Occultation event with (4834) Thoas, event index number 3400
Regions able to see the event: US,RECON,NMexico,SMexico
Geocentric closest approach at 2026/03/11 10:57:33 UTC
J2000 position of star is 12:53:32.4 +31:40:01
Equinox of date position of star is 12:54:47.9 +31:31:30
Star is 87 degrees from the moon. Moon is 50% illuminated.
Stellar brightness G=16.7, apparent brightess of occulting body is G=14.3
Use an exposure time of 1.85 seconds with the standard RECON-QHY system.
SNR of 3.0 per integration for unocculted signal
Expected flux drop is 10% with SNR of 0.3 for the occulted depth (per occulted point)
Apparent velocity is 17.1 km/sec on the sky relative to the star, or, 19.1 arcsec/hr.
Position angle of asteroid motion is 121.2 degrees
The recommended exposure time corresponds to 31.6 km per image.
The 1-sigma error in the time of the event is 2.0 seconds.
The 1-sigma cross-track error in the shadow position is 16.0 km.
The sky-plane scale is 3231.5 km/arcsec.
Diameter estimates:
89.1 km assuming a 5% albedo, maximum of 5.2 sec for a central chord
36.4 km assuming a 30% albedo, maximum of 2.1 sec for a central chord
Cross-track diameter of 72.3 km used for deployment plan.
Star training set for 4834_Thoas, (2026/03/11 10:58UT) Object RA Dec mag sep mel Arcturus 14:16:51.5 +19:02:51 0.0 22.29 65 Alkaid 13:48:34.2 +49:11:00 1.9 20.34 91 37 Com 13:01:31.5 +30:38:40 6.1 1.69 86 PPM 076763 12:52:15.2 +31:20:02 8.1 0.58 88 PPM 076777 12:53:16.8 +31:37:57 9.9 0.34 88 4834_Thoas 12:54:47.9 +31:31:30 14.3 87 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 |
|---|---|---|---|---|---|---|---|---|---|---|
| George/Scottsdale | 10:55:39 | -35.0 | Dark | Up | 66.6 | 272.7 | Up | 10:51:55-10:57:55 | -151.1 | 0.000 |
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 95.1 % chance of getting at least one chord. There is a 91.4% 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 |
|---|---|---|---|---|---|---|---|---|---|---|
| Sisters | 10:57:00 | -36.1 | Dark | Up | 70.8 | 235.0 | Up | 10:53:28-10:59:28 | 144.4 | 0.000 | Bend | 10:56:58 | -36.1 | Dark | Up | 70.8 | 236.0 | Up | 10:53:30-10:59:30 | 138.6 | 0.000 | Oregon Observatory | 10:56:58 | -36.3 | Dark | Up | 71.0 | 236.2 | Up | 10:53:25-10:59:25 | 118.2 | 0.000 | Cedarville | 10:56:43 | -37.0 | Dark | Up | 71.4 | 244.3 | Up | 10:53:24-10:59:24 | -4.7 | 0.938 | Chiloquin | 10:56:53 | -37.4 | Dark | Up | 72.0 | 238.7 | Up | 10:53:20-10:59:20 | -8.5 | 0.914 | Klamath Falls | 10:56:52 | -37.5 | Dark | Up | 72.1 | 239.8 | Up | 10:52:54-10:58:54 | -32.0 | 0.477 | Burney | 10:56:45 | -38.2 | Dark | Up | 72.7 | 243.7 | Up | 10:52:55-10:58:55 | -135.1 | 0.000 | Reno | 10:56:33 | -37.9 | Dark | Up | 71.9 | 250.4 | Up | 10:52:51-10:58:51 | -145.5 | 0.000 | North Las Vegas | 10:56:03 | -36.4 | Dark | Up | 69.2 | 264.2 | Up | 10:52:57-10:58:57 | -148.5 | 0.000 | Gimple | 10:56:40 | -38.2 | Dark | Up | 72.5 | 247.1 | Up | 10:52:50-10:58:50 | -153.7 | 0.000 | Yerington | 10:56:28 | -37.7 | Dark | Up | 71.7 | 252.8 | Up | 10:52:45-10:58:45 | -154.5 | 0.000 | Hawthorne | 10:56:25 | -37.6 | Dark | Up | 71.4 | 254.8 | Up | 10:53:05-10:59:05 | -162.9 | 0.000 | Kingman/Dolan Springs | 10:55:54 | -36.0 | Dark | Up | 68.4 | 268.0 | Up | 10:53:40-10:59:40 | -167.3 | 0.000 | Carson City | 10:56:32 | -38.0 | Dark | Up | 72.1 | 251.4 | Up | 10:54:16-11:00:16 | -173.4 | 0.000 | Quincy | 10:56:39 | -38.4 | Dark | Up | 72.6 | 247.5 | Up | 10:54:18-11:00:18 | -174.3 | 0.000 |
Star training set for 4834_Thoas, (2026/03/11 10:58UT) Object RA Dec mag sep mel Arcturus 14:15:37.7 +19:10:06 0.0 22.29 65 Alkaid 13:47:32.1 +49:18:48 1.9 20.34 91 37 Com 13:00:16.4 +30:47:06 6.1 1.69 86 PPM 076763 12:50:59.4 +31:28:33 8.1 0.58 88 PPM 076777 12:52:01.2 +31:46:28 9.9 0.34 88 4834_Thoas 12:53:32.4 +31:40:01 14.3 87 Positions are for J2000