Occultation event with (4709) Ennomos, event index number 1671
Regions able to see the event: US,RECON
Geocentric closest approach at 2025/12/12 08:06:14 UTC
J2000 position of star is 03:18:27.9 +26:32:41
Equinox of date position of star is 03:20:01.0 +26:38:17
Star is 122 degrees from the moon. Moon is 45% illuminated.
Stellar brightness G=13.7, apparent brightess of occulting body is G=13.6
Use an exposure time of 0.25 seconds with the standard RECON-QHY system.
SNR of 9.5 per integration for unocculted signal
Expected flux drop is 48% with SNR of 4.6 for the occulted depth (per occulted point)
Apparent velocity is 16.8 km/sec on the sky relative to the star, or, 19.2 arcsec/hr.
Position angle of asteroid motion is 49.8 degrees
The recommended exposure time corresponds to 4.2 km per image.
The 1-sigma error in the time of the event is 1.2 seconds.
The 1-sigma cross-track error in the shadow position is 33.3 km.
The sky-plane scale is 3160.1 km/arcsec.
Diameter estimates:
114.3 km assuming a 5% albedo, aximum of 6.8 sec for a central chord
46.7 km assuming a 30% albedo, maximum of 2.8 sec for a central chord
Cross-track diameter of 91.4 km used for deployment plan.
Star training set for 4709_Ennomos, (2025/12/12 08:06UT) Object RA Dec mag sep mel Aldebaran 04:37:24.8 +16:33:34 0.8 20.58 106 44Zet Per 03:55:46.2 +31:57:31 2.8 9.43 113 56 Ari 03:13:47.4 +27:21:11 5.6 1.56 123 59 Ari 03:21:29.2 +27:09:47 6.7 0.62 121 PPM 092358 03:19:04.8 +26:59:17 9.4 0.41 122 PPM 092370 03:19:50.5 +26:30:37 10.4 0.13 122 4709_Ennomos 03:20:01.0 +26:38:17 13.6 121 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 100.0 % chance of getting at least one chord. There is a 79.8% 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 |
|---|---|---|---|---|---|---|---|---|---|---|
| Oliver | 08:02:45 | -63.8 | Dark | Down | 56.1 | 240.2 | Up | 07:59:57-08:05:57 | 219.4 | 0.000 | Anarchist Mountain Observatory | 08:02:45 | -64.0 | Dark | Down | 56.1 | 240.7 | Up | 07:59:58-08:05:58 | 196.6 | 0.000 | Okanogan | 08:02:47 | -64.6 | Dark | Down | 56.5 | 241.3 | Up | 07:59:59-08:05:59 | 135.7 | 0.002 | Brewster | 08:02:48 | -64.9 | Dark | Down | 56.7 | 241.4 | Up | 08:00:01-08:06:01 | 113.0 | 0.014 | Manson/Chelan | 08:02:49 | -65.2 | Dark | Down | 57.0 | 241.2 | Up | 08:00:01-08:06:01 | 101.3 | 0.032 | Wenatchee | 08:02:51 | -65.6 | Dark | Down | 57.4 | 241.7 | Up | 08:00:02-08:06:02 | 57.0 | 0.295 | Royal City | 08:02:49 | -66.1 | Dark | Down | 57.2 | 243.2 | Up | 08:00:06-08:06:06 | -13.5 | 0.722 | Yakima | 08:02:53 | -66.5 | Dark | Down | 57.9 | 242.5 | Up | 08:00:06-08:06:06 | -21.1 | 0.674 | Toppenish/White Swan | 08:02:53 | -66.7 | Dark | Down | 57.9 | 243.1 | Up | 08:00:02-08:06:02 | -48.2 | 0.394 | The Dalles | 08:02:57 | -67.5 | Dark | Down | 58.7 | 243.3 | Up | 08:00:09-08:06:09 | -107.0 | 0.021 | PNWRO | 08:02:48 | -66.9 | Dark | Down | 57.1 | 245.3 | Up | 08:00:08-08:06:08 | -127.7 | 0.005 | Maupin | 08:02:58 | -67.9 | Dark | Down | 58.8 | 244.0 | Up | 08:00:04-08:06:04 | -152.0 | 0.000 | Madras | 08:02:59 | -68.4 | Dark | Down | 59.1 | 244.8 | Up | 08:00:05-08:06:05 | -207.2 | 0.000 | Sisters | 08:03:01 | -68.8 | Dark | Down | 59.5 | 244.7 | Up | 08:00:03-08:06:03 | -228.2 | 0.000 |
Star training set for 4709_Ennomos, (2025/12/12 08:06UT) Object RA Dec mag sep mel Aldebaran 04:35:55.4 +16:30:29 0.8 20.58 106 44Zet Per 03:54:07.9 +31:53:01 2.8 9.43 113 56 Ari 03:12:14.2 +27:15:25 5.6 1.56 123 59 Ari 03:19:55.8 +27:04:14 6.7 0.62 121 PPM 092358 03:17:31.6 +26:53:40 9.4 0.41 122 PPM 092370 03:18:17.5 +26:25:01 10.4 0.13 122 4709_Ennomos 03:18:27.9 +26:32:41 13.6 122 Positions are for J2000