Then get the hour angle based on RA and local sidereal time ( or RA, observer's longitude, and Greenwich sidereal time ), and use the relations you've found to convert HA & dec to altitude and azimuth.
32.
Then get the hour angle based on RA and local sidereal time ( or RA, observer's longitude, and Greenwich sidereal time ), and use the relations you've found to convert HA & dec to altitude and azimuth.
33.
Babylonian astronomers knew of the equation of time and were correcting for it as well as the different rotation rate of the stars, sidereal time, to obtain a mean solar time much more accurate than their water clocks.
34.
More exactly, sidereal time is the angle, measured from the observer's meridian, along the celestial equator, to the great circle that passes through the March equinox and both poles, and is usually expressed in hours, minutes, and seconds.
35.
Sidereal time was determined on Riefler Clock No . 220 by measuring the position of the stars in the night sky based on the position of the telescope ( which could only move north-south along a meridian line ).
36.
Sidereal time is a measure of the position of the Earth in its rotation around its axis, or time measured by the apparent diurnal motion of the vernal equinox, which is very close to, but not identical to, the motion of stars.
37.
The table is to be entered with the local apparent sidereal time of observation ( LAST ), and gives the value of " a " 0, " b " 0 directly; interpolation, with maximum differences of 0'. 7, can be done mentally.
38.
Unlike the reckoning of local solar time in time zones, incrementing by ( usually ) one hour, differences in local sidereal time are reckoned based on actual measured longitude, to the accuracy of the measurement of the longitude, not just in whole hours.
39.
Is there any need to make a similar correction when trying to read sidereal time by the stars ? ( I know there is a seasonal correction to get the time of day from sidereal time, but it is linear, no ? )-- Juuitchan
40.
Is there any need to make a similar correction when trying to read sidereal time by the stars ? ( I know there is a seasonal correction to get the time of day from sidereal time, but it is linear, no ? )-- Juuitchan
