NGC 6910

Observation Notes:

This is the first deep sky observation I’ve made from my home in a long time. I feel a debt to my observations and sketches to give deep sky objects the darkest sky I can find. But I’m finding fewer and fewer opportunities to pack up and drive to a dark site to observe these days (as if you hadn’t already noticed ;). So I bought some materials (PVC pipe, connectors, tarps and bungie cords) to assemble a temporary light shield in my front yard so I can get back to observing non-challenge DSOs from home again. With the glaring industrial lights blocked, I examined the star field around M57 and was able to get down to magnitude 14.1. Not bad I guess–that’s Pluto territory. Anyway, this is where NGC 6910 comes in. It’s my first sketched observation using the new light shield set up.

At low power, this open cluster makes a beautiful pair with Sadr’s brilliant orange light. A magnification of 120X however, shows off more stars within the cluster itself. The body of this stellar family is guarded by two bright stars–a yellow beacon to the southeast and an orange-yellow sentinel to the northwest. I estimate the diameter of the cluster to be about 5.5 arc minutes. I plotted 23 stars within the general boundaries of the cluster, adding to a total of 68 stars in the overall view.

I thought I was picking up a glow across the arc of the cluster’s core, especially around the bright southeast star. I don’t know if that glow came from unresolved stars, or if I was experiencing reflections in the eyepiece. I tried the ultrablock filter to see if the emission nebula was showing up, and the glow still seemed to be there, but I still can’t be sure if it was my cheap 10 mm Plössl playing games with me. I really need a better 10 mm EP.

Object Information:

NGC 6910 was discovered by F.W. Herschel in 1786. It is also catalogued as Cr 420, Lund 950, OCL 181, H VIII-56, h 2077, GC 4575.

Subject NGC 6910
Classification Open Cluster (I 3 m n)
Position Cygnus [RA: 20:23:12 / Dec: +40:46:43]*
Size* 7′
Brightness* 7.4 vMag
Date/Time August 12, 2007 – 01:00 AM MST (August 12, 2007 – 08:00 UT)
Observing Loc. Flagstaff, AZ – Home
Instrument Orion SVP 6LT Reflector (150 mm dia./1200 mm F/L)
Eyepieces/Mag. 10 mm Sirius Plössl (120X)
Conditions Mostly clear, calm, some passing high clouds
Seeing 4/10 Pickering
Transparency ~ Mag 5.8 NELM

* Based on published data.

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