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Re: (meteorobs) Degrees
LUNRO:
> As for solar longitude if no epoch is listed then I would assume the
> table uses 2000. If your resulting figures are far off then there is the
> possibility it uses another epoch without stating this fact.
LANMA:
> Any value for solar longitude is meaningless without the epoch specified.
> Usually I guess, sources that do not probably imply epoch J2000.
On a pedantic point J2000 is an *equinox*. Obviously, the solar
longitude varies on a given calendar day year to year, so epoch does
matter, but in this context I think both responses were referring to the
equinox. Some older works naturally used equinox B1950. This is
approximately 0.70 degrees different from J2000 because of the
precession of the equinox. So, for example, comparing times of shower
maxima have to take the different equinoxes into account.
Malcolm
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