#astronomy This Week’s Sky at a Look, August 6 – 14 – Sky & Telescope

August 7, 2021 - Comment

Nova Cas fades. Nova Cassiopeiae 2021 has bounced round in brightness ever since erupting to magnitude 7.7 in March — together with brightenings to magnitude 5.5 in early Could and 6.zero round July 27th. As of August sixth it was right down to about eight.1. Charts and comparability stars. It actually cannot maintain this up

Nova Cas fades. Nova Cassiopeiae 2021 has bounced round in brightness ever since erupting to magnitude 7.7 in March — together with brightenings to magnitude 5.5 in early Could and 6.zero round July 27th. As of August sixth it was right down to about eight.1. Charts and comparability stars. It actually cannot maintain this up ceaselessly. . . .


■ Have you ever been seeing any Perseids meteors but? For now you will discover solely an occasional Perseid throughout your observing periods, however hold on. The bathe is because of peak late this coming Wednesday evening, August 11th; see that date under. Already the sky is moonlessly darkish.

How do you inform a Perseid from a random sporadic meteor or a member of one of many lesser showers which might be presently lively, the Delta Aquariids and the Kappa Cygnids? Simply hint its path backward far throughout the sky. Does this line cross some extent in northern Perseus under Cassiopeia? That is the radiant of the Perseids: their perspective level of origin in the event you may see them approaching from the far distance.

In actuality you may see them solely at their final second as they plunge into Earth’s ambiance — and that may occur anyplace in your sky.


■ Brilliant Vega passes closest to overhead round 10 or 11 p.m. now, relying on how far east or west you’re in your time zone.

How carefully it misses your zenith depends upon how far north or south you’re. It passes proper by your zenith in the event you’re at latitude 39° north (Washington DC, Cincinnati, Kansas Metropolis, Lake Tahoe). How carefully are you able to decide this simply by trying?

Deneb crosses closest to the zenith two hours after Vega. However to see Deneb precisely straight up it’s worthwhile to be farther north, at latitude 45°: Portland, Minneapolis, Montreal, southern France, northern Italy.


■ That is the time of 12 months when the Large Dipper scoops down throughout night, as if to select up the water that it’s going to dump from excessive overhead early subsequent spring.

■ New Moon (precise at 9:50 a.m. EDT).


Crescent Moon passing Venus, Aug 9-11, 2021A brand new lunation will get below approach because the waxing crescent Moon returns to the night sky. Venus may be very apparent. Tiny, faint Mars, very low in vivid twilight, might be a troublesome catch even with binoculars.

■ As twilight fades after sundown, search for the very skinny crescent Moon coming into view far to the proper or decrease proper of Venus, as proven above.

Low, distant Mars, three° or four° left or decrease left of the Moon for North People, might be a problem certainly. It is almost on the far facet of the Solar from us and solely magnitude 1.eight, and it is swamped by thick air and low-altitude twilight.


■ Now the crescent Moon shines to the proper of Venus in twilight, as proven above.

■ Should you use a telescope a lot you are in all probability conversant in Lyra overhead, harboring Vega, the Double-Double, and the Ring Nebula amongst different sights. And close by is Albireo, the beak of Cygnus and one of many sky’s most interesting gold-and-blue double stars.

However between Albireo and Lyra, what concerning the much-overlooked globular cluster M56? At magnitude eight.three you would possibly even have the ability to detect it with giant binoculars in a darkish sky. To pinpoint the spot, hone in with Matt Wedel’s “Misplaced in Area,” his Binocular Spotlight column and chart for this lesser-known discover within the August Sky & Telescope, web page 43.


The Perseid meteor bathe ought to peak late tonight, and there is not any moonlight to intrude!

Early within the night the meteors might be relatively few, as a result of the bathe’s radiant will nonetheless be low (within the northeast). However for that very same cause, early-evening Perseids overhead might be unusually lengthy as they graze sideways by the uppermost ambiance. Later within the evening the meteors will develop into extra quite a few (and shorter) because the radiant rises excessive and so they plunge extra straight downward. One of the best present might be from about 11 or midnight till the primary gentle of daybreak on the 12th; the later the higher.

Layer up warmly even when the day was scorching; keep in mind about radiational cooling below a transparent open sky. A sleeping bag will serve for heat and mosquito armor; use DEET the place you stay uncovered.

Carry a reclining garden chair to a darkish, open spot the place no native lights get in your eyes. Lie again, and gaze up into the celebs. Be affected person. As your eyes adapt to the darkish, you might even see a meteor each jiffy through the night, and each minute or so on common because the morning hours advance. You will see fewer below gentle air pollution, however the brightest ones will nonetheless shine by. One of the best route to look is wherever your sky is darkest, often overhead.

For rather more see Bob King’s Wonderful Present Anticipated from the Perseid Meteor Bathe. And you may comply with the Worldwide Meteor Group’s exercise graph of the bathe up to now. It is primarily based on visible meteor counts reported by observers across the globe, carried out by rigorously standardized strategies to make them inter-comparable.


■ The curve of the crescent Moon this night factors towards Venus some two fists at arm’s size to the Moon’s decrease proper. Search for fainter Spica about half as far to the Moon’s left.

■ In good seeing, a telescope ought to present the tiny black shadow of Jupiter’s moon Io leaving Jupiter’s western edge at 10:14 p.m. EDT (begin trying earlier!), carefully adopted by Io itself budding off from Jupiter’s edge 10 minutes later.

■ The Large Dipper hangs diagonally within the northwest after darkish. From its midpoint, look to the proper to seek out Polaris (not very vivid) glimmering due north as at all times.

