For May 2021, the last quarter moon passes south of Saturn on the morning of May 3, and then below Jupiter on May 4. The new moon is on May 11. The slender waxing crescent is beside of Venus just after sunset on May 12 (use binocs and clear western horizon 30 minutes after sunset), then next to Mercury on the 13; the two-day old moon will be beautiful with earthshine an hour after sunset — great photo op. The waxing crescent passes close to Mars on May 15; from Europe, this will be an occultation of the Red Planet by the moon. The first quarter moon is on May 19, and the Full Moon, the Rose Moon, is on May 26.
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 map of northern hemisphere skies visit skymaps.com.
Mercury and Venus are both visible in the west this month, with Venus still very close to the Sun and next to the Moon on May 3. Mercury is higher up, and next to the Moon on May 4. But Mercury soon retrogrades Sunward, and is lost in Sun’s glare by midmonth, while Venus rises higher in the evening and dominates the western sky for the rest of 2021.
Mars is losing its race with the Sun, setting lower and sooner each evening. It passes below the Gemini at month’s end. Jupiter and Saturn are in Capricornus, in the dawn sky; they return to the evening sky by late summer.
The winter constellations will soon be swallowed up in the Sun’s glare, but Orion is still visible, with its famed Orion Nebula, M-42, seen below the three stars marking his famed belt. Dominating the southwest is the Dog Star, Sirius, brightest star of the night sky. When Sirius vanishes into the Sun’s glare in two months, this sets the period as “Dog Days”.
The brightest star in the northwest is Capella, distinctively yellow in color. It is a giant star, almost exactly the same temperature as our Sun, but about 100-times more luminous. Just south of it are the stellar twins, the Gemini, with Castor closer to Capella, and Pollux closer to the Little Dog Star, Procyon.
Overhead, the Big Dipper rides high. 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. Our feature photo for May comes with my own old iPhone 6s and the free smartphone astrophoto program, Starry Camera. It shows the Big Dipper to upper right, with the pointers directing us to Polaris at the center left edge. The little dipper runs down and to the right from Polaris at the end of its handle to the bowl behind the dark security light. The pro version is only $5 more and gives many more options for photographing the ISS, Milky Way, aurorae, etc.
If you drop south from the bowl of the Big Dipper, Leo the Lion rides high. Note the Egyptian Sphinx is based on the shape of this Lion in the sky. The “regal” star Regulus marks the heart of the celestial lion.
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. Just east of Arcturus is Corona Borealis, the “northern crown,” a shapely Coronet that Miss America would gladly don, and one of few constellations that look like their name. The bright star in the crown’s center is Gemma, the Gem Star.
Spike south to Spica, the hot blue star in Virgo, then curve to Corvus the Crow, a four-sided grouping. The arms of Virgo harbor the Virgo Supercluster of Galaxies, with thousands of “island universes” in the Spring sky. We are looking away from the place of thickly populated Milky Way, now on the southern horizon, toward the depths of intergalactic space, where even amateur telescopes can spot quasars billions of light years distant.
To the northeast Hercules rises, with his body looking like a butterfly. It contains one of the sky’s showpieces, M-13, the globular cluster faintly visible with the naked eye. Find it with binoculars midway on the top left wing of the cosmic butterfly, then take a look with a larger telescope and you will find it resolved into thousands of stars!
For more information on the Escambia Amateur Astronomers, join us onFacebook, visit our website at eaaa.net or call our sponsor, Lauren Rogers at Pensacola State at 484-1155 or lrogers@pensacolastate.edu. To be added to our astro alerts for gazes, ISS passes, club photos, etc., contact Dr. Wooten at wwooten@pensacolastate.edu and we will put you on our e-mail list serv. We also will send you a free copy of “Star Shooting,” our photo gallery of 1,500 of the best local astrophotos over the last 30 years of recording the sky. Be sure to include your PO mailing address in the email to Dr. Wooten.