This Week’s Sky at a Glance, February 21 – 29

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Betelgeuse remains dim. Orion’s Betelgeuse is still V magnitude +1.5 or +1.6 as of February 19th, much dimmer than its more typical +0.5. However, it may now be showing subtle signs of rebrightening (by 0.1 magnitude or less) as measured photoelectrically. To the eye, Orion’s two shoulder stars still look basically equal. See Is Betelgeuse Approaching a Crossroads?

Mars, Jupiter, Saturn at dawn, Feb. 22, 2020

The three dawn planets are becoming easier for early risers to spot. Bright Jupiter is the first that will catch your eye and the last that will fade away into the daylight. Use it to guide you to Mars and Saturn.

Mars, Jupiter, Saturn at dawn, end of Feb. 2020

By week’s end all three are a little higher, and Mars is a little closer to Jupiter and Saturn. It will walk the line between the two giants from March 20th to 31st.

Friday, Feb. 21

• Look high over Venus after dark for the two brightest stars of Aries, lined up almost vertically. And high above Aries, and perhaps a bit left, are the Pleiades.

Venus is a good 40° from the Pleiades right now. But for the next six weeks, watch as they head straight toward each other. On the evening of April 3rd, Venus will shine just inside the cluster’s edge.

Saturday, Feb. 22

• Have you ever seen Canopus, the second-brightest star after Sirius? It lies almost due south of Sirius by 36°. That’s far enough south that it never appears above your horizon unless you’re below latitude 37° N (southern Virginia, southern Missouri, central California). And there, you’ll need a very flat south horizon. Canopus crosses the south point on the horizon just 21 minutes before Sirius does.

When to look? Canopus is due south when Beta Canis Majoris — Murzim the Announcer, the star
about three finger-widths to the right of Sirius — is at its highest due south over your
landscape. That’s about 7 or 8 p.m. now, depending on how far east or west you live in your time zone. Look straight down from Murzim then.

• Some telescopic deep-sky objects hold secret surprises in or near them. Get out your telescope and sky atlas for a go at Bob King’s eight Hidden Gems in Common Deep-Sky Objects now in evening view.

Winter Hexagon

Shortly after nightfall, the gigantic Winter Hexagon extends from Sirius in the south-southeast to Capella almost straight overhead.

Sunday, Feb. 23

• Walk the stars of the Winter Hexagon, and seek out some of their deep-sky surroundings, with Gary Seronik’s Explore the Winter Hexagon Tonight.

• New Moon (exact at 10:32 a.m. EST).

Monday, Feb. 24

• Under the feet of Orion, and to the right of Sirius in early evening now, 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.

Tuesday, Feb. 25

• In twilight, look far below Venus for the thin crescent Moon. Think photo opportunity.

Moon passing Venus in twilight, Feb. 26-28, 2020

The waxing crescent Moon passes left of Venus in the western twilight. (For clarity, the Moon here is always drawn three times its actual apparent size.)

Wednesday, Feb. 26

• The thickening crescent Moon is closer under Venus this evening, as shown here.

Thursday, Feb. 27

• The crescent Moon is 6° or 7° left of Venus during and after twilight, as shown here. How early can you spot them both? You can start trying long before sunset!

Friday, Feb. 28

• After dinnertime at this time of year, five carnivore constellations are rising upright in a row from the northeast to south. They’re all seen in profile with their noses pointed up and their feet (if any) to the right. These are Ursa Major the Big Bear in the northeast (with the Big Dipper as its brightest part), Leo the Lion in the east, Hydra the Sea Serpent in the southeast, Canis Minor the Little Dog higher in the south-southeast, and bright Canis Major the Big Dog in the south.

Saturday, Feb. 29

• As the stars come out, look above the Moon to see how early you can detect the Pleiades. They’re about 13° over the Moon: a fist at arm’s length or a little more.

Easier to spot, and helping to guide you, will be orange Aldebaran a similar distance to the Pleiades’ left.

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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.

Jumbo Pocket Sky Atlas cover

The Pocket Sky Atlas plots 30,796 stars to magnitude 7.6, and hundreds of telescopic galaxies, star clusters, and nebulae among them. Shown above is the Jumbo Edition for easier reading in the night. Sample chart.

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.

Can a computerized telescope replace charts? Not for beginners, I don’t think, and not on mounts and tripods that are less than top-quality mechanically (meaning heavy and expensive). And as Terence Dickinson and Alan Dyer say in their Backyard Astronomer’s Guide, “A full appreciation of the universe cannot come without developing the skills to find things in the sky and understanding how the sky works. This knowledge comes only by spending time under the stars with star maps in hand.”


This Week’s Planet Roundup

Mercury is hidden from sight in the skirts of the Sun.

Venus (magnitude –4.2, in Pisces) is the big, bright “Evening Star” shining in the west during and after twilight. Look to its right or lower right as the stars come out for the Great Square of Pegasus, sinking down on one corner. Venus doesn’t set now until two hours or more after the end of twilight.

In a telescope, Venus is 18 arcseconds in diameter and gibbous (65% sunlit). It will enlarge in size and wane in phase for the rest of the winter and much of the spring — passing through dichotomy (half-lit phase) in late March before becoming a dramatic thin crescent in May.

Mars by Damian Peach Jan 31, 2020

Mars was a minuscule 4.8 arcseconds wide on January 31st, but Damian Peach was able to record lots of surface features and clouds using the 1-meter Chilescope in good seeing shortly before sunrise. South here is up. The very dark “peninsula” sticking down is Syrtis Major. South of it is a large cloudy zone over the Hellas basin. “Bright Elysium cloud [at lower left],” notes Peach. “Equatorial cloud band across Syrtis Major.”

Mars (magnitude +1.2, above the Sagittarius Teapot) glows in the southeast before and during early dawn. Don’t confuse it with Antares, shining with the same color and brightness some 25° to Mars’s upper right. Mars is still a tiny 5 arcseconds in diameter. But it’s on its way to a fine opposition in October, when it grow to 22.6 arcseconds wide.

Mars (magnitude 1.2, above the Sagittarius Teapot) glows in the southeast before and during dawn. It’s upper right of bright Jupiter. Compare Mars to Antares, similar in color and brightness, which is far over to its upper right in the south.

Jupiter (magnitude –1.9, in Sagittarius) shines much brighter (and whiter) lower left of Mars left. They’re closing in on each other; Mars is 14° from Jupiter on the morning of February 22nd and 11° from it on the 29th.

Saturn (magnitude +0.6, also in Sagittarius) is low in early dawn, 9° lower left of Jupiter, almost a fist at arm’s length. Binoculars will help as the sky brightens.

Uranus (magnitude 5.8, in southwestern Aries) is high in the west-southwest right after the end of twilight, hiding in the dark some 10° or 15° above Venus. Finder chart (without Venus).

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.






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