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
Predictions
Initial NIMA prediction
With observations of the TNO on the begging of July