Ephemeris Generator
Ephemeris Settings
Target Body: *Comet 2P/Encke [1987]*
Observer Location: *Geocentric [Code=500]*
From: *A.D. 1987-08-15 15:31 UT*
To: *A.D. 1987-08-15 16:19 *
Step: *10 minute*
Format: *Calendar Date and Time*
Output Quantities: *2-3,9,14,19-20,23-24,32*
Ref. Frame, RA/Dec Format: *J2000, HMS*
Apparent Coordinates Model: *Airless*
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HORIZONS Generated Ephemeris
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Ephemeris / WWW_USER Mon Aug 16 06:10:58 1999 Pasadena, USA / JPL-Horizons
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Target body name: Encke {source: JPL#67-DASTCOM3}
Center body name: Earth (399) {source: DE-0406LE-0406}
Center-site name: GEOCENTRIC
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Start time : A.D. 1987-Aug-15 15:31:00.0000 UT
Stop time : A.D. 1987-Aug-15 16:19:00.0000 UT
Step-size : 10 minutes
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Center geodetic : 0.000000, 0.000000, 0.00000 {E-lon(deg),Lat(deg),Alt(km)}
Center cylindric: 0.00000, 0.000, 0.000 {E-lon(deg),Dxy(km),Dz(km)}
Center pole/equ : Standard Earth Model {East-longitude +}
Center radii : 6378.1 x 6378.1 x 6356.8 km {Equator, meridian, pole}
Target pole/equ : No model available
Target radii : 3.7 km
Target primary : Sun {source: DE-0406LE-0406}
Interfering body: MOON (Req= 1737.400) km {source: DE-0406LE-0406}
Deflecting body : Sun, EARTH {source: DE-0406LE-0406}
Deflecting GMs : 1.3271E+11, 3.9860E+05 km^3/s^2
Atmos refraction: NO (AIRLESS)
RA format : HMS
Time format : CAL
Units conversion: 1 AU= 149597870.691 km, c= 299792.458 km/s, 1 day= 86400.0 s
Table cut-offs : Elevation (-90deg=NO ), Airmass (>38.0000=NO), Daylight (NO )
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Initial heliocentric osc. elements wrt ecliptic and mean equinox of J2000.0:
EPOCH= 2447000.5 != 1987-Jul-24.0000000 (TDB)
EC= .849890819 QR= .331734319 TP= 2446993.9004405
OM= 334.7398875 W= 186.2535387 IN= 11.9311942
Comet physical & dynamic parameters:
GM= n.a. RAD= 3.7 A1= -5.4D-11
A2= -1.4D-11 M1= 9.8 M2= 14.5
k1= n.a. k2= 5. PHCOF= .030
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Date__(UT)__HR:MN R.A.__(a-apparent)__DEC dRA*cosD d(DEC)/dt T-mag N-mag Ob-lon Ob-lat r rdot delta deldot S-O-T S-T-O N.Pole-RA N.Pole-DC
************************************************************************************************************************************************************************************
1987-Aug-15 15:31 12 17 56.75 -12 35 31.0 287.28 -150.31 9.54 15.93 n.a. n.a. 0.7755769644 31.32086 0.8854238654 0.14811 47.6514 74.8142 n.a. n.a.
1987-Aug-15 15:41 12 18 00.02 -12 35 56.1 287.27 -150.29 9.54 15.93 n.a. n.a. 0.7757025942 31.31962 0.8854244976 0.15939 47.6598 74.8082 n.a. n.a.
1987-Aug-15 15:51 12 18 03.29 -12 36 21.1 287.26 -150.26 9.54 15.93 n.a. n.a. 0.7758282190 31.31839 0.8854251750 0.17067 47.6683 74.8021 n.a. n.a.
1987-Aug-15 16:01 12 18 06.56 -12 36 46.1 287.25 -150.24 9.54 15.93 n.a. n.a. 0.7759538388 31.31715 0.8854258977 0.18195 47.6767 74.7961 n.a. n.a.
1987-Aug-15 16:11 12 18 09.83 -12 37 11.2 287.25 -150.21 9.54 15.93 n.a. n.a. 0.7760794537 31.31592 0.8854266656 0.19323 47.6852 74.7900 n.a. n.a.
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Column meaning:
TIME
Prior to 1972, times are UT1. Dates thereafter are UTC. Any 'b' symbol in
the 1st-column denotes a B.C. date. First-column blank (" ") denotes an A.D.
date. Calendar dates prior to 1582-Oct-15 are in the Julian calendar system.
Later calendar dates are in the Gregorian system.
The TDB uniform time scale is used internally. Conversion between TDB and the
selected non-uniform UT output scale has not been determined for UTC times
after the next July or January 1st. The last known leap-second is used over
any future interval.
NOTE: "n.a." in output means quantity "not available" at the print-time.
R.A._(a-apparent)__DEC. =
Airless apparent right ascension and declination of the target with respect
to the Earth true-equator and the meridian containing the Earth true equinox of
date. Corrected for light-time, gravitational deflection of light, stellar
aberration, precession & nutation. Units:HMS (HH MM SS.ff) and DMS (DD MM SS.f)
dRA*cosD d(DEC)/dt =
The rate of change of target apparent RA and DEC (airless). d(RA)/dt is
multiplied by the cosine of the declination. Units: ARCSECONDS PER HOUR
T-mag N-mag =
Comet's approximate apparent visual total magnitude ("T-mag") and nuclear
magnitude ("N-mag") by following definitions:
T-mag = M1 + 5*log10(delta) + k1*log10(r)
N-mag = M2 + 5*log10(delta) + k2*log10(r) + phcof*beta
Units: none
Ob-lon Ob-lat =
Planetographic longitude and latitude of the center of the target disk seen
by the OBSERVER (1997 IAU model). Units: DEGREES
r rdot =
Target apparent heliocentric range ("r") and range-rate ("rdot") as seen
by observer. Units: AU and KM/S
delta deldot =
Target apparent range ("delta") and range-rate ("delta-dot") relative to
observer. Units: AU and KM/S
S-O-T =
Sun-Observer-Target angle; target's apparent solar elongation seen from
observer location at print-time. If negative, the target center is behind
the Sun. Units: DEGREES
S-T-O =
Sun-Target-Observer angle; target's apparent PHASE ANGLE as seen at
observer's location at print time. Units: DEGREES
N.Pole-RA N.Pole-DC
ICRF/J2000.0 Right Ascension and Declination (1997 IAU rotation model)
of target body's North Pole direction at the time light left the body to
be observed at print time. Units: DEGREES
Computations by ...
Solar System Dynamics Group, Horizons On-Line Ephemeris System
4800 Oak Grove Drive, Jet Propulsion Laboratory
Pasadena, CA 91109 USA
information: http://ssd.jpl.nasa.gov/
connect : telnet ssd.jpl.nasa.gov 6775
e-mail : horizons@ssd.jpl.nasa.gov
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Last modified: 1999 June 30 13:42