Occultation event with (7543) Prylis, event index number 884
Regions able to see the event: US
Geocentric closest approach at 2025/04/05 05:37:59 UTC
J2000 position of star is 10:27:52.7 +00:23:43
Equinox of date position of star is 10:29:10.5 +00:15:56
Star is 53 degrees from the moon. Moon is 52% illuminated.
Stellar brightness G=15.1, apparent brightess of occulting body is G=15.9
Use an exposure time of 0.85 seconds with the standard RECON-QHY system.
Expected flux drop is 33% with SNR of 8.6 per integration
Apparent velocity is 12.8 km/sec on the sky relative to the star, or, 14.0 arcsec/hr.
The recommended exposure time corresponds to 10.8 km per image.
The 1-sigma error in the time of the event is 2.1 seconds.
The 1-sigma cross-track error in the shadow position is 42.3 km.
The sky-plane scale is 3288.3 km/arcsec.
Diameter estimates:
44.5 km assuming a 5% albedo, aximum of 3.5 sec for a central chord
18.1 km assuming a 30% albedo, maximum of 1.4 sec for a central chord
Cross-track diameter of 44.5 km used for deployment plan.
Star training set for 7543_Prylis, (2025/04/05 05:38UT) Object RA Dec mag sep mel Regulus 10:09:42.9 +11:50:34 1.3 12.54 43 30Bet Sex 10:31:34.9 -00:46:02 4.8 1.20 54 PPM 178186 10:28:11.5 -00:16:41 7.9 0.60 53 PPM 156872 10:29:49.1 +00:23:39 8.6 0.21 53 PPM 156856 10:28:59.1 +00:22:16 11.0 0.12 53 7543_Prylis 10:29:10.5 +00:15:56 15.9 53 Positions are for equinox of date
This table contains the target star visibility for registered US sites that are relevant for this occultation. This list has been filtered to only those sites that can see the field and are within range of the shadow given the uncertainties. The observing time range has been calculated to cover the time of the event at each site with allowances for the event timing uncertainty plus time for obtaining a pre and post event baseline lightcurve. This set of stations has a 0.0 % chance of getting at least one chord. There is a 0.0% chance of 2 or more chords assuming clear weather for all.
| Site Name | Site mid-time (UT) |
Sun alt (deg) |
Sky | Moon | Star alt (deg) |
Star az (deg) |
Target | Observing Time | Xtrack (km) |
Prob |
|---|---|---|---|---|---|---|---|---|---|---|
Star training set for 7543_Prylis, (2025/04/05 05:38UT) Object RA Dec mag sep mel Regulus 10:08:21.9 +11:58:02 1.3 12.54 43 30Bet Sex 10:30:17.4 -00:38:14 4.8 1.20 54 PPM 178186 10:26:53.9 -00:08:56 7.9 0.60 53 PPM 156872 10:28:31.3 +00:31:26 8.6 0.21 53 PPM 156856 10:27:41.4 +00:30:02 11.0 0.12 53 7543_Prylis 10:27:52.7 +00:23:43 15.9 53 Positions are for J2000