RECON observing guide for 21601_98XO89_20260615031020

Occultation event with (21601) 98XO89, event index number 3795
Regions able to see the event: US,NMexico,SMexico

Geocentric closest approach at 2026/06/15 03:10:20 UTC

J2000 position of star is 13:13:23.3 -25:35:29
Equinox of date position of star is 13:14:50.1 -25:43:52
Star is 123 degrees from the moon. Moon is 0% illuminated.
Stellar brightness G=10.8, apparent brightess of occulting body is G=15.4
Use an exposure time of 0.12 seconds with the standard RECON-QHY system.
SNR of 41.3 per integration for unocculted signal
Expected flux drop is 99% with SNR of 40.7 for the occulted depth (per occulted point)

Apparent velocity is 9.9 km/sec on the sky relative to the star, or, 10.5 arcsec/hr.
Position angle of asteroid motion is 2.3 degrees
The recommended exposure time corresponds to 1.2 km per image.
The 1-sigma error in the time of the event is 3.5 seconds.
The 1-sigma cross-track error in the shadow position is 9.4 km.
The sky-plane scale is 3387.9 km/arcsec.

Diameter estimates:
60.0 km assuming a 5% albedo, maximum of 6.0 sec for a central chord
24.5 km assuming a 30% albedo, maximum of 2.5 sec for a central chord
Cross-track diameter of 54.9 km used for deployment plan.

Star training set for 21601_98XO89, (2026/06/15 03:10UT)
Object            RA         Dec     mag  sep  mel
Spica          13:26:35.4 -11:17:55  1.0 14.70 120
9Bet Crv       12:35:46.9 -23:32:34  2.6  9.14 113
PPM 261317     13:13:05.9 -26:41:30  6.5  1.04 122
PPM 261292     13:11:56.7 -26:01:44  8.5  0.71 122
PPM 261366     13:14:50.1 -25:43:51 10.0  0.00 123
21601_98XO89   13:14:50.1 -25:43:52 15.4       123
Positions are for equinox of date

This table contains the target star visibility for registered US sites that are relevant for this occultation. This list has been filtered to only those sites that can see the field and are within range of the shadow given the uncertainties. The observing time range has been calculated to cover the time of the event at each site with allowances for the event timing uncertainty plus time for obtaining a pre and post event baseline lightcurve. This set of stations has a 0.0 % chance of getting at least one chord. There is a 0.0% chance of 2 or more chords assuming clear weather for all.
Site Name Site mid-time
(UT)
Sun alt
(deg)
Sky Moon Star alt
(deg)
Star az
(deg)
Target Observing Time Xtrack
(km)
Prob

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 21601_98XO89, (2026/06/15 03:10UT)
Object            RA         Dec     mag  sep  mel
Spica          13:25:11.5 -11:09:41  1.0 14.70 120
9Bet Crv       12:34:23.2 -23:23:50  2.6  9.14 113
PPM 261317     13:11:39.1 -26:33:06  6.5  1.04 122
PPM 261292     13:10:30.1 -25:53:20  8.5  0.71 122
PPM 261366     13:13:23.4 -25:35:28 10.0  0.00 123
21601_98XO89   13:13:23.3 -25:35:29 15.4       123
Positions are for J2000


Created by recondetail.pro, 2025/06/19 15:18:02 MT