The Sky This Week from November 22 to 29, 2024

Friday, November 22
Last Quarter Moon occurs at 8:28 P.M. EST, leaving most of the evening dark for deep-sky observing.�

About two hours after sunset, youâ€ll find the Great Square of Pegasus high in the southeastern sky. The Winged Horse is home to a fabulous globular cluster, M15, which just barely hits naked-eye magnitude at 6.2. Youâ€ll need a very dark sky (and good dark-adapted eyesight) if you want to spot it without optical aid, just over 4° northwest from the end of Pegasus†nose, which is marked by the magnitude 2.4 star Enif (Epsilon [ε] Pegasi). Enif lies to the right of the Great Square asterism in the sky early this evening, and to the upper right of Saturn, whose bright, nearly 1st-magnitude glow makes it the brightest object in this region of the sky.

Donâ€t worry if you canâ€t find the cluster unaided — any binoculars or telescope will show it. Spanning roughly 10†in amateur scopes, M15 should look like a dense, fuzzy ball at lower powers. Higher magnifications should start to resolve some of that fuzziness into individual stars, particularly on the clusterâ€s outskirts. The core of the cluster, however, is incredibly dense, and will remain an unresolved bright spot — a testament to the sheer number of stars packed into a region of space about 175 light-years across.

Sunrise: 6:54 A.M.
Sunset: 4:38 P.M.
Moonrise: 11:31 P.M.
Moonset: 12:47 P.M. 
Moon Phase: Waning gibbous (53%)
*Times for sunrise, sunset, moonrise, and moonset are given in local time from 40° N 90° W. The Moonâ€s illumination is given at 12 P.M. local time from the same location.

Saturday, November 23
Although Comet C/2023 A3 (Tsuchinshan-ATLAS) has faded from headlines, itâ€s still visible through most amateur scopes, recently observed around magnitude 9. Plus, itâ€s now up several hours after sunset, so thereâ€s less rush to catch it in your eyepiece shortly after the setting Sun.

Around 6 P.M. local time, Tsuchinshan-ATLAS hangs some 30° above the western horizon, now at the border between Serpens Cauda and Aquila. Youâ€ll find the comet less than ½° east of magnitude 4.6 Theta¹ (θ¹) Serpentis, also called Alya.�

The comet lies close to several star clusters, including the globular NGC 6760 (5° southeast of the comet) and the open cluster NGC 6755 (3° east of the comet). Also relatively nearby are M11, NGC 6709, and M14. In particular, compare the cometâ€s slowly diminishing coma to the appearance of the globulars M14 and NGC 6709.�

Sunrise: 6:55 A.M.
Sunset: 4:38 P.M.
Moonrise: — P.M.
Moonset: 1:10 P.M. 
Moon Phase: Waning crescent (44%)

Sunday, November 24
Venus lingers long after sunset in the last weeks of the month, now setting nearly three hours after the Sun. Look south just after sunset to spot the bright magnitude –4.1 planet — itâ€ll be the first point of light to pop out against the falling twilight.Â�

Viewed through a telescope, youâ€ll be able to make out Venus†gibbous phase, with the world some 70 percent lit. Now roughly 94.8 million miles (153 million kilometers) from Earth, its disk stretches 16†across. The best time to observe Venus†phase is earlier in the evening, while the background sky is still relatively light. This reduces the contrast between the planet and the sky, which actually enhances your view.

If you are outside shortly after sunset, you may also spot Mercury, which lies to Venus†lower right. Much lower in the sky, the tiny planet is just 6° high 20 minutes after sunset and much fainter, at magnitude 0.1. Still, it should become visible in the darkening sky, and binoculars or a small scope will surely pick it up — just make sure to wait until well after sunset before pulling out any optics.

Sunrise: 6:56 A.M.
Sunset: 4:37 P.M.
Moonrise: 12:32 A.M.
Moonset: 1:30 P.M. 
Moon Phase: Waning crescent (34%)

Monday, November 25
Mercury stands stationary against the background stars of Ophiuchus tonight at 11 P.M. EST. Previously moving eastward, or prograde, the tiny world now begins moving to the west, also known as retrograde motion. It will spend the rest of November and early December tracking back through Ophiuchus and into Scorpius, before switching to prograde motion once more in mid-December.

Now 0.1 magnitude fainter than yesterday, you can find Mercury at magnitude 0.2 and just over 4° high in the southwest half an hour after sunset. It currently sits in southern Ophiuchus, to the lower right of blazing Venus, which is higher in the sky in Sagittarius the Archer.

Through a telescope, Mercuryâ€s disk appears 8†across, roughly half the size of Venusâ€. The world presents a thinner crescent phase, just over 30 percent lit. The planet will continue to wane in both phase and brightness, quickly reaching and then surpassing magnitude 1 and disappearing from view as it approaches inferior conjunction early next month. So, catch your last glimpses of the innermost world now, before it is temporarily lost from sight.�

Sunrise: 6:57 A.M.
Sunset: 4:37 P.M.
Moonrise: 1:32 A.M.
Moonset: 1:49 P.M. 
Moon Phase: Waning crescent (26%)

Tuesday, November 26
The Moon reaches apogee, the farthest point from Earth in its orbit, at 6:56 A.M. EST. At that time, our satellite will sit 251,850 miles (405,313 km) away.

