Tuesday, November 10, 2015

NGC 6210 in NII-OIII: Can superturtles fly?

Here's NGC 6210, the turtle nebula in hercules:
This fairly sharp RGB-OIII image from 2007 shows at least two pairs of jets or ansae (wings).  they appear to be curving slightly, perhaps due to rotation.  Wondering if the condensations in the longer pair of jets were red FLIERS, I decided to try a deeper image in nitrogen and oxygen (NII and OIII):

This NII-OIII image suggests that the upper condensation is a red flier while the lower is not, as the lower condensation is absent in the narrow band image, but present in RGB-OIII image and the luminance (below) --probably a superimposed star.

Here's a blink of luminance (broad band including all visible wavelengths), followed by a green continuum filter (no narrow band emissions), then a stretched NII image.  Which suggests that the upper condensation is an NII red flier, while the lower a broad band star.  Not sure why i'm picking up the central glow with the continuum filter.  reflection nebula? IR leak?
NGC 6210 Luminance-Continuum-NII

There is certainly a lower condensation in the OIII, almost looks like a smeared attempt at a red flier, also note the faint outer shell to the right:
NGC 6210 OIII stretched

The NII-OIII core may represent a letter in the krypton alphabet befitting our herculean superhero*:
NGC 6210 NII-OIII linear

*Terry Pratchett fans claim to see 4 elephants (link) on the turtle's back, particularly in NII

Lastly here's a collage showing various filter images:
top: NII, OIII, NII-OIII color; linear stretch
mid: NII, OIII, NII-OIII color; non-linear stretch
bottom: continuum, luminance, NII-continuum
Answering the initial question:
with 4 wings, but only one flier, the superturtle can fly, but slowly.
QED ;)

8" LX200R, SX Trius 694 0.4"/px
astrodon 3nm NII, 3nm OIII
NII 33x20 min, OIII 35x5,6x20 min, L 155x1 min, 545x50 79x2min

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