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January 21: Ganymede and its shadow transit Jupiter
Take advantage of the dark window before the crescent Moon rises to explore the Rosette Nebula, also cataloged as NGC 2237. This gorgeous sight is made up of a central open star cluster surrounded by dusty, star-forming clouds, all located about 5,200 light-years away in the constellation Monoceros. If you aren’t familiar with this constellation, don’t worry — it’s easy to find, located just to the east of Orion and his famous three-star belt.
By 8 P.M. local time, Orion’s Belt is already more than 40° above the southeastern horizon. Below it sparkles Sirius, the brightest star in the sky. Look to the lower left of Orion’s Belt and to the upper left of Sirius — that’s the constellation Monoceros. The Rosette Nebula is located in its northwestern region, about 9° east of the bright red giant star Betelgeuse, which marks Orion’s shoulder and sits to the upper left of the belt as Orion rises tonight.
The open cluster at the center of the Rosette is NGC 2244. At 5th magnitude, it’s the easiest part of this complex to see, apparent in any telescope. To view the nebular regions around it, you’ll want to try adding a nebula filter to suppress the stars and bring out the glowing gas, as well as a low-power eyepiece to give you a larger field of view around the central cluster.
Sunrise: 7:16 A.M.
Sunset: 5:07 P.M.
Moonrise: 9:21 A.M.
Moonset: 9:24 P.M.
Moon Phase: Waxing crescent (19%)
*Times for sunrise, sunset, moonrise, and moonset are given in local time from 40° N 90° W. The Moon’s illumination is given at 10 P.M. local time from the same location.
