Friday, December 14, 2007

FINDING GHA, DEC, LHA OF THE STARS

STEP 1
Using GMT, and Greenwich date of observation, enter Nautical Almanac and record tabulated hourly value of GHA of Aries.

STEP 2
On the same daily page find the SHA and DEC of Canopus and enter them in your format. Since, there is no "d" correction, the DEC is entered on the bottom declination line.

STEP 3
Example: Turn to the yellow pages of the Nautical Almanac, and find lets say the 25 minute page and enter with 56-seconds." Then under the "ARIES" column find the increase in the GHA ARIES since the last tabulated (hourly) value. This is your M&S correction and enter this in your format.

STEP 4
Add the GHA ARIES, M&S and SHA of star to get the GHA star.

STEP 5
Bring down your DR longitude and enter it in your form. The Rule is:
LHA STAR = GHA STAR + EAST LONGITUDE

LHA STAR = GHA STAR - WEST LONGITUDE