Sky at a Glance | November 15th, 2013

Mike Broussard of Lousiana shot Comet ISON on the morning of November 14th using a 200mm lens on a DSLR. Click image for his animated gif of the comet rising through the trees as dawn brightened.
Mike Broussard

Comet ISON has brightened suddenly in the last few days to 4th magnitude as of November 20th — a popsicle comet with a small, bright green-white head and a long, thin, dim tail. It's speeding sunward near Spica and Mercury low in the east just before dawn, accelerating every day toward its November 28th perihelion and trial by fire. See new S&T press release.

Meanwhile, Comet Lovejoy glows only a little less bright much higher before dawn. Both comets are visible in binoculars despite moonlight returning to the morning sky. They're being detected naked-eye by skilled observers under good conditions. Finder charts for both. This is getting exciting!

Sky & Telescope and Celestron are sponsoring a Comet ISON photo contest with some serious prizes.



Friday, November 15

  • The bright star high in the west-northwest after dark this month is Vega, often associated with summer. The brightest star higher above it is Deneb. Farther to Vega's left or lower left is Altair, dimmer than Vega but outshining Deneb. These three form the Summer Triangle, which is sinking lower each week as summer becomes a distant memory.

    As the Moon passes through full, it moves across Taurus and Gemini in the evening sky.
    Alan MacRobert

    Saturday, November 16

  • The Moon is almost equally full this evening and tomorrow evening. Tonight, look above the Moon for the leading star or two of Aries glimmering through the moonlight.

    Sunday, November 17

  • Comet ISON is within 2° of Spica this morning and Monday morning as seen from the Americas. Their closest approach, 1/3°, comes around 1h November 18th Universal Time, good timing for observers in the longitudes of eastern Europe and western Asia. Detailed chart.

  • The full Moon this evening shines to the upper right of Aldebaran, and lower right of the delicate little Pleiades cluster.

    Monday, November 18

  • This evening look right of the just-past-full Moon for Aldebaran. Later in the evening, Orion rises below them.

    Tuesday, November 19

  • After 9 or 10 this evening, you'll find the waning gibbous Moon shining inside a huge quadrilateral: Capella to the Moon's upper left, Aldebaran to the Moon's upper right, Betelgeuse closer to its lower right, and bright Jupiter far to its lower left.

    Wednesday, November 20

  • By late evening the waning Moon is up in the east. It's now part of a long, ragged, roughly horizontal snake. From right to left: Rigel in Orion's foot in the east-southeast, Orion's Belt, Betelgeuse, the Moon, Jupiter, Pollux, and above Pollux, Castor.

    Thursday, November 21

  • Jupiter is the bright "star" upper left of the Moon late this evening. Although they look close together, Jupiter is currently 1,660 times farther away. And Pollux and Castor, to Jupiter's left and upper left, are 500,000 and 730,000 times farther than Jupiter! (at 34 and 52 light-years, respectively).

    Friday, November 22

  • The waning gibbous Moon is up in the east by about 10 p.m., depending on where you live. Look above it for bright Jupiter and (to Jupiter's left) Pollux and Castor. To the Moon's right twinkles Procyon. Much farther to the right, brighter Sirius is rising or soon to rise.

    Saturday, November 23

  • The eclipsing binary star Algol should be at minimum light, magnitude 3.4 instead of its usual 2.3, for a couple hours centered on 9:06 p.m. Eastern Standard Time. It takes several more hours to fade and to rebrighten.

  • You may think you know Cassiopeia, but I bet you've never hunted its open cluster King 20 or teased apart the multiple star ADS 16795 just ½° to the cluster's west. And, the charming double star Struve 3022 shines in the same telescopic field. See Sue French's Deep-Sky Wonders in the November Sky & Telescope, page 56.


    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. Or download our free Getting Started in Astronomy booklet (which only has bimonthly maps).

    Pocket Sky Atlas
    The Pocket Sky Atlas plots 30,796 stars to magnitude 7.6 — which may sound like a lot, but that's less than one star in an entire telescopic field of view, on average. By comparison, Sky Atlas 2000.0 plots 81,312 stars to magnitude 8.5, typically one or two stars per telescopic field. Both atlases include many hundreds of deep-sky targets — galaxies, star clusters, and nebulae — to hunt among the stars.
    Sky & Telescope

    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 (able to point with better than 0.2° repeatability, which means heavy and expensive). As Terence Dickinson and Alan Dyer say in their invaluable 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 (magnitude –0.6) shines low in the east-southeast in early dawn. This is its best morning apparition of 2013. Don't confuse Mercury with Spica to its upper right. The gap between them widens from 12° to 18° this week. To their upper left by about 30° is Arcturus.

    Venus (magnitude –4.8) is the brilliant "Evening Star" in the southwest during dusk, shining just about as high and bright as it's going to this year. It sets more than an hour after dark. In a telescope, Venus has waned to its thick-crescent phase and has enlarged to about 32 arcseconds tall.

    Mars (magnitude 1.4, in Leo) rises around 1 a.m. It's moving eastward against the background stars, pulling farther away to the lower left from Regulus. By dawn, Mars and Regulus are high in the south-southeast. Mars is still a tiny disappointment in a telescope, only 5 arcseconds wide.

    Jupiter (magnitude –2.5, in Gemini) rises in the east-northeast around 8 or 9 p.m. with Pollux and Castor to its left. It blazes highest around 3 or 4 a.m. In a telescope Jupiter has grown to 43 arcseconds wide as it heads toward its January 5th opposition.

    Saturn is deep in the glow of sunrise.

    Uranus (magnitude 5.7, in Pisces) and Neptune (magnitude 7.9, in Aquarius) are high in the southeast to south in early evening. Finder charts for Uranus and Neptune. See also the October Sky & Telescope, page 50.


    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 Standard Time (EST) is Universal Time (known as UT, UTC, or GMT) minus 5 hours.


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