[Aavso-photometry] HJDo?

[Michael Koppelman]

HJD_0 is, for binaries, the middle of the primary eclipse. For RR's  
it's the maximum. So that can vary. If you have the emphemeris you can  
calculate the min (or max) by:

HJD_Min = HJD_0 + P*k

where k is some integer number. Play with k until you get a time  
within the day you are looking for.

M.


On May 3, 2008, at 10:43 AM, Steven Orlando wrote:

> For a variable star, if you have an HJDo and a period(d), how is  
> HJDo defined, and how can you calculate an ephemeris for a star with  
> an HJDo and a period?