Saturday, February 4
The Moon reaches apogee, the farthest point from Earth in its orbit, at 3:55 A.M. EST. At that time, it will sit 252,573 miles (406,477 kilometers) away.
Luna lies in Cancer this evening, near the Beehive Cluster (M44). On the other side of the sky, the constellation Perseus is high in the north, far above the Little Dipper. The Hero is home to many stunning deep-sky objects, including the open cluster M34. This lovely group of young stars covers some 35' and shines collectively at magnitude 5.5. You can find M34 about 5° west-northwest of Algol, Perseus’ particularly famous 2nd-magnitude variable star.
Visible with binoculars or a telescope, M34 contains nearly a dozen stars brighter than 9th magnitude. Larger apertures will reveal even more cluster members. As an open cluster, its stars are quite young, estimated to have been born about 180 million years ago.
Algol itself is also a fascinating object: Sometimes called the Demon Star, it is an eclipsing binary whose companion passes in front of it from our point of view, causing Algol to brighten and dim by just over a full magnitude. When uneclipsed, Algol appears nearly as bright as Mirfak, 9.3° to its north. But when blocked by its companion star, Algol instead appears noticeably fainter, while Mirfak still blazes bright.
Sunrise: 7:06 A.M.
Sunset: 5:23 P.M.
Moonrise: 4:18 P.M.
Moonset: 6:53 A.M.
Moon Phase: Waxing gibbous (99%)
Sunday, February 5
Mars passes 8° north of Aldebaran in Taurus at 2 A.M. EST. At this time, East Coast observers will see Aldebaran just a few degrees above the horizon as the Bull sets in the west. For those farther west, the constellation will appear slightly higher in the sky.
Aldebaran is a red giant that glows at magnitude 0.9. Its light appears yellowish-orange, particularly through binoculars or a telescope, thanks to the aging star’s cool surface temperature. Mars now glows at magnitude –0.2 and appears to the star’s upper right as they set. To the Red Planet’s lower right is the Pleiades open cluster (M45).
If you aren’t able to catch the scene shortly after midnight, you can instead fight Taurus high in the southeast after sunset. Mars is still roughly 8° north (now to the upper left) of Aldebaran, with the Pleiades to Mars’ upper right.
Full Moon occurs at 1:29 P.M. EST. Now opposite the Sun in the sky, our satellite will rise roughly at sunset today. The February Full Moon is also called the Snow Moon, thanks to much of North America’s penchant for sitting beneath several inches of snow at this time of year.
Sunrise: 7:05 A.M.
Sunset: 5:23 P.M.
Moonrise: 5:20 P.M.
Moonset: 7:27 A.M.
Moon Phase: Full
Monday, February 6
Draco winds his way beneath the Little Dipper in the north shortly after sunset tonight. The Dragon’s head is marked by the asterism the Lozenge, which lies to the lower left (southeast) of the Litter Dipper’s bowl just after dark. There is a short dark-sky window in the hour between sunset and moonrise, so take advantage of it if you can.
The brightest star in Draco’s head is 2nd-magnitude Eltanin (Gamma [γ] Draconis). Moving counterclockwise, to the west (right) of Eltanin is Rastaban (Beta [β] Draconis; magnitude 2.8), followed by Kuma (Nu [ν] Draconis; magnitude 4.9) to Rastaban’s north. Northeast of Kuma is the last star in the Lozenge, magnitude 3.7 Grumium (Xi [ξ] Draconis).
If you look along the Dragon’s body as it curls beneath Ursa Minor, you’ll reach Thuban (Alpha [α] Draconis) some 29° west of the Lozenge. This magnitude 3.7 star was once the North Star, sitting close to Earth’s Celestial Pole as the sky appeared to spin around it. That honor now belongs to Polaris in Ursa Minor — the change is due to the fact that Earth’s rotational axis wobbles, or precesses, over the course of about 25,000 years. As the axis moves, it points at various stars in the sky at different times, so our North Star can change over the course of thousands of years.
Sunrise: 7:04 A.M.
Sunset: 5:25 P.M.
Moonrise: 6:22 P.M.
Moonset: 7:55 A.M.
Moon Phase: Waning gibbous (99%)