[Aavso-photometry] Reasonably Priced Sidereal Clock?

[Tim Crawford]

I just ran across what I consider to be a very
reasonably priced Sidereal Clock for $98.00 or the
Mechanism for $59.00.   It is availalbe with either
The Northern or Southern Hemisphere Star Map on the
face.

http://moggadapters.com.au/astro/adapter.asp

Our “normal” (standard time) time system is really
solar time and is based upon the solar day, which is
the time it takes the earth to make one rotation and
return the sun to the same place in the sky.

Sidereal (pronounced, Sigh-dear-ee-uhl) time is based
upon a Sidereal day, which is the time it takes the
earth to make one rotation and return the stars to the
same place in the sky.

Remember that the main advantage of Sidereal time is
that it provides us with the R.A. of objects
Transiting (passing)  the local meridian at any given
time.

As an example, If an object has a R.A. (right
ascension) of 08h 24m 16s then we know that an object
with that R.A. will transit (pass the local Meridian -
imaginary line running North to South in the sky) at a
Sidereal time of 08:24:16.

I should point out that there are several freebie pgms
availalbe that will readout Sidereal time on a PeeCee:

http://www.radiosky.com/sidclockhelp.html

http://users.zoominternet.net/~matto/

Ad Astra

Tim Crawford
Arch Cape Observatory