njcuk9999
commented
3 years ago Hi Claire,
Yer this may be a bug, I've looked at the code (here)
So the rjd column is currently is "BJD" from the header (just converted to MJD) it is definitely missing the 0.5 day difference
If "BJD" doesn't work (or is missing) it defaults to the MJDMID (again without the 0.5 day)
So from above it is:
rjd = "BJD" - 2400000.5 = 2458529.121977688 - 2400000.5 = 58528.62197768781 (the value from your rdb file)So you say ~0.5 what is the actual equation to go from:
- BJD --> RJD ( I see a JD --> RJD equation here is this correct?)
- MJDMID --> RJD
If this link is correct
rjd = "BJD" - 2440000.0and
rjd = "MJDMID" + 2400000.5 - 2440000.0This seems to be a factor of -39999.5 out - so is there a typo in this link?
I will correct both and update the version of LBL
Note we never use
clairem789
I just noticed that, although the lbl*rdb files have a column name "rjd" for the date, the content is close to the MJD keywords in the lbl.fits files. rjd is expected to be BJD-2400000. So there is a ~0.5 day difference between MJD and rjd. I asked Pascal, who should have seen a problem when fitting the literature values for planets in DACE, but for some reason it doesn't seem to be an issue. So I'm confused. The lbl code says all over "MJD" so I guess this date in the rdb files really corresponds to some of the MJD keywords, but I actually don't seem to find which one. One example:
in lbl_GL411_GL411.rdb file 2374981o has "rjd" = 58528.62197768781
while dfits ../lblrv/GL411_GL411/2374981o*|grep JD has no corresponing value (about 600s apart from MJDATE): MJDATE = 58528.6153547 / Modified Julian Date at start of observation MJD-OBS = 58528.6153547 / Modified Julian Date at start of observation MJDEND = 58528.6164779 / Modified Julian Date at end of observation TCSMJD = 58528.6152604 / TCS MJD MJDMID = 58528.61612320672 / Mid Observation time [mjd] BJD = 2458529.121977688 / Barycentric Julian data calc. in BERVSRCE
Can you please clarify?
Sorry if this is a known issue.