RECON observing guide for 9799_Thronium_20250519120640

Occultation event with (9799) Thronium, event index number 988
Regions able to see the event: Australia

Geocentric closest approach at 2025/05/19 12:06:40 UTC

J2000 position of star is 08:26:44.0 -08:36:15
Equinox of date position of star is 08:27:58.0 -08:41:20
Star is 150 degrees from the moon. Moon is 61% illuminated.
Stellar brightness G=16.5, apparent brightess of occulting body is G=15.5
Use an exposure time of 1.10 seconds with the standard RECON-QHY system.
SNR of 3.0 per integration for unocculted signal
Expected flux drop is 28% with SNR of 0.8 for the occulted depth (per occulted point)

Apparent velocity is 22.0 km/sec on the sky relative to the star, or, 19.8 arcsec/hr.
The recommended exposure time corresponds to 24.2 km per image.
The 1-sigma error in the time of the event is 1.7 seconds.
The 1-sigma cross-track error in the shadow position is 25.6 km.
The sky-plane scale is 4002.2 km/arcsec.

Diameter estimates:
70.8 km assuming a 5% albedo, aximum of 3.2 sec for a central chord
28.9 km assuming a 30% albedo, maximum of 1.3 sec for a central chord
Cross-track diameter of 70.8 km used for deployment plan.

Star training set for 9799_Thronium, (2025/05/19 12:07UT)
Object            RA         Dec     mag  sep  mel
Sirius         06:46:16.0 -16:45:09 -1.5 26.05 128
Alphard        09:28:50.1 -08:46:11  2.0 15.04 152
PPM 191380     08:29:33.6 -08:54:08  6.5  0.45 150
PPM 191348     08:28:04.3 -08:33:01  8.5  0.14 150
9799_Thronium  08:27:58.0 -08:41:20 15.5       150
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 9799_Thronium, (2025/05/19 12:07UT)
Object            RA         Dec     mag  sep  mel
Sirius         06:45:07.9 -16:43:28 -1.5 26.05 128
Alphard        09:27:35.2 -08:39:30  2.0 15.04 152
PPM 191380     08:28:19.8 -08:49:00  6.5  0.45 150
PPM 191348     08:26:50.3 -08:27:56  8.5  0.14 150
9799_Thronium  08:26:44.0 -08:36:15 15.5       150
Positions are for J2000


Created by recondetail.pro, 2025/03/15 08:36:56 MT