Skywatch Line for Friday, April 26, through Sunday, April 28, written by Sam Salem
This is Dudley Observatory’s Skywatch Line for Friday, April 26, through Sunday, April 28, written by Sam Salem.
On Friday, Sun rises at 5:56am and sets at 7:51pm; Moon sets at 7:01am and rises at 11:12pm.
On the Friday and Saturday mornings, the waning gibbous Moon will lie close to the bright star Antares in Scorpius the Scorpion. They’ll be visible from early morning until dawn.
Mars and Saturn, both about magnitude +1.2, rise around the beginning of dawn. Look for them low above the east-southeast horizon about 45 minutes before sunrise. Saturn is the easier one, on the upper right. Their separation widens to 11° apart Saturday morning.
Jupiter, magnitude –2.1 in the constellation of Aries, is the bright planet sinking low in the west-southwest in twilight. It sets before twilight ends.
Uranus, magnitude 5.8, hides close to Jupiter. Low altitude and twilight make it a hard catch. In a telescope, Uranus’s usual giveaway is that it’s slightly non-stellar at high power. But the atmospheric seeing at such a low altitude will make it hard to view.
Look for the Big and Little Dippers high in the northern sky on spring evenings. Look up overhead in the evening sky and find the well-known pattern of stars. It’s an asterism, or pattern of stars, and part of the constellation Ursa Major the Great Bear. Also, you can find the constellation Leo the Lion. Leo has another well-known asterism known as the Sickle. The Sickle looks like a backward question mark that is punctuated by the bright star Regulus. The Big Dipper can help you locate Leo and the Sickle. An imaginary line drawn southward from the pointer stars in the Big Dipper, the two outer stars in the Dipper’s bowl, points toward Leo the Lion.
The Big Dipper can direct you to find Polaris, the North Pole Star. The two outer stars in the bowl of the Dipper point to Polaris. It’s at the end of the handle of Ursa Minor the Little Bear, commonly known as the Little Dipper. As the last of twilight fades away, the dim Little Dipper extends straight to the right from Polaris. High above the end-stars of the Little Dipper’s bowl, you’ll find the end-stars of the Big Dipper’s bowl.
These spring evenings, the long, dim sea serpent Hydra snakes almost level far across the southern sky. Hydra is the largest of the 88 modern constellations, measuring 1303 square degrees. Also, it is the longest constellation at over 100 degrees. Find Hydra’s head, a dim asterism about the width of your thumb at arm’s length, in the southwest. It’s almost halfway from Procyon to Regulus. Left or lower left of Hydra’s head, by about a fist and a half, is orange, 2nd-magnitude Alphard, Hydra’s lonely heart. Hydra’s dim, irregular body and tail stretch all the way to Libra just risen in the southeast. Hydra carries Crater and Corvus on his back. Hydra’s star pattern, from forehead to tail-tip, is 95° long. That’s more than a quarter of the way around the celestial sphere. No other
constellation does that. Even the star pattern of the river Eridanus is only 66° from end to end.