About time keeping, the definition of “sidereal” is “of or with respect to the distant stars (i.e. the constellations or the fixed stars, not the sun or planets)”, as defined after a google search.

OBSERVATORY practice in the past has always been to use separate clocks for indicating solar and sidereal time. In the case of quartz crystal clocks, this practice could be continued by using two ...

IN the Paris Observatory a number of clocks provided with two dials showing sidereal and mean time were installed last year as part of the permanent equipment of the Observatory. This suggested to me ...