RECON observing guide for 4138_Kalchas_20250430105550

Occultation event with (4138) Kalchas, event index number 936
Regions able to see the event: Australia,NZ

Geocentric closest approach at 2025/04/30 10:55:50 UTC

J2000 position of star is 09:52:01.5 +11:04:12
Equinox of date position of star is 09:53:22.9 +10:57:00
Star is 69 degrees from the moon. Moon is 10% illuminated.
Stellar brightness G=16.1, apparent brightess of occulting body is G=15.8
Use an exposure time of 2.00 seconds with the standard RECON-QHY system.
SNR of 6.6 per integration for unocculted signal
Expected flux drop is 43% with SNR of 2.8 for the occulted depth (per occulted point)

Apparent velocity is 3.9 km/sec on the sky relative to the star, or, 3.9 arcsec/hr.
The recommended exposure time corresponds to 7.8 km per image.
The 1-sigma error in the time of the event is 11.1 seconds.
The 1-sigma cross-track error in the shadow position is 32.4 km.
The sky-plane scale is 3610.5 km/arcsec.

Diameter estimates:
55.7 km assuming a 5% albedo, aximum of 14.3 sec for a central chord
22.8 km assuming a 30% albedo, maximum of 5.8 sec for a central chord
Cross-track diameter of 55.7 km used for deployment plan.

Star training set for 4138_Kalchas, (2025/04/30 10:56UT)
Object            RA         Dec     mag  sep  mel
Regulus        10:09:43.1 +11:50:33  1.3  4.10  72
PPM 126849     09:52:10.9 +11:43:22  6.5  0.83  68
PPM 126854     09:52:18.2 +10:45:47  7.8  0.32  69
PPM 126880     09:53:57.2 +11:10:44 11.0  0.27  69
4138_Kalchas   09:53:22.9 +10:57:00 15.8        69
Positions are for equinox of date

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 4138_Kalchas, (2025/04/30 10:56UT)
Object            RA         Dec     mag  sep  mel
Regulus        10:08:21.9 +11:58:02  1.3  4.10  72
PPM 126849     09:50:49.2 +11:50:32  6.5  0.83  68
PPM 126854     09:50:56.8 +10:52:57  7.8  0.32  69
PPM 126880     09:52:35.8 +11:17:56 11.0  0.27  69
4138_Kalchas   09:52:01.5 +11:04:12 15.8        69
Positions are for J2000


Created by recondetail.pro, 2025/03/14 10:47:10 MT