This Week’s Sky at a Glance, November 5 – 13

Nova Cassiopeiae 2021 remains to be magnitude 8.4 as of November fifth, greater than 7 months after it erupted. Charts and comparison stars.


■ At nightfall this week, the Jupiter-Saturn line within the southern sky tilts solely mildly, as proven beneath. Look far to their decrease proper for vivid Venus.

As night progresses, Venus units and the lean of the giants steepens.

Jupiter and Saturn have handed the stationary factors of their retrograde loops and have begun shifting eastward (leftward) once more with respect to the background stars. This is most noticeable as Jupiter strikes previous Delta Capricorni, the constellation’s left nook, proven right here. Keep watch; the eastward movement of the enormous planets is rushing up.

The Summer Triangle Effect. Here it’s early November, however Deneb nonetheless shines close to the zenith because the stars come out. And brighter Vega remains to be not removed from the zenith, towards the west. The third star of the “Summer” Triangle, Altair, stays very excessive within the southwest (excessive higher proper of Jupiter and Saturn). They appear to have stayed there for a couple months! Why have they stalled out?

What you are seeing is the results of sundown and darkness arriving earlier and earlier throughout autumn. Which means should you exit and starwatch quickly after darkish, you are doing it earlier and earlier by the clock. This counteracts the seasonal westward turning of the constellations.

Of course this “Summer Triangle effect” applies to the complete celestial sphere, not simply the Summer Triangle. But the obvious stalling of that vivid landmark, lengthy after summer season’s finish, impressed Sky & Telescope to offer the impact that title many years in the past and it has caught.

Of course, as all the time in celestial mechanics, a deficit someplace will get made up elsewhere. The reverse impact makes the seasonal advance of the constellations appear to speed up in early spring. The spring-sky landmarks of Virgo and Corvus appear to sprint away westward from week to week virtually earlier than you understand it, as a consequence of darkness falling later and later. Let’s name this the “Corvus effect.”

■ New Moon (precise at 5:15 p .m. Eastern Daylight Time).


■ I do not know why I get confused looking for the open cluster NGC 7789 in Cassiopeia, a.okay.a. Caroline’s Rose, with a finderscope or binoculars. I imply it is proper there a easy, brief star-hop from the intense finish of the Cassiopeia W. Maybe it is as a result of the cluster is a very dim, clean glow regardless of being respectably massive; it is wealthy with stars however they’re all too faint for the swarm to look speckly, and I do have mild air pollution. Try with the good, clear finder chart in Matt Wedel’s Binocular Highlight column within the November Sky & Telescope, web page 43.

■ Daylight-saving time ends at 2 a.m. tonight for many of North America. Clocks fall again an hour.


■ Catch Venus and the crescent Moon collectively within the southwest as twilight fades, as proven beneath. How low are you able to comply with them down after darkish?

The Moon poses proper of Venus at nightfall Sunday. They’re solely about 2° to 4° aside relying on the place you’re in North America. On Monday, the Moon hangs farther to Venus’s higher left. These are the 2 brightest celestial objects after the Sun.


■ Now the Moon is farther higher left of Venus, as proven above.

■ When night time arrives, the Great Square of Pegasus remains to be balanced on its nook excessive within the southeast. But inside two hours it turns round to lie stage like a field, excessive within the south.

A sky landmark to recollect: The west (right-hand) aspect of the Great Square factors far down virtually to 1st-magnitude Fomalhaut. The east aspect of the Square factors down towards Beta Ceti not as instantly, and never as far.


■ Around 10 p.m., relying on the place you reside, zero-magnitude Capella rises precisely as excessive within the northeast as zero-magnitude Vega has sunk within the west-northwest.

■ As Wednesday’s daybreak brightens, carry binoculars to attempt for Mercury and Mars in conjunction, 1° aside, very low above the japanese horizon. Look for Mars, a mere magnitude +1.6, south (decrease proper) of Mercury. Mercury is magnitude –0.9, ten instances brighter. Your finest probability could be 30 or 40 minutes earlier than dawn.

■ Happy 87th birthday, Carl Sagan (November 9, 1934 – December 20, 1996). If solely.

Moon passing Saturn and Jupiter, Nov. 10-11, 2021
When the Moon passes Saturn, then Jupiter, think about how close to and much they really are. Saturn is 4,000 instances farther from us than the Moon is simply now, and it is bodily 35 instances bigger in diameter. Jupiter is 1,900 instances extra distant than the Moon and 41 instances bigger.


■ This night, search for Jupiter higher left of the Moon and for lesser Saturn roughly half as far to the Moon’s proper, as proven above. Watch via the night as this sample strikes decrease towards the west-southwest, steadily rotating a bit clockwise because it goes.


■ First-quarter Moon (precise at 7:46 a.m. EST). Jupiter shines brightly about 5° higher proper of the Moon at nightfall. Saturn shines extra modestly to their proper at nightfall, and to their decrease proper later as proven above.


■ At dusk Jupiter, Saturn, the Moon, and Venus type a lengthy, ragged diagonal line within the south to southwest, in that order from higher left to decrease proper.

