Fetus Nebula (NGC7008)

[alan4908]

NGC7008 is a planetary nebula located in Cygnus about 2800 light years distant and about 1 light year in size. The amateur astronomer Eric Honeycut named it the Fetus Nebula when he viewed it through his 22inch reflector. 

Planetary Nebula are one of the few astronomical objects that may appear green, so when processing this particular object you have to be careful when eliminating green from your image (eg SNCR green in PI)  otherwise it will significantly change the colour balance of the object.  

Since it is so small and there's not much of interest in the background, I decided to crop it quite aggressively, so that a few details of the nebula can be seen more easily.

So, here's an LRGB image consisting of 13 hours integration which was taken with my Esprit 150.

Alan

 

LIGHTS: L:26, R:17, G:17, B:18 x 600s, DARKS:30, BIAS:100, FLATS:40 all at -20C. 

[MarkAR]

Superb image, looks like a few bubbles joined together.

[alan4908]

On 29/05/2020 at 11:38, MarkAR said:

Superb image, looks like a few bubbles joined together.

Thanks - yes, it does look a little bubbly   - I think acquiring some narrow band data would help capture a few more details.

Alan

[DaveS]

I think it will really come alive in NB.

[alan4908]

25 minutes ago, DaveS said:

I think it will really come alive in NB.

Thanks Dave.

Have you seen any good hi-resolution NB images which would point me in the direction of which filters to use for the acquisition. I'm currently guessing Ha and OIII. 

Alan

[MarkAR]

42 minutes ago, alan4908 said:

I'm currently guessing Ha and OIII. 

Alan

They will get you the most data.

[DaveS]

1 hour ago, alan4908 said:

Thanks Dave.

Have you seen any good hi-resolution NB images which would point me in the direction of which filters to use for the acquisition. I'm currently guessing Ha and OIII. 

Alan

HII and [OIII] definitely, plus [SII] for a Hubble Palette perhaps. The other good filter for PN is [NII] but is only available from Astrodon at silly money, and needs a 3nm HII for separation.

[alan4908]

7 minutes ago, DaveS said:

HII and [OIII] definitely, plus [SII] for a Hubble Palette perhaps. The other good filter for PN is [NII] but is only available from Astrodon at silly money, and needs a 3nm HII for separation.

Thanks - I'm not at all keen on the Hubble Palette, so I think I shall have a go with just Ha and OIII. 

 I do already have an Astrodon 3nm Ha filter  but I don't think I can justify further spending on a NII filter. 

Alan

[DaveS]

Agreed, unless you are a PN specialist I have found my [NII] top be of questionable utility. Will give it an outing on M27 though, as it has a strong [NII] signal.