RECON observing guide for 39264_00YQ139_20250518001813

Occultation event with (39264) 00YQ139, event index number 983
Regions able to see the event: SAmericaN,SAmericaS

Geocentric closest approach at 2025/05/18 00:18:13 UTC

J2000 position of star is 09:53:31.3 -01:32:23
Equinox of date position of star is 09:54:48.9 -01:39:37
Star is 142 degrees from the moon. Moon is 75% illuminated.
Stellar brightness G=15.9, apparent brightess of occulting body is G=16.5
Use an exposure time of 0.75 seconds with the standard RECON-QHY system.
SNR of 4.2 per integration for unocculted signal
Expected flux drop is 64% with SNR of 2.7 for the occulted depth (per occulted point)

Apparent velocity is 13.5 km/sec on the sky relative to the star, or, 13.0 arcsec/hr.
The recommended exposure time corresponds to 10.2 km per image.
The 1-sigma error in the time of the event is 4.5 seconds.
The 1-sigma cross-track error in the shadow position is 17.7 km.
The sky-plane scale is 3746.2 km/arcsec.

Diameter estimates:
41.1 km assuming a 5% albedo, aximum of 3.0 sec for a central chord
16.8 km assuming a 30% albedo, maximum of 1.2 sec for a central chord
Cross-track diameter of 41.1 km used for deployment plan.

Star training set for 39264_00YQ139, (2025/05/18 00:18UT)
Object            RA         Dec     mag  sep  mel
Regulus        10:09:43.2 +11:50:32  1.3 14.00 147
Alphard        09:28:50.1 -08:46:11  2.0  9.61 140
35Iot Hya      09:41:09.1 -01:15:33  3.9  3.44 145
PPM 178019     09:55:48.1 -01:23:29  8.4  0.36 142
PPM 178013     09:54:50.2 -01:44:11  9.2  0.08 142
39264_00YQ139  09:54:48.9 -01:39:37 16.5       142
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 39264_00YQ139, (2025/05/18 00:18UT)
Object            RA         Dec     mag  sep  mel
Regulus        10:08:21.9 +11:58:02  1.3 14.00 147
Alphard        09:27:35.2 -08:39:30  2.0  9.61 140
35Iot Hya      09:39:51.4 -01:08:36  3.9  3.44 145
PPM 178019     09:54:30.5 -01:16:14  8.4  0.36 142
PPM 178013     09:53:32.6 -01:36:57  9.2  0.08 142
39264_00YQ139  09:53:31.3 -01:32:23 16.5       142
Positions are for J2000


Created by recondetail.pro, 2025/03/15 08:32:40 MT