Galaxy NGC 6118 In Serpens Caput: Many Consider This To Be The Most Difficult Object in The Entire Herschel 400 List

Many amateurs consider NGC 6118 (also known as the Blinking Galaxy) to be the most difficult object in the Herschel 400 list.  I remember first reading about this galaxy, in the AL “Reflector Magazine” maybe 20 or so years ago, in the “Tales of The Unknown Astronomer.” 

The article concerned an amateur who was just beginning to work on the list, and “as bad luck would have it” chose NGC 6118 as his first object, and was unsuccessful, after many attempts.  

He consulted with other amateurs, and was told that NGC 6118 was an extremely difficult object….probably the most difficult of all in the 400 list.   

Note:  Now this is all all from memory and I think I’m pretty accurate, but don’t remember if he ever found the galaxy, or not. (?) 

There is a lot of information online by many amateurs…sharing their successes and failures.

Just so happened, I was working on the H-400 list at that time, when reading the article, and had not attempted this galaxy. I completed about 250 of the objects, in this list, but that was all my back yard would allow, due to light pollution and a very poor southern view.  To this day, that’s where my Herschel 400 list remains and probably not to return.  

However, in recent years, I’ve always wanted to see this galaxy due to the difficulty factor, but will have to travel to one of my dark sites.  Something I rarely do these days. But for this galaxy, I’m willing to give it try, however, probably not this year.  

What got me thinking about this galaxy again?  

In the September 2022 Astronomy Magazine, Stephen James O’Meara writes about NGC 6118 in his “Secret Sky” column. Titled “A Deep-Sky Devil” and a sub-title of “The spiral galaxy NGC 6118 is fiendishly difficult to find” P-60. 

An excellent article and I also learned what a devil is on a ship!  And No…you can’t just throw him overboard!  Find out who the devil is!  Read this article today! 

The following image is a quick phone-shot using wikisky.org 

Roger Ivester 

Visual Observational Notes:

In 25 cm this galaxy is a faint, uncondensed patch 3′.5 NNW of a mag. 11.5 star. The irregular halo extends to about 4′ x 2′, elongated NE-SW. A very faint star is just off the SE flank, 1’5 E of the center. 30 cm shows the low surface brightness halo to 3′ x 1.8 in pa 60º. The surface is slightly mottled, but there is no general brightening toward the center.

Source: Observing Handbook and Catalogue of Deep-Sky Objects by Christian B. Luginbuhl and Brian A. Skiff

12.2M; 4.5′ x 2 extent; large, very soft slash, axis oriented NE-SW, very little brighter center; TOUGH!

Source: 1000+ The Amateur Astronomer’s Field Guide to Deep Sky Observing by Tom Lorenzin

Looking through my logbook, I see that I observed this one with my 11-inch Dob at the Connecticut Star Party in Ashford, CT in September 2012. I was living in Hamden, CT at the time, which was considerably more light-polluted than the CSP site. I doubt if I could have seen it from Hamden at all, as I would have been looking South towards New Haven.

I noted it as “A very faint object”. There was a bright star in the field, and next to it three others that made a “parabolic dish” shape that pointed roughly to 6118 at the “focus”. There was also a field star of roughly equal brightness next to 6118, and I was surely seeing mostly just its nucleus. Derek Lowe

The following observational notes: From the original “Observe The Herschel Objects” Ancient City Astronomy Club (First printed in 1980; Second printing 1992) by Brenda and Dave Branchett, Fr. Lucian J. Kemble, O.F.M

Published by the Astronomical League:

Magnitude estimated 11.5, spiral galaxy in Serpens Caput, 4.3′ x 1.3′ in size, very elusive and tagged “Blinking Galaxy,” use averted vision, faint and fairly large, situated near a 6th magnitude field star, located 2º west of SIGMA Serpentis. (6-inch Cass.)

Visual notes by Sue French as following:

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