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The Night Sky of June

Dr. Wayne Wooten
Professor of Astronomy

For June 2021, the waning gibbous moon passes just below Jupiter in the morning sky on June 1st. The last quarter moon rises about midnight the following evening. The Moon is new on June10th, and the young crescent is just below Venus on June 11th low in the dusk. By June 12th, it waxes above Venus, and passes above Mars on June 13th. First quarter moon is June 17th. The summer solstice this year falls at 2:40 p.m. on June 20th, the longest day of the year. The Full Moon, the Honey Moon, comes on June 24th. The waning gibbous moon passes below Saturn in late evening skies on June 27th, then below Jupiter on June 28th.

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 bed our own Milky Way, binoculars are better for spotting specific deep sky objects. For a detailed map of northern hemisphere skies, about June 30th visit the www.skymaps.com website and download the map for June; it will have a more extensive calendar, and list of best objects for the naked eyes, binoculars, and scopes on the back of the map. There is also a video exploring the June sky from the Hubble Space Telescope website at: www.hubblesite.org/explore_astronomy/tonights_sky

This June Mercury lies between us and the sun, after putting on a fine show in the western sky last month. But Venus is around to stay, getting higher and brighter in the west each evening. By the end of June, watch her overtake Mars in twilight. In the telescope, she is waning gibbous, with a brilliant cloud topped disk that is best observed while the sky is still relatively light, right after sunset. Mars is a tiny red disk, on the other side of the Sun, and lost behind it by July.

We are overtaking Jupiter and Saturn now, and both come to opposition at sunset in August. With binoculars, the four large Galilean moons of Jupiter are visible in a row around Jupiter’s equator. Larger scopes will see the famed Great Red Spot is still evident in the belts and zones. Saturn’s rings are slowly closing, but still put on a fine show. Its large moon Titan is also visible even in 60mm refractors at 30X. By month’s end, both are rising within three hours of sunset in the SE. Download the program Stellarium at www.stellarium.org and you can zoom in on the planets to find the layout of the moons of Jupiter and Saturn at any moment.

The Big Dipper is almost overhead as twilight falls, and its pointers take you north to the Pole Star. For iPhone users, the free download app Starry Camera gives you a wonderful way to introduce kids to the constellations. You will need to mount your iPhone on a sturdy stable mount such as your car cup phone holder or a camera tripod with smartphone adapter. The app allows you to take 3" (very light polluted), 10" (moderate lighting), or 30" (dark sky site) exposures, which will show you all the stars down to and below your naked eye limit. It also has a wide enough field of view to include all of both the big and little dippers in a single exposure! The pro version is only $5 more, and allows two-minute exposures with a variety of ISO settings for also capturing the Milky Way and much fainter stars and deep sky objects.

If you drop south from the bowl of the Big Dipper, Leo the Lion is in the SW. Note the Egyptian Sphinx is based on the shape of this Lion in the sky. Taking the arc in the Dipper’s handle, we "arc" SE 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.

Spike south to Spica, the hot blue star in Virgo, then curve to Corvus the Crow, a four-sided grouping. Jupiter lies just east of Spica this July. North of Corvus, in the arms of Virgo, is where our large scopes will show members of the Virgo Supercluster, a swarm of over a thousand galaxies about 50 million light years distant.

To the east, Hercules is well up, with the nice globular cluster M-13 marked on your sky map and visible in binocs. Few objects in the sky can compare with this glorious ball of stars in any telescope 6" or larger; come marvel at its beauty at our beach gazes this summer. This ball of almost a million older stars lies about 25,000 light years away, in the halo of our Milky Way Galaxy, almost directly above the Galactic Center in Sagittarius.

The brightest star of the northern hemisphere, Vega (from Carl Sagan’s novel and movie, "Contact"), rises in the NE as twilight deepens. Twice as hot as our Sun, it appears blue-white, like most bright stars. At the opposite end of the parallelogram of Lyra is M-57, the Ring Nebula. It is visible with large binoculars, but does not show its fine colors and faint central white dwarf until you get to some big deep sky scopes.

Northeast of Lyra is Cygnus, the Swan, flying down the Milky Way. Its bright star Deneb, at the top of the "northern cross" is one of the luminaries of the Galaxy, about 50,000 times more luminous than our Sun and around 3,000 light years distant. Under dark skies, note the "Great Rift", a dark nebula in front of our solar system as we revolve around the core of the Milky Way in the Galactic Year of 250 million of our own years.

To the east, Altair is the third bright star of the summer triangle. It lies in Aquila the Eagle, and is much closer than Deneb; it lies within about 13 light years of our Sun. Use your binocs to pick up many clusters in this rich region of our own Cygnus spiral arm rising now in the east.

To the south, Antares is well up at sunset in 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! Scorpius is the brightest constellation in the sky, with 13 stars brighter than the pole star Polaris! Note the fine naked eye clusters M-6 and M-7, just to the left of the Scorpion’s tail.

Just a little east of the Scorpion’s tail is the teapot shape of Sagittarius, which lies toward the center of the Milky Way. From a dark sky site, you can pick out the fine stellar nursery, M-8, the Lagoon Nebula, like a cloud of steam coming out of the teapot’s spout.

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