- Observations are requested from 23:37 to 23:45 Universal Time.
- Shadow moves from **East to West**;
- The nominal occultation time on the map, corresponds to the big dor, the closest approach.
- Each dot is separated by one minute;
- Dark gray is night and light gray is astronomical twilight (Sun at less than 18 deg below the horizon);
- *Absolute time accuracy is essential** (see important note below);
After the observation, please fill the form available on this link (form), and send it to ribas(at)on.br.
|Star J2000 coordinates:|
| RA 18 10
DEC -15 18 37.73
|Day coordinates of the object:|
|RA 18 11
DEC -15 18 16.4
|Star G mag||16.9|
|Star R mag||15.8|
|Star K mag||13.2|
|Magnitude drop in R||2.1|
|Maximum duration||51 sec
|Moon | 29% illum.||@ 90 deg
*Absolute time accuracy is essential*
To connect all the observations together after the fact. Check the time of your computer with many sources (phone talked hour, different internet sites, ideally with a GPS). 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.
05 x 05 arcmin FOV (North is up, East is left)
20 x 20 arcmin FOV (North is up, East is left)