Cora»Occultation

2023-07-21 / UCAC4 335-114291 / (171) Ophelia

#	OBS	Observer	Occ	Meth.	Instr.	CC	TSRC	UT1	UT2	UT3	UT4	UT2E	UT3E	Dur.	Chrd
1	show	Jean Bourgeois	O+	VID	M200	BE	GPS	21:15:00	21:15:42.70	21:15:46.20	21:17:00	1.2	0.6	3.50	30.4
2	show	Olivier Schreurs	O+	VID	M410	BE	GPS	21:14:19	21:15:37.7	21:15:48.3	21:17:19	0.5	0.5	10.60	92.2

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#157 : 4b4fa9e0-ddb0-11f0-547e-0bd7ffb622de [db: observed]

JPL#157 : 4b4fa9e0-ddb0-11f0-547e-2421f5fe3ccf [db: observed]

JPL#157 : 5dab10c0-ddb0-11f0-547e-20877dff223b [db: observed]

JPL#157 : 5dab10c0-ddb0-11f0-547e-64fcfdbb7758 [db: observed]

Using prediction 4b4fa9e0-ddb0-11f0-547e-0bd7ffb622de 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 = 3042.5, 5367.6 km
Circular diameter = 181 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: 2023-07-21, 21:15 UT (JD = 2460147.385)

DAMIT	Q	P (h)	λ, β	JD0	JD-JD0	φ0	Version	Modified	Vol-equiv D	Cmnt
# 1169	None	6.665	144°, 29°	2.443159e6	16988.4	0.0°	None	None	not scaled	2016-01-04
# 1170	None	6.665	329°, 23°	2.443159e6	16988.4	0.0°	None	None	not scaled	2016-01-04

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] : 4b4fa9e0-ddb0-11f0-547e-0bd7ffb622de [observed] Occultation Date + Time : 2023-07-21 at 21:21:18 UT +/- 0.01 min [1] Object Designation : (171) Ophelia Orbit Class : MBA Star Designation : GDR3 4116871911616485504 Star Coordinates (ICRF) : RA = 17 42 16.2269, DE = -23 04 27.188 [2] Star Magnitudes : G = 14.62 mag, RP = 13.3 mag, BP = 16.6 mag Object Magnitude : V = 13.71 mag Estimated Magnitude Drop : 0.4 mag Estimated Max. Duration : 13.4 sec Object Mean Diameter : 116.7 km (src: astorb) Speed of the shadow : 8.7 km/s Elongation to Moon & Sun : 102° (sunlit = 15%), Sun = 147° Cross-track uncertainty : 0.7 mas = 1 km = 0.01 path-width (1-sig) RUWE and duplicate source : 0.99 mas, dup.src = 0 (0:false, 1:true) Ephemeris Reference : JPL#157 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] : 4b4fa9e0-ddb0-11f0-547e-0bd7ffb622de [observed]

 Occultation Date + Time   : 2023-07-21 at 21:21:18 UT +/- 0.01 min  [1]
 Object Designation        : (171) Ophelia
 Orbit Class               : MBA
 Star Designation          : GDR3 4116871911616485504
 Star Coordinates (ICRF)   : RA = 17 42 16.2269, DE = -23 04 27.188  [2]
 Star Magnitudes           : G = 14.62 mag, RP = 13.3 mag, BP = 16.6 mag
 Object Magnitude          : V = 13.71 mag
 Estimated Magnitude Drop  : 0.4 mag
 Estimated Max. Duration   : 13.4 sec
 Object Mean Diameter      : 116.7 km  (src: astorb)
 Speed of the shadow       : 8.7 km/s
 Elongation to Moon & Sun  : 102° (sunlit = 15%), Sun = 147°
 Cross-track uncertainty   : 0.7 mas = 1 km = 0.01 path-width (1-sig)
 RUWE and duplicate source : 0.99 mas, dup.src = 0  (0:false, 1:true)

 Ephemeris Reference       : JPL#157
 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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