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2024-12-16 / UCAC4 466-020402 / (909) Ulla

#OBSObserverOccMeth.Instr.CC TSRCUT1UT2UT3UT4UT2EUT3EDur.Chrd
1 show Tim Haymes O+ VID M280 GB GPS 23:08:30 23:09:52.6 23:09:59.13 23:11:30 0.20 0.15 6.53 88.8
2 show Simon Kidd O+ VID M350 GB GPS 23:09:00 23:09:46.920 23:09:53.880 23:11:00 0.04 0.04 6.96 94.7
UT1/UT4: Begin/End of observation | UT2/UT3: Begin/End of occultation | Dur: Reported duration in seconds | Chrd: Corresponding chord length in km | More

2 observations found in db: sodis

Available (probably) matching predictions (click on the link to switch):
JPL#133 : 7ee547c0-866c-11ef-78cd-dba833fd1d8d [db: asteroids]
JPL#133 : cf424520-82ab-11ef-6618-74b95ee9b764 [db: asteroids]

Using prediction 7ee547c0-866c-11ef-78cd-dba833fd1d8d for map and profile fit

Get observations as KML file (reduced site location resolution)

Ellipse and circular profile fits to the timings (chords)

 Auto-Fit Result:
X0,Y0 = -735.7, 9.8 km
Circular diameter = 97 km

From 2 chords (VID)








You can enter space separated chord numbers (example: 11 4 8) or a method like VIS to ignore all visual timings, or a time source like RAD and NTP (but not GPS).
If the plot disappears, then there are less than 2 chords left (too much ignored, go back with browser).

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Check Johnston Archive for satellites.

Map with groundtrack and observer stations

Event Details 
 Occultation UUID [and DB] : 7ee547c0-866c-11ef-78cd-dba833fd1d8d [asteroids]

 Occultation Date + Time   : 2024-12-16 at 23:06:43 UT +/- 0.01 min  [1]
 Object Designation        : (909) Ulla
 Orbit Class               : MBA
 Star Designation          : GDR3 3127110025443091968
 Star Coordinates (ICRF)   : RA = 06 41 08.2334, DE = +03 03 52.061  [2]
 Star Magnitudes           : G = 13.64 mag, RP = 13.16 mag, BP = 13.95 mag
 Object Magnitude          : V = 14.0 mag
 Estimated Magnitude Drop  : 1.0 mag
 Estimated Max. Duration   : 8.6 sec
 Object Mean Diameter      : 116 km  (src: astorb)
 Speed of the shadow       : 13.6 km/s
 Elongation to Moon & Sun  : 25° (sunlit = 97%), Sun = 155°
 Cross-track uncertainty   : 1.0 mas = 1 km = 0.02 path-width (1-sig)
 RUWE and duplicate source : 1.09 mas, dup.src = 0  (0:false, 1:true)

 Ephemeris Reference       : JPL#133

 
 [1] time t0 of closest geocentric approach c/a, [2] including proper motion until t0

More Data and Informations
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