2025-09-19 / UCAC4 294-176411 / (23) Thalia

#	OBS	Observer	Occ	Meth.	Instr.	CC	TSRC	UT1	UT2	UT3	UT4	UT2E	UT3E	Dur.	Chrd
1	show	Alfonso Noschese	O+	VID	M300	IT	GPS	18:42:50	18:43:44.2	18:43:52.6	18:44:49	0.200	0.200	8.40	93.2
2	show	Antonio Vecchione	O+	VID	M250	IT	GPS	18:43:21	18:43:44.6	18:43:50.4	18:44:18	0.300	0.400	5.80	64.4

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#131 : 7475db80-ddb7-11f0-547e-28614bb6ba94 [db: observed]

Using prediction 7475db80-ddb7-11f0-547e-28614bb6ba94 for map and profile fit

Ellipse and circular profile fits to the timings (chords)

Auto-Fit Result: X0,Y0 = 964.6, -27.9 km Circular diameter = 160 km From 2 chords (VID) Chords to ignore: Fill: Grid: Show (close) miss chords: 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: 2025-09-19, 18:42 UT (JD = 2460938.279)

DAMIT	Q	P (h)	λ, β	JD0	JD-JD0	φ0	Version	Modified	Vol-equiv D	Cmnt
# 122	None	12.312	159°, -45°	2.438385e6	22553.3	0.0°	None	2013-07-24	107.0 +/- 12.0 km	2009-09-23
# 123	None	12.312	343°, -69°	2.438385e6	22553.3	0.0°	None	2013-07-24	107.0 +/- 13.0 km	2009-09-23
# 1857	3.5	12.312	158°, -46°	2.438385e6	22553.3	0.0°	None	2017-09-21	115.0 +/- 8.0 km	2017-09-21
# 1858	3.5	12.312	343°, -74°	2.438385e6	22553.3	0.0°	None	2017-09-21	114.0 +/- 8.0 km	2017-09-21

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

Map with groundtrack and observer stations

Event Details

Occultation UUID [and DB] : 7475db80-ddb7-11f0-547e-28614bb6ba94 [observed] Occultation Date + Time : 2025-09-19 at 18:39:44 UT +/- 0.01 min [1] Object Designation : (23) Thalia Orbit Class : MBA Star Designation : GDR3 4046297038978026240 Star Coordinates (ICRF) : RA = 18 17 19.1871, DE = -31 20 12.225 [2] Star Magnitudes : G = 12.4 mag, RP = 11.86 mag, BP = 12.77 mag Object Magnitude : V = 12.92 mag Estimated Magnitude Drop : 1.0 mag Estimated Max. Duration : 9.7 sec Object Mean Diameter : 107.5 km (src: astorb) Speed of the shadow : 11.1 km/s Elongation to Moon & Sun : 120° (sunlit = 4%), Sun = 97° Cross-track uncertainty : 1.0 mas = 2 km = 0.02 path-width (1-sig) RUWE and duplicate source : 0.73 mas, dup.src = 0 (0:false, 1:true) Ephemeris Reference : JPL#131 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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