This Week’s Sky at a Glance, November 25 – December 4


■ Does the Sun already appear to be setting about as early because it ever will? You’re proper! We’re nonetheless virtually a month from the winter solstice — however the Sun units its earliest every year round December Seventh, in case you’re close to latitude 40° north. And already the Sun units inside solely about 3 minutes of that point.

A stunning results of this: The Sun really units a hint earlier on Thanksgiving than on Christmas — regardless that Christmas is round solstice time!

But in celestial mechanics, each seeming abnormality is balanced out by an equal abnormality some other place. The offset of the earliest sundown from the solstice date is balanced out by the other taking place at dawn: The Sun would not come up its newest till January 4th, nicely after the solstice. Blame the tilt of Earth’s axis and the eccentricity of Earth’s orbit.

■ As daybreak begins on Friday morning the twenty sixth, the waning Moon shines at the Sickle of Leo, as proven beneath.

When the waning Moon goes via last-quarter part this month, it is passing via Leo excessive in early daybreak.


■ Venus and Jupiter, the 2 brightest celestial objects after the Sun and Moon, proceed to blaze throughout and after twilight this week. Venus is within the southwest, now at its highest and brightest of this apparition. Jupiter is could be very far to Venus’s higher left, excessive within the south to south-southwest.

Spot dimmer Saturn rising between them as twilight fades. It’s lower than midway from Jupiter to Venus early within the week, precisely midway on December 4th.

■ The last-quarter Moon rises in Leo round 11 p.m. tonight. By daybreak on Saturday the twenty seventh it is excessive within the south beneath Leo’s stomach, as proven above. The Moon is precisely last-quarter at 7:28 a.m. Saturday morning EST.


■ Around 7 or 8 p.m. this week, the Great Square of Pegasus rests in its degree place very excessive towards the south. (It’s straight overhead in case you’re as far south as Miami.) Its western (proper) facet factors very far down towards Fomalhaut. Its jap facet factors down towards Beta Ceti, also referred to as Deneb Kaitos or Diphda, much less far down and fewer instantly.

Now descending farther: If you’ve got a excellent view all the way down to a darkish south horizon — and in case you’re not a lot farther north than roughly New York, Denver, or Madrid — image an equilateral triangle with Fomalhaut and Beta Ceti as its prime two corners. Near the place the third nook could be (simply a bit proper of that time) is Alpha Phoenicis, or Ankaa, within the constellation Phoenix. It’s magnitude 2.4, not very vivid however the brightest factor in its space. It has a yellow-orange tint; binoculars assist test. Have you ever seen something of the constellation Phoenix earlier than?


■ Jupiter’s Great Red Spot ought to transit the planet’s central meridian round 7:02 p.m. EST. Features on Jupiter are in high-quality view (nearer to the central meridian than to the limb) for 50 minutes earlier than and after they transit. A lightweight blue or green filter helps a bit.

During this time, the tiny black shadow of Io might be crossing Jupiter. Bright little Io itself enters Jupiter’s jap edge at 7:16 p.m. EST. The shadow lastly departs Jupiter’s western edge at 8:34 p.m. EST.


■ What’s the subsequent most engaging star cluster in Taurus after the Pleiades and Hyades? Gotcha there, I wager! Maybe it is NGC 1647, between the horns of Taurus simply a few levels from Aldebaran and the Hyades. Matt Wedel calls it “a wonderful object for binoculars” in a actually darkish sky. It’s pretty giant as open clusters go and wealthy in faint stars. At a complete magnitude of 6.4 Matt additionally calls it “visible to the naked eye under clear, dark skies,” however for an prolonged object? I’d say he means the clear darkish sky from a excessive desert mountaintop 50 miles from the closest city, seen with a 20-year-old’s huge pupil and an hour’s darkish adaptation. Hence, binoculars or a scope for the remainder of us.

The cluster’s location is simple: it kinds a roughly equilateral triangle with Aldebaran and the opposite tip of the Hyades V. Just off its south edge you may discover “a fine optical double star,” Matt writes, very huge, each orange, magnitudes 6.0 and seven.5. Have a good examine utilizing the chart together with his Binocular Highlight column within the December Sky & Telescope, web page 43.

