[RTTY] Solar Flux Index 298

[Kok Chen]

On Oct 26, 2003, at 4:44 PM, Bill Turner wrote:

> Then I DON'T need to get out more often?

Yes you do, Bill, but not for this reason :-) :-).

Ekki is right of course (as always, ja?).  I did not use any masking of 
the corona either optically or in Photoshop :-).

The corona is much cooler than the sun (sun is at 6000 degrees Kelvin, 
give or take a couple of hundred degrees :-).  To take a picture of the 
corona, you have to mask out the solar disk, not the other way around.  
In fact those sunspots, at 2000 degrees K, look black, although they 
are much hotter than W9OL's amp.

You can see the setup at http://www.pbase.com/w7ay/astrophotography , 
just click on the picture of the telescope.  That shiny thing you see 
at the receiving end of the telescope is a very, very deep filter.  
Heck, go up the tree to http://www.pbase.com/w7ay , and you can see my 
other hobby :-).

The color of the sun in that picture is not that far off from the 
perceived color -- the sun peaks at slightly greenish yellow on the 
Planck black body curve, which is also the peak of our daytime vision 
sensitivity.  Night vision peaks towards the bluish side.  Any ape that 
didn't have that attribute died before they became homo sapiens :-).

Although we are most sensitive in the greenish yellow, we see the sun 
as orange.  Why?  Go to

http://solar-center.stanford.edu/FAQ/Qsuncolor.html

You don't really need to get out often now that there is Google.com :-)

73
Chen, W7AY