Journal Entry 2 Dec 2011 - Start Jupiter mass determination exercise

Sky clearing, seeing good.
2DegC, 86% Humidity, 1011hPa
Session stopped at 23:15hr with poor seeing.
Temp 0.5 Deg C, 88% Humidity, 1011 hPa with fast approaching Sirus cloud and slight fog

Objectives for tonight:

1. Start Jupiter mass determination exercise
2. Moon pics with Astrotrac and eyepiece projection
3. Try out Helmut's eyepiece reducer

1) Jupiter mass determination

Equipment:

• Astrotrac in lunar tracking mode
• 70/420mm APO ED Refractor
• DBK41AU02AS Astronomy camera by ImagingSource
• Baader Hyperion Zoom 8-24mm eyepiece
• Laptop + RSpec  

Setup:
70/420mm APO ED Refractor mounted on Astrotrac mount in sidereal tracking mode because I couldn't get the damm thing to go into lunar tracking mode.
Diagonal added to Hyperion 8-24mm Zoom set to 20mm no reducer for this work.
50 frames video avi captured with DBK41AU02 colour camera exposure time set to 1/10 sec.





Results:
50 frames video avi captured by DBK41AUo2 camera, stacked and process by registax.

Satellites of Jupiter for Dec 2 at 19:43 hr

Neg image by Irfanview and labelled in Gimp

Analysis of image by RSpec.

Jupiter mean position = 154 px
Io  mean position = 50 px
Callisto mean position = 75 px
Ganymede mean position = 120 px
Europa mean position = 331 px



2) Moon pics taken through 24mm eyepiece projection, tracked by Astrotrac, 200 frames captured by DBK 41 AU02. 200 frames stacked and processed with Registax.

With 0.5x Focal Reducer



Discussion: (not finished)

1. Jupiter mass experiment went well. From the no. pixels from Jupiter's center I can track the motion of Io as it moves like a pendulum. I decided to leave the numbers as pixels and not try to measure the distance from Jupiter's center in mm's. 
2.  0.5 Focal Reducer improves field of view but with slight vignetting. Still when recording the moon at 24mm via eyepiece projection I prefer to get as much as possible of object in view.