Polaris is the top of the Little Dipper’s deal with. The one different Little Dipper stars which might be even reasonably vivid are the 2 forming the outer finish of its bowl: 2nd-magnitude Kochab and Third-magnitude Pherkad. On August evenings you will discover them to Polaris’s higher left (by a few fist and a half). They’re referred to as the Guardians of the Pole, since they ceaselessly circle round Polaris by the evening and thru the 12 months.


■ As the celebs come out, search for Spica decrease proper of the Moon. They’re lower than a fist at arm’s size aside. Excessive to their higher proper shines Arcturus.


■ The brightest star excessive within the southeast these evenings is Altair, with little orange Tarazed above it by a finger-width at arm’s size. A bit greater than a fist-width to Altair’s left is delicate Delphinus, the Dolphin, leaping left.

Above Altair, barely much less far, is smaller, fainter Sagitta, the Arrow. It too is pointing leftward.



This Week’s Planet Roundup

Mercury is buried deep within the sundown, decrease proper of dimmer Mars.

Venus (sensible at magnitude –three.9) shines due west throughout twilight. It units round twilight’s finish.

Mars is deep within the sundown, very far to Venus’s decrease proper.

Jupiter and Saturn shine within the southeast in late twilight and after darkish. They’re magnitudes –2.9 and +zero.2, respectively, in or close to Capricornus. Jupiter begins the evening lowest. Saturn glows yellowly 19° (about two fists at arm’s size) to Jupiter’s higher proper. The pair ranges out round 11 or midnight daylight-saving time. By then they’re almost at their highest within the south, at their telescopic greatest.

Saturn reached opposition on August 1st. Jupiter will accomplish that on August 19th. So this month they’re at their closest, largest, and brightest of the 12 months. See “Saturnian Challenges” beginning on web page 52 of the July Sky & Telescope, additionally “Motion at Jupiter” within the August concern, web page 50, and “Canine Days with the Gasoline Giants” on web page 40 of August.

Jupiter on July 12, 2021Jupiter on July 12th, imaged by Christopher Go. South is up. The South and North Equatorial Belts have largely diminished to slim darkish strains. Pink barges and spots proceed simply north of the NEB. A lot of the Equatorial Zone continues pale yellow-tan.

Saturn on July 25, 2021Saturn on July 25. North is up. This beautiful stacked-video picture reveals element within the broad A Ring, in addition to the skinny Encke Hole simply contained in the outer fringe of the outer B Ring. Agapios Elia of Nicosia, Cyprus, took video throughout 45 minutes on July 25, 2021, utilizing a 9.25-inch Schmidt-Cassegrain scope. He de-rotated the globe throughout processing after which stacked giant numbers of the of greatest frames.

Uranus (magnitude 5.7, in Aries) is nicely up within the east after midnight.

Neptune (magnitude 7.eight, on the Aquarius-Pisces border 24° east of Jupiter) is excessive within the southeast to south within the early-morning hours.

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.

Japanese Daylight Time, EDT, is Common Time minus four hours. Common Time is also referred to as UT, UTC, GMT, or Z time. To develop into extra knowledgeable about time programs than 99% of the folks you will ever meet, see our compact article Time and the Newbie Astronomer.

Wish to develop into a greater astronomer? Be taught your approach across the constellations. They’re the important thing to finding all the things fainter and deeper to hunt with binoculars or a telescope.

That 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 concern of Sky & Telescope, the important journal of astronomy.

When you get a telescope, to place it to good use you will want an in depth, large-scale sky atlas (set of charts). The fundamental customary is the Pocket Sky Atlas (in both the unique or Jumbo Version), which reveals stars to magnitude 7.6.

Pocket Sky Atlas cover, Jumbo editionThe Pocket Sky Atlas plots 30,796 stars to magnitude 7.6, and a whole bunch of telescopic galaxies, star clusters, and nebulae amongst them. Proven right here is the Jumbo Version, which is in laborious covers and enlarged for simpler studying outdoor by crimson flashlight. Pattern charts. Extra concerning the present editions.

Subsequent up is the bigger and deeper Sky Atlas 2000.zero, plotting stars to magnitude eight.5; almost thrice as many. The following up, as soon as you understand your approach round, are the even bigger Interstellarum atlas (stars to magnitude 9.5) or Uranometria 2000.zero (stars to magnitude 9.75). And you’ll want to learn find out how to use sky charts with a telescope.

You will additionally desire a good deep-sky guidebook, akin to Sky Atlas 2000.zero Companion by Robust and Sinnott, or the larger (and illustrated) Night time Sky Observer’s Information by Kepple and Sanner.

Can a computerized telescope exchange charts? Not for inexperienced persons, I do not assume, and never on mounts and tripods which might be lower than top-quality mechanically, that means heavy and costly. And as Terence Dickinson and Alan Dyer say of their Yard Astronomer’s Information, “A full appreciation of the universe can’t come with out growing the talents to seek out issues within the sky and understanding how the sky works. This data comes solely by spending time below the celebs with star maps in hand.”

Audio sky tour. Out below the night sky along with your
earbuds in place, hearken to Kelly Beatty’s month-to-month
podcast tour of the heavens above. It is free.

“The hazards of not pondering clearly are a lot larger now than ever earlier than. It is not that there is one thing new in our mind-set, it is that credulous and confused pondering may be rather more deadly in methods it was by no means earlier than.”
            — Carl Sagan, 1996

“Info are cussed issues.”
            — John Adams, 1770


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