A frustrating night. NGC 7662 and M76

[callump]

Last night (2020-09-17) was not too bad a sky for me (SQM 20.3), but it was a rather frustrating session. Telescope alignment problems meant I had to re-do that mid-session. Some software problems. And then leaving the filter wheel on Blue for the last couple of objects.

First up here though, is NGC 7662 - the blue snowball planetary nebula - in fact it was really too bright! I tried this LRGB composite, which has a tinge of blue...
C11 on G11, f/6.3, ZWO ASI174MM mini
LRGB 2x30s each. 
Siril + Affinity Photo

M76 - this is just the Luminance frame - same equipment as above, 10 x 30s exposures. I tried a quick LRGB but the background noise was too horrible to make the image worth sharing. There is a star at the centre of the nebula, but I am not 100% sure if this is the central star, which is quoted at mag. 16.6.

 

 

Forecast for tonight is promising, so I hope I might be able to revisit last night list.

Callum

[andrew s]

No fun at all if it all works every night, honest 

Regards Andrew 

[Marvin Jenkins]

1 hour ago, callump said:

Last night (2020-09-17) was not too bad a sky for me (SQM 20.3), but it was a rather frustrating session. Telescope alignment problems meant I had to re-do that mid-session. Some software problems. And then leaving the filter wheel on Blue for the last couple of objects.

First up here though, is NGC 7662 - the blue snowball planetary nebula - in fact it was really too bright! I tried this LRGB composite, which has a tinge of blue...
C11 on G11, f/6.3, ZWO ASI174MM mini
LRGB 2x30s each. 
Siril + Affinity Photo

M76 - this is just the Luminance frame - same equipment as above, 10 x 30s exposures. I tried a quick LRGB but the background noise was too horrible to make the image worth sharing. There is a star at the centre of the nebula, but I am not 100% sure if this is the central star, which is quoted at mag. 16.6.

 

 

Forecast for tonight is promising, so I hope I might be able to revisit last night list.

Callum

If it’s in the centre then I am taking it as the central star😁In all seriousness it looks to be about as bright as the least bright stars in the background. Is there a way you could identify any of the background stars to compare 16.6 mag?

Marv

[Martin Meredith]

Hi Callum

Some of the planetary nebulae need very short exposures with our sensors. I visited this one recently (will post it in the PN thread at some point when I've found time to read up on it...) with 5s exposures and then found I needed to view it with almost no stretch.  I was quite surprised by the appearance: the lower-case 'omega' nebula! Orientated to match yours, this is 1m 20s total (4 x 5 seconds in each of LRGB).

 

BTW This is my overstretched version. Although LRGB is meant to separate luminosity and chromaticity, in practice I find that stretching the L washes out the colour and I suspect that is why you are only getting a tinge of blue.

cheers

Martin

 

Edited September 18, 2020 by Martin Meredith

[Monty]

4 hours ago, callump said:

Last night (2020-09-17) was not too bad a sky for me (SQM 20.3), but it was a rather frustrating session. Telescope alignment problems meant I had to re-do that mid-session. Some software problems. And then leaving the filter wheel on Blue for the last couple of objects.

First up here though, is NGC 7662 - the blue snowball planetary nebula - in fact it was really too bright! I tried this LRGB composite, which has a tinge of blue...
C11 on G11, f/6.3, ZWO ASI174MM mini
LRGB 2x30s each. 
Siril + Affinity Photo

This is your pic processed using Topaz DeNoiseAI to give you an idea of options.

Edited September 18, 2020 by Monty

[callump]

17 hours ago, Monty said:

This is your pic processed using Topaz DeNoiseAI to give you an idea of options.

Thanks for this - i'll have a look!

Callum