spectra of extragalactic novae

[robin_astro]

For a few years now I have been using a modified ALPY spectrograph to confirm and classify supernovae spectroscopically

http://www.threehillsobservatory.co.uk/astro/spectroscopy_20.htm

but over the past year I have also been trying my hand at novae in M31. The brightest are typically around mag 16 so similar to the supernovae I have been measuring but because the lines are narrower (due to the lower velocities involved) they need higher resolution to resolve them well so I have been using the ALPY 600 spectrograph in its standard configuration. They turned out to be tough targets for the standard ALPY and the “light pollution” from the galaxy itself does not help so the spectra are very noisy. It is just possible to though pick out the relevant features and as far as I am aware, these may be the only spectra of M31 novae taken using amateur equipment.

Cheers

Robin

[andrew s]

Impressive as always Robin.

Regards Andrew 

[Owmuchonomy]

That is great work Robin.  Must be some feat to pick individual stars out of the noise.

[robin_astro]

Thanks Andrew,Chris,

The latest one 19qcg was particularly marginal being so near the core and in bright moonlight.  Here is the image off the spectrograph guider (20x10s). ( I guided using the brighter star to the right of the core, calculating the offset needed to place the nova on the slit) and the raw unprocessed spectrum (16x10min).  The nova spectrum is the thin line above the overexposed galaxy core. The background spectrum is a combination of galaxy, moonlight, air glow and light pollution