The Sun, In All Its Glory
The aptly named “Fusion of Helios” is a fusion from the minds of two astrophotographers, Andrew McCarthy and Jason Guenzel. Using a custom-modified hydrogen alpha solar telescope, the combined data from over 90,000 individual images was jointly processed to reveal the layers of intricate details within the solar chromosphere. A geometrically altered image of the 2017 eclipse as an artistic element in this composition to display an otherwise invisible structure. Great care was taken to align the two atmospheric layers in a scientifically plausible way using NASA’s SOHO data as a reference.
I’ve included the full image and my favorite crop (the solar tornado the height of 14 Earths was a close second) above, but do yourself a big favor and check out the largest image available (which is still way smaller than the 140 megapixel final image they produced). If you’re curious about the process, here’s how McCarthy gets his Sun photos:
So how do I resolve atmospheric details, like spicules, prominences, and filaments? The trick is tuning the telescope to an emission line where these objects aren’t drown out by the bright photosphere. Specifically, I’m shooting in the Hydrogen-alpha band of the visible spectrum (656.28nm). Hydrogen Alpha (HA) filters are common in astrophotography, but just adding one to your already filtered telescope will just reduce the sun’s light to a dim pink disk, and using it without the aperture filter we use to observe the details on the photosphere will blind you by not filtering enough light. If you just stack filters, you still can’t see details. So what’s the solution?
A series of precisely-manufactured filters that can be tuned to the appropriate emission line, built right into the telescope’s image train does the trick! While scopes built for this purpose do exist (look up “coronado solarmax” or “lunt solar telescope” I employ a heat-tuned hydrogen alpha filter (daystar quark) with an energy rejection filter (ERF) on a simple 5” doublet refractor. That gives me a details up close look at our sun’s atmosphere SAFELY. I’ve made a few custom modifications that have helped me produce a more seamless final image, but am not *quite* yet ready to share them, but just the ERF+Quark on a refractor will get you great views.
Photography has always been a combination of technology, artistry, and wrangling whatever light you can get to best express the feeling that you’re going for — astrophotography certainly dials that wrangling up to 11.