RECON observing guide for 23958_98VD30_20260414044315

Occultation event with (23958) 98VD30, event index number 3628
Regions able to see the event: US,SAmericaN,UVa

Geocentric closest approach at 2026/04/14 04:43:15 UTC

J2000 position of star is 11:19:24.3 -18:32:05
Equinox of date position of star is 11:20:43.1 -18:40:43
Star is 153 degrees from the moon. Moon is 14% illuminated.
Stellar brightness G=16.0, apparent brightess of occulting body is G=15.1
Use an exposure time of 0.70 seconds with the standard RECON-QHY system.
SNR of 3.5 per integration for unocculted signal
Expected flux drop is 31% with SNR of 1.1 for the occulted depth (per occulted point)

Apparent velocity is 16.4 km/sec on the sky relative to the star, or, 19.4 arcsec/hr.
Position angle of asteroid motion is 145.0 degrees
The recommended exposure time corresponds to 11.5 km per image.
The 1-sigma error in the time of the event is 2.3 seconds.
The 1-sigma cross-track error in the shadow position is 18.7 km.
The sky-plane scale is 3052.3 km/arcsec.

Diameter estimates:
55.5 km assuming a 5% albedo, maximum of 3.4 sec for a central chord
22.6 km assuming a 30% albedo, maximum of 1.4 sec for a central chord
Cross-track diameter of 46.0 km used for deployment plan.

Star training set for 23958_98VD30, (2026/04/14 04:43UT)
Object            RA         Dec     mag  sep  mel
Spica          13:26:34.9 -11:17:52  1.0 31.23 137
4Gam Crv       12:17:09.7 -17:41:16  2.6 13.44 147
13Lam Crt      11:24:40.3 -18:55:29  5.0  0.97 153
PPM 224340     11:24:52.6 -18:27:53  8.2  1.01 153
PPM 224241     11:20:26.5 -18:39:22  9.3  0.07 153
23958_98VD30   11:20:43.1 -18:40:43 15.1       153
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 3.7 % 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
Getrost 04:46:21 -38.6 Dark Down 26.9 203.5 Up 04:43:41-04:49:41 52.6 0.037

This table contains the target star visibility for registered UVa 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
Lynchburg 04:45:57 -42.6 Dark Down 29.4 207.2 Low 04:43:04-04:49:04 173.8 0.000
Green_Bank 04:46:04 -41.5 Dark Down 28.7 206.3 Low 04:42:52-04:48:52 148.9 0.000

Azimuth is measured in degrees eastward from north. North is at an azimuth of 0, due East is at an azimuth of 90 degrees, due South is 180, and due West is 270.

Star training set for 23958_98VD30, (2026/04/14 04:43UT)
Object            RA         Dec     mag  sep  mel
Spica          13:25:11.5 -11:09:41  1.0 31.23 137
4Gam Crv       12:15:48.1 -17:32:30  2.6 13.44 147
13Lam Crt      11:23:21.3 -18:46:49  5.0  0.97 153
PPM 224340     11:23:33.6 -18:19:12  8.2  1.01 153
PPM 224241     11:19:07.7 -18:30:43  9.3  0.07 153
23958_98VD30   11:19:24.3 -18:32:05 15.1       153
Positions are for J2000


Created by recondetail.pro, 2025/06/19 10:06:23 MT