The sky this week from February 11 to 18
monday 14 february
This month, skywatchers are treated to something special: a sneak peek beyond the lunar south pole. You are looking for Mount Clementine, officially known only as M5. It is one of the easiest features to see and spends most of every lunar month in full sun.
Beginning tonight and returning over the next few nights, take out your telescope and point it to the southern regions of our satellite. You will immediately notice the fantastic 3D look of the lunar limb. Because the Moon sits just above the Earth-Sun plane, called the ecliptic, we get glimpses of features beyond the pole that we don’t normally see. You will observe rugged terrain that casts sharp black shadows; these pools of darkness extend southward as lunar noon approaches.
Use our guide above to locate both Mount Clementine and a nearby feature, M4. The Casatus, Moretus, and Newton craters should help make sure you’re in the right place. Observe day by day the shadows of these mountains move with the changing angle of the sun. If the glare is too bright, increase the magnification – this reduces the amount of lunar surface you view and also reduces its reflected light.
Sunset: 5:35 p.m.
Moonrise: 3:31 p.m.
Moon setting: 06:05
Moon phase: Waxing Gibber (96%)
tuesday 15 february
A few hours before sunrise, the Moon sets over Cancer the Crab. Instead, turn your gaze to the sky and look up to find the constellation of Bootes above your head in the south. This stellar figure is home to another of the brightest stars in the sky: Arcturus of magnitude -0.1, a red giant star in the later stages of its life. Does its glow appear orange or red to you, especially compared to its close neighbors?
Just over 10° northeast of Arcturus is magnitude 2.6 Izar (Epsilon [ϵ] Bootis). This target is a beautiful binary star about 200 light-years distant, composed of orange and white colored components. The stars are about 3″ apart and generally require a 3″ or larger telescope to resolve.
Not only is this pair gorgeous to look at, but it also offers a glimpse of Stellar Evolution in action. Today, the oldest orange-colored star is about 4 times the mass of the Sun, while the youngest, whitest star is only 2 solar masses. But over time, this more massive star will explode from its outer layers and become a smaller, less massive white dwarf – and by then, the younger star will have swelled into an orange-red giant instead.
Sunset: 5:36 p.m.
Moonrise: 4:35 p.m.
Moon setting: 06:43
Moon phase: Waxing Gibber (99%)
Wednesday February 16
The February Full Moon occurs today at 11:56 a.m. EST. This month’s full moon is called, perhaps appropriately for much of the United States, the snow moon. Its brilliant light will wash over much of the sky overnight, as the Full Moon rises and sets opposite the Sun.
But all is not lost, even in brighter skies. The planet Mercury reaches its greatest western elongation from the Sun (26°) at 4:00 p.m. EST; it is visible early this morning before sunrise, clearing the horizon around 5:30 a.m. local time. Mercury is currently in Capricorn and is now magnitude 0.1, having brightened to magnitude 0.9 in early February. It won’t get much brighter in the coming weeks though, reaching magnitude 0 on the 20th and -0.1 by the end of the month.
The tiny innermost planet disk extends 7 inches through a telescope and appears 60% illuminated. You’ll find it to the lower left (east) of brighter Venus and Mars, still in Sagittarius and rising around 4:20 a.m. and 4:50 a.m. local time, respectively.
Sunset: 5:37 p.m.
Moonrise: 5:41 p.m.
Moon setting: 7:15 a.m.
Moon phase: Full
Thursday February 17
The dwarf planet 1 Ceres rules the asteroid belt, and all month it flies past Taurus the Bull. Tonight you will find the small world, currently shining around magnitude 8.5, less than 4° southeast of the Pleiades (M45). You should be able to follow it even from the city if you have a scope measuring only 3 inches or more.
Once you have spotted Ceres, don’t forget to look towards the Pléiades to enjoy the view. Although this cluster is also called the Seven Sisters, it contains hundreds of stars, including nine of magnitude 6. Tonight’s moonlight could affect the number of stars you can easily see, especially without any help. optical. Consider jotting down a quick sketch and coming back when there is no Moon in the sky to see if the number of visible luminaries has changed. If you want to zoom in, binoculars or the same low-power scope you used to spy on Ceres is best. In fact, your ideal tool might be your telescope’s finder scope! That’s because the Pleiades covers about 110 feet in the sky, although its nine brightest stars all fit within a 1° wide field of view.
Sunrise: 6:50 am
Sunset: 5:39 p.m.
Moonrise: 6:47 p.m.
Moon setting: 7:43 am
Moon phase: Waning gibbous (99%)