Greg's post of yesterday about the nova in Centaurus promoted me to go back to my own data.
Inspired by Rolf, I tried to collect data in late December and early January. As it was then an early morning target, I was hampered by some dew issues I had with the STX 16803. A few months back Peter Ward did a great job of cleaning up my sensor and removing accumulated moisture in the chamber (thanks Peter). However, I found that in high humidity moisture would accumulate on the outside of he chamber - it would suddenly appear on my images early in the morning seemingly out of nowhere. The diagnosis was that the window heater worked fine for most of the evening until a critical air saturation level was reached and - Blam! - all the moisture would condense at once leaving a nasty blotch on the images. You can see the remnants of it left of centre on the attached images.
In case anyone has this issue - I solved it by wrapping a dew heater around the camera body. I've only had the issue once since early January - when taking sky flats in the early morning of a very dewey night.
Anyway....I managed some date on 31 December and then a bit more on 13 and 14 January. The brightness of the nova had diminished over the intervening period and the Ha emission lines that were so prominent early - which I think gave Rolf his image that beautiful rosy hue - had faded by the time I took the January data. So my image is plain by comparison.
I have been working through Warren Keller's excellent PI tutorials and playing with this data to trial a few new techniques. So I have 3 alternate images for this nova. With the golden image I used a manual Histogram Transformation stretch which I did by eye while for the other 2 I used a STF stretch which I applied to the Histogram Transformation.
To be honest, I'm not sure which one I prefer. Each time I play with the saturation, the colour gradients in the background stand out like the proverbial dogs b----s. There is also an ongoing battle with an overall green colour cast.
Here is a link to the second image -
http://www.pbase.com/equitius/image/154501032
Image details - R (81 mins), G and B (54 mins) in 3 minute subs. Taken from light polluted Sydney with a PW CDK 12.5 and STX 16803.
Pete