Sidereal Time Calculator For Any Date, Time and Longitude
PHP Program by Jay Tanner
Local Date
±
Y M D (Neg=BC)
Local Time
HH MM SS (00 to 24h)
Local Time Zone Offset
HH MM (Neg/Pos = W/E)
ΔT (Delta T)
±
HMS
UT
2460637.5
0.542152777778
-0.208333333333
+0.000000000000
Calendar Mode:
Julian
Gregorian
Longitude:
±Deg.ddd or ±D M S (Neg=W)
-76.8233097222
IMPORTANT:
Make sure that the local time, time zone and longitude are correctly matched for the location.
OPTIONAL:
NASA Polynomial ΔT estimate = +74 sec = +00h 01m 14s
Double-Click Within Text Area to Select ALL Text
SIDEREAL TIME FOR GIVEN DATE, TIME AND LONGITUDE Local Date = 2024 Nov 23 [Saturday] Gregorian JD Number = 2460638 JD00 = 2460637.5 = JD for 00h of date Local Time = 13:00:42 = 0.542152777778 day T Zone Diff = -05:00 = -0.208333333333 day Delta T = +00:00:00 = +0.000000000000 day Astronomical Julian Date: JDTT = JDNum - 0.5 + LTFrac - (TZFrac) + (dTFrac) = 2460638.250486111111 Longitude = -76° 49' 23.915" = -76.8233097222° (W) = -05h 07m 17.594s = -5.1215539815 h ================================================================= Local Mean Sidereal Time at Longitude -76.8233097222° (W) 17h 06m 12.174s = 17.1033816935 h 256° 33' 02.61" = 256.5507254028° Local True Sidereal Time at Longitude = -76.8233097222° (W) 17h 06m 12.053s = 17.1033480368 h 256° 33' 00.79" = 256.5502205513° Greenwich Mean Sidereal Time 22h 13m 29.768s = 22.2249356750 h 333° 22' 26.526" = 333.3740351251° Greenwich True Sidereal Time 22h 13m 29.647s = 22.2249020182 h 333° 22' 24.709" = 333.3735302737° ================================================================= Applied Auxiliary Computations Time Factors Corresponding to Full Astronomical JD T = 0.248959630009 Julian centuries reckoned from J2000.0 t = 0.024895963000 Julian millennia reckoned from J2000.0 Circular Trig Functions of Given Longitude Longitude = -76.8233097222° (W) sin(Lon) = -0.973671722605411 cos(Lon) = +0.227954768756023 tan(Lon) = -4.271337370649689 Nutations (IAU 2000B Series) -1.981" = -0.0005502544° = Nutation in ecliptical longitude +8.861" = +0.0024615096° = Nutation in ecliptical obliquity -0.121s = -0.0005048515° = Equation of the equinoxes Mean Ecliptic Obliquity 23° 26' 09.794" = 23.4360539987° Nutation in Obliquity +8.861" = +0.0024615096° True Ecliptic Obliquity 23° 26' 18.656" = 23.4385155083°
Jay Tanner - PHP Science Labs - 2024 - 1.7