Occultation event with (30705) Idaios, event index number 1272
Regions able to see the event: US,RECON
Geocentric closest approach at 2025/09/08 10:35:39 UTC
J2000 position of star is 01:40:56.9 +07:52:19
Equinox of date position of star is 01:42:17.9 +08:00:04
Star is 31 degrees from the moon. Moon is 99% illuminated.
Stellar brightness G=12.6, apparent brightess of occulting body is G=15.3
Use an exposure time of 0.12 seconds with the standard RECON-QHY system.
SNR of 14.8 per integration for unocculted signal
Expected flux drop is 93% with SNR of 13.7 for the occulted depth (per occulted point)
Apparent velocity is 10.6 km/sec on the sky relative to the star, or, 12.9 arcsec/hr.
Position angle of asteroid motion is 90.8 degrees
The recommended exposure time corresponds to 1.3 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 22.0 km.
The sky-plane scale is 2950.4 km/arcsec.
Diameter estimates:
48.8 km assuming a 5% albedo, aximum of 4.6 sec for a central chord
19.9 km assuming a 30% albedo, maximum of 1.9 sec for a central chord
Cross-track diameter of 44.5 km used for deployment plan.
Star training set for 30705_Idaios, (2025/09/08 10:36UT) Object RA Dec mag sep mel Aldebaran 04:37:23.9 +16:33:32 0.8 43.53 75 6Bet Ari 01:56:03.9 +20:55:57 2.6 13.35 39 110Omi Psc 01:46:45.2 +09:17:10 4.3 1.69 33 PPM 144862 01:41:56.3 +08:53:24 6.6 0.89 31 PPM 144885 01:42:57.1 +08:02:10 9.3 0.17 31 30705_Idaios 01:42:17.9 +08:00:04 15.3 32 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 52.1 % chance of getting at least one chord. There is a 4.0% 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 |
|---|---|---|---|---|---|---|---|---|---|---|
| Madras | 10:35:52 | -29.2 | Dark | Up | 53.2 | 180.6 | Up | 10:32:41-10:38:41 | 168.9 | 0.000 | Sisters | 10:35:55 | -29.6 | Dark | Up | 53.6 | 179.9 | Up | 10:32:36-10:38:36 | 138.7 | 0.000 | Bend | 10:35:53 | -29.7 | Dark | Up | 53.8 | 180.3 | Up | 10:32:40-10:38:40 | 117.8 | 0.000 | Oregon Observatory | 10:35:54 | -29.9 | Dark | Up | 54.0 | 180.1 | Up | 10:32:31-10:38:31 | 102.1 | 0.000 | Chiloquin | 10:35:57 | -31.0 | Dark | Up | 55.3 | 179.4 | Up | 10:32:35-10:38:35 | -17.9 | 0.477 | Klamath Falls | 10:35:57 | -31.2 | Dark | Up | 55.6 | 179.5 | Up | 10:32:31-10:38:31 | -49.2 | 0.084 | Cedarville | 10:35:44 | -30.8 | Dark | Up | 56.3 | 182.3 | Up | 10:31:52-10:37:52 | -111.3 | 0.000 | Burney | 10:35:56 | -32.1 | Dark | Up | 57.0 | 179.7 | Up | 10:31:57-10:37:57 | -174.3 | 0.000 |
Star training set for 30705_Idaios, (2025/09/08 10:36UT) Object RA Dec mag sep mel Aldebaran 04:35:55.4 +16:30:29 0.8 43.53 75 6Bet Ari 01:54:38.6 +20:48:26 2.6 13.35 39 110Omi Psc 01:45:23.8 +09:09:29 4.3 1.69 33 PPM 144862 01:40:35.0 +08:45:38 6.6 0.89 31 PPM 144885 01:41:36.0 +07:54:25 9.3 0.17 31 30705_Idaios 01:40:56.9 +07:52:19 15.3 31 Positions are for J2000