NGC 6118 Galaxy In Serpens: June 2024 Observer’s Challenge Object #185
Roger Ivester: Observer from North Carolina
Many amateurs consider NGC 6118, also known as “The Blinking Galaxy” to be the most difficult object in the entire Herschel 400 list.
I remember first reading about this galaxy almost 30 or more years ago in an astronomy publication, possibly the Astronomical League, Reflector Magazine. This article concerned an amateur who was just beginning his quest to see the entire list, and “as bad luck would have it” chose NGC 6118 as his first object. This galaxy is known as “The Blinking Galaxy” due to it seemingly appearing and then vanishing, similar to a few planetary nebulae. So, after consulting with other amateurs, he was told that NGC 6118 was extremely faint and was possibly the most difficult object in the entire Herschel 400 list.
I was working on the Herschel’s at the time (1994-1995) while reading this article, but had not attempted to locate and observe this galaxy. I had completed about 150 or more of the objects, but due to light pollution and a very poor southern view was forced to cancel my efforts.
However, since that time, I’ve just not been able to forget about galaxy NGC 6118 and the article, concerning its difficulty.
So, on August 5, 2023, shortly after sunset, the skies looked pretty good. The humidity was very high at 91%, which in-part caused very poor transparency. And I was also having to look over the town of Boiling Springs, with lots of light pollution. It was also a bit late in the year, as the galaxy was already too far to the west.
March, April and May 2024
I also attempted two very early morning observing sessions in March and April of 2024, from my suburban backyard, but again without success. A dark site is really needed to observe any low-surface-brightness galaxy, especially one as dim and faint as NGC 6118.
However, traveling to a dark-site has been over for me now for many years. The disassembly of a heavy equatorial mount and handling a large solid-tube Newtonian, loading, driving, unloading, reassembly, and then having to do it all again, became just too much. I will continue to do my best from the backyard.
Many years ago, I assembled light-block system, made of heavy-duty automotive-marine fabric. This simple, but effective structure has helped me on many occasions over the years to see difficult and faint deep-sky objects. The light-block system is especially helpful in some areas of the southern sky, where light pollution is significant. It’s easy to set up and take down. When the fabric is removed and folded for storage, the steel post and plastic-coated wires remain and are hardly noticeable.
I attribute my ability to finally see NGC 6118 was due to blocking a very bright LED carport light less than 1/8 mile away. This light was shining directly toward my backyard, and brightening up the area of my telescope and observing location significantly.
Saturday morning; May 11th 2024 @ 1:00 AM, with a 5.0 NELM overhead, but far less in the sky near NGC 6118, due to overlooking the town of Boiling Springs.
With a bit of difficulty and after almost an hour of careful observing, I was finally able to see the galaxy. My portable “make-shift” observatory was the answer to finally seeing this faint and difficult object from my suburban backyard.
I really don’t think this galaxy would be that difficult from a dark-site, and with my 10-inch Newtonian. However, as I’ve mentioned previously, my days of traveling with a telescope have been over for a few years now. I just love the convenience of my backyard and seeing a galaxy this faint, proves that a suburban backyard can still allow effective deep-sky observing.

Description: A tiny and subtle brighter middle, which resembles that of a planetary nebula. And like so many planetary nebulae, when using direct vision, vanishes or winks out. I now know why NGC 6118 is known as “The Blinking Galaxy.” The galaxy has a very faint and diffuse halo with mottling, which is oriented NE-SW.
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