M57 photometry data
Dataset used is done by Arne Henden available here

Image taken 7/10/2002
LX200 10 inch F10 @ F3
ToUCam Pro SC1.5
Please note: this is very preliminary and does not account for
stated magnitude errors in Mr Henden's dataset.
I loaded it into Excel:
-Threw out all stars brighter than mag 14.83
-then picked only B-V from .791 to .90 (roughly 0.1mag)
-then picked only V-R from 0.40 to 0.499 (roughly 0.1mag)
Result was 106 stars from mag 14.84 to 20.18 in a 10arcmin/sq field

Target very near zenith position.
18x75sec exposures
cam temp -11C
No darks or flats applied, no guiding used.
There were a few residual hot pixels that show up as linear 'chains'
in the image caused by lx200 long term RA drift after PEC training.

Kudo's to:

NOAO Image Library for M57
Used with permission from NOAO/AURA Image Library
The original image was adapted from one created by N.A.Sharp, REU program/NOAO/AURA/NSF.
The 1229x1024 image from link above was annotated

Photometry data by Arne Henden
Data used with permission from Mr Henden
Original dataset:

The following is a prelimiary annotation of a subset of Mr Henden's data.
As of this date July 19, 2002, it has not been verified for accuracy
and there is no implied use of the annotated image other than as
an annotated image :)
This is meant to be a work in progress that can change at any time.

Data Subset used with identifiers