NavList:

I suggest caution in suggesting errors in USNO data. Earlier the discussion seemed never about 'errors', but about 'incomplete' data. (It turned out to be a browser issue. Unfortunately, for the reasons Frank suggests, pointed out to USNO as an 'error'.)

In the case of the delta T question, I suggest similar caution. I have made a few ephemeris calculations based on JPL 405 data. Using dT of 66.184, I get:

Geocentric:
RA 2-45-50.973837, Dec 16-00-59.604557 N

Topocentric:
RA 2-45-50.988242, Dec 16-00-54.658768 N

(Agreeing at .01 second level with JPL-Horizons and IMCCE results. Remaining differences due to UT-UT1 and polar motion.)

Using dT of 72.184:

Geocentric:
RA 2-45-50.989878, Dec 16-00-59.676789 N

Topocentric:
RA 2-45-51.004283, Dec 16-00-54.731003 N

(I hope no typo's!)

So, I don't conclude the USNO online is using the wrong dT.
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