[time-nuts] Re: Derivation of time from celestial sight

[Bruce Griffiths]

Surely Polaris is a spectacularly poor choice for obtaining accurate Sidereal time via a meridian transit of a known star?
A theodolite suited to high altitude observations like the Wild T4 was is desirable.

Otherwise a prism and a mercury mirror 9or equivalent) can be used to covert a theodolite into a prismatic astrolabe.

Bruce.

> On 28/12/2021 09:18 Brent <brent.evers at gmail.com> wrote:
> 
>  
> My understanding (and I could be wrong) is that one could derive 'stellar'
> time from a start sight/fix on polaris or another well tracked celestial
> object.  I was once told that early editions of Bowditch provided the
> process (for the moon I was told) although one of the relatively old
> edition's that I have doesn't provide it.
> 
> Some theodolite manufacturers provided attachments to aid the process (for
> the high zenith where a theodolite experiences reduced accuracy), and those
> attachments were dated and calibrated for their year of manufacture and
> came with tables for use in future years.
> 
> That's about all I know or can find on the subject.  Can anyone here point
> me to any published literature?  Anyone have experience trying?  Any idea
> what type of accuracy can be expected?
> 
> Got some new toys coming and need something to do with them....
> 
> Brent
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