Mark__Blackford
Affiliation
Variable Stars South (VSS)
Thu, 06/19/2014 - 05:10
Hi All,
not sure if this is the right forum to ask my questions but it does relate to my observations of eclipsing binaries. I am aware of several websites where Julian dates can be entered from which Heliocentric Julian Dates are then calculated but I want to do the calculation in a my own Excel spreadsheet.
Can anyone provide the relevant equations? The only input parameters as far as I can see would be JD and the object's RA and Dec.
Any advice would be much appreciated. Cheers,
Mark
These two links should help:
http://en.wikipedia.org/wiki/Heliocentric_Julian_Day
http://en.wikipedia.org/wiki/Position_of_the_Sun
You'll need the second link to compute the RA and DEC of the sun.
Thanks Alexandru,
I'll take a look at these. Cheers,
Mark
Here's one: I haven't used it myself...
www.lewcook.com/SUNTime.htm
Cheers, Gary Billings
Thanks Gary,
I've used Lew Cook's spreadsheets, very useful but the details of calculations are hidden. I was contacted off-line by a colleague who provided his spreadsheet based on info in Astronomical Algorithms by Jean Meeus, so I think I have what I've been looking for. Cheers,
Mark