Some daily events in the changing sky for January 25 – February 2.
Comet Holmes remains near Algol, dimming and widening more and more; it's well over 1½° across. Now that the Moon is gone from the early-evening sky, keep trying for the comet both with your naked eyes and with binoculars. When will you last be able to see it? Dim as it may become, Holmes will remain in the evening sky through April; see chart.
While you're checking in on Comet Holmes with binoculars, look also for the two Messier objects nearby in Perseus: M34 (which is easy) and M76 (much tougher). See Gary Seronik's Binocular Highlight column and chart in the January Sky & Telescope, page 58.
Friday, January 25
Saturday, January 26
Sunday, January 27
Monday, January 28
Tuesday, January 29
Wednesday, January 30
Thursday, January 31
Friday, February 1
At any random time you glance up at Algol, you have a 1-in-30 chance of catching it at least 1 magnitude fainter than normal.
Saturday, February 2
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 standard is Sky Atlas 2000.0) 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 enchanting though increasingly dated Burnham's Celestial Handbook). Read how to use them effectively.
More beginners' tips: "How to Start Right in Astronomy".
This Week's Planet Roundup
Mercury drops down from its good evening apparition this week, while also fading from magnitude 0 to +2. Early in the week you can still catch it above the west-southwest horizon about 45 minutes after sundown. (Don't confuse it with twinklier Fomalhaut, far to the left in the southwest, or Altair, even farther to Mercury's right.)
Venus (magnitude –3.9, in Sagittarius) is the brighter of the two "Morning Stars" low in the southeast during dawn. The other is Jupiter, which closes in on Venus day by day (from the lower left) until their conjunction on the morning of February 1st.
Mars (about magnitude –0.5, in eastern Taurus) shines high in the southeast after dark and highest toward the south around 9 or 10 p.m., high above Orion. The fairly bright star near it is Beta (β) Tauri, also known as El Nath, magnitude +1.6 and pale blue-white.
Mars diminishes from 12.8 to 11.9 arcseconds in apparent diameter this week; it's falling farther behind us as Earth moves ahead in our faster orbit around the Sun. See the telescopic observing guide and surface-feature map in the November Sky & Telescope, page 66, or the short version online.
Jupiter (magnitude –1.9, in Sagittarius) is closing in on brighter Venus low in the dawn. They have a close conjunction, 0.6° apart, on the morning of February 1st.
Saturn (magnitude +0.4, in Leo) rises in the east around 7 or 8 p.m. and is highest in the south after midnight. Fainter Regulus (magnitude +1.4) is 7° west of Saturn: to its upper right after they rise. Only a little dimmer than Regulus is Gamma (γ) Leonis (magnitude +2.1), located 8° to Regulus's north. The three make an eye-catching triangle.
Uranus (magnitude 5.9, in Aquarius) is sinking low in the southwest after dark.
Neptune is hidden in the glow of dusk (in the vicinity of Mercury).
Pluto is hidden in the glow of dawn (above Venus and Jupiter).
All descriptions that relate to your horizon or zenith — including the words up, down, right, and left — are written for the world's midnorthern latitudes. Descriptions that also depend on longitude (mainly Moon positions) are for North America. Eastern Standard Time (EST) equals Universal Time (UT, UTC, or GMT) minus 5 hours.
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