Sunday, February 27
If you can bring yourself to get up early on a weekend, the planets will richly reward you with a wonderful lineup that includes the crescent Moon this morning.
The Moon passes 9° south of Venus at 1 A.M. EST, although both are below the horizon at that time. Our satellite then passes 4° south of Mars at 4 A.M. EST — still invisible to our eyes. But by 5:30 A.M. EST on the East Coast, it’s a different story: Venus, Mars, and the Moon have all cleared the horizon, standing in a line in eastern Sagittarius. Give it another hour in the Midwest, and you’ll see the same sight.
Regardless of your location, by 30 minutes before sunrise, two more planets have joined the scene. Starting at the top, Venus sits nearly 20° high and shines at magnitude –4.8. Through a telescope, it is 37 percent lit. Below Venus is Mars, just over 13° high and a dimmer magnitude 1.3. The Red Planet now sits a little less than 5° northwest of the 26-day-old Moon, which is just 13 percent illuminated and 9° above the horizon.
Look to the lower left (east) of the Moon, and much closer to the horizon are Mercury — 4° high and magnitude 0 — and Saturn — just 2.5° high and magnitude 0.7. You might need binoculars or a telescope to spot the ringed planet in the growing twilight, but take care to stop scanning the horizon with any kind of optical aid several minutes before the Sun rises to avoid accidental damage to your eyes.
Sunrise: 6:36 A.M.
Sunset: 5:50 P.M.
Moonrise: 4:58 A.M.
Moonset: 2:16 P.M.
Moon Phase: Waning crescent (12%)
Monday, February 28
Mercury reaches aphelion today, less than two weeks after its greatest western elongation. The solar system’s smallest planet is now 75 percent lit and rises around 5:40 A.M. local time. Through a telescope, you’ll see it spans 6″. If you got a look at the eastern sky yesterday, you may notice today that Mercury and Saturn are now closer together as well — they’ve moved from 4° apart on the 27th to less than 3° apart today. The pair is headed for a close conjunction in just a few days, so stay tuned.
The Moon has also moved, continuing its trek eastward along the ecliptic. Our satellite is now just 7 percent lit. Look for earthshine — reflected sunlight bouncing off Earth — lighting up the portion of the Moon’s face otherwise in shadow. The Moon passes 4° south of Mercury at 3 P.M. EST today, then passes 4° south of Saturn at 7 P.M. EST.
Sunrise: 6:34 A.M.
Sunset: 5:51 P.M.
Moonrise: 5:45 A.M.
Moonset: 3:31 P.M.
Moon Phase: Waning crescent (5%)
Tuesday, March 1
Let’s begin March with a look at the American Association of Variable Star Observers’ monthly featured variable star: Betelgeuse. This famous luminary marks the right shoulder of Orion the Hunter, assuming he is drawn facing us. It’s a bright, prominent star, visible even from most light-polluted areas. Betelgeuse is an aging star called a red giant — you may notice its reddish color even with the naked eye, and its hue becomes more apparent when viewed with binoculars or a telescope. An hour after sunset, Orion is already high in the sky. You’ll find Betelgeuse glowing about 57° above the southern horizon, to the upper left (north) of Orion’s famous three-star belt.
If you look up Betelgeuse’s magnitude, you’ll likely see it listed as 0.7. That makes it the 11th brightest star in the sky. But Betelgeuse is, as you may have guessed, a variable star whose magnitude changes from 0.3 at its brightest to 1.1 at its dimmest. The physics behind these changes are complex and result in several timescales for variability ranging from just a few months to a few years. You can spot its changing brightness over time by comparing it to the stars around it: notably magnitude 1.6 Bellatrix (Orion’s left shoulder), magnitude 1.7 Alnitak (the rightmost star in Orion’s Belt — again drawn facing us, so it appears leftmost on the sky), magnitude 2.1 Saiph (Orion’s right knee), and magnitude 0.2 Rigel (Orion’s left knee).
Sunrise: 6:33 A.M.
Sunset: 5:52 P.M.
Moonrise: 6:22 A.M.
Moonset: 4:45 P.M.
Moon Phase: Waning crescent (1%)
The Sky This Week: A planetary conjunction
Source: Trending Update Article
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