Skywatch Line for Friday, April 12, through Sunday, April 14, written by Sam Salem
This is Dudley Observatory’s Skywatch Line for Friday, April 12, through Sunday, April 14, written by Sam Salem.
On Friday, Sun rises at 6:18am and sets at 7:35pm; Moon rises at 8:26am.
On the Friday evening, the waxing crescent Moon will lie between two bright stars. The golden star is Capella in the constellation Auriga the Charioteer. And in vivid contrast to golden Capella is the bright red supergiant star Betelgeuse, the second brightest star in Orion the Hunter. You can follow them until around midnight.
On Saturday and Sunday evenings, the almost first quarter Moon will shine near Castor and Pollux, the twin stars of Gemini. These “twin brothers,” don’t really look alike. Pollux is a bit brighter and a golden star, while Castor shines as a white light. But both stars are bright, and they’re noticeable for being close together on the sky’s dome. You may need dark skies to locate the rest of the constellation. They’ll rise before sunset and travel across the sky’s dome before setting a few hours after midnight.
Mars and Saturn, both about magnitude +1.2, rise soon after dawn begins. Look just above the east-southeast horizon about 45 minutes before sunrise. Mars is the redder one, on the left. They widen from 2.6° apart on Saturday morning to 6.5° next weekend.
Jupiter, at 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, at 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 next weekend when they’re even lower. Immediately after dark, as soon as you’re done with Comet Pons-Brooks lower still, use binoculars or a good finderscope to identify Uranus using the finder charts. The dim planet’s giveaway in a telescope is that it’s slightly nonstellar at high power. It’s 3.4 arcseconds wide. The atmospheric seeing at such a low altitude will be bad.
This is the time of year when, as the last of twilight fades away, the bowl of the dim Little Dipper extends straight to the right of Polaris. High above the two end-stars of the Little Dipper’s bowl, you’ll find the two end-stars of the Big Dipper’s bowl.
Arcturus shines brightly in the east these evenings. The Big Dipper, high in the northeast, points its curving handle to the lower-right down toward it. Arcturus forms the pointy end of a long, narrow kite asterism formed by the brightest stars of Boötes, the Cowherd. The kite is currently lying on its side to Arcturus’s left. The head of the kite, at the far left, is bent slightly upward. The kite is 23° long, about two fist-widths at arm’s length.