Possible supernova at2016gxp was discovered in NGC51 on 5th Oct by the US amateur POSS team at mag 18.6, too faint then even for the ALPY200. On 12th Oct I was alerted by the POSS team that it had brightened considerably and asked if i could get a confirming spectrum. I managed to grab a quick 10 min exposure spectrum though a gap in the clouds which, although noisy, was good enough to confirm it as type 1a
https://wis-tns.weizmann.ac.il/object/2016gxp.
A full moon and cloudy nights prevented me trying again until 23rd when I was surprised to find it further increased in brightness to around mag 15 so I swapped the ALPY from the 200 to the standard 600 grism. This latest spectrum (2 hour exposure) confirms it as 1a, probably a peculiar superluminous type as suggested by the NUTS team in ATel 9645
http://www.astronomerstelegram.org/?read=9645
The plot below shows my ALPY 600 spectrum of sn2016gxp (black) overlaid on a spectrum of sn2007if (red) 5 days post maximum from the SNID library.
![](https://britastro.org/wp-content/uploads/2016/10/sn2016gxp_20161023_824_SNID_small.png)
ngc51 is well placed high in the sky at the moment, making sn2016gxp an interesting target for anyone interested in testing the limiting magnitude of their low resolution spectrograph
Robin