Messier 29 (NGC 6913): A Petite Pretty Star Cluster in Cygnus

Messier 29, also known as the Cooling Tower, is an open star cluster in the constellation Cygnus. It’s best viewed in summer and early autumn.

M29 is accompanied by M39 as the sole Messier objects in Cygnus. At a magnitude of +6.6, Messier 29 is fairly bright with around 50 stars, and it appears like a mini Pleiades if you ask me. On an interesting note, M29 would even appear brighter to us, but the presence of interstellar dust in the area causes some of its light to be absorbed.

As you’re looking at the cluster, just envision it flying toward you—because it is! It’s approaching us at a whopping 28 kilometers per second! Knowing the cluster is more than 5,000 light-years away, we can breathe a sigh of relief; it won’t hit us anytime soon.

Historically speaking, Charles Messier discovered M29 on July 29, 1764.

My Observations

Entry for September 5, 2020, at 10:39 p.m.: This is my first time observing M29 in a telescope. It is a small, yet nice and bright compact cluster. There is a bright quadrilateral of stars. Overall, while not memorable, the cluster still provides skygazers a good target.

Also viewed on July 30, 2022, at 10:35 p.m.: Tonight, I’m enjoying the “blueness” of the brighter stars in this cluster. Perhaps credit goes to this evening’s superior seeing conditions as the handful of stars colored ocean-blue appear. I’m glad I took a few quiet minutes to let the colors “sink in.”

Also imaged on November 22, 2025, at 9:30 p.m. from Tampa, FL: I’m taking advantage of haze-free skies in Florida to capture M 29. This image is from a Seestar S50, taking 10-second exposures over 11 minutes.

Key Stats

Constellation	Cygnus
Best Viewing	September
Visual Magnitude	+6.6
Absolute Magnitude	-4.35
Distance from Earth	5,240 ly
Diameter	15 ly
Apparent Size	10 arcmin
My Viewing Grade	B+
Designations	NGC 6913

Historical Observations

July 29, 1764 observation by Charles Messier

“In the night of July 29 to 30, 1764, I have discovered a cluster of six or seven very small stars which are below Gamma Cygni, & which one sees with an ordinary [non-achromatic] refractor of 3 feet & a half.” ¹

April 6, 1783 observation by Caroline Herschel

“About 1 deg under Gamma Cygni; in my telescope 5 small stars thus [diagram]. My Brother looked at them with the 7 ft and counted 12.” ¹

Sources

Photo at top of page by “Jschulman555” is approved by the author under the Creative Commons Attribution-Share Alike 4.0 International license.

¹ Guy McArthur, Hartmut Frommert. Messier 29, https://www.messier.seds.org/Mdes/dm029.html.