Occultation event with (5126) Achaemenides, event index number 3883
Regions able to see the event: SAmericaN
Geocentric closest approach at 2026/07/23 22:37:22 UTC
J2000 position of star is 12:05:49.7 +26:10:38
Equinox of date position of star is 12:07:10.9 +26:01:46
Star is 73 degrees from the moon. Moon is 73% illuminated.
Stellar brightness G=14.9, apparent brightess of occulting body is G=16.4
Use an exposure time of 0.40 seconds with the standard RECON-QHY system.
SNR of 6.1 per integration for unocculted signal
Expected flux drop is 79% with SNR of 4.8 for the occulted depth (per occulted point)
Apparent velocity is 32.0 km/sec on the sky relative to the star, or, 27.7 arcsec/hr.
Position angle of asteroid motion is 125.5 degrees
The recommended exposure time corresponds to 12.8 km per image.
The 1-sigma error in the time of the event is 0.7 seconds.
The 1-sigma cross-track error in the shadow position is 23.9 km.
The sky-plane scale is 4161.7 km/arcsec.
Diameter estimates:
45.9 km assuming a 5% albedo, maximum of 1.4 sec for a central chord
18.8 km assuming a 30% albedo, maximum of 0.6 sec for a central chord
Cross-track diameter of 51.9 km used for deployment plan.
Star training set for 5126_Achaemenides, (2026/07/23 22:37UT) Object RA Dec mag sep mel Arcturus 14:16:52.5 +19:02:45 0.0 30.66 49 Denebola 11:50:24.8 +14:25:25 2.1 12.25 69 4 Com 12:13:11.8 +25:43:21 5.7 1.39 72 PPM 101671 12:09:58.3 +26:20:44 7.8 0.70 73 PPM 101632 12:06:54.6 +26:12:49 9.8 0.19 73 5126_Achaemeni 12:07:10.9 +26:01:46 16.4 73 Positions are for equinox of date
Star training set for 5126_Achaemenides, (2026/07/23 22:37UT) Object RA Dec mag sep mel Arcturus 14:15:37.7 +19:10:06 0.0 30.66 49 Denebola 11:49:02.7 +14:34:16 2.1 12.25 69 4 Com 12:11:51.1 +25:52:12 5.7 1.39 72 PPM 101671 12:08:37.4 +26:29:36 7.8 0.70 73 PPM 101632 12:05:33.4 +26:21:41 9.8 0.19 73 5126_Achaemeni 12:05:49.7 +26:10:38 16.4 73 Positions are for J2000