2007 JJ43 11/07/2019


Observation tips:

- Observations are requested from 05:39 to 05:50 Universal Time.

- Shadow moves from **East to West** (see the arrow);
- The nominal occultation time on the map, corresponds to the big dot, the closest approach.
- Each dot is separated by one minute;
- Dark grey is night and light grey 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.

Event information: 

Star J2000 coordinates:
RA 16 46 47.3051
DEC -26 16 50.385
Day coordinates of the object:
RA 16 47 59.6577
DEC -26 18 50.175

Star G mag 11.9
Star R mag 11.4
Star K mag 10.3
Magnitude drop in R 8.8
Maximum duration 30 sec
Moon | 70% illum. @ 33 deg

Important note:

*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 second (for example), but 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 [chance of missing = 1 - {1/(1+2)}]. 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 [chance of getting = 4/(4+2)].

Finding charts from DSS:

05 x 05 arcmin FOV (North is up, East is left)


20 x 20 arcmin FOV (North is up, East is left)

FITS , No Labels


Initial NIMA prediction


With observations of the TNO on the begging of July


Link to Lucky Star Prediction

Click for a Open Street Interactive Map