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2025-01-02 / UCAC4 397-130655 / (177) Irma

#OBSObserverOccMeth.Instr.CC TSRCUT1UT2UT3UT4UT2EUT3EDur.Chrd
1 show William Stewart O+ VID M279 GB GPS 18:34:16 18:35:14.910 18:35:16.030 18:36:14 0.16 0.16 1.12 44.2
2 show Alex Pratt O+ VID M280 GB GPS 18:34:44 18:35:15.20 18:35:16.50 18:35:44 0.3 0.5 1.30 51.4
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#121 : a2373dc0-854d-11ef-78cd-31e0fbcb48ed [db: asteroids]
JPL#121 : e02a25d0-825e-11ef-6618-e967ffdd2335 [db: asteroids]

Using prediction e02a25d0-825e-11ef-6618-e967ffdd2335 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 = 1483.9, 13.8 km
Circular diameter = 59 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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Map with groundtrack and observer stations

Event Details 
 Occultation UUID [and DB] : e02a25d0-825e-11ef-6618-e967ffdd2335 [asteroids]

 Occultation Date + Time   : 2025-01-02 at 18:33:21 UT +/- 0.0 min  [1]
 Object Designation        : (177) Irma
 Orbit Class               : MBA
 Star Designation          : GDR3 2614706584349855104
 Star Coordinates (ICRF)   : RA = 22 14 51.6133, DE = -10 46 08.911  [2]
 Star Magnitudes           : G = 13.44 mag, RP = 12.97 mag, BP = 13.75 mag
 Object Magnitude          : V = 14.52 mag
 Estimated Magnitude Drop  : 1.4 mag
 Estimated Max. Duration   : 1.9 sec
 Object Mean Diameter      : 73 km  (src: astorb)
 Speed of the shadow       : 39.5 km/s
 Elongation to Moon & Sun  : 14° (sunlit = 9%), Sun = 49°
 Cross-track uncertainty   : 1.3 mas = 2 km = 0.03 path-width (1-sig)
 RUWE and duplicate source : 1.0 mas, dup.src = 0  (0:false, 1:true)

 Ephemeris Reference       : JPL#121

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

More Data and Informations
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