Binocular Universe: The Winter Triangle

Above: Winter star map from Star Watch by Phil Harrington.

Above: Finder chart for this month's Binocular Universe.

Chart adapted from Touring the Universe through Binoculars Atlas (TUBA)

Monoceros may not hold much for constellation watchers, but it overflows with open star clusters for us binocularists.  Despite the fact that many are visible in binoculars, only one found its way into Charles Messier's eyepiece field.  That's our first target, M50.  Even though it lies in the middle of nowhere, M50 is surprisingly easy to find.  Begin at Sirius and slowly scan northeastward toward Procyon. Stop a little less than halfway along and look for a tiny blur of starlight punctuated by possibly one or two dim points.  That's M50.  The brightest cluster star, lying just south of center, shines at 8th magnitude and may appear faintly golden through 80-mm and larger binoculars.

Before we leave M50, try your luck with Pakan's 3, a fun asterism first spotted by amateur Randy Pakan from Edmonton, Alberta.  Depending on your binoculars, it might be in the same field as M50, since both are only separated by only 3 degrees.  Put M50 in the northeastern part of your view, and then look to the southwest for a collection of faint stars that together form the number 3.  The figure covers an area equal to that of the Full Moon, so it's large enough to be pretty obvious through binoculars.  But since none of the stars shine brighter than 8th magnitude, moonlight as well as light pollution could play havoc.  Wait for that special, dark February night to try your luck.

Now, up stakes and continue on your way toward Procyon.  Before you reach it, you'll first bump into Delta Monocerotis. Binoculars easily show that 4th-magnitude Delta is accompanied by 5th-magnitude 21 Mon just to its northwest.  They make a pretty, if not faux, double star.

Place Delta and 21 toward the eastern limit of your field of view and then look toward the western edge. Can you just make out a half dozen or so faint points lined up in an undulating north-south procession?  If so, you've spotted NGC 2301, one of my favorite little "unknown" clusters.  My 10x50 binoculars show those half dozen stars and a slight background glow from fainter cluster suns, while my 16x70s further resolve that glow into a north-south string of 8th- and 9th-magnitude stars marked at mid-span by a hazy triangular clump of many stars that remain too faint to resolve.  In my book Touring the Universe through Binoculars (1990: John Wiley & Sons), I call this the "Great Bird of the Galaxy" Cluster.  The "bird's" two wings are represented by the string of stars extending from the three-sided body.  Can you see it, too?  Or am I crazy??

Left:  Open cluster NGC 2301 as portrayed through the author's 16x70 binoculars.  The "Great Bird's" wings extend north and south of the hazy triangular body. North is up.

Next month, spring is in the air -- well, almost.  Until we meet again under the stars, here's hoping that you can grab those binoculars and get in some quality star time this month.  And of course, remember that two eyes are better than one.