Tristram Brelstaff wrote in message ...
You might be interested in the following paper on the Double Cluster red
supergiants that I published in the Journal of the British Astronomical
Association a few years ago: snip

Great article. I really enjoyed it. I have always used Ptolemy's
Cluster M7 with the Double Cluster as contrasting examples of a near
cluster and two distant clusters in the summer sky. I did not realize
that the Double Cluster also contained examples of distant M
supergaints, that can be contrasted with near supergaint Anatares in
the summer sky or Mira in the autumn sky.

I have always been interested in putting together a tour list of
optical Perseus Arm tracers. The Humphreys 1970 article (ApJ 160:1149
6/1970), cited in your J. Br. Astron. Assoc. 106:5 1996 article gave
me another useful list of M supergaint tracers in Perseus Arm OB
Assocations.

Do you have any recommendations for any articles provided such a list.
I have been working with the list of optical spiral arm tracers in
Table I of Kimeswenger, An Optical Spiral Arm Beyond the Perseus arm,
Astron. Astrophys. 209:51 (1989).

Regards, Kurt