Planewave CDK12.5 - AIS6200MM
A-P 1100 GTO AE, Antlia Pro 3nm NB & RGB filters
H,O: (2 x 45 x 360s exposures, Bin 2x2, Gain 200)
S: (1 x 45 x 420s exposures, Bin 2x2, Gain 200)
R,G,B: (3 x 33 x 180s exposures, Bin 2x2, Gain 100)
Total Integration Time = 19.2 hours

The Tadpoles are yet another stellar nursery, along the same lines as the Elephant Trunk, and Rosette nebula available in this gallery and elsewhere. In the middle of such nurseries, are generally found open star clusters of young stars that are actually composed of the nebular material itself. Once the stars form, however, they blow away remaining material through winds and radiation. This radiation is also adsorbed by the material, and then re-emitted in a colour (frequency) related to its composition, and finally captured approximately 20,000 years later by the camera.

Near the centre/bottom of the image you can see two "structures", resembling the namesake "Tadpoles". These are similar to the "Pillars of Creation" of Hubble/JWST fame found in the Eagle Nebula. The heads of the tadpoles are facing the stars formed by the young, hot star cluster, and are very bright due to the radiation hitting them head-on. These tadpoles heads are likely denser and heavier than the material surrounding them, which has already been blown away further out by the stars. Interestingly, the heads shield material behind them (within the "tadpole tails"), keeping it cold and dark - conditions that are needed to form additional stars possibly in the future (or at least what the future was 20,000 years ago). To see what the whole structure looks like from behind the tadpole heads, check out the dark patches / nebula in the centre of the structure. This is being shielded from the nebula / star cluster along our line of sight and thus appears, well, cold and dark. When it is cold and dark, gravity will cause the material to eventually coalesce enough to ignite fusion and create a new star.

The SHO palette uses filters that specifically capture the frequencies emitted by hydrogen, oxygen, and sulfur and the quantities can be surmised by the hue - hydrogen is everywhere but dominates in the yellows and greens. Red indicates the presence of sulfur ion (S+) emissions, while blues indicate oxygen ions (O2+). The exception to this rule is that the stars themselves have been left their natural colours is a processing trick.

The brightness is related to the total emissions given off both by these elements and also broadband emissions give off by the stars and reflections that happen to be of the right frequencies/wavelengths.

The original (mouse-over if I can figure it out) uses the same data as the other image of the same object. The luminance of the image is still provided by the narrowband data, as it is best used on stellar nurseries to reveal details.  However, this time the colour comes from data gathered by broadband red, green, and blue filters to better illustrate how we, with our human eyes, would percieve it. The outstanding red colour comes from the dominance of hydrogen in the nebulosity which emits dominantly in the red spectrum, but also helped by sulphur which also emits red. The blues and even greens that you see here are sourced more from light reflected from stars off of dust and gases, rather than emissions.