Cora»Occultation

2025-09-17 / UCAC4 344-157320 / (167) Urda

#	OBS	Observer	Occ	Meth.	Instr.	CC	TSRC	UT1	UT2	UT3	UT4	UT2E	UT3E	Dur.	Chrd
1	show	Andreas Schweizer	O+	VID	M250	CH	GPS	20:22:46	20:23:13.419	20:23:17.859	20:23:46	0.805	0.805	4.44	47.1
2	show	Andreas Schweizer, Stefan MEISTER	O+	VID	M500	CH	GPS	20:22:47	20:23:14.500	20:23:17.340	20:23:47	0.300	0.180	2.84	30.1

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#76 : 71525460-ddb7-11f0-547e-54d1febe8528 [db: observed]

Using prediction 71525460-ddb7-11f0-547e-54d1febe8528 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 = -308.2, -3.6 km
Circular diameter = 68 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).

Check SiMDA for size and mass data.

Check Johnston Archive for satellites.

Sky projection (artificial light) for occ. time: 2025-09-17, 20:22 UT (JD = 2460936.349)

DAMIT	Q	P (h)	λ, β	JD0	JD-JD0	φ0	Version	Modified	Vol-equiv D	Cmnt
# 171	None	13.061	107°, -69°	2.443363e6	17573.3	0.0°	None	2019-05-31	51.0 +/- 15.0 km	2011-03-28
# 172	None	13.061	249°, -68°	2.443363e6	17573.3	0.0°	preferred	2011-04-11	44.0 +/- 15.0 km	2011-03-28

Q: model quality flag (0-5, 5=highest) | P: rotation period | λ,β: ecl. lon. and lat. of spin axis (J2000) | JD: initial time (epoch) | φ0: initial rotation angle for JD0

Image size: 300px. Transparent image background for copy & paste

Map with groundtrack and observer stations

Event Details
Occultation UUID [and DB] : 71525460-ddb7-11f0-547e-54d1febe8528 [observed] Occultation Date + Time : 2025-09-17 at 20:20:08 UT +/- 0.01 min [1] Object Designation : (167) Urda Orbit Class : MBA Star Designation : GDR3 4091662957459845376 Star Coordinates (ICRF) : RA = 18 36 30.7661, DE = -21 15 58.950 [2] Star Magnitudes : G = 14.7 mag, RP = 13.79 mag, BP = 15.56 mag Object Magnitude : V = 14.43 mag Estimated Magnitude Drop : 0.6 mag Estimated Max. Duration : 3.8 sec Object Mean Diameter : 39.9 km (src: astorb) Speed of the shadow : 10.6 km/s Elongation to Moon & Sun : 150° (sunlit = 16%), Sun = 103° Cross-track uncertainty : 0.4 mas = 0 km = 0.02 path-width (1-sig) RUWE and duplicate source : 1.02 mas, dup.src = 0 (0:false, 1:true) Ephemeris Reference : JPL#76 Note : FP:true [1] time t0 of closest geocentric approach c/a, [2] including proper motion until t0

Event Details

 Occultation UUID [and DB] : 71525460-ddb7-11f0-547e-54d1febe8528 [observed]

 Occultation Date + Time   : 2025-09-17 at 20:20:08 UT +/- 0.01 min  [1]
 Object Designation        : (167) Urda
 Orbit Class               : MBA
 Star Designation          : GDR3 4091662957459845376
 Star Coordinates (ICRF)   : RA = 18 36 30.7661, DE = -21 15 58.950  [2]
 Star Magnitudes           : G = 14.7 mag, RP = 13.79 mag, BP = 15.56 mag
 Object Magnitude          : V = 14.43 mag
 Estimated Magnitude Drop  : 0.6 mag
 Estimated Max. Duration   : 3.8 sec
 Object Mean Diameter      : 39.9 km  (src: astorb)
 Speed of the shadow       : 10.6 km/s
 Elongation to Moon & Sun  : 150° (sunlit = 16%), Sun = 103°
 Cross-track uncertainty   : 0.4 mas = 0 km = 0.02 path-width (1-sig)
 RUWE and duplicate source : 1.02 mas, dup.src = 0  (0:false, 1:true)

 Ephemeris Reference       : JPL#76
 Note                      : FP:true

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

More Data and Informations

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