RECON observing guide for 2357_Phereclos_20261120220729

Occultation event with (2357) Phereclos, event index number 4788
Regions able to see the event: Europe

Geocentric closest approach at 2026/11/20 22:07:29 UTC

J2000 position of star is 05:13:14.4 +19:52:02
Equinox of date position of star is 05:14:49.8 +19:53:50
Star is 70 degrees from the moon. Moon is 82% illuminated.
Stellar brightness G=16.1, apparent brightess of occulting body is G=14.1
Use an exposure time of 1.45 seconds with the standard RECON-QHY system.
SNR of 4.1 per integration for unocculted signal
Expected flux drop is 14% with SNR of 0.6 for the occulted depth (per occulted point)

Apparent velocity is 15.9 km/sec on the sky relative to the star, or, 17.4 arcsec/hr.
Position angle of asteroid motion is 83.0 degrees
The recommended exposure time corresponds to 23.1 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 33.5 km.
The sky-plane scale is 3287.1 km/arcsec.

Diameter estimates:
95.9 km assuming a 5% albedo, maximum of 6.0 sec for a central chord
39.2 km assuming a 30% albedo, maximum of 2.5 sec for a central chord
Cross-track diameter of 94.6 km used for deployment plan.

Star training set for 2357_Phereclos, (2026/11/20 22:07UT)
Object            RA         Dec     mag  sep  mel
Aldebaran      04:37:28.0 +16:33:40  0.8  9.48  61
Alnath         05:27:59.6 +28:37:39  1.6  9.23  73
PPM 120839     05:21:53.5 +19:36:12  6.5  1.69  72
PPM 094204     05:16:47.3 +20:05:04  8.4  0.50  71
PPM 120699     05:13:37.5 +19:58:55  9.0  0.30  70
PPM 120739     05:15:52.8 +19:54:37 10.1  0.25  70
2357_Phereclos 05:14:49.8 +19:53:50 14.1        71
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 2357_Phereclos, (2026/11/20 22:07UT)
Object            RA         Dec     mag  sep  mel
Aldebaran      04:35:55.4 +16:30:29  0.8  9.48  61
Alnath         05:26:17.6 +28:36:22  1.6  9.23  73
PPM 120839     05:20:18.3 +19:34:41  6.5  1.69  72
PPM 094204     05:15:11.7 +20:03:21  8.4  0.50  71
PPM 120699     05:12:02.0 +19:57:05  9.0  0.30  70
PPM 120739     05:14:17.3 +19:52:52 10.1  0.25  70
2357_Phereclos 05:13:14.4 +19:52:02 14.1        70
Positions are for J2000


Created by recondetail.pro, 2025/06/21 03:30:22 MT