Sun, 09/20/2020 - 11:38
this Nova has a a lot of AAVSO observer dara. Up to day 4,489 data points from 80 observers if I counted correctly. There is a kind of oscillation with 8 days period visible.
The Nova was detected end of July, therefore data now cover a period of approx. 50 days.
Based on the classificationschem from Strope, Shaefer, Henden (Tehe Astronomical Journal, 140:34-62, 2010) this could fit into several classes like J, O., but I find it difficult to decide. For O calss, the oscillations start early and for J they seem to be too regular.
Any ideas? Does anyone know more about the origin of those oscillations? Repeating thermonuclear events of pulsation driven or...?
Brightness of V1391 Cas has been declining drastically over the last week. The Nova is developping to a D Nova according to the classification of Strope, Schaefer and Henden (2010). I estimate the nova to be approx. 4 kpc away.
A cloud of dust is probably building up and apparent brightness decreases. Due to the clouds expansion it should brighten again.
It is very similar to the bright Nova V5668 Sgr (see comparison attached, 1d binned AAVSO data).
As the Nova is fading, the number of observations goes down significantly. I probably will also not be able to continue my observations due to eqipment boundaries.
Therefore to all: Please take measurements to see if the Nova brightens up again in a few days/weeks as ususal for D novae or not.