[vsnet-campaign-be 246] Re: [amateur_spectroscopy] FWHM of Del Sco H Alpha Line

[DWest61506@aol.com]

In a message dated 7/12/2003 9:11:32 AM Central Daylight Time, lolife@bitstream.net writes:


> How about focus? The group I work with at the UofM measures what they 
> call equivalent width, which is the width of the feature if it was 
> squared into a rectangle. This makes focus a non-issue, or so I'm told.
>
> This would be an interesting result.


Michael:
I take into account focus into my FWHM calculations.  I first measure the instrumental FWHM using a neon lamp.  Without changing anything, I then record the spectra of the stars.  I can subtract out (using squares) the instrumental FWHM which only leaves the component from the H alpha emission.
Regards,
Doug