sn2104AS at mag ~16.5 with ALPY 200

[Robin Leadbeater]

This supernova was discovered by amateur Dave Grennan. Attached is my spectrum with the ALPY 200 (At mag ~16.5 This is a new record brightness for me)
More information, the reduced spectrum and classification on my website here
http://www.threehillsobservatory.co.uk/ ... tra_44.htm

Cheers
Robin

[SteveCuthbert]

Nice catch Robin !
Did you find out what those two horizontal dark lines were?
Steve

[Robin Leadbeater]

Nice catch Robin !
Did you find out what those two horizontal dark lines were?
Steve

Thanks Steve,

They are just the outer limits of the sky background subtraction regions. ISIS displays them a guidelines even if as in this case the background was not subtracted. You can see here that (as requested) ISIS has cleared up all the transient hot pixels in the region between the two limits.

I was interested in an estimate of the SNR in the resulting spectrum so I measured the variability between spectra produced from the individual exposures. The SNR works out at ~30 (in a ~25A bin size) for the combined exposures compared with a theoretical value of ~45 based on the counts. Not too bad considering the deterioration in SNR that must inevitably take place subtracting the large background.

Cheers
Robin

[Paolo Berardi]

That's a great result, congratulation Robin! Also to Dave that discovered the SN.

Yesterday another mag 16.5 PSN (in NGC6240) entered in TOCP. No follow-up now.

http://www.cbat.eps.harvard.edu/unconf/ ... 23367.html

You could try to observe it (I saw that present weather in UK seems not collaborative...).

Paolo