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Re: (IAAC) estimating magnitudes



Dear Mark,

> http://archive.eso.org/skycat/servers/usnoa
> This site will give a printout like the one that follows.  I have two
> questions that I hope someone can answer.  How do you convert the right
> ascension format used below to the one that uses actual hours and
> minutes?  Also, how do red and blue magnitudes generally compare to
> visual magnitudes?
>

The first question is rather simple. The format uses 360 degree's for the RA
instead of the 24 hours. Hence you need to divide the degree value by 15
(24x15=360) to get the hours and the remainder you have to multiply by 60 to
get the minutes and so on.

The other question I do not know the answer. The main sensitivity of the
human eye lies around the green-yellow part of the spectrum during night.
Maybe a good start would be to take the avaerage of the two magnitudes (just
a guess).

Regards, Josch

> Thanks,
> Mark
>
>   nr ID                ra        dec    r_mag b_mag qual  field  gsc
> d'     pa
>    1 U0975_06559340 161.03434  11.70866 19.1  19.8   0    00491   -
> 0.063  71.537
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