Planetary rotation calculator

[spaceman_spiff]

Hi all,

I'm in the middle of processing a sequence of videos of Jupiter taken during the Europa transit on 02/04/2017. I recorded videos lasting about 2 mins. I chose 2 minutes primarily because I used it before and got good results. But I wanted to know the exact maximum time I should video before the planet rotates across more than 1 pixel...so I wrote a small program to calculate this. You will need to know the angular diameter of the planet at its equator (you can get this from Stellarium), the pixel size of your camera and the effective focal length or your telescope (including any Barlows).

It's written in Python so if you want to run it download Planet_rotation_calc.py and go to your terminal. Change the directory to the folder containing Planet_rotation_calc.py (use cd /folder/Planet_rotation_calc.py). Then type: python Planet_rotation_calc.py

The program spits out the theoretical max time you can image before rotation spreads features across more than 1 pixel. In reality, poor seeing and imperfect optics will mean that planet rotation will probably not affect the image if you go slightly over this time.

Anyway, please feel free to comment, use, modify and improve the program then post it for others to use.

Dan

Planet_rotation_calc.py