RECON observing guide for 9142_Rhesus_20261208092805

Occultation event with (9142) Rhesus, event index number 5116
Regions able to see the event: NZ

Geocentric closest approach at 2026/12/08 09:28:05 UTC

J2000 position of star is 05:02:46.4 +08:26:14
Equinox of date position of star is 05:04:14.5 +08:28:26
Star is 160 degrees from the moon. Moon is 1% illuminated.
Stellar brightness G=16.2, apparent brightess of occulting body is G=15.7
Use an exposure time of 0.75 seconds with the standard RECON-QHY system.
SNR of 3.0 per integration for unocculted signal
Expected flux drop is 37% with SNR of 1.1 for the occulted depth (per occulted point)

Apparent velocity is 18.0 km/sec on the sky relative to the star, or, 20.0 arcsec/hr.
Position angle of asteroid motion is 88.4 degrees
The recommended exposure time corresponds to 13.5 km per image.
The 1-sigma error in the time of the event is 0.4 seconds.
The 1-sigma cross-track error in the shadow position is 28.4 km.
The sky-plane scale is 3230.6 km/arcsec.

Diameter estimates:
43.7 km assuming a 5% albedo, maximum of 2.4 sec for a central chord
17.8 km assuming a 30% albedo, maximum of 1.0 sec for a central chord
Cross-track diameter of 42.3 km used for deployment plan.

Star training set for 9142_Rhesus, (2026/12/08 09:28UT)
Object            RA         Dec     mag  sep  mel
Aldebaran      04:37:28.2 +16:33:40  0.8 10.39 170
Bellatrix      05:26:34.6 +06:22:19  1.6  5.92 155
14 Ori         05:09:21.0 +08:31:53  5.7  1.26 159
PPM 148427     05:07:02.6 +08:30:14  8.3  0.69 160
PPM 148329     05:03:17.7 +08:30:24  9.8  0.24 160
9142_Rhesus    05:04:14.5 +08:28:26 15.7       160
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 9142_Rhesus, (2026/12/08 09:28UT)
Object            RA         Dec     mag  sep  mel
Aldebaran      04:35:55.4 +16:30:29  0.8 10.39 170
Bellatrix      05:25:07.8 +06:20:58  1.6  5.92 155
14 Ori         05:07:52.9 +08:29:53  5.7  1.26 159
PPM 148427     05:05:34.6 +08:28:09  8.3  0.69 160
PPM 148329     05:01:49.7 +08:28:10  9.8  0.24 160
9142_Rhesus    05:02:46.4 +08:26:14 15.7       160
Positions are for J2000


Created by recondetail.pro, 2025/06/21 17:28:50 MT