7 Panel Narrowband Mosaic of this Massive Nebula!

7 panel Mosaic of Eta Carina Nebula in Narrowband.
a few numbers…
1 Massive Nebula
2 Telescopes
3 Attempts to get this right
4 Months data collection
5 Days processing
6 Filters
7 Apps
8 Gb file
15min subs
16 Gig of Ram barely copes
250 + NB subs
270 RGB subs
42 Data sets
80+ hrs data
188,000+ stars
several dozen drinks!

My most ambitious project to date – NGC 3372 – Eta Carina in Narrowband with RGB stars.
Taken in it’s entirety to give context of where it begins & ends in space.
This project began six months ago when I thought it would be pretty cool to get the whole nebula. Three attempts later, it ultimately it took 6 panels to get it all in frame, very tricky object to balance and compose with assymetric elements – Gabrielle Mistral/gem cluster at one end and the smoking man at the other, so I’ve kept the core pretty close to the centre so the other bits can radiate outwards.
I also wanted more resolution in the core, so I brought out my William Optics FLT 110 to get more detail there.
Took forever to get all the data, and Melbourne’s inclement weather didn’t co-operate often so some were taken under a full moon, resulting in a trip to gradient city with the RGB & O3!
Totally a processing challenge, but perseverance and sheer force of will kept me going though, not sure I’d recommend attempting this for the feint hearted.
Registar is incredible, worth every penny of the US$250 odd I paid – it registered over 188,000 stars! Gob smakkingly clever software.
Photoshop photo merge worked well with these registered files to build the mosaic.
I’ve used a different technique here to overlay RGB stars over the NB ones. Basically removing the colour from them & shrinking them a bit, then overlaying the RGB.
There are way too many (did I mention Registar counted over 188,000?) to use star removal technique on this image.
I made a lot of mistakes along the way, and kept going back and re-doing elements and processes, learned a great deal about what to do and not to do for next time. Time to move on at last!
For what it’s worth, I’d like to thank the following astrophotographers –  Bert for inspiration, Marc for his forum tips on mosaics, and Mike, M&T & Fred for constructive criticism on the journey.

Silver Award (with Distinction) 2017 AIPP Australian Professional Photography Awards 

NGC 3372 Carina Nebula mosaic in Narrowband
NGC 3372 Carina Nebula mosaic in Narrowband

Capture Details

TelescopeStellarvue SV70T
CameraQSI 683 WSG8
MountSkywatcher EQ6 Pro
FiltersAstrodon 3nm Ha, O3, S2 &RGB
Guiding CameraStarlight Xpress Lodestar X2
Integration time (Exposure)80+ Hrs
LocationBurwood, Melbourne, Victoria, Australia
DateJan - Mar 2018

About this Nebula

A jewel of the southern sky, the Great Carina Nebula, also known as NGC 3372, spans over 300 light-years, one of our galaxy’s largest star forming regions. Like the smaller, more northerly Great Orion Nebula, the Carina Nebula is easily visible to the unaided eye, though at a distance of 7,500 light-years it is some 5 times farther away. This gorgeous telescopic close-up reveals remarkable details of the region’s central glowing filaments of interstellar gas and obscuring cosmic dust clouds. The field of view is over 50 light-years across. The Carina Nebula is home to young, extremely massive stars, including the stars of open cluster Trumpler 14  and the still enigmatic variable Eta Carinae, a star with well over 100 times the mass of the Sun. Eta Carinae is the brightest star, centered here just below the dusty Keyhole Nebula (NGC 3324). While Eta Carinae itself maybe on the verge of a supernova explosion, X-ray images indicate that the Great Carina Nebula has been a veritable supernova factory.
(from APOD)

“The heart of a star is a furnace. Not much unlike the human heart.”

- C. JoyBell C.