Sky Object of the Month – February 2018

Print Friendly, PDF & Email

Sky Object of the Month – February 2018

(Courtesy LVAS Observer’s Challenge*)

Messier 41 – Open Cluster in Canis Major (Mag. 4.5; Size 40’)


            The open star cluster Messier 41 might not seem like much of an observer’s challenge. It’s bright enough (magnitude 4.5) to be seen with the unaided eye and is resolvable with binoculars. A small telescope magnifying just 30X will capture about two dozen cluster members scattered across an area slightly larger than a full moon. Large aperture scopes will capture upwards of 100.

One of the cluster’s more interesting features is a ruddy star located near the center. I learned about it in William Tyler Olcott’s Field Book of the Skies – my primary guide during my early days as a backyard astronomer in the mid 1960s and early 1970s. My earliest attempts with a 3-inch f/10 reflector proved disappointing. I expected a ruby red star to dominate the eyepiece field. No such luck, and it wasn’t until 1977 that I saw what seemed to be a reddish star near the heart of M41. I wasn’t positive this was the star Olcott referred to and wrote, “Bright star in center seems reddish, but this may be a result of prior knowledge.” I re-observed M41 with a 4.5-inch f/8 reflector in 2004 and labeled the red star on a drawing I made (see below). Compare it with an image made by Mario Motta using a 6-inch scope.

M41 is easily found just 4 degrees south of Sirius. It was possibly seen by Aristotle around 325 B.C and recorded by the Italian astronomer Giovanni Battista Hodierna around 1654. Situated about 2100 light years away, M41 spans some 25 light years.

Glenn Chaple for the LVAS



Mario Motta MD


Glenn Chaple

Comments are closed.

Copyright © 2019 North Shore Amateur Astronomy Club.
A non-profit organization under Section 501(c)(3) of the IRS code.