Some, nevertheless, would as a substitute give the rank of third-place Taurus cluster to NGC 1746, additionally between the Taurus horns. It’s bigger and maybe a little extra photogenic and crowd pleasing, situated 3/5 of the way from Aldebaran to Beta Tauri. The two clusters typically get confused not least as a result of their NGC numbers are the identical digits rearranged.


■ Mars is taking its candy time rising from behind the Sun’s glare into the morning sky, because it does at the beginning of each apparition. But on Wednesday and Thursday mornings the curve of the crescent Moon factors down to indicate the place to look, as illustrated beneath.

The crescent Moon points the way to low Mars at dawn, Dec. 1-2, 2021
The waning crescent Moon factors the way all the way down to low little Mars in early daybreak. The blue 10° scale is concerning the width of your fist at arm’s size.


■ As the stars come out, the Cassiopeia W stands on finish (its fainter finish) excessive within the northeast. Watch Cas flip round to turn into a flattened M, even increased within the north, by late night.

Two faint fuzzies naked-eye: The Andromeda Galaxy (M31) and the Perseus Double Cluster are two of essentially the most well-known deep-sky objects. They’re each cataloged as 4th magnitude, and in a pretty good sky you may see each with the unaided eye. Binoculars make them a lot simpler. They’re situated solely 22° aside, very excessive towards the east at the top of twilight — to the proper of Cassiopeia and nearer beneath Cassiopeia, respectively. Later within the night they cross extra overhead.

Though comparable in brightness they appear quite totally different even to the bare eye, the extra so the darker your sky. See for your self. You can discover them with the all-sky constellation map within the heart of the November or December Sky & Telescope.


Comet Leonard passes M3. Comet Leonard (C/2021 A1) has in all probability brightened to sixth magnitude by tonight. It’s excessive within the east earlier than the very first mild of daybreak, crossing the Canes Venatici / Bootes border. North Americans late tonight will discover it lower than 1° beneath the Seventh-magnitude globular cluster M3. Quite an fascinating visible comparability to be made, and suppose picture alternative!

The comet ought to peak round 4th or fifth magnitude that means it will solely be a dim binocular object; a comet is extra diffuse than a star round December tenth or eleventh. By then it will be a lot decrease at the start of daybreak, beginning to lose its battle with morning twilight. See “Comet Leonard Races Across the Sky” within the December Sky & Telescope, web page 48, with the required finder charts.


■ Vega nonetheless shines brightly nicely up within the west-northwest after darkish. The brightest star above it’s Deneb, the pinnacle of the large Northern Cross shaped by the brightest stars of Cygnus. At dusk the shaft of the cross extends decrease left from Deneb. By about 11 p.m., it vegetation itself roughly upright on the northwest horizon.


■ Saturn is now precisely midway between Jupiter and Venus; look throughout late twilight or shortly after. Although Saturn is a very respectable magnitude +0.7, the opposite two fairly overpower it.

■ For West Coasters, Algol in Perseus must be in eclipse at minimal brightness, magnitude 3.4 as a substitute of its standard 2.1, for a couple hours centered on 11:49 p.m. PST. Algol takes a number of extra hours to fade and to rebrighten.

■ New Moon (precise at 2:43 a.m. on this date Eastern Standard Time).

■ Total eclipse of the Sun for elements of West Antarctica. Partial eclipse covers all of Antarctica, a lot of the Southern Ocean, and nicks South Africa. See the December Sky & Telescope, web page 50.


This Week’s Planet Roundup

Mercury is out of sight along side the Sun.

Venus, a dazzling magnitude –4.9, shines within the southwest throughout and after twilight. Venus has reached its biggest peak and biggest brilliancy for this apparition.

Mars, far and faint at magnitude +1.6, is step by step rising low within the dawn. Try for it with binoculars simply above the east-southeast horizon about 45 minutes earlier than sunup. See the graphic for Dec. 1-2 above. You’re catching Mars at the beginning of its new apparition, which is able to run for nearly two years.

