2004 PF115 28/09/2018
*Prediction based on Gaia DR2*
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 01:30 to 01:40 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 23 01 47.578 DEC -20 31 01.22 |
| Star V mag | 16.7 |
| Star R mag | 15.8 |
| Star K mag | 14.1 |
| Magnitude drop in R | 4.2 |
| Maximum
duration |
21
sec |
| Moon
| 91% illum. |
@
60 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 Update
Prediction from Lucky Star web page (i).
(i)
http://lesia.obspm.fr/lucky-star/predictions/single.php?p=5236
Please,
see the observation tips at the top!With
recent observation from Liverpool Telescope, J.L Ortiz and team
obtained this map. It should be correct within +/- one diameter.
