Hi David,

Another nice spectrum. I say in my talks on spectroscopy that it is the opposite of supermarket economics; you get one star for the price of two! A good way to calibrate with the Star Analyser is to capture the spectrum of a nearby A- or B-type reference star, ideally no more than +/- 5 deg dec from the target. The strong Balmer lines can then be used to calibrate the target spectrum and the shape of the reference can be used to correct the target spectrum for instrument response and atmospheric effects. It’s invaluable 

cheers

hugh

The advice is always appreciated. My RSpec trial ended recently, and I’m battling with the free software and accompanying example files the mo. This workflow you describe seems a good plan for when I resume taking spectra.

For several years now Matt Armitage has asked if I would do spectroscopy as part of his Astrophotography Courses series. The link is here http://astrophotographycourses.co.uk/courselist.html Matt does make a charge and the courses are based at his boat yard in Banbury - not sure if either the cost or location are attractive to you, but it is an opportunity to climb much more quickly the learning curve. For example I cover both RSpec and BASS software for data reduction. Anyway I'm always happy to offer advice at any time

Cheers

Hugh