Without being sure of where this is going...
A common complaint of some purists is that brightening or darkening of a photo is "enhancement". It isn't real evident in
@davenn's photo (indeed, I'd suggest more...still nice though), but it is done by stretching the data and cuting off the low end greyness to make the background black while also brightening the middle and bright side. Mathematically, this technique is identical to scaling a graph so it shows the data stretched out instead of bunched-up at the bottom of the graph. Is that "enhancement"?
Similarly, a basic contrast adjustment changes the shape of the graph (photo brightness curve) in a way similar to choosing a linear vs logarithmic scaling on a scientific graph. Of course, there are more complex options for scaling a photo's brightness curve...
What about color correction? Whether done on purpose or not, all photos are shot in separate colors and then combined in software to produce a color image. And because the chip sensitivity isn't the same for different colors, either the exposures have to be made different for each color (common in astrophotography) or the colors corrected by the software (regular photography).
How about false colors? Any data can be mapped to colors for visual representation. It's common in CFD analysis, for example. But most direct would be mapping infrared light to visible. So are false colors really "enhancement"?
How about running an experiment/taking a photo 10 times and then averaging the data...?
Or, rather, is "enhancement" really a negative thing?
When it comes to my photos I consider what I'm doing more art than science so utimately I don't care if they are judged to be over-processed unless that makes them look bad (in the extreme; I've put threads in front of my telescope to create diffraction spikes). But I still find people often have an incorrect view of what "processed" means for the scientific or realism value of a photo.