This Week's Sky at a Glance, June 7 – 16

To repeat, there's no spectacular "planet parade" now dazzling the world. It's just another crazy-weird falsehood that has ballooned across the internet and certain "news" outlets. Details last week. Pass this on to friends and relatives who ask you.

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FRIDAY, JUNE 7

■ The waxing crescent Moon returns to the evening sky, crossing the upright Gemini twins as they set for the season feet first, as shown below. This evening the low, thin crescent is only 1½ days old.

SATURDAY, JUNE 8

■ The crescent Moon forms a roughly right triangle with Pollux and Castor over it, as shown above. How perfect the right triangle is will depend on your location. Hint: If you're in the Mountain time zone, examine the triangle really carefully.

SUNDAY, JUNE 9

■ The Big Dipper has now swung around to hang down by its handle high in the northwest after dark. The middle star of its 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 is now the brightest star shining in the east.

■ When Vega shines well up in the east as it does now, Arcturus is the brightest star higher toward the south, neatly overhead. Draw a line from Arcturus to Vega. A third of the way along the line is dim Corona Borealis, the semicircular Northern Crown, as shown here:

Corona's one moderately bright star is Alpha Cor Bor, a.k.a. Gemma or Alphecca, magnitude 2.2. But sometime within the next year or so, astronomers expect there may suddenly be two! Because T Coronae Borealis, a famous recurrent nova, shows signs (a gradual dimming) of being about to blow again for its first time since 1946. If it does, if could match the brightness of Alphecca.

Normally T CrB simmers along uneasily at about 10th magnitude. Its explosive rise may take only about a day. Use the finder chart with Bob King's article from 2016. The chart there is detailed enough for identifying T with a telescope even at 10th magnitude.

But no guarantees an eruption will happen anytime soon. It didn't in 2016.

MONDAY, JUNE 10

■ The Big Dipper hangs high in the northwest as the stars come out. The Dipper's Pointers, currently its bottom two stars, point lower right toward Polaris. Above Polaris, and looking very similar to it, is Kochab, the lip of the Little Dipper's bowl, the rest of which is very dim.

Kochab stands precisely above Polaris around the end of twilight or a little after. How precisely can you time this event for your location, perhaps using the vertical edge of a building?

■ After nightfall is complete, Vega is the brightest star very high in the east. Barely lower left of it is 4th-magnitude Epsilon Lyrae, the Double-Double. Epsilon forms one corner of a roughly equilateral triangle with Vega and Zeta Lyrae. The triangle is less than 2° on a side, hardly the width of your thumb at arm's length.

Binoculars easily resolve Epsilon. And a 4-inch telescope at 100× or more should resolve each of Epsilon's wide components into a tight pair.

Zeta Lyrae is also a double star for binoculars; much tougher, but plainly resolved in a telescope.

Delta Lyrae, below Zeta, is a much wider and easier pair, reddish orange and pale blue.

TUESDAY, JUNE 11

■ After dusk, look for Regulus a few degrees lower left of the thick waxing crescent Moon. Algieba, Gamma Leonis, is about twice as far above the Moon (for North America). It's a fine telescopic double star, magnitudes 2.4 and 3.6, separation 4.7 arcseconds.

WEDNESDAY, JUNE 12

■ Bright Arcturus, magnitude 0, shines pale yellow-orange high overhead toward the south these evenings. The kite shape of Boötes, its constellation, extends from Arcturus. The kite is narrow, slightly bent, and 23° long: about two fists at arm's length. It extends up from Arcturus when you face south after dark now.

THURSDAY, JUNE 13

■ First-quarter Moon (exactly first-quarter at 1:18 a.m. tonight EDT). The Moon shines at the Leo-Virgo border, two fists upper left of Regulus and three fists right of Spica, the brightest stars of the two constellations.

About a fist above the Moon right after dark is 2nd-magnitude Denebola, Leo's tail. Denebola forms an almost perfectly equilateral triangle with Spica off to its left and brighter Arcturus above them. All three sides of the triangle are close to 35° long (35.3°, 35.1°, and 32.8°). S&T columnist George Lovi named it the Spring Triangle (in the March 1974 issue), and for such a near-perfect equilateral, I say the name ought to be revived.

