Some daily sky sights among the ever-changing Moon, planets, and stars.
The slow nova in Sagittarius has faded to magnitude 8.5 as of June 17th. See article with charts and a link to an up-to-date light curve.
Friday, June 12
The two brightest stars high on June evenings are Vega, the brightest high in the east, and Arcturus, way overhead toward the southwest. They're relatively close to us: 25 and 37 light-years, respectively. Vega is more than twice as hot as Arcturus; their absolute temperatures are 9,600 and 4,300 kelvins, respectively. Which is why Vega shines pale bluish white, while Arcturus appears pale yellow-orange.
Saturday, June 13
Jupiter and bright Venus have closed to within 11° of each other in the west at nightfall. Once the sky is dark enough, binoculars can show that this evening, Venus shines in the top fringe of M44, the Beehive Star Cluster.
Sunday, June 14
Saturn is the brightest point glowing in the southeast to south these evenings. The stars of upper Scorpius glitter below it.
For instance, to the the lower left of Saturn by 3½° (about two finger-widths at arm's length) is Beta Scorpii, a fine double star for telescopes. Just 1° below Beta is the very wide naked-eye pair Omega1 and Omega2 Scorpii, not quite vertical. Binoculars may show their slight color difference.
And to Beta's left by 1.6° is Nu Scorpii, another fine telescopic double. And, high power in good seeing reveals that Nu's brighter component is itself a close binary, separation 2 arcseconds.
Monday, June 15
Spica shines in the southwest after dark — very far to the right of Saturn, Antares and company. Look below Spica (by about two fists at arm's length) and a bit right for the four-star constellation Corvus, the Crow — a spring sign on its way down and out as spring nears its end.
Tuesday, June 16
Look very high in the northeast for the Big Dipper hanging down by its handle. The middle star of the handle is Mizar, with tiny little Alcor right next to it. On which side of Mizar should you look for Alcor? As always, on the side toward Vega! Which now dominates the eastern sky.
Wednesday, June 17
Can you see the big Coma Berenices star cluster? Does your light pollution really hide it, or do you just not know exactly where to look? It's currently in the west after dark; look 40% of the way from Denebola (Leo's tail) to the end of the Big Dipper's handle (Ursa Major's tail). Its brightest members form an inverted Y. The cluster is about 5° wide — a big, dim glow when seen in at least a moderately dark sky. It nearly fills a binocular view with its sparsely scattered points.
Thursday, June 18
With summer just three days away, the Summer Triangle now stands high and proud in the east after dark. Its top star is bright Vega. Deneb is the brightest star to Vega's lower left (by 2 or 3 fists at arm's length). Look for Altair a greater distance to Vega's lower right.
Friday, June 19
The Venus-Jupiter pairing is growing ever more striking in the west at dusk, as they near their June 30th closest approach. And as twilight fades this evening, look below them for the waxing crescent Moon as shown here.
Saturday, June 20
The Moon, Jupiter, and Venus form a striking triangle in the west during and after dusk, as shown here. Regulus and the Sickle of Leo look on from the upper left. Think photo opportunity! The whole array is less than 20° tall or wide.
Tomorrow, the 21st, is the longest day of the year in the Northern Hemisphere; the shortest in the Southern Hemisphere. The solstice is at 12:38 p.m. on the 21st EDT (16:38 UT), marking the start of northern summer. Because the time of the solstice so closely splits the nights before and after in the Eastern time zone, you might end up going to two Midsummer Night parties!
Want to become a better astronomer? Learn your way around the constellations. They're the key to locating everything fainter and deeper to hunt with binoculars or a telescope.
This is an outdoor nature hobby. For an easy-to-use constellation guide covering the whole evening sky, use the big monthly map in the center of each issue of Sky & Telescope, the essential guide to astronomy.
Once you get a telescope, to put it to good use you'll need a detailed, large-scale sky atlas (set of charts). The standards are the little Pocket Sky Atlas, which shows stars to magnitude 7.6; the larger and deeper Sky Atlas 2000.0 (stars to magnitude 8.5); and once you know your way around, the even larger Uranometria 2000.0 (stars to magnitude 9.75). And read how to use sky charts with a telescope.
You'll also want a good deep-sky guidebook, such as Sue French's Deep-Sky Wonders collection (which includes its own charts), Sky Atlas 2000.0 Companion by Strong and Sinnott, the bigger Night Sky Observer's Guide by Kepple and Sanner, or the beloved if dated Burnham's Celestial Handbook.
Can a computerized telescope replace charts? Not for beginners, I don't think, and not on mounts and tripods that are less than top-quality mechanically (meaning heavy and expensive). As Terence Dickinson and Alan Dyer say in their Backyard Astronomer's Guide, "A full appreciation of the universe cannot come without developing the skills to find things in the sky and understanding how the sky works. This knowledge comes only by spending time under the stars with star maps in hand."
This Week's Planet Roundup
Mercury is deep in the glow of sunrise.
Venus (magnitude –4.5) is the brightest point in the west during and after twilight. Jupiter, to Venus's upper left, is the second-brightest. They're closing in on each other day by day: from 12° apart on June 12th to 7° on the 19th.
Venus and Jupiter will have a spectacularly close appulse (closest approach) on June 30th, when they'll appear just 1/3° apart at dusk in the time zones of the Americas. (Their conjunction in right ascension is on July 1st, when they're slightly farther apart.)
Mars is hidden behind the glare of the Sun.
Saturn (magnitude +0.2, above the head of Scorpius) is highest in the south after dusk. Some 12° lower left of Saturn is twinklier orange Antares, less bright. In a telescope, Saturn's rings are tilted a generous 24° from edgewise.
Uranus (magnitude +5.9, in Pisces) is low in the east before dawn begins to brighten.
Neptune (magnitude +7.9, in Aquarius) is in the southeast before the first light of dawn.
All descriptions that relate to your horizon — including the words up, down, right, and left — are written for the world's mid-northern latitudes. Descriptions that also depend on longitude (mainly Moon positions) are for North America.
Eastern Daylight Time (EDT) is Universal Time (UT, UTC, or GMT) minus 4 hours.
“This adventure is made possible by generations of searchers strictly adhering to a simple set of rules. Test ideas by experiments and observations. Build on those ideas that pass the test. Reject the ones that fail. Follow the evidence wherever it leads, and question everything. Accept these terms, and the cosmos is yours.”
— Neil deGrasse Tyson, 2014