and June. Within it is the marvelous Jewel Box cluster (NGC 4755), though you’ll need a small telescope to fully appreciate it.
Illustration of the constellation Leo, showing the constellation boundary and principle stars.
5. The constellation of Leo
Rising after sunset right now in both hemispheres is the large constellation of Leo “the lion,” which is most easily seen by identifying bright stars Regulus at one of the animal’s front paws and Denebola at the end of its tail. Denebola is 36 light years away, Regulus 79 light years—close neighbors of our Sun.
The constellation of Orion with stars made into points to make them easier to find.
6. Orion and his three ‘Belt Stars’
It’s past its best, but still visible after dark in both hemispheres is Orion “the hunter”—home to some of the very brightest stars in the night sky. The “Belt of Orion” (or the “Three Kings”) contains three blue supergiant stars—Alnitak, Alnilam and Mintaka—while the corners of the hunter are marked by Betelgeuse and Bellatrix at the top, with and Rigel at the bottom.
The M81 and M82 galaxies are a fabulous sight in a small telescope.
7. The Cigar galaxy and Bode’s galaxy
Here’s a bonus sight for owners of a small telescope in the northern hemisphere. Small, diffuse patches of light northwest of bright star Dubhe in the Big Dipper, Bode’s galaxy (M81) and the Cigar galaxy (M82) can be seen in the same field of view of a small telescope. Bode’s galaxy is a large spiral galaxy and the Cigar galaxy is a starburst galaxy. Both are about 12 million light-years from Earth.
Wishing you clear skies and wide eyes.
