Occultation event with (23135) Pheidas, event index number 3253
Regions able to see the event: US,SwRI-CO,NMexico
Geocentric closest approach at 2026/02/16 09:49:16 UTC
J2000 position of star is 12:31:37.9 -23:53:27
Equinox of date position of star is 12:33:00.4 -24:02:06
Star is 115 degrees from the moon. Moon is 1% illuminated.
Stellar brightness G=16.7, apparent brightess of occulting body is G=15.1
Use an exposure time of 2.00 seconds with the standard RECON-QHY system.
SNR of 3.5 per integration for unocculted signal
Expected flux drop is 19% with SNR of 0.7 for the occulted depth (per occulted point)
Apparent velocity is 8.1 km/sec on the sky relative to the star, or, 9.2 arcsec/hr.
Position angle of asteroid motion is 73.7 degrees
The recommended exposure time corresponds to 16.2 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 42.3 km.
The sky-plane scale is 3179.0 km/arcsec.
Diameter estimates:
60.0 km assuming a 5% albedo, maximum of 7.4 sec for a central chord
24.5 km assuming a 30% albedo, maximum of 3.0 sec for a central chord
Cross-track diameter of 66.2 km used for deployment plan.
Star training set for 23135_Pheidas, (2026/02/16 09:49UT) Object RA Dec mag sep mel Spica 13:26:34.4 -11:17:49 1.0 18.00 111 9Bet Crv 12:35:45.9 -23:32:27 2.6 0.80 115 PPM 260421 12:31:39.8 -23:50:26 5.1 0.36 116 PPM 260470 12:33:59.9 -24:20:42 7.9 0.38 115 PPM 260446 12:32:56.3 -23:59:33 9.6 0.04 115 23135_Pheidas 12:33:00.4 -24:02:06 15.1 115 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 58.3 % chance of getting at least one chord. There is a 0.4% 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 |
|---|---|---|---|---|---|---|---|---|---|---|
| George/Scottsdale | 09:47:17 | -54.2 | Dark | Down | 32.1 | 172.9 | Up | 09:44:17-09:50:17 | -18.5 | 0.459 | Patrick | 09:46:13 | -49.6 | Dark | Down | 31.1 | 178.9 | Up | 09:43:13-09:49:13 | -74.6 | 0.128 |
This table contains the target star visibility for registered SwRI-CO 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 0.1 % chance of getting at least one chord. There is a 0.1% 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 |
|---|---|---|---|---|---|---|---|---|---|---|
| Dunrhomin | 09:45:55 | -46.6 | Dark | Down | 25.9 | 179.8 | Low | 09:42:55-09:48:55 | 167.8 | 0.000 | Nederland | 09:45:58 | -46.9 | Dark | Down | 26.1 | 179.5 | Low | 09:42:56-09:48:56 | 162.7 | 0.001 | TinkerMill | 09:45:54 | -46.6 | Dark | Down | 26.0 | 179.8 | Low | 09:42:55-09:48:55 | 162.4 | 0.001 | Nikitin | 09:45:55 | -46.7 | Dark | Down | 26.0 | 179.8 | Low | 09:42:58-09:48:58 | 159.8 | 0.001 | CU-SBO | 09:45:56 | -46.8 | Dark | Down | 26.1 | 179.7 | Low | 09:42:54-09:48:54 | 158.6 | 0.001 |
Star training set for 23135_Pheidas, (2026/02/16 09:49UT) Object RA Dec mag sep mel Spica 13:25:11.5 -11:09:41 1.0 18.00 111 9Bet Crv 12:34:23.2 -23:23:50 2.6 0.80 115 PPM 260421 12:30:17.4 -23:41:48 5.1 0.36 116 PPM 260470 12:32:37.3 -24:12:03 7.9 0.38 115 PPM 260446 12:31:33.8 -23:50:55 9.6 0.04 115 23135_Pheidas 12:31:37.9 -23:53:27 15.1 115 Positions are for J2000