RECON observing guide for 12242_Koon_20261210131438

Occultation event with (12242) Koon, event index number 5160
Regions able to see the event: Australia

Geocentric closest approach at 2026/12/10 13:14:38 UTC

J2000 position of star is 06:01:45.0 -03:23:59
Equinox of date position of star is 06:03:05.7 -03:24:05
Star is 149 degrees from the moon. Moon is 2% illuminated.
Stellar brightness G=15.2, apparent brightess of occulting body is G=16.0
Use an exposure time of 0.45 seconds with the standard RECON-QHY system.
SNR of 5.1 per integration for unocculted signal
Expected flux drop is 67% with SNR of 3.4 for the occulted depth (per occulted point)

Apparent velocity is 19.1 km/sec on the sky relative to the star, or, 21.2 arcsec/hr.
Position angle of asteroid motion is 68.9 degrees
The recommended exposure time corresponds to 8.6 km per image.
The 1-sigma error in the time of the event is 0.1 seconds.
The 1-sigma cross-track error in the shadow position is 33.3 km.
The sky-plane scale is 3238.6 km/arcsec.

Diameter estimates:
39.8 km assuming a 5% albedo, maximum of 2.1 sec for a central chord
16.2 km assuming a 30% albedo, maximum of 0.9 sec for a central chord
Cross-track diameter of 37.9 km used for deployment plan.

Star training set for 12242_Koon, (2026/12/10 13:15UT)
Object            RA         Dec     mag  sep  mel
Betelgeuse     05:56:37.9 +07:24:35  0.4 10.93 159
Saiph          05:49:02.1 -09:39:43  2.1  7.17 142
PPM 188676     06:01:24.3 -03:04:31  4.7  0.53 149
PPM 188692     06:02:18.6 -03:24:36  8.5  0.20 149
12242_Koon     06:03:05.7 -03:24:05 16.0       149
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 12242_Koon, (2026/12/10 13:15UT)
Object            RA         Dec     mag  sep  mel
Betelgeuse     05:55:10.3 +07:24:26  0.4 10.93 159
Saiph          05:47:45.4 -09:40:11  2.1  7.17 142
PPM 188676     06:00:03.4 -03:04:29  4.7  0.53 149
PPM 188692     06:00:57.9 -03:24:32  8.5  0.20 149
12242_Koon     06:01:45.0 -03:23:59 16.0       149
Positions are for J2000


Created by recondetail.pro, 2025/06/21 19:03:15 MT