Sun right ascension and declination at date with different values on different calculators and also with my implementation

I'm reading the book "Practical Astronomy with your Calculator or Spreadsheet 4th Edition" implementing its formulas with C++.

Now, I have implemented formula 47 "Calculating orbits more precisely".

I get, with my implementation, that the right ascension and declination of the Sun on Greenwich date 10 March 1986 at 0 h UT is:

• right ascension: 23h 20m 1.73s = 350.007226656 = 23.333815110378847
• declination: -04º 18' 9.83" = -4.3027310799565921

I have checked it with two calculators:

In the Sun Ephemeris Calculator the values are:

• right ascension: 23h 19m 59.56s = 349.9981665°
• declination: -04° 18' 25.97" = -4.307214°

And in the Sun & Moon Position Calculator, the values are:

• right ascension: 23h 20m 1.6s = 350.007°
• declination: -04° 18' 10.8" = -4.303

All of them are different.

Do I have to be worried about it?

• You can check your calculations against the Jet Propulsion Laboratory Development Ephemeris. You can access (a lot of) that data via the Horizons website. It's not hard to write code that accesses Horizons, but it's simpler to just use the web interface & copy the results to your own machine. Jun 26, 2021 at 18:15