Rcw 104

[Placidus (Mike and Trish)]

A seriously faint (mag 18, surface brightness 24/sq arcmin) Wolf-Rayet nebula in Norma.

It is easy enough in H-alpha, in which at 5 hrs we see a pretty clam-shell structure. In OIII, it is very difficult to see anything at all against the billions of milky way stars, but after 10 hours, we see a much smaller ring-like structure. We were unable to convince ourselves that there was any meaningful SII, which would fit with it being a WR rather than and SNR.

Here we've mapped H-alpha (from 2015) to orange, and OIII (from the last several nights) to teal-blue.

There are so many stars, and so bright compared with the nebula, that it was unfruitful trying to do anything with the stars other than leave them as-is.

Large version here (slightly cropped).


You can see the structure better in the single channel monochrome images. The 5 hrs of H-alpha is here, and the 10 hrs of OIII is here.


Aspen CG16M on 20inch PlaneWave on MI-750 mount. H-alpha 5 x 1hr subs. OIII 10 x 1hr subs. -30C. Moon averaging about 50% illuminated.

Although difficult, we think it is a very pretty example of a WR nebula, and worth trying to see the structure against the starry background.

Cheers,
MnT

[gregbradley]

Its a shame its a dim target as it has some nice structure to it.

Greg.

[topheart]

Hi M+T,

A very interesting image!
Thanks.
well done!
Cheers,
Tim

[Stevec35 (Steve)]

Still looks pretty good to me M&T

Cheers

Steve

[Atmos (Colin)]

Quite faint WR but you’ve shown in nicely.
That’s the problem with faint targets and stars, they get dragged up and look messy compared to the brighter nebula.

[RickS (Rick)]

That's a subtle and tricky target, M&T! Well done I'd be interested to see the Oiii and Ha in isolation if you have the time and inclination.

Cheers,
Rick.

[strongmanmike (Michael)]

Very cool, faint!..but cool, interesting structure too...I'm guessing by the colours Mike processed this one..?

Mike

[Placidus (Mike and Trish)]

Greg. Steve. Tim, Colin, Rick, Mike,

Many thanks for your comments insights and encouragements.

Rick, the 5 hrs of H-alpha is here, and the 10 hrs of OIII is here. I think you can see the structural differences more clearly by blinking between the two.

Very best,
Mike

[Geoff45 (Geoff)]

Nice delicate object Mike and Trish. No need to go after the flashy stuff when there are all these challenging objects. Very well processed.

[RickS (Rick)]

Originally Posted by Placidus

Rick, the 5 hrs of H-alpha is here, and the 10 hrs of OIII is here. I think you can see the structural differences more clearly by blinking between the two.

Thanks, Mike. Very interesting to blink between them and see how they fit together

[Ryderscope (Rodney)]

A great project and resulting image MnT. Nice work to bring out the detail in such a faint object.

[Placidus (Mike and Trish)]

Geoff, Rick, Rodney,

Thanks muchly, and glad you like it.

Best,
MnT

[atalas]

That object is so cool guys....wonderful structure bubble like

[Paul Haese]

That's a tough target and you made good use of those 20"s. I reckon I would need to do at least 30 hours of more with the Newtonian to come close to what you have here and maybe nearly 50 hours with the RC.

[Placidus (Mike and Trish)]

Originally Posted by atalas

That object is so cool guys....wonderful structure bubble like

Thanks Louie. The OIII bubble looks a bit like an eyeball in cross section.

Originally Posted by Paul Haese

That's a tough target and you made good use of those 20"s. I reckon I would need to do at least 30 hours of more with the Newtonian to come close to what you have here and maybe nearly 50 hours with the RC.

Thanks Paul. As well as aperture and time, what it perhaps really needs is an observatory somewhere very high and dry like the Atacama, so that the stars would be 40,000 unobtrusive pin-points instead of 40,000 great big blurry beacons blocking the view.

Cheers,
MnT