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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?

James K
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user2256790
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  • 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. –  Jan 01 '15 at 23:29
  • 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? – James K Nov 16 '15 at 19:38
  • http://astronomy.stackexchange.com/questions/8390/cancelling-out-earth-rotation-speed-altazimuth-mount/8415#8415 –  Nov 16 '15 at 20:03

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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.

adrianmcmenamin
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