Sky at a Glance | January 23rd, 2009

Some daily events in the changing sky for January 23 – 31.

Comet Lulin remains about magnitude 7.0 as it rises rapidly higher in the southeast to south before dawn. Small-telescope users are spotting it easily, with the Moon now gone from the morning sky. The comet is moving toward Earth and should reach 5th magnitude in late February. Full story and charts.

Orion
Orion is already high in the southeast after nightfall in late January. Orion's Belt points down diagonally to bright Sirius in Canis Major, between the pine trees here.
Ken Hewitt-White

Friday, January 23

  • Dim, distant Uranus is still within 2° of dazzling Venus this evening; Venus is 10.4 magnitudes (15,000 times) brighter. You can identify the faint speck of Uranus using binoculars or a low-power telescope and the illustration in the January Sky & Telescope, page 62.

    Saturday, January 24

  • By as early as 8 p.m. now the Big Dipper has completely cleared the east-northeast horizon (depending on your latitude), to stand in full view on its handle.

    Sunday, January 25

  • Around the dim end of the Cassiopeia W are five star clusters that you can try for with good binoculars. Do you know them? See Gary Seronik's "Binocular Highlight" column in the January Sky & Telescope, page 58.

    Monday, January 26

  • New Moon (exact at 2:55 a.m. EST).
    Facing west-southwest in twilight
    Late in the week, the Moon climbs out of the sunset and waxes to meet Venus. (These scenes are drawn for the middle of North America. European observers: move each Moon symbol a quarter of the way toward the one for the previous date. In the Far East, move it halfway.)

  • An annular eclipse of the Sun crosses the Indian Ocean and parts of Indonesia. The eclipse is partial for a much wider area including southern Africa, southeast Asia, southern India, and Australia. Full details.

    Tuesday, January 27

  • Around mid-twilight, look far lower right of Venus for the thin crescent Moon, as shown at right.

    Wednesday, January 28

  • The dim curled hand of Perseus — the one he's not holding his sword in — is dotted with nice telescopic star clusters and nebulae. Don't know what we're talking about? See Sue French's "Deep-Sky Wonders" column and maps in the the January Sky & Telescope starting on page 77.

    Thursday, January 29

  • The waxing crescent Moon shines about 5° lower right of Venus this evening for North America, as shown at right.

    Friday, January 30

  • The Moon poses about 8° above Venus tonight for North America. After dark, look to the right of the Moon for the Great Square of Pegasus tipped onto one corner (the star α Pegasi).

    Saturday, January 31

  • Right at the end of January, the Little Dipper hangs straight down from Polaris right at the end of twilight.


    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).

    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 81,000 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 — 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 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.

    Can a computerized telescope take their place? 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, they note, "the sky never becomes a friendly place."

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


    This Week's Planet Roundup

    Mercury is hidden deep in the sunrise glare for most of the week. But by about January 30th, try looking for it just above the east-southeast horizon about 30 minutes before sunup. Bring binoculars.

    Venus (magnitude –4.6, near the Circlet of Pisces) is the dazzling "Evening Star" high in the southwest during and after twilight. It doesn't set until about 9 p.m. In a telescope Venus is now 27 arcseconds wide and 46% sunlit, just on the crescent side of dichotomy. Telescopically, Venus is best seen in bright twilight or even broad daylight. (It's less glary when seen against a bright sky, and it's also higher.)

    Mars is hidden deep in the glow of sunrise — and will remain so all winter and into the spring.

    Jupiter is lost in the sunset. It's at superior conjunction with the Sun on January 24th.

    William Rison of Newburg, Maryland, took these images of Saturn with the same setup 10 months apart. North is up; note that Saturn's northern latitudes are still bluer than its southern latitudes. Rison used a Meade 12-inch LX200R scope on an Astro-Physics 900GTO mount, and a Lumenera SKYnyx2-0 camera with a Barlow lens producing f/20. Video from the camera was processed with ImagesPlus 3.5 to produce the final pictures.
    Sean Walker
    Saturn (magnitude +1.0, near the hind foot of Leo) rises around 9 p.m. It's highest in the south around 3 or 4 a.m. Don't confuse Saturn with similarly-bright Regulus 21° (about two fist-widths at arm's length) to its upper right after they rise, and more directly to its right in the early-morning hours.

    This week Saturn's rings are still only 1.1° to 1.2° from edge on. The view in a telescope is almost alarming: The rings are not only very narrow but quite dim, as seen at right, and Saturn's globe is slashed by the dark black line of the rings' shadow.

    The rings will gradually open to 4° by late May, then will close to exactly edge-on early next September — when, unfortunately, Saturn will be out of sight practically in conjunction with the Sun.

    Uranus (magnitude 5.9, in Aquarius) is near Venus early in the week, below it later.

    Neptune is lost in the sunset.

    Pluto is low in the southeast just before the start of dawn.

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


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