Special to CosmicTribune.com, August 5, 2024

Excerpts from weekly Sky&Telescope report.

SUNDAY, AUGUST 4

■ New Moon (exact at 7:13 a.m. on this date EDT).

■ The T Cor Bor Watch continues. Have you been checking Corona Borealis overhead these clear evenings? The recurrent nova T Coronae Borealis could erupt to 2nd magnitude anytime this summer. Or fall. Or later? Astronomers are pretty sure it’s preparing to blow sometime fairly soon for the first time since 1946.

What’s the exact spot to watch?

Look a third of the way from Arcturus to Vega. There’s Alpha Coronae Borealis, also known as Alphecca. At magnitude 2.2 it’s the only moderately bright star in the delicate Northern Crown. Alphecca is easy to see through my suburban light pollution. The rest of Corona Borealis is not.

Keep an eye out a third of the way from Arcturus to Vega. Arcturus shines in the west these evenings; Vega is nearly overhead. So, turn this view about 90° clockwise to match the current evening panorama.
Sky & Telescope

Is Alphecca alone? One of these days, it won’t be!

The point in Corona Borealis to examine. Again, turn this 90° clockwise.
Bob King

In 1866 and 1946 T Cor Bor peaked at 2nd or 3rd magnitude, roughly matching Alphecca. See Bob King’s Is the Blaze Star About to Blow? You May Be the First to Know, with more information and detailed charts.

Even now, as it simmers along near its normal 10th magnitude, T CrB is a pretty easy pickup using Bob’s charts with a small telescope. Give it a look while it’s still gathering its forces.

T Cor Bor’s rise last time took just a few hours, and its peak brightness lasted only a day or so.

But for your best chance of catching it early, just look. Every night you can.

MONDAY, AUGUST 5

■ A hairline-thin crescent Moon, less than two days old, hangs just 1° or so above Venus, just above the west horizon in bright twilight. Use optical aid starting 15 or 20 minutes after sunset. Good luck.

■ Standing atop Scorpius in the south after darkness is complete, and butting heads with Hercules much higher, is enormous Ophiuchus the Serpent-Holder. Just east of his east shoulder (Beta Ophiuchi or Cebelrai) is a dim V-shaped asterism like a smaller, fainter Hyades. This is part of the defunct constellation Taurus Poniatovii, “Poniatowski’s Bull.”

The top two stars of the V are the faintest, magnitudes 4.8 and 5.5. The middle star of its left (east) side is the famous K-dwarf binary 70 Ophiuchi, visual magnitudes 4.2 and 6.2, distance just 17 light-years. The two stars of the pair are currently 6.7 arcseconds apart in their 88-year orbit: close but nicely separated at medium-high power in any telescope.

TUESDAY, AUGUST 6

■ Today we’re finally halfway through summer. (Astronomical summer, that is. We’re probably — hopefully — a little more than halfway through it temperature-wise.) The exact mid-moment between the June solstice and the September equinox comes today at 12:47 p.m. Eastern Daylight Time (16:47 UT). That minute is the exact top of the circle of the year.

■ So, W-shaped Cassiopeia, a constellation best known for fall and winter evenings, is already wheeling up in the north-northeast as evening advances. And at nightfall the Great Square of Pegasus, eternal emblem of fall, balances on one corner just over the eastern horizon.

WEDNESDAY, AUGUST 7

■ Have you been seeing any Perseid meteors yet? The shower should be at its best late on the nights of August 11-12 (next Sunday night) and 12-13 (Monday night). The shower ramps up for more than a week and a half before peak, then drops off more quickly. This year will bring a first-quarter Moon to the evening sky on the peak nights, but it will set by about midnight if not earlier.

Tonight the Moon is no problem at all; it’s only a crescent and sets around the end of twilight.

THURSDAY, AUGUST 8

■ As twilight fades, spot the waxing crescent Moon low in the west. About a fist and a half upper left of it is Spica. A little farther upper right of the Moon is Denebola, the tail-tip of Leo, not quite as bright.

FRIDAY, AUGUST 9

■ Look west-southwest in late dusk to spot Spica just 4° or 5° upper left of the crescent Moon. Very high above or upper right of them is Arcturus, brighter and pale yellow-orangish.

SATURDAY, AUGUST 10

■ Now Spica shines a little farther to the Moon’s right or lower right as twilight fades out.

SUNDAY, AUGUST 11

■ It’s peak Perseid meteor night! And maybe the first of two. The actual peak of the shower is supposed to be from about 13h UT to 16h UT on the 12th, which is 9 a.m. to noon on the 12th Eastern Daylight Time; 6 to 9 a.m. Pacific Daylight time. That’s not long after the ideal Perseid meteor-watching hours before dawn. But who knows, the next night could be just as good or nearly so.

In early evening the meteors will be few, but those that do appear will be Earth-grazers skimming far across the top of the atmosphere. As the hours pass and the shower’s radiant (in northern Perseus near Cassiopeia) rises higher in the northeast, the meteors will become shorter and more numerous. The radiant is highest before dawn.

Layer up warmly even if the day was hot; remember about radiational cooling late at night under an open clear sky! A sleeping bag makes good mosquito armor, and use DEET on whatever parts of you remain exposed.

Bring a reclining lawn chair to a dark, open spot where no local lights get in your eyes. Lie back, and gaze up into the stars. Be patient. As your eyes adapt to the dark, you may see a meteor every minute or so on average as night grows late. You’ll see fewer under light pollution, but the brightest ones will shine through.

The best direction to look is wherever your sky is darkest, usually overhead. The shower’s radiant (the meteors’ perspective point of origin, if you could see them coming from far away in space) is in northern Perseus under Cassiopeia. But the meteors only become visible when they hit the upper atmosphere, and this can occur anywhere in your sky.

This Week’s Planet Roundup

Venus, magnitude –3.8, is getting very slightly more visible week by week, very low above the west horizon in bright twilight. Scan for it with binoculars a little to the right of due west starting 15 or 20 minutes after sundown. Binoculars will help. Much will depend on the clarity of the air; humid means hazy. Good luck.

Mars and Jupiter (magnitudes +0.9 and –2.1, respectively, in Taurus) rise around 1 a.m. daylight-saving time with Mars-like Aldebaran tagging along to their right. Watch for the trio to come up in the east-northeast.

Mars shines upper right of brighter Jupiter, closer to it day by day. On the morning of August 3rd the two planets are 5½° apart. They close to 0.3° for their conjunction on the 14th. Above all three points are the Pleiades.

As dawn overtakes the scene, the whole array is much higher in the east with Orion beneath them.

In the east before dawn, Jupiter and Mars shine nearly in conjunction on Saturday morning the 10th with Mars-like Aldebaran looking on from their right. Mars-like Betelgeuse is farther below.The two planets are now 2.1° apart. They’ll be 0.3° apart at their closest on the morning of August 14th.

  Aug. 4-11: Here come the Perseid meteors, The Sky