Occultation event with (4791) Iphidamas, event index number 3892
Regions able to see the event: Australia
Geocentric closest approach at 2026/07/26 19:57:57 UTC
J2000 position of star is 04:14:45.3 +31:37:19
Equinox of date position of star is 04:16:26.6 +31:41:14
Star is 154 degrees from the moon. Moon is 93% illuminated.
Stellar brightness G=16.3, apparent brightess of occulting body is G=15.6
Use an exposure time of 0.80 seconds with the standard RECON-QHY system.
SNR of 3.1 per integration for unocculted signal
Expected flux drop is 36% with SNR of 1.1 for the occulted depth (per occulted point)
Apparent velocity is 28.5 km/sec on the sky relative to the star, or, 26.2 arcsec/hr.
Position angle of asteroid motion is 82.8 degrees
The recommended exposure time corresponds to 22.8 km per image.
The 1-sigma error in the time of the event is 0.1 seconds.
The 1-sigma cross-track error in the shadow position is 29.8 km.
The sky-plane scale is 3917.0 km/arcsec.
Diameter estimates:
59.2 km assuming a 5% albedo, maximum of 2.1 sec for a central chord
24.1 km assuming a 30% albedo, maximum of 0.8 sec for a central chord
Cross-track diameter of 49.5 km used for deployment plan.
Star training set for 4791_Iphidamas, (2026/07/26 19:58UT) Object RA Dec mag sep mel Aldebaran 04:37:26.9 +16:33:38 0.8 15.86 155 44Zet Per 03:55:48.5 +31:57:37 2.8 4.39 150 PPM 069071 04:06:24.7 +32:38:31 6.5 2.33 152 PPM 069196 04:13:22.3 +31:37:03 7.7 0.66 153 PPM 069239 04:16:14.9 +31:54:08 9.2 0.22 154 4791_Iphidamas 04:16:26.6 +31:41:14 15.6 154 Positions are for equinox of date
Star training set for 4791_Iphidamas, (2026/07/26 19:58UT) Object RA Dec mag sep mel Aldebaran 04:35:55.4 +16:30:29 0.8 15.86 155 44Zet Per 03:54:07.9 +31:53:01 2.8 4.39 150 PPM 069071 04:04:43.1 +32:34:16 6.5 2.33 152 PPM 069196 04:11:41.1 +31:33:02 7.7 0.66 153 PPM 069239 04:14:33.4 +31:50:13 9.2 0.22 154 4791_Iphidamas 04:14:45.3 +31:37:19 15.6 154 Positions are for J2000