Re: Mbol zero point

[Jan Hollan <jhollan@amper....muni.cz>]

Dear Roger Cayrel,

thank you very much for the definition of the bolometric scale. It's nice
that some things in astronomy cease to be vague. 

Also the "nominal Sun" is a handy thing: the standardized value 
(1367.57 W.m-2 in terms of the "solar constant") 
seems to sit just on the top of the variability band of the most recent
data, as given at
         http://www.pmodwrc.ch/solar_irr/solar_irr.html

I attach a very simple programme doing the conversions and using now the
value you gave me. There is a Pascal source and a binary for DOS and
Linux. It is a pity that the zero-level flux densities for
the non-bolometric cases remain poorly known. Or don't they? 


To be perhaps more useful, I offer two texts of Tom van Flandern, which
helped me much to chose a place for viewing the August 11 eclipse --- from
the very edge of the band of totality: 

            http://www.metaresearch.org/edge/eclipses.htm  
and mainly
            http://www.aspsky.org/html/mercury/9701/vanflan.html

It seems that his simple advice is not at all well known, and I would
surely behave foolish if I had not come across a text like that some years
ago.

Perhaps the Paris Observatory might incorporate some of that advice
in its www pages.

Best regards,

Jan

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  [    described as "conversion programme"                               ]