Am I correct in assuming that spectroscopic coverage of del Sco, at least
by amateurs, is minimal or non-existent from the southern hemisphere? As I'm
located in southern Australia (Melbourne) I am very fortunate to have it
nearly overhead (at 21.00 currently) , so imaging it is easy. Although I am
presently limited to using my Lhires III with only a C8 from close to the
centre of a big city (my C14 is mothballed until my rural observatory is
rebuilt next year) this should not be a major problem due to del Sco's
Having read the literature by Miroshnichenko and Ernst Pollman with
interest, and seen the extensive BeSS spectral data coverage, I would like
to join in the effort to get good spectral coverage during the upcoming
A few questions regarding coverage:
a) I can use 2400, 1800 or 1200 gratings but have installed the 1800 grating
as it will allow simultaneous coverage of both Ha and HeI. Am I better using
the 2400 (higher resolution) with separate runs on the Ha and HeI or is the
lower resolution single run a better approach?
b) Should I also obtain BVRI data, or is that well covered elsewhere?
c) I doubt I can achieve SNR of 400, as mentioned by Ernst, due to my small
scope, so what would the acceptable lowest SNR be?
I did try for an Ha spectra a couple of nights ago (clear nights not very
frequent at the moment, being mid-winter down here) but found that my
spectral camera (an Audine) was suffering from CCD icing :( I have now
switched cameras (to a DSI III Pro) and am ready to go again on the next