Occultation event with (16974) Iphthime, event index number 3838
Regions able to see the event: Australia
Geocentric closest approach at 2026/07/09 11:39:44 UTC
J2000 position of star is 10:50:07.9 -06:22:21
Equinox of date position of star is 10:51:28.3 -06:30:48
Star is 128 degrees from the moon. Moon is 32% illuminated.
Stellar brightness G=15.5, apparent brightess of occulting body is G=15.9
Use an exposure time of 0.50 seconds with the standard RECON-QHY system.
SNR of 4.3 per integration for unocculted signal
Expected flux drop is 59% with SNR of 2.6 for the occulted depth (per occulted point)
Apparent velocity is 27.8 km/sec on the sky relative to the star, or, 23.3 arcsec/hr.
Position angle of asteroid motion is 99.5 degrees
The recommended exposure time corresponds to 13.9 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 52.6 km.
The sky-plane scale is 4302.5 km/arcsec.
Diameter estimates:
62.2 km assuming a 5% albedo, maximum of 2.2 sec for a central chord
25.4 km assuming a 30% albedo, maximum of 0.9 sec for a central chord
Cross-track diameter of 57.3 km used for deployment plan.
Star training set for 16974_Iphthime, (2026/07/09 11:40UT) Object RA Dec mag sep mel Regulus 10:09:46.9 +11:50:12 1.3 21.08 111 Alphard 09:28:53.4 -08:46:29 2.0 20.58 109 PPM 193861 10:52:26.3 -03:14:02 5.8 3.29 127 PPM 193890 10:54:08.9 -06:57:53 7.5 0.80 128 PPM 193823 10:50:50.0 -06:44:29 9.5 0.28 128 16974_Iphthime 10:51:28.3 -06:30:48 15.9 128 Positions are for equinox of date
Star training set for 16974_Iphthime, (2026/07/09 11:40UT) Object RA Dec mag sep mel Regulus 10:08:21.9 +11:58:02 1.3 21.08 111 Alphard 09:27:35.2 -08:39:30 2.0 20.58 109 PPM 193861 10:51:05.3 -03:05:34 5.8 3.29 127 PPM 193890 10:52:48.6 -06:49:24 7.5 0.80 128 PPM 193823 10:49:29.6 -06:36:02 9.5 0.28 128 16974_Iphthime 10:50:07.9 -06:22:21 15.9 128 Positions are for J2000