Extended name  Unit  Column name  Full description  Picture 
TIME  Date__(UT)__HR:MN  TIME  
Solar presence  Solar presence  Time tag is followed by a blank, then a solarpresence symbol: '*' Daylight (refracted solar upperlimb on or above apparent horizon) 'C' Civil twilight/dawn 'N' Nautical twilight/dawn 'A' Astronomical twilight/dawn ' ' Night OR geocentric ephemeris 

Lunar presence  Lunar presence  The solarpresence symbol is immediately followed by a lunarpresence symbol: 'm' Refracted upperlimb of Moon on or above apparent horizon ' ' Refracted upperlimb of Moon below apparent horizon OR geocentric ephemeris 

1. Astrometric RA and Dec  HH MM SS.ffff  R.A._(ICRF/J2000.0) 
Astrometric(*) right ascension and declination of the target with respect
to the specified observing center/site, epressed with respect to the planetary ephemeris ICRF/J2000 equator and equinox (i.e. for equator and equinox calculated for date J2000). Compensated for light travel time only. (*) Not depending on features of body where observer is located. 

DEC_(ICRF/J2000.0)  
*2. Apparent RA and Dec  HH MM SS.ffff  R.A._(aapp)  Airless apparent(*) right ascension and declination of the target center with respect to specified observing center/site. Corrections and reference system vary depending on body where observing site is located:
(*) Corrected as per abovelised quantities. Reference 1 Reference 2 

DEC_(aapp)  
3. Rates; RA and Dec  ARCSECONDS PER HOUR  dRA*cosD  The rate of change of target center apparent RA and DEC (airless). d(RA)/dt is multiplied by the cosine of the declination.
Reference system:


d(DEC)/dt  
*4. Apparent Az and Elev  DEGREES  Azi_(aapp)  Airless apparent azimuth and elevation of target center. Adjusted for lighttime, the gravitational deflection of light, stellar aberration, precession and nutation. Azimuth measured North(0) > East(90) > South(180) > West(270) > North (360). Elevation is with respect to plane perpendicular to local zenith direction. Topocentric only  
Elev_(aapp)  
5. Rates; AZ and El  ARCSECOND/MINUTE  dAZ*cosE  The rate of change of target center apparent azimuth and elevation (airless). d(AZ)/dt is multiplied by the cosine of the
elevation angle. Topocentric only 

d(ELV)/dt  
6. X & Y satellite coordinates & position angle  ARCSECONDS  X_(satprim)  Satellite differential(*) X coordinate WRT the primary body. X=[(RA_sat  RA_primary)*COS(DEC_primary)] NonLunar satellites only. (*)Differences between angles on the celestial sphere 
(Click for detailed explanation) 
Y_(satprim)  Satellite differential Y coordinate WRT the primary body. Y=(DEC_satDEC_primary). NonLunar satellites only. (*)Differences between angles on the celestial sphere 

SatPANG  Satellite position angle in celestial sphere. Angle start: line joining primarybody center to North Celestial Pole Angle end: line joining primarybody center to target center (=satellite orbiting the primary body) Direction: counterclockwise (CCW, or east) 

7. Local apparent sidereal time  HH MM SS.ffff  L_Ap_Sid_Time  Local Apparent Sidereal Time Angle measured over the plane of "trueequator ofdate" of the body. Angle start: Meridian containing the observer on the centerbody. Angle end: meridian containing the true Earth equinox (defined by intersection of the true Earth equator of date with the ecliptic of date). Direction: Westward Topocentric only. 

8. Airmass  None (airmass) and magnitudes (extinction)  amass  Available only for topocentric Earth sites when the target is above the horizon. Relative optical airmass and visual magnitude extinction. Airmass is the ratio between the absolute optical airmass for the target's refracted CENTER point to the absolute optical airmass at zenith. Also output is the estimated visual magnitude extinction due to the atmosphere, as seen by the observer. 

9. Visible magnitude and surface brightness  magnitudes  mag_ex  Target's approximate apparent visual magnitude & surface brightness. For planets and satellites, values are available only for solar phase angles in the range generally visible from Earth. This is to avoid extrapolation of models beyond their valid (databased) limits.  
MAGNITUDE  APmag  
VISUAL MAGNITUDES PER SQUARE ARCSECOND  Sbrt  
10. Illuminated fraction  PERCENT  Illu%  Fraction of target circular disk illuminated by Sun (phase), as seen by observer (=quantity 25). For value of phase angle see quantities 24 and 43  
11. Defect of illumination  ARCSECONDS  Def_illu  Defect of illumination. Maximum angular width of target circular disk diameter not illuminated by the Sun.  
12. Satellite angle separation/visibility  ARCSECONDS  angsep  Targetprimary angular separation. Angle start: line joining observer to target (satellite) Angle end: line joining observer to primary body around which the satellite is orbiting Direction: not used 

