Great conjunction of Saturn and Jupiter | 木星土星大合
At December 19, Saturn stand away Jupiter is about 13 arcminute, which we call the conjunction of Saturn and Jupiter. I point the 750mm telescope to southern west where Sun fall. It is the first time for me to see and capture them: Saturn, Jupiter and its moons. Form the layout of Jupiter's moons, I'm happy to image that the moon's orbit plane, Saturn ring, even the relative position of Sun, Earth, Saturn, Jupiter. I can feel where I'm in the Solar system. If I don't try to capture it in person, I won't find this kind of fun.
I'm very luck. First, the floor door in laboratory was opened which was always closed. Second, I captured them at December 19 rather after that, although only little time for me to do it after 19:00. After December 19, sky is filled with cloud in Shenzhen.
Photograph with tree silhouette is good. But it is better to choose tree more far away. I want to catch more moon, so I don't aware that exposure is too long to see the Jupiter surface and Saturn ring. More, I don't calibrate telescope's light pathway, capture dark frame......
Note to calculate Field of View( F.O.V): \[F.O.V = l/f\], where F.O.V is in rad, \(l\) is the camera sensor size and \(f\) is telescope focal length. Two telescope with Sony A7 full-frame(35.8mmx23.9mm), APS-C(23.6mmx15.7mm): + Sky-Watcher DOB 16', focus length of 1800mm: (23.9/1800)/(2pi/360)=0.76 degree + Sky-Watcher Newtonian Reflector, 750mm: (23.9/750)/(2pi/360)=1.83 degree, 1.20 degree for APS-C. + Obsession 22" UC(F4), focus length of 2235mm: (35.8/2235)/(2*3.14/360)=0.918 degree
Reference
- Photograph Tip from NASA
- https://en.wikipedia.org/wiki/Great_conjunction
- Jupiter-Saturn Conjunction Series from 0 CE to 3000 CE
- Calibrate Newtonian reflector