Cora»Occultation

2025-11-25 / UCAC4 616-027593 / (209) Dido

#	OBS	Observer	Occ	Meth.	Instr.	CC	TSRC	UT1	UT2	UT3	UT4	UT2E	UT3E	Dur.	Chrd
1	show	Alberto Ossola	O+	VID	M230	CH	GPS	20:45:32	20:46:42.6	20:46:51.7	20:48:02	1.300	1.100	9.10	109.2
2	show	Stefano Sposetti	O+	VID	M420	CH	GPS	20:44:45	20:46:39.6	20:46:50.2	20:48:45	0.400	0.400	10.60	127.2

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#138 : cda1a850-ddb8-11f0-547e-d89093e647f9 [db: observed]

Using prediction cda1a850-ddb8-11f0-547e-d89093e647f9 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 = -355.6, 38.6 km
Circular diameter = 141 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: 2025-11-25, 20:45 UT (JD = 2461005.365)

DAMIT	Q	P (h)	λ, β	JD0	JD-JD0	φ0	Version	Modified	Vol-equiv D	Cmnt
# 3659	1.0	5.736	217°, -39°	2.450856e6	10149.4	0.0°	None	2019-09-26	not scaled	2019-05-07
# 3660	1.0	5.736	43°, -34°	2.450856e6	10149.4	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] : cda1a850-ddb8-11f0-547e-d89093e647f9 [observed] Occultation Date + Time : 2025-11-25 at 20:40:49 UT +/- 0.01 min [1] Object Designation : (209) Dido Orbit Class : MBA Star Designation : GDR3 3454287444211696512 Star Coordinates (ICRF) : RA = 05 48 50.0664, DE = +33 11 28.726 [2] Star Magnitudes : G = 14.87 mag, RP = 14.04 mag, BP = 15.6 mag Object Magnitude : V = 13.35 mag Estimated Magnitude Drop : 0.2 mag Estimated Max. Duration : 13.3 sec Object Mean Diameter : 159.9 km (src: astorb) Speed of the shadow : 12.0 km/s Elongation to Moon & Sun : 142° (sunlit = 26%), Sun = 154° Cross-track uncertainty : 0.7 mas = 1 km = 0.01 path-width (1-sig) RUWE and duplicate source : 0.93 mas, dup.src = 0 (0:false, 1:true) Ephemeris Reference : JPL#138 Note : FP:true Object is a Gaia mass determination target ! [1] time t0 of closest geocentric approach c/a, [2] including proper motion until t0

Event Details

 Occultation UUID [and DB] : cda1a850-ddb8-11f0-547e-d89093e647f9 [observed]

 Occultation Date + Time   : 2025-11-25 at 20:40:49 UT +/- 0.01 min  [1]
 Object Designation        : (209) Dido
 Orbit Class               : MBA
 Star Designation          : GDR3 3454287444211696512
 Star Coordinates (ICRF)   : RA = 05 48 50.0664, DE = +33 11 28.726  [2]
 Star Magnitudes           : G = 14.87 mag, RP = 14.04 mag, BP = 15.6 mag
 Object Magnitude          : V = 13.35 mag
 Estimated Magnitude Drop  : 0.2 mag
 Estimated Max. Duration   : 13.3 sec
 Object Mean Diameter      : 159.9 km  (src: astorb)
 Speed of the shadow       : 12.0 km/s
 Elongation to Moon & Sun  : 142° (sunlit = 26%), Sun = 154°
 Cross-track uncertainty   : 0.7 mas = 1 km = 0.01 path-width (1-sig)
 RUWE and duplicate source : 0.93 mas, dup.src = 0  (0:false, 1:true)

 Ephemeris Reference       : JPL#138
 Note                      : FP:true

 Object is a Gaia mass determination target !

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

More Data and Informations

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