Enhanced image of the 2019 Total Solar Eclipse from Cerro Tololo, showing the full extend of the solar corona together with the constellations of Gemini and Orion (high res here).
Where in the Universe does such extraordinary landscape exist? The familiar sight of Orion and Gemini constellations as well as distant city lights betray that this sight is from our home planet. For the handful of seconds of a total solar eclipse, our routine world can feel like some alien exoplanet as the shadow of the moon skims Earth’s surface.
Unfortunately, the horizon is already floodlit, announcing that the precious seconds of darkness are soon terminated and the sun glare is already about to come back!
The image reveals the full size of the solar corona with the scale of the familiar constellations Gemini and Orion. It corresponds to a time around mid-totality, with the edge of the Moon shadow visible and the eclipse already over on the left hand side of the image. The arrival and departure of the Moon’s shadow can be better seen on my video of the totality.
The shape of the solar corona was typical of solar minimum, with the equatorial jets along the ecliptic that are pointing at the planet Venus.
It was necessary to stack more than 200 images acquired with a 35mm lens used at full f/1.4 aperture allowed to reveal the constellations, full extend of the solar corona, La Serena city lights, and translucent cloud structures, none of which were visible to the unaided eye. Stars down to magnitude 7 stars are visible in the areas with best signal to noise ratio.
This image was recorded with unfiltered Sony A7S camera body and Sigma Art 35mm f/1.4 lens. The lens was used at full aperture and the camera used at base ISO to gather the maximum amount of light and get best SNR. Altogether, more than 200 frames were during the totality, with exposure from 1/13s to 1.3s. The inner corona was recorded with the high resolution setup and the 85mm lens setup.
Uncalibrated, single image showing the actual view during the eclipse. Venus was the only “star” visible. This image corresponds to the beginning the totality, with the Moon’s shadow covering the whole horizon (high res here). The city lights of “La Serena” were not seen visually. (Note: the white balance of the unfiltered camera body is not perfect on uncalibrated images)
However, after background subtraction, the stars forming Orion and Gemini constellations are visible on single, uncalibrated raw exposures, as well as the city lights of La Serena (high resolution here). Calibrating and stacking all the 200+ images acquired during the totality allows to reveal stars down to magnitude ~7
HDR astrophotography by Nicolas Lefaudeux 