Cora»Occultation

2023-04-08 / UCAC4 558-018608 / (4138) Kalchas

#	OBS	Observer	Occ	Meth.	Instr.	CC	TSRC	UT1	UT2	UT3	UT4	UT2E	UT3E	Dur.	Chrd
1	show	Anna Marciniak	O+	CCD	M400	PL	GPS	19:13:17	19:13:42.400	19:13:43.500	19:14:58	0.20	0.20	1.10	26.8
2	show	Anna Marciniak	O+	CCD	M350	PL	GPS	19:12:40	19:13:39.280	19:13:40.650	19:14:58	0.14	0.14	1.37	33.4

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#71 : 8a09fc00-ddb3-11f0-547e-9e54ebc71799 [db: observed]

Using prediction 8a09fc00-ddb3-11f0-547e-9e54ebc71799 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 = 247.6, 52.4 km
Circular diameter = 71 km

From 2 chords (CCD)

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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Map with groundtrack and observer stations

Event Details
Occultation UUID [and DB] : 8a09fc00-ddb3-11f0-547e-9e54ebc71799 [observed] Occultation Date + Time : 2023-04-08 at 19:11:17 UT +/- 0.01 min [1] Object Designation : (4138) Kalchas Orbit Class : JTRO Star Designation : GDR3 3402956709507255808 Star Coordinates (ICRF) : RA = 05 39 04.6765, DE = +21 31 25.327 [2] Star Magnitudes : G = 13.36 mag, RP = 12.78 mag, BP = 13.76 mag Object Magnitude : V = 18.04 mag Estimated Magnitude Drop : 4.7 mag Estimated Max. Duration : 1.3 sec Object Mean Diameter : 32.0 km (src: astorb) Speed of the shadow : 24.4 km/s Elongation to Moon & Sun : 145° (sunlit = 93%), Sun = 66° Cross-track uncertainty : 0.1 mas = 0 km = 0.01 path-width (1-sig) RUWE and duplicate source : 1.06 mas, dup.src = 0 (0:false, 1:true) Ephemeris Reference : JPL#71 Note : FP:true [1] time t0 of closest geocentric approach c/a, [2] including proper motion until t0

Event Details

 Occultation UUID [and DB] : 8a09fc00-ddb3-11f0-547e-9e54ebc71799 [observed]

 Occultation Date + Time   : 2023-04-08 at 19:11:17 UT +/- 0.01 min  [1]
 Object Designation        : (4138) Kalchas
 Orbit Class               : JTRO
 Star Designation          : GDR3 3402956709507255808
 Star Coordinates (ICRF)   : RA = 05 39 04.6765, DE = +21 31 25.327  [2]
 Star Magnitudes           : G = 13.36 mag, RP = 12.78 mag, BP = 13.76 mag
 Object Magnitude          : V = 18.04 mag
 Estimated Magnitude Drop  : 4.7 mag
 Estimated Max. Duration   : 1.3 sec
 Object Mean Diameter      : 32.0 km  (src: astorb)
 Speed of the shadow       : 24.4 km/s
 Elongation to Moon & Sun  : 145° (sunlit = 93%), Sun = 66°
 Cross-track uncertainty   : 0.1 mas = 0 km = 0.01 path-width (1-sig)
 RUWE and duplicate source : 1.06 mas, dup.src = 0  (0:false, 1:true)

 Ephemeris Reference       : JPL#71
 Note                      : FP:true

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

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