天王星 ALPO-Japan Latest

Uranus Image 2011/11/12(UT)

Frank J Melillo
Frank

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The idea was to image Uranus with a 200mm  telephoto lens with the  
stars' background and then compare with both without and  with the  methane 
absorption filter (890nm+/-10nm). I use star '1' and star  '2'  as 
references. 
This will help me to locate where Uranus should be in  methane  light. 
Uranus 
is extremely dark at this wavelength. Anything  that is not  methane like a 
white spot should be very bright.  Therefore, I would  like to see whether 
if Uranus has any surge of  brightness when  the white spot is on the disk 
in 
methane light.  

First on October 31st, 2011 at 3:10 UT (top  two  images), I imaged 
Uranus with a 200mm telephoto lens without any  filter(s). The  CM was at 
205 
degrees longitude and the white spot's CM  was at 003 degrees.  Therefore, 
the 
spot was not out and Uranus is not  visible.

Then on Nov. 12th, 2011 at 0:10 UT (bottom  two  images), Uranus' CM was 
at 36 degrees longitude and the spot's  longitude  was at 349 degrees 
longitude. Therefore it was on the disk  at the time I was  imaging. The 
image was 
taken without the filter to  see  Uranus against the star's background. 
Then 
I imaged it with a  methane  absorption filter (890nm+/-10nm) with the same 
stars that  marked as '1' and  '2'. There is no surge of brightness. Uranus 
is  
still not visible even with  the white spot on the disk.   

So far, Uranus is not visible in methane light even  with  and without 
the spot on the disk. Perhaps the white spot is not  bright enough or  not 
enough contrast for Uranus to be visible or the  aperture of the 200mm  
telephoto lens is too small. 

[Frank J Melillo  Holtsville NY U.S.A]

ALPO-Japan Latest Uranus Section	2011/11/13
	2011/11/09