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Observation by Kevin Gurney: Balmer line widths using an Alpy

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Kevin Gurney


Kevin Gurney


2018 Mar 18 - 12:00


2018 Mar 18 - 18:30

  • Celestron 8SE
  • Altair Astro RC10
  • Alpy 600
  • Atik 460EX
  • Celestron 0,63 FR, ASA 0.77FR

West Sheffield

Target name

Type A stars with variety of luminance classes


Balmer line widths using an Alpy

About this image

Stuck indoors with a snow storm, I was reading Richard Walkers Spectral Atlas for Amateurs. I came to the part about luminance classes (I thru V)  changing the line width in the Balmer series, and wondered if I could see this in my collection of Alpy 600 spectra. I trawled through it and found a set of A-type candidates (taken at various times). I think I can see the effect here....

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Hugh Allen
Hugh Allen, 2018 Apr 07 - 19:00 UTC

Hi Kevin,

This is really interesting. In particular eta Leo wonderfully shows the narrower lines in the low density supergiant class I, I shall have to look at some of my Alpy data as well. Would the H-beta line in eta Leo be expected to be weaker especially since it's an A0 star? Fascinating stuff



Kevin Gurney
Kevin Gurney, 2018 Aug 13 - 16:26 UTC

Hi Hugh

Apologies for delay - just seen your post..[Better late than never?!]

I think eta Leo is weaker - see plot B which is not auto-scaled...



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