[Aavso-photometry] M67 Finder Chart

[Arne Henden]

On Mon, Jan 19, 2009 at 11:47 PM, Bill Perkins
<billperkins at birdlandobservatory.net> wrote:
> Barbara,
>
> FYI,
>
> 4 of the 64 stars in the list of stars that Arne has generously made
> available to others prior to publication at
>
> http://binaries.boulder.swri.edu/binaries/fields/m67.html
>
> are variable stars (which takes nothing away from the measurements made at
> the time).
>
> Star 26 is EW Cnc
> Star 35 is HW Cnc
> Star 49 is Hv Cnc
> Star 55 is EV Cnc
>
> I found this by using VSP to find the M67 star field. There are other
> variable stars in this field, but no others that coincide with the
> measurements mentioned above. Good luck with your examination of this rich
> star field.
>
Actually, you missed EX Cnc also.  Several of the stars are suspected variables,
though their mean error doesn't indicate any large variability.  I've had Dirk
Terrell update the table on the SwRI site to include additional nights
of calibration,
plus a column of cross-identification.  To be safe, even though the
errors are small,
you should probably avoid any star with a GCVS or NSV designation.  This list
covers all stars brighter than V=13 in my 11x11arcmin field of view with the
USNO 1.0m telescope, except for 3 stars where the formal error is considerably
larger (probable variable or else contamination from a nearby neighbor).
I have additional calibration down to V=25 or so that will get published one
of these days.
Arne