[time-nuts] Sidereal time

[J. Forster]

True. At the observatory where I worked in the 70s there was a very
accurate pendulum clock with a contact that incremented the clocks in the
domes every siderial second.

-John

=============




> 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
>>>
>>> _______________________________________________
>>> time-nuts mailing list -- time-nuts at 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 at febo.com
> To unsubscribe, go to
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>
>