The α Cam Campaign

Observations of our Campaign

Eight amateur spectroscopist delivered spectra to this campaign. The reduced spectra are mostly stored in the BAA database. Some were sent directly to me. A mixed bag of equipment was used. Two different echelles, one Star'Ex long slit spectrograph, some Lhires3 and an objective grating spectrograph.

Observations started on Sept. 11 in 2022 and were interrupted by continous cloudy nights in December 2022. A very busy observer delivered up to 18 spectra a night! A calendar shows the distribution of observations during campaign.

Calendar of the campaign
Each dot represents an observation. Observations less than 6 hours apart are stacked.
Preliminary Work

Most of the spectra were reduced by the observers themselves using their own naming conventions. First of all, all files were renamed according to a uniform scheme.

alfCam_YYYYMMTThhmmss_XX.fits with XX or XXX as a mnemonic of the observer.

The headers were also harmonised to describe the geo location, exposure time and observing time and the name of the object. With the help of astropy the headers VHEL, VBARY and ZA, for zenith angle and BUNIT were added. The Fits Standard 4.0 introduced the new keyword SPECSYS to define the origin of the spectral axis, i.e. TOPOCENTRIC, at the telescope, BARYCENTRIC, at the barycenter of the solar system or SOURCE, if even the doppler shift due to the radial velocity the object is removed from the spectral axis.

The Spectra

We have

  • 113 echelle spectra that cover a large wavelength region
  • 93 long slit spectra with Hα and HeI6678
  • 26 long slit spectra with Hα alone.
The resolutions range from 8000 to 15000.

The lines of interest are Balmer lines and HeI and HeII. All this lines are variable. But most of all Hα. We therefore start with Hα.

Last modified: 2023 Jun 04