IFN between NGC3403 and NGC3147 in Draco

[gorann]

For my two RASAs this is IFN season. IFN (Integrated Flux Nebulosity) is thought to be dust at the outskirts of our galaxy energized by the collective radiation of the galaxy. I do find that there seem to be a variety of IFN when it comes to colour and structure. Here is an image with quite a lot of galaxies behind the IFN and the second image shows an annotation of them.

Data collected over two nights 1 - 2 April with a RASA 8 and ASI2600MC (no filter, gain 100) on an iOptron CEM70. 68 x 5 min, so 5.7 hours.

Processed in PI and PS. Annotated in PI.

I have recently had quite a lot of messages from other RASA users aiming at IFN under more light polluted skies. Hunting IFN is a very rewarding activity under dark skies, and I have a quite dark site. SQM was around 21.6 these nights, so Bortle 2. Sadly, with more light pollution, like at Bortle 4-5, many times longer integration times will be needed get an S/N ratio good enough to get a decent IFN image. @wimvbtells me that for every unit decrease in SQM, 2.5 times more integration time is needed, so at SQM 20.6 (Bortle 4.5), you would need 14 hours and at SQM 19.6 (Bortle 5) your will need 30 hours.

[petevasey]

Well done, Göran.  As I said to Paul Clark, not an easy target, and on my 'Must do' list.  Thanks for sharing - it must have taken you ages to do the annotations!

Cheers,

Peter

[gorann]

Thanks a lot Peter! PI did the annotations in 1 minute😉