This question is about finding the elevation and bearing of a given star at a particular time at Latitude 52N.

I look up the RA and Declination of my star. How do I calculate its bearing and elevation at hourly intervals?

  • $\begingroup$ The RA of a star is pretty much fixed. Do you mean the azimuth and elevation? There are several websites that should help you convert RA/declination to azimuth/altitude, or I can give you the insanely complicated formula I gave for another answer. $\endgroup$ – barrycarter Jan 1 '15 at 23:29
  • $\begingroup$ I think the OP uses "Bearing", and by that means azimuth.The use of RA at the end looks like an error. Edited.... @barry could you link that other answer? $\endgroup$ – James K Nov 16 '15 at 19:38
  • $\begingroup$ astronomy.stackexchange.com/questions/8390/… $\endgroup$ – barrycarter Nov 16 '15 at 20:03

The Right Ascension of a star is fixed (ignoring precession of the equinoxes). What you need or want to know is the "sidereal time" - that is to say the "time" based on which RA is at your local meridian at a given time. The sidereal day is slightly shorter than the mean solar day (ie the 24 hour day) and so sidereal and solar times drift apart - only being equivalent at the vernal equinox.

  • $\begingroup$ Also ignoring proper motion (which is negligible over moderate time scales). $\endgroup$ – Keith Thompson Jun 16 '15 at 21:30

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