Castor in Profile

 

Low resolution line profile of the A1V class star Castor in the constellation Gemini taken with the Observatory's new spectrometer. The line profile has been produced using RSpec software and has been adjusted to compensate for the camera response across the wavelengths shown.

The 3d printed cell holding the 500lines/mm transmission grating can be seen sandwiched between the camera and the camera nosepiece .

The 3d printed cell and friction washer.

“During the Covid lockdown, the Jodrell Plank Observatory Instrumentation Engineer, Jolene McSquint-Fleming, has been ‘beavering away’ converting a QHY5L-ii mono video camera for use as a low resolution 'slit-less' spectrometer for attachment to a number of telescopes.

The newly commissioned 3d printer was used to create a cell for the holographic printed film transmission grating and this was mounted between the camera and the nosepiece to ensure the zero and first order spectra would fit upon the imaging chip.

Once the spectrometer was completed, it was tested on the Observatory’s Altair Lightwave 66mm refractor at f=400mm andF6.

The star Castor was selected as a target because it is relatively bright, is currently high in the sky and is a class A1V star with strong Hydrogen Balmer lines in its spectrum.

Our outreach coordinator, Karl Seguine, has been asked to assume Observatory responsibility for obtaining and processing spectra. To this purpose he is currently evaluating three data reduction softwares – Rspec, VSpec and ISIS.

Our first spectra obtained using the new spectrometer , The Castor profile, was produced by Karl using RSpec.  One small step for man.........” - Kurt Thrust current Director of the Jodrell Plank Observatory.