[time-nuts] Sidereal time

[Bruce Griffiths]

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<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 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
>>
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>
>
>