The zodiacal light over the South Pacific
Using more sophisticated methods (see results from the La Silla Observatory), I was able to re-process my data of the all-night zodiacal light panorama over the Mangaia Island (the Cook Islands) in the end of August 2014. Used Canon 6D, Sigma 15 mm, f2.8, ISO 6400, panorama of 7 singular images, each 61×20 s, darkframes applied, captured from tripod and Canon 450D IR modified with Sigma 15 mm, f2.8, ISO 1600, 4 singular images, each 135×30 s, darkframes applied, tripod.
The image in full resolution (4620×1200 px, 300 dpi PNG; 10,6 MB) you can download here: The zodiacal light above the South Pacific – full.
The original text (2014):
Here comes another view to the sky above Mangaia, The Cook Islands, in the night 25th – 26th August 2014. Probably the best night sky conditions I have ever been experienced, allowed me to capture this unusual panorama. This is all 360 degrees of the zodiacal light from the west (right) to the east (left). The western horizon on the right is part of Mangaia airport including the silent and abandoned airport building. Morning eastern horizon on the top left is just a lagoon under the cliff of Mangaia airport. You can see a reflections of the stars and the zodiacal light on the water. Thanks to the position of Mangaia island (and my observing spot) just 21,9 degrees south from the Equator, the zodiacal light was sloped almost upright after sunset and enough before the sunrise. Those conditions plus the dark sky were favorable to finish the panorama, even if lot of light clouds passed during the night (as seen above both horizons). The only problem I had with energy in the batteries of my cameras, which I couldn’t charge during the night due to unreachable electric power to my observing spot. Just after finishing the last image the last battery lost the rest of the energy. I was so lucky!
As known, the zodiacal light is sunlight scattered on a dust particles in the level of our solar system. This level is in the sky projected to ecliptic, where lie all zodiacal constellations. That’s why astronomers call it this way. The brightest parts of zodiacal light are close to the Sun, visible like bright columns after sunset or before sunrise. In the middle of the panorama is so-called Gegenshein, the opposite of Sun position in the sky. From this direction the dusty particles scattering the sunlight are illuminated straight as the full Moon. For the size of those interplanetary particles is typical Mie scattering, which causes the visibly isolated bright part of otherwise faint zodiacal bridge between two columns close to the Sun. The first explanation of the origin of the light came from astronomers in the end of the 17th century.
This image is actually a response for the amazingly great job of prof. Miloslav Druckmüller (of the Institute of Mathematics of FME Brno, Czech Republic) and prof. Shadia Habbal (Astronomy University of Hawaii Institute for Astronomy, USA), who captured the same panoramatic view 3,5 years ago from Mauna Kea, Hawaii. My response is quite different in the timing – their panorama shows April situation (the Gegenschein is in constellation Virgo), while mine is captured in the end of August and the Gegenshein is projected in constellation Aqaurius. As the Earth moves on its orbit, the Sun projects itself in other constellations and so does the Gegenshein during the year.