■ The largest asteroid, 1 Ceres, is at present passing via the Hyades close to Aldebaran this week. At magnitude 7.3 Ceres is faintly in binocular vary. Its path is mapped within the November Sky & Telescope, web page 50 (the place the date ticks are for 0:00 Universal time, which falls on the night of the earlier date for North America.)

Aldebaran and the Hyades are effectively up within the east by 9 p.m. commonplace time. Robert C. Victor factors out to us that on the nights of November 11-12 and 12-13 , “Ceres is passing north of the naked-eye pair Theta-1 and Theta-2 Tauri,” a landmark pair of Hyads simply west of Aldebaran. “These stars are 5.5 arcminutes apart, magnitudes 3.8 and 3.4. The 5.0-mag. star 75 Tauri is 24 arcminutes north of Theta-1. On November 12, Ceres passes within 9 arcminutes north of 75 Tauri. This conjunction takes place in the afternoon in North America, with Ceres moving west by 12 arcminutes per day.”


■ Look excessive above the Moon for the Great Square of Pegasus.

■ Vega is the brightest star excessive within the west on November evenings. Its little constellation Lyra extends to its left, pointing as all the time to Altair, the brightest star within the southwest.

Three of Lyra’s stars close to Vega are fascinating doubles. Barely above Vega is 4th-magnitude Epsilon Lyrae, the Double-Double. Epsilon varieties one nook of a roughly equilateral triangle with Vega and Zeta Lyrae. The triangle is lower than 2° on a aspect, hardly the width of your thumb at arm’s size.

Binoculars simply resolve Epsilon. And a 4-inch telescope at 100× or extra ought to resolve every of Epsilon’s broad parts into a tight pair.

Zeta can be a double star for binoculars; a lot more durable, however plainly resolved in a telescope.

And Delta Lyrae, higher left of Zeta by a related distance, is a a lot wider and simpler binocular pair.


This Week’s Planet Roundup

Mercury is deeper down within the dawn glow each morning. Look for it low above the east-southeast horizon about 30 or 40 minutes earlier than dawn. At least it is at present vivid, about magnitude –0.9. By the tip of the week it’s going to in all probability be out of sight.

Don’t confuse Mercury with Arcturus glowing some 30° (three fists) to its higher left.

Venus, a sensible magnitude –4.7, shines in southwest throughout and after twilight. It’s now encroaching into the vastly fainter Sagittarius Teapot. Venus would not set now till about an hour after darkish. It will proceed to shine a little larger and brighter via the tip of November.

Mars, a mere magnitude +1.6, is rising deep within the dawn within the neighborhood of Mercury, which is ten instances brighter at magnitude –0.9. Catch them in conjunction on the morning of November tenth, when Mars is 1° south (decrease proper) of Mercury. Bring binoculars.

Jupiter and Saturn proceed to shine within the south throughout night, 16° aside in Capricornus. Jupiter is the intense one at magnitude –2.4. Saturn, to its proper or decrease proper, is magazine +0.6.

In twilight they’re simply starting to tilt. As night advances they tilt extra steeply and transfer westward. Saturn units round 10 p.m. commonplace time, Jupiter about an hour later.

Look 23° (two fists at arm’s size) decrease left of Jupiter for Fomalhaut, magnitude +1.2.

Jupiter within the information: The Roots of Jupiter’s Great Red Spot Run Deep.

Uranus (magnitude 5.7, in southern Aries) is effectively up within the east by 7 p.m. commonplace time. See Bob King’s Uranus Queues Up for Opposition.

Neptune (magnitude 7.9, at the Aquarius-Pisces border) is already excessive within the southeast at dusk.

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 that additionally depend upon longitude (primarily Moon positions) are for North America.

Eastern Daylight Time, EDT, is Universal Time (additionally referred to as UT, UTC, or GMT) minus 4 hours. Eastern Standard Time, EST, is Universal Time minus 5 hours. Standard time begins Sunday Nov. seventh for many of North America.

Want to grow to be a higher astronomer? Learn your way across the constellations. They’re the important thing to finding all the pieces fainter and deeper to hunt with binoculars or a telescope.

This is an outside nature passion. For an easy-to-use constellation information protecting the entire night sky, use the massive month-to-month map within the middle of every situation of Sky & Telescope, the journal of the American Astronomical Society.

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

Pocket Sky Atlas cover, Jumbo edition
The Pocket Sky Atlas plots 30,796 stars to magnitude 7.6, and lots of of telescopic galaxies, star clusters, and nebulae amongst them. Shown right here is the Jumbo Edition, which is in onerous 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; almost thrice as many. The subsequent up, as soon as you understand your way round, are the even bigger Interstellarum atlas (stars to magnitude 9.5) or Uranometria 2000.0 (stars to magnitude 9.75). And you should definitely learn How to Use a Star Chart with a Telescope.

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

Can a computerized telescope substitute charts? Not for freshmen, I do not suppose, and never on mounts and tripods which are lower than top-quality mechanically, which 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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