Cees BassaJan 4, 2025
For the 4th year in a row, my all-sky camera has been taking an image of the sky above the Netherlands every 15 seconds. Combining these images reveal the length of the night changing throughout the year, the passage of clouds and the motion of the Moon and the Sun through the sky. #astrophotography
Show threadchrysnJan 4, 2025
@cgbassa Is the yellow at night light pollution, and are street lights dimmed fromidnight to 06:00 in December? Or is that something else?
Show threadCees BassaJan 4, 2025
@chrysn The yellow is due to low-altitude cloud cover and fog, which, with this camera, comes out as yellowish, probably due to illumination from streetlights. There is no dimming of street lights, more that clouds change color to gray/white in daytime. Here's a plot of all of December 2024.
Show threadchrysnJan 4, 2025
@cgbassa Nice, it shows New Year's Eve's fireworks even. Still looks like a dark rectangle up and to the right from there, but it's hard to tell whether clouds become less there or human light decreases (car headlights, maybe?)
Show threadCees Bassa
@chrysn Can you draw on that plot with December which rectangle you mean? There might be some garden lamp on a timer somewhere in the neighborhood that I haven't noticed before.
Jan 4, 2025 at 4:35pmWeb
Show threadchrysnJan 4, 2025
@cgbassa It's clearest on the clouded days EoY: