In the diagram, Pluto and the moons are modeled as triaxial ellipsoids, and are drawn with latitude and longitude contours at 15 degree intervals. Illuminated regions are indicated with black lines; unilluminated regions and terminators are shown as light gray. Penumbral shadows are not indicated.
The diagram is oriented with J2000 declination increasing upward and with right ascension increasing to the left. The frame has uniformly-spaced tick marks along each axis. The declination axis is labeled in degrees, minutes and seconds; the right ascension axis is labeled in hours, minutes and seconds.
Each diagram includes a caption that summarizes the key parameters used to generate it.
Body: The diagram will be centered on the location of the selected body.
Orbit ansa: The diagram will be centered on the tip of the selected orbital path. Specify the east or west tip using the second box. Note that east is toward the left in the diagram.
J2000 RA and dec: The diagram will be centered on the specified pair of right ascension and declination coordinates. The first box is for the RA and the second box is for the dec. You may also specify whether the RA is in units of hours or degrees. Enter up to three values in each box, separated by spaces; these values are interpreted as degrees/hours, minutes and seconds, respectively. Any or all values can have fractional parts.
Star name: Enter the name of a star as it appears in the current list. The name must match exactly.
Latitude & Longitude: If your desired observatory or location is not on the observatory list, you can enter its latitude, longitude and altitude in the three boxes provided. Latitudes and longitudes can each be specified by up to three values, interpreted as degrees, minutes and seconds. Longitudes can be specified either east or west.
If you wish to have an observatory added to the standard list, or to refine the coordinates of a listed observatory, email the necessary information to Mark Showalter.
Standard stars: Check the box to include any of a standard list of stars that happen to fall inside the field of view of the diagram. The Viewer does not access a star catalog; instead, it only plots stars from a finite list. To view the current star list, click here. This list is updated periodically at the request of the users; if you would like to have a star added to the list, email the necessary information to Mark Showalter.
Additional star: In addition to or instead of the standard stars, you can specify one additional star to be included in the diagram. Check the box to the left and enter the star's RA, dec, and name in the three boxes. You may also specify whether the RA is in units of hours or degrees. Enter up to three values in the RA and dec boxes, separated by spaces; the values are interpreted as hours/degrees, minutes and seconds, respectively. Any or all values can have fractional parts.
Other bodies: Check each box to mark the location of the specified body or spacecraft in the diagram.
Last updated 28 February 2014.