Pluto 14/06/2012
Dark
gray is night and light gray is astronomical twilight (Sun at less
than 18° below the horizon).
Shadow moves from right to left, each red dot is separated by one minute, the nominal occultation time on the map, is for the big red dot, the closest approach.
See finding charts bellow.
Shadow moves from right to left, each red dot is separated by one minute, the nominal occultation time on the map, is for the big red dot, the closest approach.
See finding charts bellow.
| Star J2000 coordinates: |
| RA
18 35 48.6931 DEC -19 17 43.617 |
| Day coordinates: |
|
RA
18 36 35.1412 DEC -19 16 58.152 |
| Star R mag | 13.7 |
| Star K mag | 8.9 |
| Magnitude drop in R | 0.94 |
| Contrast | 58% |
| Max. duration | 68 sec |
Observation tips:
Absolute time accuracy is essential to connect together all the observations after the fact. Check the time of your computer with many sources (phone talked hour, different internet sites, ideally with a GPS). As images should be acquired for a long time (10min at least), its advised to check the registered time right after and right before the integrations, so if there is a drift, we can correct it by having the difference.
Beware of the dead time between the images. If you manage an exposure time of 1 sec (for example), but have your camera takes 2 sec to read the image, then there is a 67% chance that you miss the dis(re)-appearance of the star. So it's better to have, for example, a 4 sec integration, so you have 67% chance to get the occultation in one of your exposures.
