Navigation: Deep-Sky Planner Help > About Documents > Brief Planet Ephemeris Document >

Brief Planet Ephemeris Report

Planet Ephemeris Report

The Planet Ephemeris Report contains an ephemeris calculation for each instant in the Ephemeris time period selected. Times are accurate for the observer's location. Dates, times and angular values are given in the format selected in Preferences.

Printed and exported documents contain a header section that on-screen documents provide in the settings pane of the document window. The header includes:

▪document name

▪observer's location (can be omitted from printing by activating the Print Saver)

▪Ephemeris time period (can be omitted from printing by activating the Print Saver)

The body of the Detailed Planet Ephemeris report (on-screen, printed, and exported) is section-oriented by solar system object and time. All ephemeris calculations for an object appear together in chronological order, followed by all calculations for the next object, if any. Preceding the first ephemeris calculation for each day, the date, rise time, azimuth at rise time, set time, azimuth at set time, transit, and altitude at transit time are listed. The ephemeris calculations for each time during the day follow.

The body of the Brief Planet Ephemeris report (on-screen, printed, and exported) contains a line of information per solar system object and time. Physical ephemeris information is not available in this style report.

Name	Description
Con	Constellation in which the object is located.
RA/ Decl	Apparent topocentric position. The angles are formatted as specified in Preferences.
Size	Angular size taking into account distance from earth.
Mag	Apparent magnitude taking into account phase, and distance from earth and sun.
Elng	Angular distance from the object to the sun, and direction (E=East, W=West)
Ph	Percent of the disk that is illuminated by sun light.
Alt/ Az	Apparent altitude and azimuth at the instant of the ephemeris calculation. The data are formatted as specified in Preferences.
LHA	Local hour angle at the ephemeris date and time. The angle is formatted as hours and minutes East or West of the meridian.
SA2000	Chart number on which the object appears in Sky Atlas 2000.0.
U2000	Volume and page number on which the object appears in Uranometria 2000.0. Note that there is some overlap in the two volumes, but the page number is valid for either volume.
MSA	Volume and page number on which the object appears in Millennium Star Atlas
HB	Chart series (B & C) and page number on which the object appears in Herald-Bobroff AstroAtlas.
U2000.2	Volume and page number on which the object appears in Uranometria 2000.0 2d Ed. Note that there is some overlap in the two volumes, but the page number is valid for either volume
PSA	Chart number on which the object appears in Pocket Sky Atlas.
IDSA	Chart number on which the object appears in interstellarum Deep Sky Atlas.
Dist (Earth)	Distance between object and earth measured in astronomical units (au), except moon which is measured in kilometers (km).
Dist (Sun)	Distance between object and sun measured in astronomical units (au).
Motion	Angular distance traveled by the object between this instant of the ephemeris calculation and the previous (blank if there is no previous instant in this report)
Rise, Set, Az	Time of rise, set, and apparent azimuth at rise, and set time for your location. If your location has a local horizon model defined for it and the model is applied to the ephemeris calculation, rise & set times are the approximate times at which an object rises above and sets beneath the local horizon model. The data are formatted as specified in Preferences.
Transit, Alt	Time of transit and apparent altitude at transit time for your location. The data are formatted as specified in Preferences.
Vis Pred	Predicted visibility of the planet computed by a combination of visibility models. Please see visibility modeling for possible values.

The physical ephemeris section appears only in detailed reports and varies according to object.

Physical Ephemeris data for Sun:

Name	Description
Lat of solar disk's center	Heliographic latitude of the center of the Sun. If this angle is positive, we see the north pole of the Sun; if negative, we see the south pole. This value is commonly known as B0 (B0.)
Lng of solar disk's center	Heliographic longitude of the center of the Sun. The Sun rotates at about 13°.2 per day towards the west. This value is commonly known as L0 (L0.)
PA of N pole	Angle measured eastward from the Solar north pole.
Carrington rotation number	A rotation occurs when L0 passes through 0° (about every 27.25 days.) Rotation number 1 occurred on 9 Nov 1853.

Physical Ephemeris data for Mars:

Name	Description
Decl of Earth from Mars	Planetocentric declination of the Earth. If this angle is positive, we see the north pole of Mars; if negative, we see the south pole. This is commonly referred to as De.
Decl of Sun from Mars	Planetocentric declination of the Sun. If this angle is positive, the north pole of Mars is illuminated; if negative, the south pole is illuminated. This is commonly referred to as Ds.
Greatest defect of illum	Largest angular distance between the dark limb and the terminator on Mars.
PA of defect of illum	Angle measured eastward from north of the greatest defect of illumination. This is also PA of the bright limb + 180°.
Lng of central meridian	Planetographic longitude of the meridian line between poles. This is the Martian longitude of the center of the disk as you see it.
PA of N pole	Angle measured eastward from the Martian north pole.

Physical Ephemeris data for Jupiter:

Name	Description
Decl of Earth from Jupiter	Planetocentric declination of the Earth. If this angle is positive, we see the north pole of Jupiter; if negative, we see the south pole. This is commonly referred to as De.
Decl of Sun from Jupiter	Planetocentric declination of the Sun. If this angle is positive, the north pole of Jupiter is illuminated; if negative, the south pole is illuminated. This is commonly referred to as Ds.
Lng of central meridian Sys I	Planetographic longitude of the meridian at low latitude (<10° N or S). This is the Jovian longitude of the center of the disk in and near the Equatorial Zone.
Lng of central meridian Sys II	Planetographic longitude of the meridian at high latitude (>10° N or S). This is the Jovian longitude of the center of the disk at the extremes of and above the equatorial belts.
PA of N pole	Angle measured eastward from the Jovian north pole.

Physical Ephemeris data for Saturn:

Name	Description
Outer diameter of Ring A	Dimensions of the elliptical outermost visible ring of Saturn. Ring F lies outside Ring A but is not visible to most amateur observers. The minor axis of this ellipse is 0" when the inclination of Saturn's rings to earth is 0°.
Outer diameter of Ring B	Dimensions of the elliptical inner ring of Saturn. Ring B is separated from Ring A by the Cassini Division. Ring C lies within Ring B but is not visible to most amateur observers.
Width of Cassini's Division	Dimensions of the dark ellipse between Rings A & B.
Lat of Earth from Saturn	Planetocentric latitude of the Earth. This is also the inclination angle of the rings to earth. If this angle is positive, we see the north pole of Saturn and the north surface of the rings; if negative, we see the south pole and surface.
Lat of Sun from Saturn	Planetocentric latitude of the Sun. If this angle is positive, the north pole of Saturn and the north surface of the rings are illuminated; if negative, the south pole and surface are illuminated.
PA of N pole	Angle measured eastward from the Saturnian north pole.

Physical Ephemeris data for Moon:

Name	Description
Phase angle	Selenocentric elongation of the earth from the sun (180° = new, 0° = full)
PA of N pole	Angle measured eastward from the lunar north pole
PA of bright limb	Angle measured eastward between the midpoint of the illuminated limb and the north point of the lunar disk
Optical libration	variation in the position of the earth with respect to the moon
Physical libration	'wobble' of the moon about its axis of rotation
Total libration	sum of optical and physical librations