[time-nuts] Sidereal time
jim77742 at gmail.com
Fri Jan 15 11:51:07 UTC 2010
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.
2010/1/15 Bruce Griffiths <bruce.griffiths at 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
> using setting circles and the known coordinates of the (astronomical)
> object of interest.
> 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.
>> 2010/1/15 Brian Kirby<kilodelta4foxmike at 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
>>> 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
>>> 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
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