Occultation by Pluto (2018-08-15)

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Important : If you plan to observe, please download and read the protocol in order to prepare the observation. It will help us to standardise the post-treatment. If you succeed in the observation, please fill the report by following the instructions.

News: (2018.07.13) new updated prediction

Information about the map:

• The straight and continue dark blue lines are the shadow limits considering the estimated radius (corresponding for Pluto half-light level where the star's flux will be reduced by 50%). The light blue lines are the 1% stellar drop (the theorical limit of detection of the occultation);
• Each blue dot is spaced by one minute and the big blue dot corresponds to the nominal occultation time (which is the geocentric closest approach);
• The arrow shows the direction of the shadow motion;
• The 1-σ precision along the path is represented by the red dotted line;
• The star G* and RP* are the G (from Gaia) and RP (red photometer from GaiaDR2) magnitudes, normalized to a body moving at 20km/s in order to enhance very slow events;
• The body offset is at the upper right corner, if JPL ephemeris is used;
• Areas in dark grey correspond to full night (Sun elevation below -18 degrees) and areas in light grey correspond to twilight (Sun elevation between -18 and 0 degrees) while daytime is in white;
• Be careful, the dates are from the moment of the event in Universal Time, the night of the event may begin at the date before.

Download the FOV image -- clear version -- annoted version

The red line represents the centrality of the occultation. The green lines represent the half-light level where the star's flux will be reduced by 50%. The blue lines are the 1% stellar drop (the theorical limit of detection of the occultation).
The path goes from East to West.
By clicking on one place, you will have an infobox with :

• Coordinates: longitude and latitude;
• Δd: projected distance to the central line;
• mid time: mid time of the occultation at the selected place;
• duration: expected duration of the occultation at the selected place (assuming a radius of 1216km);
• Sun elevation: Sun's elevation above the horizon at the selected place at the mid time.
• Pluto elevation: Pluto's elevation above the horizon at the selected place at the mid time.

Note that the uncertainty of the event is estimated to be about 60km in distance and about 5sec in time.