Occultation event with (5258) Rhoeo, event index number 3509
Regions able to see the event: Australia
Geocentric closest approach at 2026/03/26 17:53:04 UTC
J2000 position of star is 10:43:44.7 +00:14:19
Equinox of date position of star is 10:45:05.4 +00:06:01
Star is 55 degrees from the moon. Moon is 61% illuminated.
Stellar brightness G=16.5, apparent brightess of occulting body is G=15.0
Use an exposure time of 1.15 seconds with the standard RECON-QHY system.
SNR of 3.0 per integration for unocculted signal
Expected flux drop is 20% with SNR of 0.6 for the occulted depth (per occulted point)
Apparent velocity is 13.8 km/sec on the sky relative to the star, or, 17.4 arcsec/hr.
Position angle of asteroid motion is 118.7 degrees
The recommended exposure time corresponds to 15.9 km per image.
The 1-sigma error in the time of the event is 2.2 seconds.
The 1-sigma cross-track error in the shadow position is 25.2 km.
The sky-plane scale is 2849.4 km/arcsec.
Diameter estimates:
51.3 km assuming a 5% albedo, maximum of 3.7 sec for a central chord
20.9 km assuming a 30% albedo, maximum of 1.5 sec for a central chord
Cross-track diameter of 53.3 km used for deployment plan.
Star training set for 5258_Rhoeo, (2026/03/26 17:53UT) Object RA Dec mag sep mel Regulus 10:09:46.0 +11:50:17 1.3 14.65 42 33 Sex 10:42:44.3 -01:52:48 6.3 2.07 56 PPM 157096 10:43:42.6 +00:43:27 8.2 0.71 54 PPM 157113 10:44:47.9 +00:27:13 9.6 0.36 55 5258_Rhoeo 10:45:05.4 +00:06:01 15.0 55 Positions are for equinox of date
Star training set for 5258_Rhoeo, (2026/03/26 17:53UT) Object RA Dec mag sep mel Regulus 10:08:21.9 +11:58:02 1.3 14.65 42 33 Sex 10:41:24.0 -01:44:33 6.3 2.07 56 PPM 157096 10:42:21.8 +00:51:44 8.2 0.71 54 PPM 157113 10:43:27.1 +00:35:31 9.6 0.36 55 5258_Rhoeo 10:43:44.7 +00:14:19 15.0 55 Positions are for J2000