Occultation event with (5258) Rhoeo, event index number 1459
Regions able to see the event: SAmericaN
Geocentric closest approach at 2025/11/05 06:00:05 UTC
J2000 position of star is 10:51:30.0 +01:24:43
Equinox of date position of star is 10:52:49.7 +01:16:28
Star is 125 degrees from the moon. Moon is 100% illuminated.
Stellar brightness G=14.7, apparent brightess of occulting body is G=15.8
Use an exposure time of 0.45 seconds with the standard RECON-QHY system.
SNR of 7.8 per integration for unocculted signal
Expected flux drop is 73% with SNR of 5.7 for the occulted depth (per occulted point)
Apparent velocity is 28.9 km/sec on the sky relative to the star, or, 27.4 arcsec/hr.
Position angle of asteroid motion is 117.1 degrees
The recommended exposure time corresponds to 13.0 km per image.
The 1-sigma error in the time of the event is 1.0 seconds.
The 1-sigma cross-track error in the shadow position is 25.5 km.
The sky-plane scale is 3796.3 km/arcsec.
Diameter estimates:
51.3 km assuming a 5% albedo, aximum of 1.8 sec for a central chord
20.9 km assuming a 30% albedo, maximum of 0.7 sec for a central chord
Cross-track diameter of 53.3 km used for deployment plan.
Star training set for 5258_Rhoeo, (2025/11/05 06:00UT) Object RA Dec mag sep mel Regulus 10:09:44.7 +11:50:24 1.3 15.03 111 55 Leo 10:57:02.1 +00:35:55 6.2 1.25 126 PPM 157292 10:53:33.3 +00:53:15 6.6 0.43 125 PPM 157269 10:52:32.6 +01:15:11 9.7 0.07 125 5258_Rhoeo 10:52:49.7 +01:16:28 15.8 126 Positions are for equinox of date
Star training set for 5258_Rhoeo, (2025/11/05 06:00UT) Object RA Dec mag sep mel Regulus 10:08:21.9 +11:58:02 1.3 15.03 111 55 Leo 10:55:42.5 +00:44:13 6.2 1.25 126 PPM 157292 10:52:13.7 +01:01:31 6.6 0.43 125 PPM 157269 10:51:12.9 +01:23:26 9.7 0.07 125 5258_Rhoeo 10:51:30.0 +01:24:43 15.8 125 Positions are for J2000