Gemini North captures mesmerising view of Comet NEOWISE’s rotation

Gemini North captures mesmerising view of Comet NEOWISE’s rotation
By Astronomy Now

The rotation of Comet NEOWISE is revealed in eight images captured over one-and-a-half hours on 1 August by the Gemini North telescope using the Gemini Multi-Object Spectrograph. In the compressed time-lapse sequence below, the images are looped nine times. Image: International Gemini Observatory/NOIRLab/NSF/AURA/M. Drahus/P. Guzik

While amateur astronomers around the world captured stunning wide-angle views of Comet NEOWISE (C/2020 F3) as it passed through the inner solar system, researchers using the 8.1-metre Gemini North telescope in Hawaii were able to zoom in, capturing images of a spiralling stream of molecular gas that revealed the comet’s rotation.

The close-up observations, led by Michal Drahus and Piotr Guzik of Jagiellonian University in Krakow, were carried out under a program to study the rotational dynamics of the comet. Despite limitations imposed by the comet’s proximity to the Sun, the researchers were able to confirm a 7.5-hour rotation period by measuring the spiral outflow of molecular gas as NEOWISE spun about.

Eight images collected on 1 August were assembled into a time-lapse movie by International Gemini Observatory/NOIRLab/NSF/AURA/M. Drahus/P. Guzik/J. Pollard:

“It is thought that most comets release gasses in geyser-like jets and that is what researchers think is happening in the Gemini images,” the National Science Foundation’s NOIRLab said in a description.

“As the vaporised material erupts from the comet its rotation causes it to appear to spiral outward, much like the water from a spinning garden hose. The very same material impacts the comet’s rotation causing its nucleus to spin-up or spin-down, though for most comets, the effect is too weak to detect.”

August 25, 2020 at 08:32PM
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