Skywatch Line for Friday, February 13, through Sunday, February 15, written by Sam Salem
This is Dudley Observatory’s Skywatch Line for Friday, February 13, through Sunday, February 15, written by Sam Salem.
On Friday, Sun rises at 6:55am and sets at 5:24pm; Moon rises at 4:52am and sets at 1:16pm.
On the Saturday and Sunday mornings, the waning crescent Moon hangs between Antares and the asterism of Sagittarius, the Teapot. Look for them about 90 minutes before sunrise. On Sunday morning, the thin waning crescent Moon follows the Teapot asterism up from the eastern horizon shortly before sunrise.
On Friday, Mercury passes close to the star Lambda (λ) Aquarii in the evening sky. Lambda Aquarii is a variable star in the equatorial constellation of Aquarius. This star lies just 0.39 degrees south of the ecliptic, therefore, it’s subject to lunar and planetary occultations. Mercury can be spotted low in the west-southwest about 30 minutes after sunset. Binoculars will help. Mercury gets a little higher every evening.
Half an hour after the Sun goes down, bright Venus glows at magnitude –3.9 just above the western horizon. About 7.5° above it, Mercury shines at magnitude –0.9.
Much brighter Venus sits way down below Mercury. It’s creeping up much more slowly day by day. Venus is 8° below Mercury on Friday.
Jupiter, magnitude –2.6, shines in the middle of the constellation Gemini the Twin. Spot it very high in the east-southeast as twilight fades. Jupiter shines highest in the south by 9pm. In a telescope, it’s 45 arcseconds wide.
Saturn, magnitude +1.1 in the constellation Pisces the Fishes, is the brightest object low in the west-southwest at nightfall, lower left of the Great Square of Pegasus. It sets a little more than an hour after dark. In a telescope, Saturn’s rings are still very thin but gradually opening up, now tilted 2° or 3° to our line of sight.
Uranus, magnitude 5.7, sits very high in the southwest in the constellation Taurus 5° south of the Pleiades. At high power in a telescope it’s a tiny non-stellar dot, 3.6 arcseconds wide.
Neptune, magnitude 7.9, sits near Saturn. On Sunday, Saturn is 0.9 degrees south of Neptune.
Orion stands high in the south by about 8 pm. It looks smaller than appearing early in the winter when it sits low. Constellations are like the Moon. They look bigger when they’re low in the sky. Below Orion, to the right of Sirius, hides constellation Lepus the Hare. It looks like a crouching bunny, with its nose pointing lower right and its faint ears extending up toward Orion’s foot, bight star Rigel. The Hare’s body is bunched to the left.
Galileo Galilei was born on February 15, 1564. The Italian scientist and natural philosopher applied the new techniques of the scientific method to make significant discoveries in physics and astronomy. His great accomplishments include perfecting the telescope design and consequent contributions to astronomy. He studied the science of motion, inertia, the law of falling bodies, and parabolic trajectories. His formulation of the scientific method parallels the writings of Francis Bacon.