Betelgeuse is starting to recover. After bottoming out at magnitude +1.6 during mid-February, Orion's Betelgeuse had brightened a trace to about V magnitude +1.43 as of March 3rd. Can you detect any difference by eye yet, using Orion's other shoulder star, Bellatrix, as a comparison? See The Fall and Rise of Betelgeuse.
Friday, February 28
• The Moon and Venus this evening form a roughly equilateral triangle with the two or three brightest stars of Aries. How soon in the deepening dark can you spot these, above Venus and to the Moon's left?
• Algol dips to its minimum brightness, magnitude 3.4 instead of its usual 2.1, for a couple hours centered on 10:55 p.m. EST (7:55 p.m. PST) February 28th. Algol takes several additional hours to fade and to rebrighten.
Saturday, Feb. 29
• As the stars come out, look above the Moon to see how early you can first detect the Pleiades. The little cluster, the size of a fingertip at arm’s length, is about 13° above the Moon: a fist at arm's length or a bit more.
Easier to spot, and helping to guide you, will be orange Aldebaran a similar distance to the Pleiades' left.
Sunday, March 1
• This is the time of year when Orion stands straight upright due south as the stars come out. Later in the evening, and later in the month, he begins his long tilt down toward the west.
Under Orion’s feet, and to the right of Sirius and Canis Major, hides Lepus the Hare. Like Canis Major, this is a constellation with a connect-the-dots that really looks like what it's supposed to be. He's a crouching bunny, with his nose pointing lower right, his faint ears extending up toward Rigel (Orion's western foot), and his body bunched to the left. His brightest two stars, 3rd-magnitude Beta and Alpha Leporis, form the front and back of his neck.
Monday, March 2
• First-quarter Moon (exact at 2:57 p.m. EST). Aldebaran shines below the Moon after dark. Farther to their lower left stands Orion.
Tuesday, March 3
• Now the Moon shines straight over Orion after dark, in the dim feet of Gemini.
• It's early March, so quite soon after dark now, the Big Dipper rises as high in the northeast as Cassiopeia has descended to in the northwest. Midway between them, as always, is Polaris.
Wednesday, March 4
• At nightfall, the Moon forms a nearly equilateral triangle with Procyon to its lower left and Betelgeuse to its lower right. Those are the top two stars of the Winter Triangle; the third is brighter Sirius below them. The addition of the Moon turns it this evening into a temporary “Winter Diamond.”
Thursday, March 5
• Now the gibbous Moon shines near Pollux and Castor, high overhead after dark. Lower right of the Moon is Procyon, the Little Dog Star, and farther on in roughly the same direction you’ll come to Sirius, the big Dog Star.
Friday, March 6
• It's not officially spring for another 13 days, but the Spring Star Arcturus seems eager to thrust itself into view. It rises above the east-northeast horizon fairly soon after dusk now, depending on your latitude.
Where should you watch for it to rise? Find the Big Dipper as soon as the stars come out; it's high in the northeast. Follow the curve of its handle down and around to the lower right by a little more than a Dipper-length. That's the spot on the horizon to keep your eye on.
Saturday, March 7
• Regulus shines below the nearly full Moon after dark, as shown below. Can you make out the rest of the Sickle of Leo, almost enclosing it, through the moonlight? Binoculars help.
Want to become a better astronomer? Learn your way around the constellations. They're the key to locating everything fainter and deeper to hunt with binoculars or a telescope.
This is an outdoor nature hobby. For an easy-to-use constellation guide covering the whole evening sky, use the big monthly map in the center of each issue of Sky & Telescope, the essential guide to astronomy.
Once you get a telescope, to put it to good use you'll need a detailed, large-scale sky atlas (set of charts). The basic standard is the Pocket Sky Atlas (in either the original or Jumbo Edition), which shows stars to magnitude 7.6.
Next up is the larger and deeper Sky Atlas 2000.0, plotting stars to magnitude 8.5; nearly three times as many. The next up, once you know your way around, are the even larger Interstellarum atlas (stars to magnitude 9.5) and Uranometria 2000.0 (stars to magnitude 9.75). And read how to use sky charts with a telescope.
You'll also want a good deep-sky guidebook, such as Sue French's Deep-Sky Wonders collection (which includes its own charts), Sky Atlas 2000.0 Companion by Strong and Sinnott, or the bigger Night Sky Observer's Guide by Kepple and Sanner.
This Week's Planet Roundup
Mercury is hidden deep in the sunrise .
Venus (magnitude –4.3, moving from Pisces into Aries) is the big, bright "Evening Star" shining in the west during and after twilight. It doesn't set until more than two hours after the end of twilight.
In a telescope, Venus is 19 arcseconds in diameter and gibbous (about 61% sunlit). It will continue to enlarge in size and wane in phase for the next three months — passing through dichotomy (half-lit phase) in late March and becoming a dramatic thin crescent in May.
Mars (magnitude +1.1, above the handle of the Sagittarius Teapot) glows in the southeast before and during early dawn. Find it upper right of bright Jupiter. Mars is slowly creeping toward Jupiter, by about half a degree per day.
Telescopically Mars is still a tiny 5.5 arcseconds in diameter, a shimmering little orange blob. But it's on its way to a fine opposition in October, when it grow to 22.6 arcseconds wide.
Jupiter (magnitude –2.0, in Sagittarius) shines much brighter and whiter to the lower left of Mars. They're closing in on each other; Mars is 10° from Jupiter on the morning of February 29th and 7° from it on March 7th.
Saturn (magnitude +0.7, also in Sagittarius) is low in early dawn, 8° lower left of Jupiter, as shown above. Binoculars will help as the sky brightens.
Uranus (magnitude 5.8, in southwestern Aries) hides in the vicinity of Venus right after dark.
Neptune is lost in the sunset.
All descriptions that relate to your horizon — including the words up, down, right, and left — are written for the world's mid-northern latitudes. Descriptions that also depend on longitude (mainly Moon positions) are for North America.
Eastern Standard Time (EST) is Universal Time (UT, UTC, GMT, or Z time) minus 5 hours.
Audio sky tour. Out under the evening sky with your earbuds in place, listen to Kelly Beatty's monthly podcast tour of the heavens above. It's free.