RECON observing guide for 7641_Cteatus_20260509173215

Occultation event with (7641) Cteatus, event index number 3732
Regions able to see the event: SAfrica

Geocentric closest approach at 2026/05/09 17:32:15 UTC

J2000 position of star is 10:11:43.3 -27:13:54
Equinox of date position of star is 10:12:56.2 -27:21:45
Star is 134 degrees from the moon. Moon is 52% illuminated.
Stellar brightness G=15.5, apparent brightess of occulting body is G=14.8
Use an exposure time of 1.05 seconds with the standard RECON-QHY system.
SNR of 6.3 per integration for unocculted signal
Expected flux drop is 34% with SNR of 2.1 for the occulted depth (per occulted point)

Apparent velocity is 16.9 km/sec on the sky relative to the star, or, 18.3 arcsec/hr.
Position angle of asteroid motion is 22.5 degrees
The recommended exposure time corresponds to 17.8 km per image.
The 1-sigma error in the time of the event is 2.1 seconds.
The 1-sigma cross-track error in the shadow position is 29.7 km.
The sky-plane scale is 3334.7 km/arcsec.

Diameter estimates:
76.6 km assuming a 5% albedo, maximum of 4.5 sec for a central chord
31.3 km assuming a 30% albedo, maximum of 1.8 sec for a central chord
Cross-track diameter of 71.8 km used for deployment plan.

Star training set for 7641_Cteatus, (2026/05/09 17:32UT)
Object            RA         Dec     mag  sep  mel
Bet Cru        12:49:16.8 -59:49:56  1.3 41.94  93
Lam Vel        09:08:58.0 -43:32:24  2.2 20.69 119
PPM 257358     10:14:32.3 -27:09:36  6.4  0.41 134
PPM 257337     10:13:23.6 -27:23:29  8.4  0.11 134
PPM 257316     10:12:30.3 -27:22:22  9.5  0.10 134
7641_Cteatus   10:12:56.2 -27:21:45 14.8       134
Positions are for equinox of date

Azimuth is measured in degrees eastward from north. North is at an azimuth of 0, due East is at an azimuth of 90 degrees, due South is 180, and due West is 270.

Star training set for 7641_Cteatus, (2026/05/09 17:32UT)
Object            RA         Dec     mag  sep  mel
Bet Cru        12:47:43.1 -59:41:20  1.3 41.94  93
Lam Vel        09:07:59.7 -43:25:57  2.2 20.69 119
PPM 257358     10:13:19.3 -27:01:43  6.4  0.41 134
PPM 257337     10:12:10.7 -27:15:38  8.4  0.11 134
PPM 257316     10:11:17.6 -27:14:31  9.5  0.10 134
7641_Cteatus   10:11:43.3 -27:13:54 14.8       134
Positions are for J2000


Created by recondetail.pro, 2025/06/19 13:29:20 MT