Inconsistent results

Forums Computing Heliocentric Julian date Inconsistent results

James Screech

I’ve now compared 3 different resources for the calculation and they all come out different! I’ve tried the BAA applet, a sppreadsheet I found on the web (HeliocentricJulianDay.xls) and the web site. For a test I’ve used an observation of NR Cam at JD 2457388.40539.

BAA app -> 4.609 min (276.54 sec)
Spreadsheet -> 281.3 sec -> 344.98 sec

The first two are less than 5sec different however the ohio site is over a minute off from the others. It would appear that they all use different methods of calculation that are not consistent! I’m wondering if there are issues with floating point rounding due to the number of significant figures required.