Above an image of my allsky camera , created with AllskEye software, at the observatory. It is updated every 60 secs., so more or less realtime.
The keogram of the images taken with the allsky camera. A small slice of each taken image is put together in a timeline. Below the startrail of last night’s images. (If any. Clouds = no startrails 😉 )
This allskycamera is equipped with a liquid crystal shutter. It’s basically a large single pixel LCD added in the lightpath. A pulse generator makes the LCD go black and transparant 16 times each second. This acts as the old rotating sector. One of the disadvantages is its transparancy. Even at an “open” stage the LCD blocks light. Add this to the “closed” state and even more light is blocked. The high QE of the ZWO ASI 183mc helps in this matter. Together with the F1.8 Fujinon lens the image is still very good.Â
The liquid crystal shutter is used to determine the speed of a meteor while travelling the Earth’s atmosphere. The closed or dark state of the LCD: a short brake will appear in the meteor’s lightpath creating a chopped lighttrail on the image. The signal generator is set to 16 breaks per second, so you now can tell how long a meteor was visible. The picture above: The earthgrazing meteoroid on the slightly foggy night of september 22, 2020. A Jupiter family meteoroid entered the atmosphere and bounced back into space. It was visible from Germany to as far as the UK.
