Skywatch Line for Friday, April 19, through Sunday, April 21, written by Sam Salem
This is Dudley Observatory’s Skywatch Line for Friday, April 19, through Sunday, April 21, written by Sam Salem.
On Friday, Sun rises at 6:06am and sets at 7:43pm; Moon sets at 4:32am and rises at 3:37pm.
The Moon will reach apogee, its farthest distance from Earth in its elliptical orbit around Earth, on Friday when it’s 252,042 miles away.
The peak morning for Lyrid meteor shower is on Monday. But this year the waxing gibbous Moon, just one day before full, will interfere. The best time to watch is before dawn. Lyrid meteors radiate from near the bright star Vega in the constellation Lyra the Harp. You don’t need to identify Vega or Lyra to watch the Lyrid meteor shower. But you do need to know when the radiant rises, in this case in the northeast before midnight. That’s why the Lyrids are typically best between midnight and dawn. You’ll see the most meteors after the radiant has come over the horizon. The meteors radiate from there, but will appear unexpectedly, in all parts of the sky. On nights when the Moon is full, or nearly full, you’ll notice that the Moon casts shadows. When you’re out there watching the Lyrids, don’t stand under a wide-open sky. Instead, find a Moon shadow somewhere that still provides you with a wide expanse of sky for meteor-viewing.
Saturn and Mars have widened to 6½° apart this weekend. Saturn will reach opposition on September 8th, but Mars won’t get to that point in our sky until January 15, 2025. By then the two planets will be 130° apart. Mars and Saturn, both about magnitude +1.2, rise soon after dawn begins. Look for the two planets just above the east-southeast horizon about 45 minutes before sunrise. Mars is the redder one, on the left.
Jupiter, magnitude –2.1 in the constellation of Aries, is the bright “star” low in the west-southwest in twilight. It sinks lower after dark and sets less than an hour after full dark.
Uranus, magnitude 5.8, hides a mere 1½° above Jupiter early in the week. Low altitude and lingering twilight make it a hard catch. It’s in conjunction with Jupiter, ½° to Jupiter’s upper right, on Saturday when they’re even lower. Immediately after dark, use binoculars or a good finder-scope to identify Uranus using finder charts.
Look high in the west as night descends for Pollux and Castor lined up almost horizontally. These two stars, the heads of the Gemini twins, form the top of the enormous Arch of Spring. To their lower left is Procyon, the brightest star in the constellation of Canis Minor, the left end of the Arch. Farther to their lower right is the other end, formed by Menkalinan, Beta Aurigae, then Capella, the brightest star in the constellation of Auriga. They all sink in the west through the evening.
Arcturus, the brightest star in the constellation of Boötes, climbs high in the east these evenings. Equally bright Capella descends high in the northwest. They stand at exactly the same height above horizon at some moment between about 9 and 10 pm. While Arcturus, pale yellow-orange, is the brightest star high in the east these evenings, Spica, pale blue-white star in the constellation of Virgo, shines lower right of it, by about three fists at arm’s length. To the right of Spica by half that distance, look for the distinctive four-star constellation of Corvus, the springtime Crow.