Saturn remains visible all evening in Aquarius, setting around local midnight. The magnitude 0.9 planet hosts a plethora of moons, the largest and brightest of which is mid-8th-magnitude Titan. Tonight, that moon lies nearly 2†to the planetâ€s west, out of the spotlight — though it will sit just 40†northwest of Saturn tomorrow night, and roughly the same distance northeast of the planet on the 28th.�

But tonight, thereâ€s more going closer to the ringed world, where two of its smaller, fainter moons — 10th-magnitude Tethys and Dione — are transiting. Your best chance to view them will be through a large scope under good conditions; high-speed video capture will also help you pick up the tiny worlds as they transit, as their glow is faint compared with the brighter background of Saturnâ€s cloud tops.�

Dione leads, moving in from the east to pass in front of the disk south of the rings around 5:10 P.M. EST, as it is getting dark on the East Coast. Within an hour, the moonâ€s tiny, dark shadow has also appeared on the cloud tops, just south of the rings. Tethys†transit begins at the eastern limb just after 7 P.M. EST, when Dione is more than halfway across, closer to the western limb. Tethys†shadow follows around 7:35 P.M. EST, but this tiny dark blot falls on the thinnest part of the rings rather than the planetâ€s disk, rendering it extremely difficult to pick up. Dioneâ€s transit ends some 10 minutes before 8 P.M. EST, with its shadow disappearing an hour later. Tethys ends its transit around 9:45 P.M. EST.�

Sunrise: 6:58 A.M.
Sunset: 4:36 P.M.
Moonrise: 2:30 A.M.
Moonset: 2:07 P.M. 
Moon Phase: Waning crescent (18%)

Wednesday, November 27

The Moon passes 0.4° north of Spica at 7 A.M. EST. Virgoâ€s brightest star, Spica is also cataloged as Alpha (α) Virginis and shines at magnitude 1. It lies 250 light-years away and is nearly 2,000 times brighter than our Sun. But this is no ordinary star — in fact, it is not “a†star at all, but a binary blue dwarf system with components that orbit each other every 4  days from a distance roughly a tenth of the distance of Earth from the Sun.�

You can catch the pair in the early-morning sky, where our satellite occults the star for observers in the eastern half of Canada and the U.S. They are rising together in the east by 3:45 A.M. local time, climbing slowly higher as the hours pass and dawn approaches. The Moon is now a slim waning crescent some 13 percent lit, offering a gorgeous view. Spica will vanish behind the sunlit western limb and reappear roughly an hour later from behind the darkened eastern limb.�

From Boston, Spica disappears just before 5:40 A.M. EST, reappearing just after 6:52 A.M. EST. From Chicago, the occultation begins seconds before 4:29 A.M. CST and ends just after 5:37 A.M. CST. You can visit the International Occultation Timing Associationâ€s webpage for the event to see which cities will observe an occultation and find the timing from your location.�

Sunrise: 6:59 A.M.
Sunset: 4:36 P.M.
Moonrise: 3:30 A.M.
Moonset: 2:28 P.M. 
Moon Phase: Waning crescent (11%)

Thursday, November 28
In 2020, NASAâ€s Astronomy Picture of the Day featured a humorous take on a nearby star-forming region, transforming the Orion Nebula (M42) into the Great Turkey Nebula for the Thanksgiving holiday.Â�

You, too, can cap off your feast this Turkey Day with a glimpse of this star-forming fowl, as Orion the Hunter is readily visible in the evening sky at this time of year. By 10:30 P.M. local time, Orionâ€s famous three-star belt is already more than 30° high in the southeast. The nebula sits on Orionâ€s “sword,†which hangs below the lowest (leftmost as the constellation is rising) star on his belt, 2nd-magnitude Alnitak. Look for a fuzzy glow about 3.8° to the lower right of that star — you may be able to see it with the naked eye if your sky is clear and dark!�

Binoculars or any telescope will show the large nebula in all its glory, glowing at magnitude 4 and spanning nearly 90†at its largest. Tucked within the wispy tendrils of gas at the center is the Trapezium Cluster, housing several hot, bright stars whose radiation is slowly pushing away the gas and dust around them, clearing out the center of the nebula.

If youâ€re looking for the Great Turkey, the larger, rounder part of the nebula to the south is the birdâ€s body, while the smaller offshoot to the north, partly separated by a dark dust lane, is the turkeyâ€s head. Can you picture it?

Sunrise: 7:00 A.M.
Sunset: 4:36 P.M.
Moonrise: 4:31 A.M.
Moonset: 2:51 P.M. 
Moon Phase: Waning crescent (6%)

Friday, November 29
Jupiter blazes in the late-evening sky, now more than 50° high in the east by 10 P.M. local time. The gas giant sits within the western bounds of the large asterism known as the Winter Hexagon, which connects seven stars (two of which count as one “point,†so the shape still has six sides) prominent in the wintertime sky. We might not be quite into Northern Hemisphere winter just yet, but these stars are already all visible, glowing like diamonds as they rise higher in the east this evening.�

Letâ€s start at the “bottom†of the Hexagon, at Sirius in Canis Major. This is the brightest star in the sky and should stand out well, even as it sits just 10° above the horizon at this time. Moving clockwise from this star, next is Procyon in Canis Minor, then Castor and Pollux (the two stars serving as one point) in Gemini. The “top†of the Hexagon is Capella in Auriga; then thereâ€s Aldebaran in Taurus and Rigel in Orion. Finally, you can close the loop back at Sirius.�

Sunrise: 7:01 A.M.
Sunset: 4:35 P.M.
Moonrise: 5:35 A.M.
Moonset: 3:19 P.M. 
Moon Phase: Waning crescent (2%)

Sky This Week is brought to you in part by Celestron.