For August 2021, the third quarter moon is on August 1. The New moon is on August 8, and the waxing crescent passes four degrees north of Venus in western twilight on August 10. The moon will set well before midnight for ideal viewing conditions for the Perseid Meteor Shower, peaking on the morning of August 12. Look for perhaps a meteor a minute coming out of the northeast after midnight until dawn. The almost full moon passes four degrees south of Saturn on August 20, and the Thunder Full Moon is four degrees south of Jupiter on August 22. The last quarter moon is on August 30.
While the naked eye, dark adapted by several minutes away from any bright lights, is a wonderful instrument to stare up into deep space, far beyond our own Milky Way, binoculars are better for spotting specific deep sky objects. For a detailed guide to the stars, visit skymaps.com.
Mercury is too close to sun for viewing this month, but Venus dominates the western twilight for the rest of this year. Jupiter and Saturn both reach opposition in the southeast this month, with Saturn closest to us on August 2, and Jupiter at its best on August 19, with the Full Moon beside it in Aquarius. The Great Red Spot is easy to spot with small telescope, as are the four larger moons. Much more distant, fainter Saturn is to the upper right of Jupiter in Capricornus, just east of brighter Jupiter. Enjoy the rings, now 22 degrees open and tilted toward earth and sun. Look closer and you may see its huge moon Titan, the most earth-like surface geology elsewhere in the solar system.
The Big Dipper rides high in the northwest at sunset, but falls lower each evening. Good scouts know to take its leading pointers north to Polaris, the famed Pole Star. For us, it sits 30 degrees (our latitude) high in the north, while the rotating earth beneath makes all the other celestial bodies spin around it from east to west.
Taking the arc in the Dipper’s handle, we “arc” southeast to bright orange Arcturus, the brightest star of Spring. Cooler than our yellow Sun, and much poorer in heavy elements, some believe its strange motion reveals it to be an invading star from another smaller galaxy, now colliding with the Milky Way in Sagittarius in the summer sky. Moving almost perpendicular to the plane of our Milky Way, Arcturus was the first star in the sky where its proper motion across the historic sky was noted, by Edmund Halley.
Hercules is overhead, with the nice globular cluster M-13 marked on your sky map and visible in binocs. It is faintly visible with the naked eye under dark sky conditions.
The brightest star of the northern hemisphere, Vega dominates the northeast sky. Binoculars reveal the small star just to the northeast of Vega, epsilon Lyrae, as a nice double. Larger telescopes at 150X reveal each of this pair is another close double, hence its nickname, the “double double,” a fine sight under steady sky conditions.
Below Vega are the two bright stars of the Summer Triangle; Deneb (to the north) and Altair. It is one of the most luminous stars in our Galaxy, about 50,000 times brighter than our Sun. It sits atop the cross, and lies in a region where new stars and born and old stars die literally in front of our eyes.
I was lucky enough to discover one such stellar death, Nova Cygni 1975, on August 27, 1975. It peaked at magnitude +1.8, the sixth brightest star of the summer sky, in two days, but faded below naked eye visibility in just two weeks, alas. A far grander supernova some 15,000 years ago happened southeast of the eastern wing of the Swan, epsilon Cygni. The Veil Nebula is faintly visible in big binocs and wide field scopes under very dark skies, but a colorful photographic target. Look to the west at brilliant Venus, and imaging transposing it overhead to the wing of Cygnus; how our ancestors must have been awed by the sudden and perplexing change in the changeless stars. Far more material was blasted out into space than in my nova, and the shock wave from this supernova, now spanning three degrees (six moon diameters), continues expanding at a million miles per hour.
To the south is the southernmost member of the Triangle, Altair, the brightest star of Aquila the Eagle. If you scan the Milky Way with binocs or a small spotting scope between Altair and Deneb, you will find many nice open star clusters and also a lot of dark nebulae, the dust clouds from which new stars will be born in the future.
To the southeast, Antares is bright in the heart of Scorpius. It appears reddish (its Greek name means rival of Ares or Mars to the Latins) because it is half as hot as our yellow Sun; it is bright because it is a bloated red supergiant, big enough to swallow up our solar system all the way out to Saturn’s orbit! Just above the tail of the Scorpion are two fine naked eye star clusters, M-7 (discovered by Ptolemy and included in his catalog about 200 AD) and M-6, making one of the best binocular views in the sky.
East of the Scorpion’s tail is the teapot shape of Sagittarius, which marks the heart of our Milky Way galaxy. Looking like a cloud of steam coming out of the teapot’s spout is the fine Lagoon Nebula, M-8, easily visible with the naked eye. Above it is the Trifid Nebula, M-20, another fine and very colorful stellar nursery. Just east of these young star birthplaces is the fine globular cluster M-22, faintly visible to the naked eye and spectacularly resolved in scopes of 8” or larger aperture. Look just east of the top star in the teapot of Sagittarius with binoculars.
The EAAA can again schedule public gazes at the Pensacola Beach Pavilion. We will set up on the weekends of the first quarter, hand out free star charts, show off a variety of telescopes in all size and price ranges, help you learn to us your own new scope or binoculars or smartphone for astrophotography, and teach you the brighter constellations with our green laser pointers. With clear skies permitting, we plan to be south of the famed Beach Ball Water Tower on August 13 and 14 (Perseid Meteor Shower), September 10 and 11, and finally October 15 and 16, 2021.
We have set new dates for our public gazes at Big Lagoon State Park west of Pensacola for these Saturdays: July 31, August 28, and September 25. Be sure to check in at the gate before sunset.
For more information on the Escambia Amateur Astronomers, visit www.eaaa.net , join us on Facebook, or call our sponsor, Lauren Rogers at Pensacola State College at (850) 484-1155, or e-mail her at the college at lrogers@pensacolastate.edu. All EAAA events are free and open to the public.