AT 2019vww - an amateur international discovery

[robin_astro]

I thought I would share the discovery of this dwarf nova as nice example of  international amateur cooperation

On 2019-11-30 Simone Leonini ,  a member of the amateur Italian Supernova Search Project,  http://italiansupernovae.org/ discovered a supernova candidate at mag 16.5 close to the galaxy UGC11775 in Cygnus. This was posted on the IAU Transient Name Server, the official site used by both amateurs and professionals for posting possible supernova discoveries. https://wis-tns.weizmann.ac.il/object/2019vww

I monitor  TNS as I can potentially confirm supernovae spectroscopically provided they are bright enough using a specially modified ALPY spectrograph  http://www.threehillsobservatory.co.uk/astro/spectroscopy_20.htm .  I recorded a spectrum of the object, designated AT 2019vww the following evening. The spectrum (seen on the TNS site) showed clear hydrogen alpha emission but the red shift was zero rather than the expected 0.016 for the nearby galaxy so likely to be a Cataclysmic Variable (a nova or dwarf nova) in our galaxy, though the signal/noise in the spectrum of this faint object and the resolution of my instrument, designed specifically for supernovae was not sufficient to determine the exact nature.

An Astronomical Telegram was issued on 2019-12-11 announcing the discovery. http://www.astronomerstelegram.org/?read=13345

The centre for Backyard Astronomy  are an international group of amateurs who observe CV outbursts using high cadence, high precision photometry.  Tonny Vanmunster, based in Belgium is a member of CBA and author of Peranso software used to analyse these variations. http://www.cbabelgium.com/   He observed AT 2019vww over several nights and has announced the discovery of superhumps,  short period regular variations in brightness, confirming it as a new SU  UMa type dwarf nova. 

http://ooruri.kusastro.kyoto-u.ac.jp/mailarchive/vsnet-alert/23781

Monitoring of  AT 2019vww continues and it has  been added to VSX, the AAVSO database of variable stars https://www.aavso.org/vsx/index.php?view=detail.top&oid=1499962

Robin