Comet Input dialog box (Data | Comets and Minor Planets, Comet tab, Edit/Add button)

Use the Comet Input dialog box to edit the orbital element data for a comet. TheSky6 uses this information to compute the comets' position and display it on the Virtual Sky.

The format of

Name

This is a name you assign to the comet for identification purposes.

Orbital elements group

Eccentricity (a'/a)

The measure of an ellipse's distortion from a circle. This defines the shape of the comet's orbit.

Perihelion distance (P-Sun)

The distance, in astronomical units, of the comet's closest approach to the Sun.

Orbital inclination (i)

The tilt of the comet's orbital plane relative to the plane of the ecliptic

Longitude of the ascending node (arc YN)

The angle, as viewed from the Sun, between the comet and the first point of Aries, when the comet passes through the plane of the ecliptic from below.

Argument of perihelion (arc NP)

The angle, as viewed from the Sun, between the comet's perihelion position (closest approach to the Sun) and the point of its ascending node.

Ecliptic epoch

The standard year (1950 or 2000) to which the orbital elements refer.

Absolute magnitude

The brightness of the comet as seen by a viewer at a standard distance.

Magnitude constant

A value which represents the change in the comet's brightness during its orbit.

Date of Perihelion (Epoch of the Elements)

The date (time) at which the object is closest to the Sun. This date should be in Universal Time (UT).

Computed position

As an aid in quickly verifying the accuracy of your data entry, click the Compute button to see the position of the comet as calculated for the Site's Date and Time.

Import button

This command is used to add a comet whose orbital elements are already specified in a compatible file format.