690 AD, not 690 BC

E.P. Grondine — 9/28/2004 1:59:28 PM (archived)

Hi Raoul -

That's 690 AD - I prefer CE (Christian Era) to AD (Anno Domine - Year of our Lord).

I see the first link you gave me claimed Halley returned in 684 AD, while the second gives a date for Halley's return of 690 AD, I assume based on Chinese observations and a correction for the effects of Jupiter's gravity on Halley's orbit.

Any idea what ancient observation record the second astronomer used, or if his calculation of the effect of Jupiter's gravtiy is correct?

ep

The whole thread (18 posts)

Raoul, your help please, concerning comets - E.P. Grondine - 9/27/2004 8:54:04 PM
- Oooops... - E.P. Grondine - 9/27/2004 9:01:20 PM
  - re: Halley's Comet - Raoul - 9/27/2004 9:07:03 PM
    - re: Sorry....I went too fast - Raoul - 9/27/2004 9:10:57 PM
      - re: However, 4 orbits earlier... - Raoul - 9/27/2004 9:17:56 PM
        
        re: Here - Raoul - 9/27/2004 9:28:31 PM
        
        Thanks! - E.P. Grondine - 9/28/2004 12:02:50 AM
        
        re: Comets - Raoul - 9/28/2004 7:43:10 AM
        
        690 AD, not 690 BC - E.P. Grondine - 9/28/2004 1:59:28 PM
        
        re: 690 AD, - Raoul - 9/28/2004 2:37:32 PM
        
        re: 690 AD, - E.P. Grondine - 9/28/2004 7:07:16 PM
        
        re: re:J'en ai bien peur, en effet:) (n/t) - Raoul - 9/28/2004 9:44:37 PM
        
        pas de responsabilitie, mais avec "thanks" - une autre question - E.P. Grondine - 9/29/2004 12:15:25 AM
        
        re: Encke - Raoul - 9/29/2004 7:42:54 AM
        
        re: Encke - E.P. Grondine - 9/29/2004 2:18:41 PM
        
        re: Encke - Raoul - 9/29/2004 5:13:50 PM
        
        re: Comets - REB - 9/28/2004 1:20:53 PM
        
        Ooops - still problems - you're not the only one moving too fast - E.P. Grondine - 9/28/2004 12:12:27 AM

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