Occultation event with (11552) Boucolion, event index number 1723
Regions able to see the event: US,RECON
Geocentric closest approach at 2025/12/26 09:46:21 UTC
J2000 position of star is 04:22:41.1 +05:04:34
Equinox of date position of star is 04:24:03.8 +05:08:07
Star is 78 degrees from the moon. Moon is 35% illuminated.
Stellar brightness G=16.0, apparent brightess of occulting body is G=15.4
Use an exposure time of 0.85 seconds with the standard RECON-QHY system.
SNR of 3.8 per integration for unocculted signal
Expected flux drop is 35% with SNR of 1.3 for the occulted depth (per occulted point)
Apparent velocity is 14.6 km/sec on the sky relative to the star, or, 15.8 arcsec/hr.
Position angle of asteroid motion is 100.9 degrees
The recommended exposure time corresponds to 12.4 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 31.0 km.
The sky-plane scale is 3316.4 km/arcsec.
Diameter estimates:
57.3 km assuming a 5% albedo, aximum of 3.9 sec for a central chord
23.4 km assuming a 30% albedo, maximum of 1.6 sec for a central chord
Cross-track diameter of 51.1 km used for deployment plan.
Star training set for 11552_Boucolion, (2025/12/26 09:46UT) Object RA Dec mag sep mel Aldebaran 04:37:24.9 +16:33:34 0.8 11.88 82 67Bet Eri 05:09:07.7 -05:03:17 2.8 15.18 88 45 Tau 04:12:43.5 +05:35:19 5.7 2.86 75 PPM 147540 04:27:20.3 +05:12:27 7.6 0.82 79 PPM 147463 04:23:00.9 +05:26:56 9.0 0.41 78 PPM 147473 04:23:43.4 +05:23:30 10.8 0.27 78 11552_Boucolio 04:24:03.8 +05:08:07 15.4 78 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 |
|---|---|---|---|---|---|---|---|---|---|---|
This table contains the target star visibility for registered RECON 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 99.6 % chance of getting at least one chord. There is a 72.4% 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 |
|---|---|---|---|---|---|---|---|---|---|---|
| Kelowna | 09:43:42 | -56.5 | Dark | Down | 25.3 | 245.9 | Low | 09:40:33-09:46:33 | 181.5 | 0.000 | Peachland | 09:43:43 | -56.7 | Dark | Down | 25.5 | 245.7 | Low | 09:40:31-09:46:31 | 171.0 | 0.000 | Summerland | 09:43:42 | -56.7 | Dark | Down | 25.5 | 245.8 | Low | 09:40:27-09:46:27 | 163.0 | 0.000 | Penticton | 09:43:41 | -56.7 | Dark | Down | 25.5 | 245.9 | Low | 09:40:26-09:46:26 | 160.3 | 0.000 | Oliver | 09:43:39 | -57.0 | Dark | Down | 25.6 | 246.1 | Low | 09:40:19-09:46:19 | 138.4 | 0.000 | Anarchist Mountain Observatory | 09:43:37 | -57.0 | Dark | Down | 25.6 | 246.3 | Low | 09:40:24-09:46:24 | 130.8 | 0.000 | Okanogan | 09:43:34 | -57.5 | Dark | Down | 26.0 | 246.4 | Low | 09:40:21-09:46:21 | 86.6 | 0.019 | Brewster | 09:43:33 | -57.8 | Dark | Down | 26.2 | 246.3 | Low | 09:40:19-09:46:19 | 66.6 | 0.071 | Manson/Chelan | 09:43:33 | -58.1 | Dark | Down | 26.5 | 246.1 | Low | 09:40:18-09:46:18 | 48.3 | 0.186 | Victoria | 09:43:46 | -59.2 | Dark | Down | 28.2 | 242.9 | Low | 09:40:16-09:46:16 | 44.8 | 0.215 | Wenatchee | 09:43:31 | -58.5 | Dark | Down | 26.8 | 246.2 | Low | 09:40:16-09:46:16 | 15.2 | 0.472 | Royal City | 09:43:27 | -58.5 | Dark | Down | 26.6 | 247.0 | Low | 09:40:10-09:46:10 | -7.8 | 0.507 | Yakima | 09:43:27 | -59.2 | Dark | Down | 27.3 | 246.3 | Low | 09:40:08-09:46:08 | -42.1 | 0.239 | Toppenish/White Swan | 09:43:26 | -59.3 | Dark | Down | 27.3 | 246.6 | Low | 09:40:00-09:46:00 | -54.2 | 0.142 | PNWRO | 09:43:19 | -58.7 | Dark | Down | 26.5 | 248.0 | Up | 09:40:01-09:46:01 | -58.0 | 0.118 | The Dalles | 09:43:24 | -60.2 | Dark | Down | 28.1 | 246.3 | Up | 09:39:54-09:45:54 | -117.6 | 0.001 | Maupin | 09:43:21 | -60.4 | Dark | Down | 28.2 | 246.5 | Low | 09:39:49-09:45:49 | -144.9 | 0.000 | Madras | 09:43:19 | -60.8 | Dark | Down | 28.5 | 246.8 | Low | 09:39:47-09:45:47 | -183.1 | 0.000 | Sisters | 09:43:18 | -61.2 | Dark | Down | 28.9 | 246.6 | Low | 09:39:44-09:45:44 | -212.8 | 0.000 |
Star training set for 11552_Boucolion, (2025/12/26 09:46UT) Object RA Dec mag sep mel Aldebaran 04:35:55.4 +16:30:29 0.8 11.88 82 67Bet Eri 05:07:50.8 -05:05:13 2.8 15.18 88 45 Tau 04:11:20.5 +05:31:23 5.7 2.86 75 PPM 147540 04:25:57.5 +05:09:01 7.6 0.82 79 PPM 147463 04:21:38.0 +05:23:21 9.0 0.41 78 PPM 147473 04:22:20.6 +05:19:56 10.8 0.27 78 11552_Boucolio 04:22:41.1 +05:04:34 15.4 78 Positions are for J2000