Jupiter with Great Red Spot and two dark barges on Nov. 22, 2021.
Jupiter on November twenty second, imaged by Christopher Go within the Philippines. South is up. Because Jupiter is way previous opposition, its following (jap) edge is barely shaded. Jupiter has shrunk to 38 arcseconds huge now however remains to be price watching! The seeing typically steadies in twilight, when Jupiter and Saturn are at the moment at their highest.

The South Equatorial Belt, with the Great Red Spot in its southern edge, is generally pale. The North Equatorial Belt is comparatively darkish red alongside its south edge and sports activities two darkish red barges. (Color and brightness contrasts are exaggerated right here, in comparison with Jupiter’s visible look, as they’re in just about each picture.)

Jupiter and Saturn, each in Capricornus, shine within the south to southwest throughout night far higher left of Venus. Jupiter is the brilliant one at magnitude –2.3. Saturn, 16° to Jupiter’s decrease proper, is magazine +0.7, only one/16 as vivid.

Look 22° (two fists at arm’s size) decrease left of Jupiter for Fomalhaut, the Autumn Star, magnitude +1.2.

Saturn units round 9 p.m. Jupiter units a little greater than an hour later.

Uranus (magnitude 5.7, in southern Aries above the pinnacle of Cetus) is excessive within the east after darkish. See Bob King’s story and finder chart.

Neptune (magnitude 7.9, at the Aquarius-Pisces border) is excessive within the south after darkish.

All descriptions that relate to your horizon — together with the phrases up, down, proper, and left — are written for the world’s mid-northern latitudes. Descriptions and graphics that additionally rely on longitude (primarily Moon positions) are for North America.

Eastern Standard Time, EST, is Universal Time (additionally known as UT, UTC, GMT, or Z time) minus 5 hours.

Want to turn into a higher astronomer? Learn your way across the constellations. They’re the important thing to finding every little thing fainter and deeper to hunt with binoculars or a telescope.

This is an out of doors nature interest. For an easy-to-use constellation information overlaying the entire night sky, use the large month-to-month map within the heart of every problem of Sky & Telescope, the journal of the American Astronomical Society.

Once you get a telescope, to place it to good use you may want a detailed, large-scale sky atlas (set of charts). The primary customary is the Pocket Sky Atlas (in both the original or Jumbo Edition), which exhibits stars to magnitude 7.6.

Pocket Sky Atlas cover, Jumbo edition
The Pocket Sky Atlas plots 30,796 stars to magnitude 7.6, and a whole bunch of telescopic galaxies, star clusters, and nebulae amongst them. Shown right here is the Jumbo Edition, which is in laborious covers and enlarged for simpler studying outdoor by red flashlight. Sample charts. More about the current editions.

Next up is the bigger and deeper Sky Atlas 2000.0, plotting stars to magnitude 8.5; practically thrice as many. The subsequent up, as soon as you already know your way round, are the even bigger Interstellarum atlas (stars to magnitude 9.5) or Uranometria 2000.0 (stars to magnitude 9.75). And make sure to learn How to Use a Star Chart with a Telescope.

You’ll additionally need a good deep-sky guidebook, reminiscent of the large Night Sky Observer’s Guide set by Kepple and Sanner.

Can a computerized telescope change charts? Not for newbies, I do not suppose, and never on mounts and tripods which are lower than top-quality mechanically, that means heavy and costly. And as Terence Dickinson and Alan Dyer say of 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.”

Audio sky tour. Out beneath the night sky together with your
earbuds in place, take heed to Kelly Beatty’s month-to-month
podcast tour of the heavens above. It’s free.

“The dangers of not thinking clearly are much greater now than ever before. It’s not that there’s something new in our way of thinking, it’s that credulous and confused thinking can be much more lethal in ways it was never before.”
            — Carl Sagan, 1996

“Facts are stubborn things.”
            — John Adams, 1770

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