天王星 ALPO-Japan Latest
Uranus Image 2008/09/28(UT)
David Arditti,Christophe Pellier
These images of Uranus were taken in fair seeing 3 hours after culmination.
They are oriented with celestial south at the top. They show the oblate shape of
the planet with the equator running in the 1.30/7.30 o'clock direction,and
perhaps a hint,in the green image,of a darker belt running along the equator,
strongest at the top of the image,but it is hard to be certain.
[David Arditti: Edgware Middlesex HA8 5LW: United Kingdom]
Seeing was very good that night. It has been the first time that I saw raw frames with sharp edges on Uranus ! None the less the G and B frames are disappointing ; perhaps a bit misfocused. Note the the RG630 images are more circular due to the stronger limb absorption in long wavelenghts.
The main project was to stack a hudge number of frames with a RG 630 filter (R+IR), to eventually detect some belts, regardless of the rotation of the planet.
The result is really curious ; if dark patches do appear, only with this filter, and although they look to be present on each one of the three files, they do not ressemble to anything.
Moreover, the brighter zone on the lower left edge of the planet (west edge) is more likely to be the result of the sligh defect of collimation that I detected before imaging.
[Christophe Pellier Bruz City,France]