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ryanvarley / open_exoplanet_catalogue

The Open Exoplanet Catalogue Atmospheres - Contains Spectra and Errors
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Transit times and Julian Days #4

Open ryanvarley opened 11 years ago

ryanvarley commented 11 years ago

Transit time in the literature are quoted in BJD, HJD and in some cases JD, MJD. In addition there no strict standard for BJD and HJD as they can either be modified or not or even a different system (although i havent observed this to be the case currently).

I dont see a problem with BJD and HJD as (unless i'm mistaken) they are within seconds of each other. The issue is how to record the type of julian day used and what to do with normal Julian days.

The current system we've been using is to simply state the JD system used in the unit tag. Im not sure if unit is fully appropriate here as the true unit is a day so maybe type instead?

I would suggest that we avoid using both MJD and JD together as it would throw a transit off by half a day. we could modify the cleanup script to look for values below 2400000.5 and add it on if not present or vise-versa.

hannorein commented 11 years ago

I like the idea of having just one unit. I don't know which one. Whatever people are using most, I guess. And yes, a script to convert the other units would be nice, although it might be non trivial (a quick google search only gave me IDL routines).