A spectrum of NEOWISE tail

[robin_astro]

Here is an emission line spectrum taken from the tail of C2020 F3 (NEOWISE), compared with that of the inner coma. It was taken with an ALPY600 and the intensity in the spectrum is only ~1% of that in the coma. 

It is very different from the spectrum of the coma that you usually see. The C2 Swan bands are absent and are replaced by a series of double lines from CO+  which give the ion tail its blue colour

Cheers

Robin

[andrew s]

Excellent spectra Robin, nice to see a comparison of the coma and tail.

Fine work as always.

Regards Andrew 

[Bajastro]

Great result, Robin. Which telescope did you use?

[Macavity]

Fantastic stuff! Personally a bit of Chemistry revision helped a bit... 😛
https://en.wikipedia.org/wiki/Swan_band



Spectroscopy (a bit more "terrestrial"?) was a sometime... interest. 😏

Edited July 20, 2020 by Macavity

[robin_astro]

On 20/07/2020 at 13:14, Bajastro said:

Great result, Robin. Which telescope did you use?

This  was with the ALPY 600 on the Celestron C11 (same as here but the science camera is now an ATIK 428)

The ATK 314 there is now used on the LHIRES III so I can swap the instruments over complete with cameras in a few minutes

[markse68]

Silly question but why do you have a light bulb fitted to the end of the scope Robin? is it for calibration? 

[robin_astro]

11 hours ago, markse68 said:

Silly question but why do you have a light bulb fitted to the end of the scope Robin? is it for calibration? 

Ha-Ha yes it does look silly 🙂    It is a "filly dot" decorative gas discharge lamp from Habitat, famous among amateur spectroscopists looking for calibration sources  

http://astrosurf.com/buil/calibration/lamp1.htm

I don't often use it now as the spectrographs now have internal lamps (Richard Walker discovered that fluorescent lamp starters also worked so could be built into spectrographs, more amateur resourcefulness ! )

It is still useful for superimposing  lines directly on the measured spectrum for very high precision wavelength calibration though as here for example  (at 18min 35 sec)

https://britastro.org/video/13862/14769

[markse68]

Thanks for the links Robin- I started watching the second and will definitely finish watching later when i have time- looks fascinating