Just a general question wrt the conversion of JNow to J2000. I understand the differences but am curious as to some possible nuances to the conversion process. My mount, GTD G53F, reports in JNow and a reported position will exactly match that in CDC. C2A is off slightly as is Stellarium. Stellarium reports both JNow and J2000 but when their J2000 coordinates are compared to SGP they are close in RA but off in Dec. Nothing that a plate solve won’t cure but it has me wondering what would account for the differences? Would using different catalogues account for minor variances? Is there perhaps a difference in the formulae or catalogue references used in the conversion process?
Not a big deal but just curious.
As a part deux to this question, Is there a rationale for SGP only reporting J2000 and converting rather than having a JNow option?
I believe that I have solved one of my pointing issues today as my gotos have always been off a bit. I seem to have been inputting JNow coordinates into my sequences. Presumably, if SGP converts my mount from JNow to J2000 the goto coordinates should be J2000.