Cora»Occultation

2025-08-12 / UCAC4 346-125460 / (2230) Yunnan

#	OBS	Observer	Occ	Meth.	Instr.	CC	TSRC	UT1	UT2	UT3	UT4	UT2E	UT3E	Dur.	Chrd
1	show	Carsten Ziolek	O+	VID	M356	CH	GPS	19:51:52	19:52:22.873	19:52:25.225	19:52:52	0.134	0.134	2.35	6.6
2	show	Gregor Krannich	O+	VID	M350	DE	GPS	19:50:48	19:51:49.766	19:51:51.476	19:52:48	0.141	0.141	1.71	4.8
3	show	Zdenek Moravec	O+	CCD	T600	CZ	GPS	19:50:02	19:50:34.2	19:50:37.72	19:51:57	0.200	0.150	3.52	9.9
4	show	Anna Marciniak	O-	CCD	M350	PL	NTP	19:48:42	::	::	19:50:46

UT1/UT4: Begin/End of observation | UT2/UT3: Begin/End of occultation | Dur: Reported duration in seconds | Chrd: Corresponding chord length in km | More

4 observations found in db: sodis

Available (probably) matching predictions (click on the link to switch):

JPL#70 : 97dd2960-ddb8-11f0-547e-43d66edf7c92 [db: observed]

Using prediction 97dd2960-ddb8-11f0-547e-43d66edf7c92 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:
Size = 18 x 9 km
a',b' = 9.1, 4.4 km
X0,Y0 = 2442.8, 17.7 km
Mean diameter = 13 km

From 3 chords (CCD,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: 2025-08-12, 19:52 UT (JD = 2460900.328)

DAMIT	Q	P (h)	λ, β	JD0	JD-JD0	φ0	Version	Modified	Vol-equiv D	Cmnt
# 4004	1.0	10.038	337°, 42°	2.449809e6	11091.3	0.0°	None	2019-09-26	not scaled	2019-05-07
# 4005	1.0	10.038	149°, 43°	2.449809e6	11091.3	0.0°	None	2019-09-26	not scaled	2019-05-07

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] : 97dd2960-ddb8-11f0-547e-43d66edf7c92 [observed] Occultation Date + Time : 2025-08-12 at 20:08:46 UT +/- 0.02 min [1] Object Designation : (2230) Yunnan Orbit Class : MBA Star Designation : GDR3 4070829862149313408 Star Coordinates (ICRF) : RA = 18 00 03.1107, DE = -20 51 14.681 [2] Star Magnitudes : G = 13.98 mag, RP = 12.75 mag, BP = 15.66 mag Object Magnitude : V = 17.06 mag Estimated Magnitude Drop : 3.1 mag Estimated Max. Duration : 4.5 sec Object Mean Diameter : 12.6 km (src: astorb) Speed of the shadow : 2.8 km/s Elongation to Moon & Sun : 96° (sunlit = 85%), Sun = 130° Cross-track uncertainty : 0.2 mas = 0 km = 0.03 path-width (1-sig) RUWE and duplicate source : 0.89 mas, dup.src = 0 (0:false, 1:true) Ephemeris Reference : JPL#70 Note : FP:true [1] time t0 of closest geocentric approach c/a, [2] including proper motion until t0

Event Details

 Occultation UUID [and DB] : 97dd2960-ddb8-11f0-547e-43d66edf7c92 [observed]

 Occultation Date + Time   : 2025-08-12 at 20:08:46 UT +/- 0.02 min  [1]
 Object Designation        : (2230) Yunnan
 Orbit Class               : MBA
 Star Designation          : GDR3 4070829862149313408
 Star Coordinates (ICRF)   : RA = 18 00 03.1107, DE = -20 51 14.681  [2]
 Star Magnitudes           : G = 13.98 mag, RP = 12.75 mag, BP = 15.66 mag
 Object Magnitude          : V = 17.06 mag
 Estimated Magnitude Drop  : 3.1 mag
 Estimated Max. Duration   : 4.5 sec
 Object Mean Diameter      : 12.6 km  (src: astorb)
 Speed of the shadow       : 2.8 km/s
 Elongation to Moon & Sun  : 96° (sunlit = 85%), Sun = 130°
 Cross-track uncertainty   : 0.2 mas = 0 km = 0.03 path-width (1-sig)
 RUWE and duplicate source : 0.89 mas, dup.src = 0  (0:false, 1:true)

 Ephemeris Reference       : JPL#70
 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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