Occultation event with (5283) Pyrrhus, event index number 921
Regions able to see the event: US,SwRI-CO,NMexico
Geocentric closest approach at 2025/04/21 03:58:36 UTC
J2000 position of star is 10:36:13.0 +29:57:26
Equinox of date position of star is 10:37:37.7 +29:49:32
Star is 150 degrees from the moon. Moon is 49% illuminated.
Stellar brightness G=13.0, apparent brightess of occulting body is G=15.1
Use an exposure time of 0.12 seconds with the standard RECON-QHY system.
SNR of 10.9 per integration for unocculted signal
Expected flux drop is 88% with SNR of 9.5 for the occulted depth (per occulted point)
Apparent velocity is 7.9 km/sec on the sky relative to the star, or, 8.6 arcsec/hr.
The recommended exposure time corresponds to 0.9 km per image.
The 1-sigma error in the time of the event is 3.9 seconds.
The 1-sigma cross-track error in the shadow position is 47.0 km.
The sky-plane scale is 3313.5 km/arcsec.
Diameter estimates:
65.8 km assuming a 5% albedo, aximum of 8.3 sec for a central chord
26.9 km assuming a 30% albedo, maximum of 3.4 sec for a central chord
Cross-track diameter of 65.8 km used for deployment plan.
Star training set for 5283_Pyrrhus, (2025/04/21 03:59UT) Object RA Dec mag sep mel Regulus 10:09:43.0 +11:50:33 1.3 19.12 152 68Del Leo 11:15:27.0 +20:23:05 2.6 12.73 140 33 LMi 10:33:17.2 +32:14:56 5.8 2.60 150 PPM 100441 10:33:26.5 +29:36:06 8.4 0.94 151 PPM 075336 10:37:21.4 +30:16:08 9.3 0.45 150 PPM 100480 10:36:29.2 +29:46:47 11.2 0.25 150 5283_Pyrrhus 10:37:37.7 +29:49:32 15.1 150 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 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 0.0 % 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 |
|---|---|---|---|---|---|---|---|---|---|---|
Star training set for 5283_Pyrrhus, (2025/04/21 03:59UT) Object RA Dec mag sep mel Regulus 10:08:21.9 +11:58:02 1.3 19.12 152 68Del Leo 11:14:06.7 +20:31:22 2.6 12.73 140 33 LMi 10:31:51.4 +32:22:46 5.8 2.60 150 PPM 100441 10:32:01.6 +29:43:57 8.4 0.94 151 PPM 075336 10:35:56.6 +30:24:02 9.3 0.45 150 PPM 100480 10:35:04.4 +29:54:41 11.2 0.25 150 5283_Pyrrhus 10:36:13.0 +29:57:26 15.1 150 Positions are for J2000