Messier Column - March 2021

Original article appears in GuideStar March, 2021.

By Jim King

M46 M47 M93 M41.PNG

I started this month’s column on 02.14.21: St. Valentine’s Day.  Why? Primarily because my wife has zero interest in going out to eat on a day like this regardless of the occasion.  Of course, you may remember the weather forecast for today and the next several days will be a challenge for Texans in general, but especially for us astronomers…as it has been for the past few weeks.  One of the things that makes our passion a challenge and frequently frustrating, is that the opportunities to do the fun stuff sometimes are few and far-between.  Steve G. just this morning sent out a picture of the all-sky camera at our dark site…already ice-glazed…and the really bad weather has about six more hours to percolate before it arrives here in beautiful downtown Fulshear, Texas.  Time to poke my lip out and pout? 

I think not.

 

I am blessed in that I have a reason to be an astronomer even on a sucky weather day like today: I get to compose this column.  This science-y-stuff does not come easily or naturally to me simply because my background for the past 50 years has been counting beans.  Once I moved past multiplication and division (very complicated long division, I might add), the need for hard science seemingly ended. All my book-learning revolved around facts, figures, rules, regulations, and incidentally, occasionally screwing up the best-laid plans of the IRS…much to my glee and joy. With the advent of calculators and desk-top computers, even remedial math 100 went bye-bye.  At one time, I was lightning-fast and deadly accurate on a 10-key calculator. But with the advent of spread-sheet software, I met my match.

Now, I get to do personal research. I get to study what Charlie Messier and Jimmy O’Meara and Alphonse Wikipedia…and all those other learned sources opine as to why an object is the way it is.  In other words, I have a cause, and thus the motivation, to learn new and fascinating things.

I want to encourage you to find a reason to do things astronomical that may not be right in your wheelhouse today…but maybe tomorrow?  Astronomy offers so many opportunities that none of us has a legitimate reason to waste a perfectly good rainy, snowy, Icy afternoon watching Big Bang Theory reruns (of which, I happen to have 82.5 episodes on my DDR).  

For now, let us continue our journey through Messier’s catalog and in the process, we will finish up his winter objects.

 

M41 Open Cluster (2) Easy

As Canis Major, the great dog of Orion rises, this open cluster hangs below its collar like a tag reflecting Moonlight.  One of the faintest objects recorded in classical history, M41 was recorded by Aristotle as a star with a tail.  With the naked eye, it is surprisingly similar to the Beehive Cluster, M44, only a tad smaller.

Unfortunately, for many of todays observers, light pollution makes it a difficult naked-eye object.  But if you enjoy access to dark skies, M41 looks like a ghost image of Sirius.   In 7 x 35 binoculars, both Sirius and M41 fit into the same FOV…and the binoculars resolve the cluster quite well.

Messier notes: (Observed January 16, 1765) Cluster of stars below Sirius, close to Canis Majoris.  This cluster appears nebulous in a simple one-foot refractor.  It is no more than a cluster of Faint stars.

NGC note: Cluster, bright, very large, little compressed stars of 8th magnitude and fainter.  Note, the NGC incorrectly recorded this cluster as M14.

Data: Messier 41 aka NGC 2287

Con: Canis Major                                               Mag: 4.5

RA: 06h 46.1m                                                   Dec: -20.46

Dist: 2,100 ly

 

M78 Diffuse Nebula (3) Detectable

M78 is far enough away from the nebula madness of Orion’s belt and sword to be easily overlooked.  In fact, M78 is the brightest of three specter-like glows in the region.  Its companion nebulae are NGC 2067 and NGC 2071.  All three shine by reflected light from hot, young B-type stars and are part of a greater complex of nebulosity sweeping through much of Orion.    Most sources do not publish a magnitude for M78, even though it is visible with 7 x 35 binoculars.  The reason is, there are very few good measurements of nebula magnitudes.  James O’Meara’s estimates of 8.0 was made with binoculars. If you have good to excellent eyesight, try detecting M78 without aid.

Messier notes: (Observed December 17th, 1780) Cluster of stars with a lot of nebulosity in Orion, and on the same parallel as the belt, which was used to determine its position. 

NGC note:  Bright, large wisp, gradually much brighter to a nucleus, three stars involved, mottled.

Data:                     Messier 78 aka NGC 2068

                                Con: Orion                                                     Mag 8.0 (O’Meara)                         

                                RA: 05h 46.7m                                               Dec: -00.03

                                Dist: 1,630 ly     

 

M46 (2) Easy, M47 (1) Obvious, Open Clusters

Use your binoculars and scan about 15 degrees east of Sirius in a line due south of Procyon and Alpha Monocerotis. There, hiding amongst the monotonously faint star fields of the Puppis Milky Way, are the curious Messier open clusters M46 and M47. 

M46 is a relatively young galactic star cluster with an age of 245 million years.  It appears as a round, uniform 6th magnitude glow.  Gawky M47 is an irregular gathering of reasonably bright but dissimilar stars.  The cluster’s age is about 70 million years, comparable to the Pleiades. What becomes immediately obvious, even in binoculars, is that whatever M46 lacks in visual grandeur, M47 lacks in visual grace, and vice-versa.  It is like trying to compare a flower with a rock.

M46 Messier notes: (Observed February 19, 1771) Cluster of very faint stars between the head of Canis Major and the two rear hoofs of Monoceros.

NGC note: Remarkable, cluster, very rich, very bright very large, involving a planetary nebula.

Data:                     Messier 46 aka NGC 2437

                                Con: Puppis                                                                    Mag: 6. 1

                                RA: 07h41.8m                                                               Dec: -14.49-

                                Dist: ~5,300ly

 

M47 Messier notes: (Observed February 19, 1771) Cluster of stars not far from M46.  The stars are brighter.

NGC notes: Cluster, bright, very large, pretty rich, with bright and faint stars.

Data:                     Messier 47 aka NGC 2478

                                Con: Puppis                                                                    Mag: 4.4

                                RA: 07h36.6m                                                                Dec: -14.29

                                Dist: ~1,500ly                                                    

 

M93 Open Cluster (1) Obvious

There are three reasons to consider this open cluster to be a stunning visual treat.  First, its stars are like tiny gems scattered in a rich field of even tinier gems; these are subtle beauties, as delicate as tiny pearls on white satin.  Second, the core of the cluster has a distinct arrowhead shape.  Third, in binoculars, M93 appears asymmetrical and one might discern a cat’s eye pattern.  

The cluster lies almost exactly on the galactic plane, though it is reddened by less than 0.05 magnitude. It is of moderate size, extending across 10 light years of space.  It is a rich cluster with a strong central concentration comprised of bright and faint stars.

Messier notes: (Observed March 20, 1781) Cluster of faint stars without nebulosity.

NGC note: Cluster, large, rich, little compressed, with 8th to 13th magnitude stars

Data:                     Messier 93 aka NGC  2447

                                Con: Puppis                                                                    Mag: 6.2              

                                RA: 07h44.5m                                                               Dec: -23.51.2

                                Dist: ~3,400 ly                                   

               

Finis: It is now February 25th.  Except for a final edit and submission to Stephen Jones to add charts, I am done.  It is once again a yucky, rainy, miserable day…thankfully considerably warmer than last week by about 60 blessed degrees.  I began this column by lamenting the upcoming weather pattern but with an upbeat slant of hidden opportunities.  But, once again, nature had its way and put me out of business for several days with a lack of power output from some of our newer gadgets. 

Maybe that’ll teach me to keep quiet about some things.

Nah!!!

Keep looking up!

Jim King

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