Nonlunar natural satellite visibility codes (limbtolimb)  v  Target visibility w.r.t its primary body (i.e. eclipses/occultations). Possible values: /t = Transitting primary body disk /O = Occulted by primary body disk, /p = Partial umbral eclipse /P = Occulted partial umbral eclipse /u = Total umbral eclipse /U = Occulted total umbral eclipse, / = Target is the primary body /* = None of above ("free and clear") 

13. Target angular diam.  ARCSECONDS  Angdiam  The equatorial angular width of the target body full disk, if it were fully visible to the observer.  
14. Observer sublongitude and sublatitude  DEGREES  Oblon  Apparent planetodetic longitude and latitude (IAU2009 model) of the center of the target disk seen by the observer
at printtime. For a nonspherical target shape, this is not exactly the same as the "subobserver" (nearest) point , but if not an irregular body shape, it is generally very close. Downleg light traveltime from target to observer is taken into account. Latitude is the angle between the equatorial plane and the line perpendicular to the reference ellipsoid of the body. The reference ellipsoid is an oblate spheroid with a single flatness coefficient in which the yaxis body radius is taken to be the same value as the xaxis radius. For the gas giants Jupiter, Saturn, Uranus and Neptune, IAU2009 longitude is based on the "System III" prime meridian rotation angle of the magnetic field. By contrast, pole direction (thus latitude) is relative to the body dynamical equator. There can be an offset between the magnetic pole and the dynamical pole of rotation. Positive longitude is to the EAST. 

Oblat  
15. Sun sublongitude and sublatitude  DEGREES  Sllon  Apparent planetodetic longitude and latitude of the Sun (IAU2009) as seen by the observer at printtime. For a nonspherical target shape, this is not exactly the same as the "subsolar" (nearest) point , but if not an irregular body shape, it is generally very close. Light traveltime from Sun to target and from target to observer is taken into account. Latitude is the angle between the equatorial plane and the line perpendicular to the reference ellipsoid of the body. The reference ellipsoid is an oblate spheroid with a single flatness coefficient in which the yaxis body radius is taken to be the same value as the xaxis radius. For the gas giants Jupiter, Saturn, Uranus and Neptune, IAU2009 longitude is based on the "System III" prime meridian rotation angle of the magnetic field. By contrast, pole direction (thus latitude) is relative to the body dynamical equator. There can be an offset between the magnetic pole and the dynamical pole of rotation. Positive longitude is to the EAST. 

Sllat  
16. Sub Sun Position Angle and Distance  DEGREES  SN.ang  Target subsolar point position angle (CCW, or east, with respect to the direction of the trueofdate Celestial North Pole)  
ARCSECONDS  SN.dist  Target subsolar point angular distance from the subobserver point (center of disk) at print time. Negative distance indicates the subsolar point is on the hemisphere hidden from the observer.  
17. North Pole Position Angle and Distance  DEGREES  NP.ang  Target's North pole position angle (CCW, or east, with respect to direction of trueofdate Celestial North Pole) at observation time.  
ARCSECONDS  NP.dist  Target's North pole angular distance from the subobserver point (center of disk) at observation time. Negative distance indicates the planet's North pole is on the hidden hemisphere.  
18. Helio eclip. longitude and latitude  DEGREES  hEclLon  Geometric heliocentric J2000 ecliptic longitude and latitude of target center at the instant light leaves it to be observed at print time (print time minus 1way lighttime).  
hEclLat  
19. Helio range and rng rate  AU  r  Heliocentric range ("r", lighttimecorrected) of the target center at the instant light seen by the observer at printtime would have left the target center (printtime minus downleg lighttime). The Suntotarget distance traveled by a ray of light emanating from the center of the Sun that reaches the target center point at some instant and is recordable by the observer one downleg lighttime later at printtime.  
20. Obsrv range and rng rate  AU  delta  Observercentric range ("delta") of the target center at the instant light seen by the observer at printtime would have left the target center (printtime minus downleg lighttime); the targettoobserver distance traveled by a light ray emanating from the center of the target and recorded by the observer at printtime.  
21. OneWay LightTime  MINUTES  1way_LT  1way downleg lighttime from target center to observer. The elapsed time since light (observed at printtime) would have left or reflected off a point at the center of the target.  
22. Speed wrt Sun and observer  KM/S  VmagSn  Heliocentric magnitude of target center velocity at the time light left the target center to be observed (print time minus 1way lighttime). These are absolute values of the velocity vectors (total speeds) and do not indicate direction of motion.  
VmagOb  Observercentric magnitude of target center velocity at the time light left the target center to be observed (print time minus 1way lighttime). These are absolute values of the velocity vectors (total speeds) and do not indicate direction of motion.  
23. SunObserverTarget ELONG angle  DEGREES  SOT  SunObserverTarget angle; target's apparent SOLAR ELONGATION seen from the observer location at printtime. The '/r' column indicates the target's apparent position relative to the Sun in the observer's sky, as described below:
NOTE: The SOT solar elongation angle is numerically the minimum separation angle of the Sun and target in the sky in any direction. It does NOT indicate the amount of separation in the leading or trailing directions, which are defined in the equator of a spherical coordinate system. 

