Occultation event with (4791) Iphidamas, event index number 1517
Regions able to see the event: Australia
Geocentric closest approach at 2025/11/15 09:45:22 UTC
J2000 position of star is 01:12:33.5 +33:35:59
Equinox of date position of star is 01:14:00.3 +33:44:11
Star is 143 degrees from the moon. Moon is 20% illuminated.
Stellar brightness G=16.7, apparent brightess of occulting body is G=14.9
Use an exposure time of 1.55 seconds with the standard RECON-QHY system.
SNR of 3.0 per integration for unocculted signal
Expected flux drop is 16% with SNR of 0.5 for the occulted depth (per occulted point)
Apparent velocity is 16.9 km/sec on the sky relative to the star, or, 20.5 arcsec/hr.
Position angle of asteroid motion is 35.3 degrees
The recommended exposure time corresponds to 26.1 km per image.
The 1-sigma error in the time of the event is 1.3 seconds.
The 1-sigma cross-track error in the shadow position is 30.8 km.
The sky-plane scale is 2966.0 km/arcsec.
Diameter estimates:
59.2 km assuming a 5% albedo, aximum of 3.5 sec for a central chord
24.1 km assuming a 30% albedo, maximum of 1.4 sec for a central chord
Cross-track diameter of 59.2 km used for deployment plan.
Star training set for 4791_Iphidamas, (2025/11/15 09:45UT) Object RA Dec mag sep mel Aldebaran 04:37:24.5 +16:33:33 0.8 48.58 110 57Gam1And 02:05:30.0 +42:27:09 2.3 13.34 130 PPM 066072 01:14:43.2 +34:14:06 6.5 0.52 143 PPM 066076 01:15:02.6 +33:37:38 9.7 0.24 143 4791_Iphidamas 01:14:00.3 +33:44:11 14.9 143 Positions are for equinox of date
Star training set for 4791_Iphidamas, (2025/11/15 09:45UT) Object RA Dec mag sep mel Aldebaran 04:35:55.4 +16:30:29 0.8 48.58 110 57Gam1And 02:03:54.1 +42:19:46 2.3 13.34 130 PPM 066072 01:13:16.2 +34:05:54 6.5 0.52 143 PPM 066076 01:13:35.7 +33:29:27 9.7 0.24 143 4791_Iphidamas 01:12:33.5 +33:35:59 14.9 143 Positions are for J2000