Dawn and Sundown Instances (Jap Daylight Time) — Solar rises at 6:00 am and units at 8:16 pm on Aug. 1st; Solar rises at 6:28 am and units at 7:36 pm on Aug. thirty first.
Moon’s Phases in August — Full “Sturgeon Moon” on Aug. eleventh; New Moon on Aug twenty seventh.
Stars and Constellations
As darkness falls on August evenings, the constellations of summer time – and likewise a couple of left over from spring – start to emerge from the glow of twilight. Dealing with north, the Massive Dipper, part of the spring constellation Ursa Main, is dipping into the northwest. The 2 entrance stars within the Dipper level to Polaris, the North Star, whereas the arc of the Dipper’s deal with results in the orange big star Arcturus, which stands excessive within the west. Arcturus is simply 37 mild years away, whereas many of the stars within the Ursa Main cluster lie at roughly 80 mild years from us. However Polaris is 430 mild years distant, or over 10 occasions farther than Arcturus and 5 occasions farther than the celebs comprising the Massive Dipper.
Extending above Polaris is the Little Dipper, essentially the most well-known asterism inside Ursa Minor, the Little Bear. Snaking its means across the Little Dipper is Draco, the Dragon, a big however comparatively faint summer time constellation. Draco is particularly notable as a result of certainly one of its stars, Alpha Draconis, or Thuban (which means “serpent”), was the polestar some 4,700 years in the past, at in regards to the time the Pyramids of Egypt have been being constructed. Thuban is simply about one-fifth as brilliant as Polaris
Dealing with south, get one final glimpse of the spring star Spica in Virgo because it units within the southwest. To Spica’s far left is orange-red Antares in Scorpius, which stands low within the south-southwest. The physique of the Scorpion snakes down towards the horizon after which upward right into a curved stinger. The “cat’s eyes,” a pair of unequally brilliant stars – Shaula and Lesath – are positioned on the finish of the tail. To the higher left of the cat’s eyes is the “teapot” of Sagittarius, a straightforward grouping to establish. And the Summer time Triangle, which consists of Vega within the constellation Lyra, Deneb in Cygnus, and Altair in Aquila, stands excessive within the east-northeast.
In the course of the late night hours, the W-shaped constellation Cassiopeia is rising low within the northeast. Additionally, the Nice Sq. of Pegasus, which consists of 4 stars within the type of a rectangle mendacity on its edge, might be seen rising within the east. The ascendence of Cassiopeia and Pegasus above the jap horizon can solely imply one factor: the season of autumn is ready on our doorstep.
Bare-Eye Planets within the Night and Morning Sky
Mercury leads the parade of planets throughout the night time sky from nightfall to daybreak this August; Mercury resembles a brilliant star fairly low within the west about half-hour after sundown. Mercury’s visibility at nightfall improves towards the top of August; it reaches most brightness and best elongation with the Solar on the twenty seventh.
Saturn is in opposition with the Solar on August thirteenth, when it reaches peak brightness (since it’s at its closest to Earth) and can also be seen all night time, rising at sunset, standing due south at midnight, and setting at dawn. Cream-colored Saturn stands out among the many faint stars of Capricornus, and is clearly brighter than Altair, which lies nicely above it, however a lot fainter than Jupiter, which rises a few hours later. Even a small telescope will clearly reveal Saturn’s lovely ring system and its largest moon Titan.
Jupiter resides within the non-zodiac constellation Cetus the Whale slightly below Pisces’s southern border, and nicely to the east of its gasoline big sibling Saturn, which it follows for two hours. Sensible Jupiter peeks above the jap horizon a couple of minutes earlier than 11 pm EDT on August 1st, and by 8:30 pm on the thirty first. Jupiter’s flip in opposition with the Solar happens subsequent month, on September twenty sixth.
Mars continues to steadily brighten because it marches towards its closest strategy to Earth in December. Whereas Mars is nowhere close to as brilliant as Jupiter (or Venus), it now simply outshines Saturn and rivals the night time sky’s brightest luminaries Vega and Arcturus. Mars rises after midnight, at 12:30 am, or almost 2 hours after Jupiter, at first of August, and an hour earlier because the month ends. Search for what seems to be a brilliant, orangish star above the jap horizon a half-hour after it rises, and excessive within the south at daybreak’s first mild.
Venus is the dazzling “morning star” low above the northeastern horizon at daybreak. In the beginning of August, Venus rises simply after 4:15 am EDT, which is lower than two hours earlier than dawn. By month’s finish, Venus is rising round 5:15 am, or solely a little bit over an hour earlier than dawn. Venus will go behind the Solar (superior conjunction) in late October, then steadily reappear at nightfall.
Across the night time of August 12-13, Earth will go by the particles of Comet Swift-Tuttle, producing the Perseid Meteor Bathe. Meteors will seem to radiate from the constellation Perseus, however they are often seen in any a part of the sky. Sadly, this 12 months the Moon might be in the future previous the complete part, and so brilliant moonlight will wash out all however the brightest meteors.
Astronomy Query for August: Why does the North Star all the time keep in the identical place within the sky? (Reply might be supplied in subsequent month’s column.)
Reply to Final Month’s Query: The aurora borealis (and the aurora australis within the southern hemisphere) happens when massive bursts of electrically charged particles (electrons, protons) are emitted by the Solar, particularly during times of excessive sunspot exercise. Flowing outward into the photo voltaic system, a few of these particles get trapped by the Earth’s magnetic area and are funneled down towards the polar areas, the place they collide with atmospheric molecules of nitrogen and oxygen, inflicting them to fluoresce within the typical greenish or reddish glow.
Harry J. Augensen is Emeritus Professor of Physics & Astronomy, Widener College. Astronomical info is obtained from The Astronomical Almanac (2021-2025) by Richard J. Bartlett, and from Astronomical Calendar 2022 by Man Ottewell, accessible on-line at https://www.universalworkshop.com/astronomical-calendar-2022/. For extra info on the night time sky, go to the Widener Observatory Stargazing web site at http://www.widener.edu/stargazing/. A set of free sky maps might be obtained at http://www.skymaps.com/.