We still use it at the observatory. For example, my object of interest is up between 0h and 17h LMST and a quick glance at the sideral clock let's me know where I am.
Jim 2010/1/15 Bruce Griffiths <bruce.griffi...@xtra.co.nz> > Before the advent of automated telescopes that can point to an object of > interest a > wall clock displaying local sidereal time was commonly used to help point a > telescope > using setting circles and the known coordinates of the (astronomical) > object of interest. > > Bruce > > > Steve Rooke wrote: > >> Hi Brian, >> >> I really love this group, it appeals to the technophile inside me and >> it's interesting to see the answers that are given. >> >> You should have know that posting to a nuts group would mean you would >> get lots of highly technical responses but frequently the questions >> posed are not answered as things go off in a tangent. Perhaps we >> should have asked you how accurately bang on the "sidereal second??" >> you wish this clock to be or perhaps you just wish it to tick over the >> sidereal time without some frame of reference? >> >> Sounds like an interesting idea, sorry but I cannot answer your >> questions conclusively but it looks sound to me. What you are doing is >> fitting a sidereal day into a wall clock day display by driving the >> clock with fast seconds so it's 24 hours is over in 23 hours 56 >> minutes and 4.091 seconds. If that's what you want to do, it sounds >> great even though I'm not sure that a sidereal day is normally >> presented that way. >> >> 73, >> Steve >> >> 2010/1/15 Brian Kirby<kilodelta4foxm...@gmail.com>: >> >> >>> I would like to have an electronic clock to keep sidereal time. I am >>> planning on using a HP 59309A, which can except an external clock of >>> 1/5/10 >>> Mhz. >>> >>> According to Wikipedia sidereal time is 23 hours 56 minutes and 4.091 >>> seconds - a total of 86,164.091 seconds >>> >>> So 86,400 seconds for a normal "atomic defined" day divided by 86,164.091 >>> = >>> 1.002,737,903,89 >>> >>> If I set the 59309A to 10 Mhz external clock and dial a synthesizer up to >>> 10.0273790, the unit should be able to keep sidereal time. >>> >>> Is my math and theory correct ? >>> >>> Brian - KD4FM >>> >>> _______________________________________________ >>> time-nuts mailing list -- time-nuts@febo.com >>> To unsubscribe, go to >>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >>> and follow the instructions there. >>> >>> >>> >> >> >> >> > > > > _______________________________________________ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.