FRIDAY, JUNE 14

■ As we count down the last six days to official summer (the solstice comes on June 20th), the Summer Triangle finally 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 farther to Vega's lower right. Altair is midway in brightness between Vega and Deneb.

SATURDAY, JUNE 15

■ As the stars come out in North America, the Moon shines nearly midway between Spica to its lower left and fainter Gamma Virginis (Porrima) to its upper right; see below. Gamma Vir is a lovely, equal-brightness double star for telescopes, separation 3.4 arcseconds this year; it's slowly widening. The pair is oriented almost north-south.

SUNDAY, JUNE 16

■ In twilight as summer nears, look very low in the north-northwest for wintry Capella very out of season. The farther north you are, the less low it will appear. You may need binoculars. But if you're as far north as Montreal or either of the Portlands (Oregon or Maine), Capella is actually circumpolar.

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This Week's Planet Roundup

Mars and Saturn are in nice view just as dawn begins. The highest and easiest is Saturn, in the southeast. It's magnitude 1.2, fairly modest, but there's nothing else that bright anywhere near it. Its background is dim Aquarius.

Look for Mars far lower left of Saturn, by about four fists at arm's length; it's almost due east. Mars is magnitude 1.1. Don't confuse it with twinkly Alpha Arietis, magnitude 2.0, about a fist to Mars's upper left.

Mercury, Venus, Jupiter, and Uranus remain hidden in the Sun's glare.

Neptune, 8th magnitude in Pisces, is fairly low in the east-southeast just before dawn begins, about 10° lower left of Saturn — for the adventurer with large binoculars or a telescope, a detailed enough finder chart showing Neptune's current location among the many similarly faint stars, and skill in using sky charts outdoors in the night (whether on paper or a screen).

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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 and graphics that also depend on longitude (mainly Moon positions) are for North America.

Eastern Daylight Time (EDT) is Universal Time minus 4 hours. UT is also known as UTC, GMT, or Z time.

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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 a more detailed constellation guide covering the whole evening sky, use the big monthly map in the center of each issue of Sky & Telescope, the essential magazine of astronomy.

Once you get a telescope, to put it to good use you'll need a much more detailed, large-scale sky atlas (set of charts). The basic standard is the Pocket Sky Atlas (in either the original or Jumbo Edition), which shows all stars to magnitude 7.6.

Next up is the larger and deeper Sky Atlas 2000.0, plotting stars to magnitude 8.5; nearly three times as many. (It's currently out of print.) The next up are the even larger Interstellarum atlas (stars to magnitude 9.5) or Uranometria 2000.0 (stars to mag 9.75). And read How to Use a Star Chart with a Telescope. It applies just as much to charts on your phone or tablet, the preferred versions for many observers these days, as it does to charts on paper.

You'll also want a good deep-sky guidebook. A beloved old classic is the three-volume Burnham's Celestial Handbook. An impressive more modern one is the big Night Sky Observer's Guide set (2+ volumes) by Kepple and Sanner. The top of the hill for total astro-geeks is the Annals of the Deep Sky series, currently at 10 volumes as it slowly works forward through the constellations alphabetically. So far it's only up to F.

Can computerized telescopes replace charts? Not for beginners I don't think, and not for scopes on mounts and tripods that are less than top-quality mechanically. Unless, that is, you prefer spending your time getting finicky technology to work rather than learning the sky. And 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 and a curious mind." Without these, "the sky never becomes a friendly place."

If you do get a computerized scope, make sure its drives can be disengaged so you can swing it around and point it readily by hand when you want to, rather than only slowly by the electric motors (which eat batteries).

However, finding faint telescopic objects the old-fashioned way with charts isn't simple either. Learn the essential tricks at How to Use a Star Chart with a Telescope. It applies just as much to charts on a screen as on paper.

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Audio sky tour. Out under the evening sky with your
earbuds in place, listen to Kelly Beatty's monthly
podcast tour of the naked-eye heavens above. It's free.

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"The dangers of not thinking clearly are much greater now than ever before. It's not that there's something new in our way of thinking, it's that credulous and confused thinking can be much more lethal in ways it was never before."
            — Carl Sagan, 1996

"Facts are stubborn things."
            — John Adams, 1770

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