Occultation event with (5285) Krethon, event index number 715
Regions able to see the event: US
Geocentric closest approach at 2025/02/26 01:38:38 UTC
J2000 position of star is 11:49:15.7 +15:42:30
Equinox of date position of star is 11:50:33.4 +15:34:06
Star is 140 degrees from the moon. Moon is 5% illuminated.
Stellar brightness G=15.5, apparent brightess of occulting body is G=15.2
Use an exposure time of 0.75 seconds with the standard RECON-QHY system.
Expected flux drop is 57% with SNR of 5.6 per integration
Apparent velocity is 18.6 km/sec on the sky relative to the star, or, 21.0 arcsec/hr.
The recommended exposure time corresponds to 13.9 km per image.
The 1-sigma error in the time of the event is 1.9 seconds.
The 1-sigma cross-track error in the shadow position is 31.4 km.
The sky-plane scale is 3193.9 km/arcsec.
Diameter estimates:
56.0 km assuming a 5% albedo, aximum of 3.0 sec for a central chord
22.9 km assuming a 30% albedo, maximum of 1.2 sec for a central chord
Cross-track diameter of 56.0 km used for deployment plan.
Star training set for 5285_Krethon, (2025/02/26 01:39UT) Object RA Dec mag sep mel Regulus 10:09:42.5 +11:50:36 1.3 24.76 161 Denebola 11:50:20.5 +14:25:53 2.1 1.14 139 PPM 128581 11:50:32.6 +16:06:09 6.3 0.53 140 PPM 128574 11:50:19.6 +15:59:34 7.7 0.43 140 PPM 128597 11:51:57.2 +15:35:21 8.8 0.34 139 5285_Krethon 11:50:33.4 +15:34:06 15.2 139 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 5285_Krethon, (2025/02/26 01:39UT) Object RA Dec mag sep mel Regulus 10:08:21.9 +11:58:02 1.3 24.76 161 Denebola 11:49:02.7 +14:34:17 2.1 1.14 139 PPM 128581 11:49:14.9 +16:14:33 6.3 0.53 140 PPM 128574 11:49:01.8 +16:07:57 7.7 0.43 140 PPM 128597 11:50:39.4 +15:43:45 8.8 0.34 139 5285_Krethon 11:49:15.7 +15:42:30 15.2 140 Positions are for J2000