Varuna 26/03/2019
Observation tips:
- Shadow moves from **East to West**;
- The nominal occultation time on the map, corresponds to the big red dot, the closest approach.
- Each red 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);
- Observations are requested from 03:00 to 03:20 Universal Time.
After the observation, please fill the form available on this link (form), and send it to ribas(at)on.br.
| Star J2000 coordinates: |
|
RA 08 17 58.4978 DEC +27 12 32.543 |
| Day coordinates of the object: |
| RA 08 19 07.9653 DEC +27 08 54.765 |
| Star G mag | 18.5 |
| Star RP mag | 17.4 |
| Magnitude drop in R | 2.8 |
| Maximum
duration |
87
sec |
| Moon
| 70% illum. |
@
130 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 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.
Prediction
Prediction from Lucky Star web page (i).
With images taken from Obs Sierra Nevada during six nights on the beginning of March, J.L. Ortiz obtained the following prediction:
Please, see the observation tips at the top!