Collaborative Occultation Resources and Archive (CORA)

2025-02-02 / UCAC4 484-017448 / (909) Ulla

#	OBS	Observer	Occ	Meth.	Instr.	CC	TSRC	UT1	UT2	UT3	UT4	UT2E	UT3E	Dur.	Chrd
1	show	Ferran Casarramona	O+	VID	M200	ES	GPS	23:38:01	23:39:21.1	23:39:24.7	23:39:55	0.8	0.5	3.60	40.7
2	show	Deborah Smith	O+	CCD	M300	ES	NTP	23:37:34	23:39:23.52	23:39:30.82	23:41:34	0.34	0.34	7.30	82.5

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 : 7a2f12b0-866c-11ef-78cd-4deafffeb1cb [db: asteroids]

Using prediction 7a2f12b0-866c-11ef-78cd-4deafffeb1cb 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 = -3322.3, 30.0 km
Circular diameter = 89 km

From 2 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).

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Check Johnston Archive for satellites.

Map with groundtrack and observer stations

Event Details
Occultation UUID [and DB] : 7a2f12b0-866c-11ef-78cd-4deafffeb1cb [asteroids] Occultation Date + Time : 2025-02-02 at 23:38:07 UT +/- 0.02 min [1] Object Designation : (909) Ulla Orbit Class : MBA Star Designation : GDR3 3319111934207601664 Star Coordinates (ICRF) : RA = 06 10 26.2267, DE = +06 44 16.080 [2] Star Magnitudes : G = 14.52 mag, RP = 14.11 mag, BP = 14.78 mag Object Magnitude : V = 14.34 mag Estimated Magnitude Drop : 0.7 mag Estimated Max. Duration : 10.3 sec Object Mean Diameter : 116.4 km (src: astorb) Speed of the shadow : 11.3 km/s Elongation to Moon & Sun : 80° (sunlit = 24%), Sun = 136° Cross-track uncertainty : 1.0 mas = 1 km = 0.02 path-width (1-sig) RUWE and duplicate source : 1.05 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

Event Details

 Occultation UUID [and DB] : 7a2f12b0-866c-11ef-78cd-4deafffeb1cb [asteroids]

 Occultation Date + Time   : 2025-02-02 at 23:38:07 UT +/- 0.02 min  [1]
 Object Designation        : (909) Ulla
 Orbit Class               : MBA
 Star Designation          : GDR3 3319111934207601664
 Star Coordinates (ICRF)   : RA = 06 10 26.2267, DE = +06 44 16.080  [2]
 Star Magnitudes           : G = 14.52 mag, RP = 14.11 mag, BP = 14.78 mag
 Object Magnitude          : V = 14.34 mag
 Estimated Magnitude Drop  : 0.7 mag
 Estimated Max. Duration   : 10.3 sec
 Object Mean Diameter      : 116.4 km  (src: astorb)
 Speed of the shadow       : 11.3 km/s
 Elongation to Moon & Sun  : 80° (sunlit = 24%), Sun = 136°
 Cross-track uncertainty   : 1.0 mas = 1 km = 0.02 path-width (1-sig)
 RUWE and duplicate source : 1.05 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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