PNs with narrowband filters

[Steve in Boulder]

[Note; I posted a similar report over at CN.  This report owes itself almost entirely to Jocular, so I thought I'd post it over on Jocular's home turf.  Please let me know if you like it, or if I should keep this stuff over on the other side of the pond!]

Jocular has increasingly excellent support for using filters with mono cameras.  I had my first extended session with version 0.6 last night and decided to concentrate on PNs.  They typically emit in H-alpha and OIII wavelengths, so narrowband filters are suitable, especially with a bright moon (though OIII is somewhat affected).   Jocular now can create a synthetic luminance (L) layer from narrowband (as well as RGB) data, so I decided to just take Ha and OIII subs, all 120 seconds.  They can be displayed in HOO palette, that is, Ha data mapped to red, and OIII data mapped to blue and green.   I posted an example with M27 in the Jocular EEVA Equipment thread.

My setup is a garden variety Celestron C8, with the stock 0.63x focal reducer, on a CEM40 equatorial mount.  I use a ZWO electronic filter wheel with ZWO LRGBSHO filters, a ZWO EAF, and a ZWO ASI533MM, this time running at gain 300, cooled to 5 degrees.  Guiding with a Williams Optics Uniguide (30 mm aperture, 120 mm focal length), ZWO ASI120MM mini, and PhD2.  (Yes, even the Uniguide is red to match all the ZWO stuff.)  NINA controls everything, including me sort of:  I used the NINA Sky Atlas to pick PNs above 40 degrees in altitude, at least 30 degrees from the moon, sorted in descending size.  I figured the larger the PN, the better chance of seeing some details.  

To start things off, here's an example with NGC 7008.  The first image is HOO palette, the second shows the strong OIII signal, and the third the weaker Ha signal.

[Steve in Boulder]

Here are the other NGC objects I viewed:

 

[Steve in Boulder]

Next, a set of Abell PNs, HOO view or Ha/mono view.

 

[Steve in Boulder]

Two more Abell PNs, in both HOO and Ha views:

[Steve in Boulder]

And a couple of oddballs, again in HOO and Ha views.

 

[Steve in Boulder]

Oops, that was the OIII view for Abell 71.  This is better:

 

 

[Mike JW]

Hi Steve,

No problem posting this side of the pond. Rather a fine set of captures and I like your idea of showing an object using different filters,  although I am not sure of the significance of the different filters in terms of what it reveals about the particular DSO. Martin/myself tried to set up quite a few threads to cover different DSOs, in an attempt to keep observations together. There is a thread for PNs - Planetary Nebulae EEVA style.  Also where possible it is good to add observational details, rather than simply post an image (hence my interest in your images with different filters). By adding observational details, facts, maybe links to research papers it then makes EEVA more worthwhile through the encouragement to observe, learn about the DSO - in contrast to posting an image and not making any observational comments.

I shall look forward to your next observations.

Cheers,

Mike

 

[Steve in Boulder]

3 minutes ago, Mike JW said:

Hi Steve,

No problem posting this side of the pond. Rather a fine set of captures and I like your idea of showing an object using different filters,  although I am not sure of the significance of the different filters in terms of what it reveals about the particular DSO. Martin/myself tried to set up quite a few threads to cover different DSOs, in an attempt to keep observations together. There is a thread for PNs - Planetary Nebulae EEVA style.  Also where possible it is good to add observational details, rather than simply post an image (hence my interest in your images with different filters). By adding observational details, facts, maybe links to research papers it then makes EEVA more worthwhile through the encouragement to observe, learn about the DSO - in contrast to posting an image and not making any observational comments.

I shall look forward to your next observations.

Cheers,

Mike

 

Thanks, Mike!  I’ll try to do better to adhere to that protocol when I post again.