Astronomy is essentially based on very sophisticated instruments with which the sky is observed. Now well beyond the age of "telescopes," today's instruments for observing the heavens are very complex entities. It takes a multitude of disciplines to set up today's high performance space telescope.
The ELT (Extremely Large Telescope) currently under construction by the European Southern Observatory in Chile, for example, will have a primary mirror 39 m in diameter; there will be a lot to see. To see here means that the partial mirrors capture radiation and direct it to sensors, which then record it so that it can be processed computationally.
So there will be a lot of calculating, correcting, analyzing and assembling to finally give us an idea of what is going on out there, strictly speaking, has been going on, since a look at the sky is always a look into the past.
Thus, with the latest telescopes, one would like to have such a high sensitivity and resolution that one can even look into the time shortly after the Big Bang. We would like to watch our own birth, so to speak. What a fascinating thought.
Currently already available and accessible are fascinating images of nascent galaxies, gas clouds and bizarre formations in space, translated into bright colors; the colors go back to the excited states of the elements present. For example, excited hydrogen alpha produces a red and 2-ionized oxygen (OIII) produces spectral lines in the blue-green range.
There are red, blue, turquoise and even green galaxies and nebulae that seem to draw from an inexhaustible wealth of colors and shapes.
Also widely known became images of the Hubble telescope, which were produced with the so-called Hubble palette. Here, a new color assignment has now been made in order to achieve the best possible resolution for our eye: it is a false color representation in which, for example, H alpha has been assigned to the green channel and OIII to the blue channel.
Inspired by these infinitely energetic processes of galaxy formation and interstellar nebulae, which nevertheless produce harmonious mixtures of wavelengths in a strangely familiar way, she translated her idea of these natural events into images with her Fluid Art:
a technique that should be particularly well suited to depicting diversity of form and dynamics, but at the same time, in accordance with the inherent regularity, a certain harmony.
Here now is a picture of her series that reflects her very personal view of what is happening in space.
Recently I saw by chance the pictures of Paul Heiser, he is photographing the night sky with a Canon EOS 700 Da and the APO 72/400 lens, so with a little more manageable equipment than Hubble:
ISO: 1600, Lights: 30x120s 30x180s 6x300s, Darks: 30, Moon: 25%; Lens Filter: L-Pro, Guide Scope: ZWO Mini 30mm ASI 120MC-S, Aperture: 5.6, Flats: 60, Bias: 60, Software: Power Point, APP, Topaz.
Looking at this list, one can see that already a number of features of scientific astrophotography have found their way into the sophisticated amateur field. Besides the actual images, dark frames are generated to correct internal errors; then there are further corrections via bias frames and flat frames, so technically already very elaborate compared to a simple shot of the night sky.
After all the corrections and calculations, there is the complex image processing, which first peels the actual object of desire out of the unspectacular image of the night sky, e.g. the image of a galaxy or an emission nebula.
This time Paul was aiming at the Triangle Nebula M33 (spiral galaxy with a diameter of about 50,000-60,000 light years, after the Andromeda Nebula and the Milky Way the third largest object in the Local Group. The distance from Earth to M33 is just under three million light-years).
the color gradations of Petra's image are quite close to Paul's M33 image!
How can that be?
As described above, astronomers and astrophotographers draw on the findings of biology to make their images easier to "read". The (arbitrary) translation of the spectral lines emitted by the excited elements into red, blue and green corresponds to the absorption maxima of our cones in our eyes, so that we get the best possible resolution.
This is exactly what artists do; they also prefer to work with the color tones for which we have a very high sensitivity.
The similarity is therefore no coincidence; both groups strive to ensure that we can perceive their works in the best possible way.
The fact that a very characteristic aesthetic emerges on both sides is nevertheless astonishing to me; obviously, beyond color recognition, certain "natural" patterns are also perceived as beautiful in our brain. These patterns seem to be similar in the small world directly surrounding us and in the large world of galaxies.
This still somewhat mysterious bridge allows us to experience the world of galaxies personally.
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