Sky at a Glance | January 27th, 2012

Some daily events in the changing sky for January 27 – February 4

Friday, January 27

  • The Moon shines high above Venus at nightfall. Once the stars come out, look a similar distance to the Moon's right for the bottom star of the Great Square of Pegasus.

    Saturday, January 28

  • This evening, look right of the Moon for a different star of the Great Square of Pegasus: its leftmost corner.

    Early evening view
    Watch the waxing gibbous march across the evening sky from Jupiter to Aldebaran and the Pleiades. (Moon positions are for the middle of North America. European observers: move each Moon symbol a quarter of the way toward the one for the previous date. For clarity, the Moon is shown three times actual size.)

    .

    Sunday, January 29

  • The Moon shines about 8° right or upper right of Jupiter this evening (for North America), as shown above.

  • This evening the faint asteroid 1746 Brouwer will occult (cover) a 7.0-magnitude star in Aries for up to 4 seconds as seen from a path running from Oregon through the Minneapolis/St. Paul area to Massachusetts. Maps and details for planning your watch. The star is bright enough in a telescope that the Moon so nearby shouldn't compromise things too much.

    Monday, January 30

  • The first-quarter Moon shines about 8° upper left of Jupiter this evening (for North America), as shown above.

    Tuesday, January 31

  • Jupiter is lower right of the Moon this evening. Continue the line much farther lower right to hit Venus.

  • The first near-Earth asteroid discovered was 433 Eros in 1898. It's currently making its closest pass by Earth since 1975, shining at magnitude 8.6. It stays this bright for the next two weeks. Find it in Sextans south of Leo using the charts in the January Sky & Telescope, page 52, or online.

    Wednesday, February 1

  • The Moon shines between the Pleiades and Aldebaran, as shown above.

    Thursday, February 2

  • Now that it's February, Orion strides high in early evening. It's below the Moon tonight. Orion's top left corner is fiery Betelgeuse. Far below Betelgeuse shines brighter Sirius. Betelgeuse and Sirius form the equilateral Winter Triangle with Procyon off to their left.

  • Comet Garradd, still about magnitude 6.6, is passing a mere ½° west of the globular cluster M92 in Hercules in the early hours of Friday morning. The two fuzzballs are similar in brightness but different in looks. They're highest in the hour before the first light of dawn at your site.

    Friday, February 3

  • After dinnertime, the waxing gibbous Moon is shining high in the southeast. Look to its upper left for bright Capella, to its upper right for Aldebaran, lower right for Orion, and lower left for Gemini including Castor and Pollux.

    Saturday, February 4

  • The Moon shines in the feet of Gemini this evening, with Castor and Pollux to its left and Orion farther to its right. Well below the Moon shines Procyon.


    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 map in the center of 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 81,312 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 the even larger Uranometria 2000.0 (stars to magnitude 9.75). And read how to use sky charts effectively.

    You'll also want a good deep-sky guidebook, such as Sue French's new 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 classic if dated Burnham's Celestial Handbook.

    Can a computerized telescope replace charts? I don't think so — not for beginners, anyway, and especially not on mounts that are less than top-quality mechanically. 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

    Mars on Jan. 29, 2012
    Mars had grown to 11.6 arcseconds in diameter by January 29th, when Jim Phillips took this image with a 10-inch apo refractor and a Skynyx color video camera. South is up. The North Polar Cap is by far the most obvious feature. The big dark prong near center is Syrtis Major. Note the edge of the South Polar Cloud Hood just visible around the southern limb, and faint clouds on the morning limb (the celestial east side, at right).
    Jim Phillips

    Mercury is hidden in the glare of the Sun.

    Venus (magnitude –4.0, crossing the Aquarius-Pisces border) is the brilliant “Evening Star” shining in the southwest during and after dusk. It doesn't set now until more than 1½ hours after dark. Venus will continue to appear a bit higher, and stay up later, all winter. In a telescope Venus is still a small gibbous disk, 15 arcseconds in diameter and 75% lit.

    Mars (about magnitude –0.5, at the Leo-Virgo border) rises in the east around 8 or 9 p.m., far beneath Regulus and the Sickle of Leo. It's 8° or 9° south (lower right during evening) of 2nd-magnitude Denebola, Leo's tail. Mars is brightening rapidly now as it approaches Earth. It shines highest in the south, in best telescopic view, around 3 a.m.

    Jupiter on Jan. 29, 2012
    Jupiter is shrinking as Earth leaves it farther behind, but Christopher Go in the Philippines caught some excellent seeing on January 29th for this extraordinary shot of developments around the Great Red Spot. South is up. Note the white turbulence on the following (right; celestial east) side, and the stark red part of the South Equatorial Belt on the spot's preceding side.The red transitions to white as it squeezes past the spot.

    In a telescope Mars grows to 12 arcseconds wide this week, close to the 13.9″ it will display when closest to Earth in early March. It's only slightly gibbous now: 96% lit.

    Jupiter (magnitude –2.5, still at the Aries-Pisces border) shines high in the south-southwest at dusk, moves lower toward the southwest as evening advances, and sets in the west around midnight. In a telescope Jupiter has shrunk to 40 arcseconds wide.

    Saturn (magnitude +0.6, in Virgo) rises in the east around 11 or midnight and is high in the south before dawn. Spica, a bit fainter at magnitude +1.0, is 7° to its right or upper right. Saturn's rings are now tilted a generous 15° from our line of sight.

    Saturn on Jan. 21, 2012
    Saturn's rings are tipped a good 15° from our line of sight. Not since 2007 have they appeared this open. South is up. Note the very pale light band in the north temperate region, apparently the remnant of the dramatic, billowing white outbreak that attracted so much attention last year. Christopher Go took this image on January 21, 2012.

    Uranus (magnitude 5.9, near the Circlet of Pisces) is still in the southwest right after dark.

    Neptune is lost in twilight.


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


    Like This Week's Sky at a Glance? Watch our new weekly SkyWeek TV short, now also playing on PBS!


    To be sure to get the current Sky at a Glance, bookmark this URL:
    http://SkyandTelescope.com/observing/ataglance?1=1

    If pictures fail to load, refresh the page. If they still fail to load, change the 1 at the end of the URL to any other character and try again.