126 lines
6.2 KiB
Plaintext
126 lines
6.2 KiB
Plaintext
API VERSION: 1.2
|
|
API SOURCE: NASA/JPL Horizons API
|
|
|
|
*******************************************************************************
|
|
Revised: April 22, 2021 Neptune 899
|
|
|
|
PHYSICAL DATA (update 2021-May-03):
|
|
Mass x10^24 (kg) = 102.409 Density (g/cm^3) = 1.638
|
|
Equat. radius (1 bar) = 24766+-15 km Volume, 10^10 km^3 = 6254
|
|
Vol. mean radius (km) = 24624+-21 Polar radius (km) = 24342+-30
|
|
Geometric Albedo = 0.41 Flattening = 0.0171
|
|
Sid. rot. period (III)= 16.11+-0.01 hr Sid. rot. rate (rad/s) = 0.000108338
|
|
Mean solar day, h =~16.11 h
|
|
GM (km^3/s^2) = 6835099.97 GM 1-sigma (km^3/s^2) = +-10
|
|
Equ. grav, ge (m/s^2) = 11.15 Pol. grav, gp (m/s^2) = 11.41+-0.03
|
|
Visual magnitude V(1,0)= -6.87
|
|
Vis. mag. (opposition)= +7.84 Obliquity to orbit = 28.32 deg
|
|
Sidereal orbit period = 164.788501027 y Sidereal orbit period = 60189 d
|
|
Mean daily motion = 0.006020076dg/d Mean orbit velocity = 5.43 km/s
|
|
Atmos. temp. (1 bar) = 72+-2 K Escape speed (1 bar) = 23.5 km/s
|
|
Aroche(ice)/Rp = 2.98 Hill's sphere rad., Rp = 4700
|
|
Perihelion Aphelion Mean
|
|
Solar Constant (W/m^2) 1.54 1.49 1.51
|
|
Maximum Planetary IR (W/m^2) 0.52 0.52 0.52
|
|
Minimum Planetary IR (W/m^2) 0.52 0.52 0.52
|
|
*******************************************************************************
|
|
|
|
|
|
*******************************************************************************
|
|
Ephemeris / API_USER Thu Aug 14 15:51:58 2025 Pasadena, USA / Horizons
|
|
*******************************************************************************
|
|
Target body name: Neptune (899) {source: nep097_merged}
|
|
Center body name: Sun (10) {source: nep097_merged}
|
|
Center-site name: BODY CENTER
|
|
*******************************************************************************
|
|
Start time : A.D. 2025-Jan-01 00:00:00.0000 TDB
|
|
Stop time : A.D. 2025-Jan-01 00:01:00.0000 TDB
|
|
Step-size : 1 minutes
|
|
*******************************************************************************
|
|
Center geodetic : 0.0, 0.0, 0.0 {E-lon(deg),Lat(deg),Alt(km)}
|
|
Center cylindric: 0.0, 0.0, 0.0 {E-lon(deg),Dxy(km),Dz(km)}
|
|
Center radii : 695700.0, 695700.0, 695700.0 km {Equator_a, b, pole_c}
|
|
Output units : AU-D
|
|
Calendar mode : Mixed Julian/Gregorian
|
|
Output type : GEOMETRIC cartesian states
|
|
Output format : 2 (position and velocity)
|
|
Reference frame : Ecliptic of J2000.0
|
|
*******************************************************************************
|
|
JDTDB
|
|
X Y Z
|
|
VX VY VZ
|
|
*******************************************************************************
|
|
$$SOE
|
|
2460676.500000000 = A.D. 2025-Jan-01 00:00:00.0000 TDB
|
|
X = 2.987992735576156E+01 Y =-6.341879950443392E-01 Z =-6.754997950415415E-01
|
|
VX= 3.941595250081164E-05 VY= 3.160389775728832E-03 VZ=-6.636996572427530E-05
|
|
2460676.500694444 = A.D. 2025-Jan-01 00:01:00.0000 TDB
|
|
X = 2.987992738313355E+01 Y =-6.341858003292957E-01 Z =-6.754998411317725E-01
|
|
VX= 3.941539715732043E-05 VY= 3.160389549672231E-03 VZ=-6.636990015457822E-05
|
|
$$EOE
|
|
*******************************************************************************
|
|
|
|
TIME
|
|
|
|
Barycentric Dynamical Time ("TDB" or T_eph) output was requested. This
|
|
continuous coordinate time is equivalent to the relativistic proper time
|
|
of a clock at rest in a reference frame co-moving with the solar system
|
|
barycenter but outside the system's gravity well. It is the independent
|
|
variable in the solar system relativistic equations of motion.
