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Observation by Hugh Allen: Spectra of the bright stars of Cassiope...

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Hugh Allen


Hugh Allen


2018 Feb 11 - 20:30


2018 Mar 11 - 13:44



  • 8" Meade LX90 at f6.3
  • Alpy 600 spectroscope
  • Ati 314L mono camera
  • Spectra processed in BASS software

Oakhill Somerset

Target name

Bright stars of Cassiopeia


Spectra of the bright stars of Cassiopeia

About this image

Over the last few months I have been spending much of my spectroscopic observing time following the eclipse of VV Cep. This night  I decided to relax with a little project on the contrasting spectra of the bright stars of Cassiopeia. They include the famous gamma Cassiopeiae whose spectrum shows intensely bright hydrogen Balmer emission lines first observed by Angelo Secchi, one of the 19th century pioneers of astronomical spectroscopy. The other stars wonderfully illustrate how photospheric temperature affects the shape of the spectrum and the expression of elemental absorption lines, ranging from 18,000 Kelvin (spectral type B3) down to 5,200 Kelvin (spectral type K0). Cassiopeia is a beautiful constellation both visually and spectroscopically.

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