Cora»Occultation

2025-02-20 / UCAC4 502-050474 / (4902) Thessandrus

#	OBS	Observer	Occ	Meth.	Instr.	CC	TSRC	UT1	UT2	UT3	UT4	UT2E	UT3E	Dur.	Chrd
1	show	Carsten Ziolek	O+	VID	M356	CH	GPS	18:40:18	18:40:49.125	18:40:50.964	18:41:18	0.043	0.043	1.84	29.6
2	show	Stefan Meister	O+	VID	M500	CH	GPS	18:40:20	18:40:50.731	18:40:53.531	18:41:29	0.098	0.098	2.80	45.1

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#65 : 7977c790-8a04-11ef-78cd-11865bd9b47e [db: asteroids]

Using prediction 7977c790-8a04-11ef-78cd-11865bd9b47e 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 = -976.7, 9.8 km
Circular diameter = 61 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.

Map with groundtrack and observer stations

Event Details
Occultation UUID [and DB] : 7977c790-8a04-11ef-78cd-11865bd9b47e [asteroids] Occultation Date + Time : 2025-02-20 at 18:35:31 UT +/- 0.04 min [1] Object Designation : (4902) Thessandrus Orbit Class : JTRO Star Designation : GDR3 0591759911143640576 Star Coordinates (ICRF) : RA = 09 10 20.3325, DE = +10 19 31.849 [2] Star Magnitudes : G = 14.56 mag, RP = 14.09 mag, BP = 14.87 mag Object Magnitude : V = 16.77 mag Estimated Magnitude Drop : 2.3 mag Estimated Max. Duration : 2.3 sec Object Mean Diameter : 36.4 km (src: astorb) Speed of the shadow : 16.1 km/s Elongation to Moon & Sun : 105° (sunlit = 50%), Sun = 164° Cross-track uncertainty : 2.0 mas = 5 km = 0.16 path-width (1-sig) RUWE and duplicate source : 0.98 mas, dup.src = 0 (0:false, 1:true) Ephemeris Reference : JPL#65 [1] time t0 of closest geocentric approach c/a, [2] including proper motion until t0

Event Details

 Occultation UUID [and DB] : 7977c790-8a04-11ef-78cd-11865bd9b47e [asteroids]

 Occultation Date + Time   : 2025-02-20 at 18:35:31 UT +/- 0.04 min  [1]
 Object Designation        : (4902) Thessandrus
 Orbit Class               : JTRO
 Star Designation          : GDR3 0591759911143640576
 Star Coordinates (ICRF)   : RA = 09 10 20.3325, DE = +10 19 31.849  [2]
 Star Magnitudes           : G = 14.56 mag, RP = 14.09 mag, BP = 14.87 mag
 Object Magnitude          : V = 16.77 mag
 Estimated Magnitude Drop  : 2.3 mag
 Estimated Max. Duration   : 2.3 sec
 Object Mean Diameter      : 36.4 km  (src: astorb)
 Speed of the shadow       : 16.1 km/s
 Elongation to Moon & Sun  : 105° (sunlit = 50%), Sun = 164°
 Cross-track uncertainty   : 2.0 mas = 5 km = 0.16 path-width (1-sig)
 RUWE and duplicate source : 0.98 mas, dup.src = 0  (0:false, 1:true)

 Ephemeris Reference       : JPL#65

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

More Data and Informations

SiMDA \| 3D Asteroid Catalogue \| Johnston Archive \| Star at CDS (Vizier) \| JPL Small-Body Node \| Minor Planet Center \| Wikipedia

(If error 404: link not valid which means no data available)

Aladin Sky Atlas

Aladin Lite direct link (has Gaia overlay)

Collaborative Occultation Resources and Archive (CORA)

2025-02-20 / UCAC4 502-050474 / (4902) Thessandrus