|
|
|
|
TDB runs at a uniform rate of one SI second per second and is independent
|
|
of irregularities in Earth's rotation.
|
|
|
|
CALENDAR SYSTEM
|
|
|
|
Mixed calendar mode was active such that calendar dates after AD 1582-Oct-15
|
|
(if any) are in the modern Gregorian system. Dates prior to 1582-Oct-5 (if any)
|
|
are in the Julian calendar system, which is automatically extended for dates
|
|
prior to its adoption on 45-Jan-1 BC. The Julian calendar is useful for
|
|
matching historical dates. The Gregorian calendar more accurately corresponds
|
|
to the Earth's orbital motion and seasons. A "Gregorian-only" calendar mode is
|
|
available if such physical events are the primary interest.
|
|
|
|
REFERENCE FRAME AND COORDINATES
|
|
|
|
Ecliptic at the standard reference epoch
|
|
|
|
Reference epoch: J2000.0
|
|
X-Y plane: adopted Earth orbital plane at the reference epoch
|
|
Note: IAU76 obliquity of 84381.448 arcseconds wrt ICRF X-Y plane
|
|
X-axis : ICRF
|
|
Z-axis : perpendicular to the X-Y plane in the directional (+ or -) sense
|
|
of Earth's north pole at the reference epoch.
|
|
|
|
Symbol meaning [1 au= 149597870.700 km, 1 day= 86400.0 s]:
|
|
|
|
JDTDB Julian Day Number, Barycentric Dynamical Time
|
|
X X-component of position vector (au)
|
|
Y Y-component of position vector (au)
|
|
Z Z-component of position vector (au)
|
|
VX X-component of velocity vector (au/day)
|
|
VY Y-component of velocity vector (au/day)
|
|
VZ Z-component of velocity vector (au/day)
|
|
|
|
ABERRATIONS AND CORRECTIONS
|
|
|
|
Geometric state vectors have NO corrections or aberrations applied.
|
|
|
|
Computations by ...
|
|
|
|
Solar System Dynamics Group, Horizons On-Line Ephemeris System
|
|
4800 Oak Grove Drive, Jet Propulsion Laboratory
|
|
Pasadena, CA 91109 USA
|
|
|
|
General site: https://ssd.jpl.nasa.gov/
|
|
Mailing list: https://ssd.jpl.nasa.gov/email_list.html
|
|
System news : https://ssd.jpl.nasa.gov/horizons/news.html
|
|
User Guide : https://ssd.jpl.nasa.gov/horizons/manual.html
|
|
Connect : browser https://ssd.jpl.nasa.gov/horizons/app.html#/x
|
|
API https://ssd-api.jpl.nasa.gov/doc/horizons.html
|
|
command-line telnet ssd.jpl.nasa.gov 6775
|
|
e-mail/batch https://ssd.jpl.nasa.gov/ftp/ssd/horizons_batch.txt
|
|
scripts https://ssd.jpl.nasa.gov/ftp/ssd/SCRIPTS
|
|
Author : Jon.D.Giorgini@jpl.nasa.gov
|
|
*******************************************************************************
|