Sky at a Glance | June 13th, 2008

Some daily events in the changing sky for June 13 – 21.

The Moon shines above the spout of the Sagittarius Teapot on the night it's full, and closer to the right of Jupiter the next night.

Friday, June 13

  • After dark, the gibbous Moon shines in the south with Spica to its upper right. Very high above the Moon (almost overhead as seen from mid-northern latitudes) is brighter Arcturus.

    Arcturus looks brighter only because it's nearer: 37 light-years away, compared to Spica's 260. In reality, hotter Spica is 16 times as luminous as Arcturus.

    And oh yes, the Moon there is only 1.3 light-seconds away.

    Saturday, June 14

  • Arcturus shines its highest in the south at the end of dusk (almost overhead as seen from mid-northern latitudes). The brightest star high in the east-northeast is Vega, Arcturus's equal; they both shine at magnitude zero. These are the two brightest stars of summer — which begins next Friday.

    Sunday, June 15

  • Look a third of the way from Arcturus to Vega for the dim little semicircle of Corona Borealis, the Northern Crown. Through light pollution, or through moonlit haze and humidity, you may only be able to see its modestly bright "jewel star," Gemma.

    Monday, June 16

  • The Moon shines close to Antares in the heart of Scorpius. Seen from North America, the Moon passes just 1° below Antares in the middle of the night.

    Tuesday, June 17

  • The red long-period variable stars R Ophiuchi, R Sagittarii, and RU Sagittarii should be at maximum light (7th or 8th magnitude) this week.

    Wednesday, June 18

  • Full Moon (exact at 1:30 p.m. EDT).

    Thursday, June 19

  • Jupiter is near the Moon late this evening (see illustration above) and tomorrow evening.

    Friday, June 20

  • The June solstice occurs at 7:59 p.m. Eastern Daylight Time, marking the start of summer in the Northern Hemisphere; winter in the Southern Hemisphere. This is when the Sun reaches its farthest north in Earth's sky and begins its six-month return southward.

    In the Northern Hemisphere, this is the longest day and shortest night of the year. The night of summer solstice is traditionally called Midsummer's Night, though this is a misnomer by the modern definition of when the seasons begin and end. Traditionally, on this night spirit creatures were thought to be especially apparent (hence Shakespeare's A Midsummer Night's Dream), and the occasion was celebrated with all-night bonfires.

  • Pluto is at opposition.

    Saturday, June 21

  • With summer here, it's only appropriate that the big Summer Triangle is up in view after dark. Its top star is Vega, the brightest star in the eastern sky. Look two or three fists lower left of Vega for Deneb. Look farther to Vega's lower right for Altair. A finger-width above Altair is its little companion star Gamma Aquilae, or Tarazed.

    Want to become a better amateur astronomer? Learn your way around the constellations. They're the key to locating everything fainter and deeper to hunt with binoculars or a telescope. For an easy-to-use constellation guide covering the whole evening sky, use the big monthly foldout map in each issue of Sky & Telescope, the essential magazine of astronomy. Or download our free Getting Started in Astronomy booklet (which only has bimonthly maps).

    Once you get a telescope, to put it to good use you'll need a detailed, large-scale sky atlas (set of maps; the standards are Sky Atlas 2000.0 or the smaller Pocket Sky Atlas) and good deep-sky guidebooks (such as Sky Atlas 2000.0 Companion by Strong and Sinnott, the even more detailed Night Sky Observer's Guide by Kepple and Sanner, or the classic Burnham's Celestial Handbook). Read how to use them effectively.

    More beginners' tips: "How to Start Right in Astronomy".

    This Week's Planet Roundup

    Looking west at dusk
    All week, Mars draws closer to Regulus and Saturn in the western twilight.
    Mercury and Venus are lost in the glare of the Sun.

    Mars (magnitude +1.6, in Leo) is getting low the west after dusk, to the lower right of Saturn and Regulus as shown here. It's closing in on them daily! On June 23rd the three of them will be equally spaced, with each planet just over 4° from Regulus.

    In a telescope Mars is a minuscule 4.6 arcseconds wide — a tiny blob.

    Jupiter (magnitude –2.7, in eastern Sagittarius) now rises around the end of twilight, left of the Sagittarius Teapot. It gets highest in the south in the early-morning hours.

    Saturn (magnitude +0.8, in Leo) glows in the west after dark about 4° upper left of fainter Regulus (magnitude +1.4) as shown here. Look early before they get too low. In particular, get a telescope on Saturn as soon after sunset as you can find it.

    Uranus and Neptune (magnitudes 6 and 8, respectively, in Aquarius and Capricornus) are well up in the southeast before the first light of dawn. Use our article and finder charts.

    Jupiter on May 24, 2008
    Jupiter on May 24th. The dark North Equatorial Belt is above center. The black dot on it is the shadow of Io. Visible below center are not just one red spot but three; see article. The Great Red Spot remains near System II longitude 121°. North is up (though many telescopes show south up).
    Pluto (magnitude 14.0, in northwestern Sagittarius) is highest in the south around 1 a.m., but wait a week or two until the moonlight is gone from the late-night sky.

    All descriptions that relate to your horizon or zenith — 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) equals Universal Time (UT, UTC, or GMT) minus 4 hours.

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