24. SunTargetObserver approximate PHASE angle  DEGREES  STO  "STO" is the Sun>Target>Observer angle; the interior vertex angle at target center formed by a vector to the apparent center of the Sun at reflection time on the target and the apparent vector to the observer at printtime. Slightly different from true PHASE ANGLE (requestable separately as quantity "43") at the few arcsecond level in that it includes stellar aberration on the downleg from target to observer. See also quantities 10 and 25 for illumination percentage.  
25. TargetObserverMoon/Illumination percentage  DEGREES  TOM  TargetObserverMoon (or TargetObserverInterferingBody) apparent elongation angle, seen by the observer, between the target
body center and the center of a potential visually interfering body (such
as the Moon but, more generally, the largest body in the system except for
the one the observer is on). A negative elongation angle indicates the target center is behind the interfering body. The specific interfering body for an observing site is given in the output header. Labels: TOM, Illu% (Earth observer, 'M' denoting "Moon") TOI, Illu% (NonEarth observer). 

%  MN_Illu%  Moon/Body illuminated percentage Fraction of the Moon (or Interfering Body) disk that is illuminated by the Sun (=quantity 10). 

26. ObserverPrimaryTarget angle  DEGREES  OPT  ObserverPrimaryTarget angle; apparent angle between a target satellite, its primary's center and an observer, at observing location, at print time.  
27. Radial and vel posn.ang  DEGREES  PsAng  The position angles of the extended Sun>target radius vector as seen in the observer's planeofsky, measured CCW (east) from reference frame North Celestial Pole. Primarily intended for ACTIVE COMETS, "PsAng" is an indicator of the comet's gastail orientation in the sky (being in the antisunward direction)  
PsAMV  Negative of the target's heliocentric velocity vector, as seen in the observer's planeofsky, measured CCW (east) from reference frame North Celestial Pole. Primarily intended for ACTIVE COMETS, "PsAMV" is an indicator of dusttail orientation.  
28. Orbit Plane Angle  DEGREES  PlAng  Angle between observer and target orbital plane, measured from center of target at the moment light seen at observation time leaves the target. Positive values indicate observer is above the object's orbital plane, in the direction of reference frame +z axis.  
29. Constellation name  text  Cnst  Constellation ID; the 3letter abbreviation for the name of the constellation containing the target center's astrometric position, as defined by IAU (1930) boundary delineation. See documentation for list of abbreviations.  
30. DeltaT (TDB  UT)  SECONDS  TDBUT  Difference between the uniform Barycentric Dynamical timescale and the Earthrotation dependent Universal Time. Prior to 1962, the difference is with respect to UT1 (TDBUT1) and the 0.002 second maximum amplitude distinction between TT and TDB is not maintained. For 1962 and later, the difference is with respect to UTC (TDBUTC) and periodic terms less than 1.e6 second are ignored. Values beyond the next July or January 1st may change if a leapsecond is later required by the IERS. Values from the present date forward through the next ~78 days are predictions; beyond that prediction interval, the last prediction is taken as a constant for all future dates.  
*31. Observer ecliptic longitude and latitude  DEGREES  ObsEcLon  Observercentered Earth eclipticofdate longitude and latitude of the target center's apparent position, adjusted for lighttime, the gravitational deflection of light and stellar aberration. Although centered on the observer, the values are expressed relative to coordinate basis directions defined by the Earth's true equatorplane, equinox direction, and mean ecliptic plane at print time.  
ObsEcLat  
32. North pole RA and Dec  DEGREES  N.PoleRA  ICRF/J2000.0 Right Ascension and Declination (IAU2009 rotation model) of target body's North Pole direction at the time light left the body to be observed at print time.  
N.PoleDC  
33. Galactic latitude  DEGREES  GlxLon  Observercentered Galactic System II (post WW II) longitude and latitude of the target center's apparent position. Adjusted for lighttime, gravitational deflection of light, and stellar aberration.  
GlxLat  
34. Local apparent SOLAR time  HH MM SS.ffff  L_Ap_SOL_Time  Topocentric only. Local Apparent SOLAR Time for observing site. This is the time indicated by a sundial.  
35. Earth > site lighttraveltime  MINUTES  399_ins_LT  Instantaneous lighttime of the station with respect to Earth center at printtime. The geometric (or "true") separation of site and Earth center, divided by the speed of light.  
>36. RA and Dec uncertainty  ARCSECONDS  RA_3sigma  Uncertainty in RightAscension and Declination. Output values are the formal +/ 3 standarddeviations (sigmas) around nominal position.  
DEC_3sigma  
>37. POS error ellipse  ARCSECONDS  SMAA_3sig  Planeofsky (POS) error ellipse data. These quantities summarize the target's 3dimensional 3standarddeviation formal uncertainty volume projected into a reference plane perpendicular to the observer's lineofsight. SMAA_3sig = Angular width of the 3sigma error ellipse semimajor axis in POS. 

ARCSECONDS  SMIA_3sig  Planeofsky (POS) error ellipse data. These quantities summarize the target's 3dimensional 3standarddeviation formal uncertainty volume projected into a reference plane perpendicular to the observer's lineofsight. SMIA_3sig = Angular width/ of the 3sigma error ellipse semiminor axis in POS. 

DEGREES  Theta  Planeofsky (POS) error ellipse data. These quantities summarize the target's 3dimensional 3standarddeviation formal uncertainty volume projected into a reference plane perpendicular to the observer's lineofsight. Theta = Orientation angle of the error ellipse in POS; the clockwise angle from the direction of increasing RA to the semimajor axis of the error ellipse, in the direction of increasing DEC. 

ARCSECONDS ^ 2  Area_3sig  Planeofsky (POS) error ellipse data. These quantities summarize the target's 3dimensional 3standarddeviation formal uncertainty volume projected into a reference plane perpendicular to the observer's lineofsight. Area_3sig = Area of sky enclosed by the 3sigma error ellipse. 

>38. POS uncertainty (RSS)  ARCSECONDS  POS_3sigma  The RootSumofSquares (RSS) of the 3standard deviation planeofsky error ellipse major and minor axes. This single pointing uncertainty number gives an angular distance (a circular radius) from the target's nominal position in the sky that encompasses the errorellipse.  
>39. Range and rngrate sig.  KM  RNG_3sigma  Range +/ 3 standarddeviation formal uncertainty.  
RNGRT_3sig  
>40. Doppler/delay sigmas  HERTZ  DOP_S_3sig  Doppler radar uncertainties at Sband (2380 MHz) frequency  
HERTZ  DOP_X_3sig  Doppler radar uncertainties at Xband (8560 MHz) frequency  
SECONDS  RT_delay_3sig  Doppler radar roundtrip (total) delay to firstorder.  
41. True anomaly angle  DEGREES  Tru_Anom  Apparent true anomaly angle of the target's heliocentric orbit position; the angle in the target's instantaneous orbit plane from the orbital periapse direction to the target, measured positively in the direction of motion. The position of the target is taken to be at the moment light seen by the observer at printtime would have left the center of the object. That is, the heliocentric position of the target used to compute the true anomaly is one downleg lighttime prior to the printtime.  
*42. Local apparent hour angle  HH MM SS.fff  L_Ap_Hour_Ang  Earth topocentric only Local apparent HOUR ANGLE of target at observing site. The angle between the observer's meridian plane, containing Earth's axis ofdate and local zenith direction, and a great circle passing through Earth's axisofdate and the target's direction, measured westward from the zenith meridian to target meridian along the equator. Negative values are angular times UNTIL transit. Positive values are angular times SINCE transit. Exactly 24_hrs/360_degrees.  
43. PHASE angle and bisect  DEGREES  phi  "phi" is the true PHASE ANGLE at the observer's location at print time. See also 10, 24 and 25  
PABLON  J2000 ecliptic longitude of the phase angle bisector direction; the outward directed angle bisecting the arc created by the apparent vector from Sun to target center and the astrometric vector from observer to target center. For an otherwise uniform ellipsoid, the time when its longaxis is perpendicular to the PAB direction approximately corresponds to lightcurve maximum (or maximum brightness) of the body. PAB is discussed in Harris et al., Icarus 57, 251258 (1984).  
PABLAT  J2000 ecliptic latitude of the phase angle bisector direction; the outward directed angle bisecting the arc created by the apparent vector from Sun to target center and the astrometric vector from observer to target center. For an otherwise uniform ellipsoid, the time when its longaxis is perpendicular to the PAB direction approximately corresponds to lightcurve maximum (or maximum brightness) of the body. PAB is discussed in Harris et al., Icarus 57, 251258 (1984). 