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2019-09-09 / 4UC 454-000904 / (171) Ophelia

#OBSObserverOccMeth.Instr.CC TSRCUT1UT2UT3UT4UT2EUT3EDur.Chrd
1 show Henk De Groot O+ VID M356 NL GPS++ 22:47:53 22:49:58.20 22:50:08.56 22:52:11 0.03 0.03 10.36 128.5
2 show Jan-Maarten Winkel O+ VID M310 NL GPS++ 22:48:52 22:49:56.39 22:50:05.79 22:50:52 0.33 0.33 9.40 116.6
3 show W. Nobel et al O+ VID M460 NL GPS++ 22:42:00 22:50:01.77 22:50:09.45 22:56:00 0.32 0.32 7.68 95.2
4 show Roland Boninsegna O- VID M400 BE 22:47:18 22:53:09
5 show O. Schreurs et al O- VID M406 BE 22:48:56 22:51:07
UT1/UT4: Begin/End of observation | UT2/UT3: Begin/End of occultation | Dur: Reported duration in seconds | Chrd: Corresponding chord length in km | More

5 observations found in db: euraster

Available (probably) matching predictions (click on the link to switch):
JPL#141 : 3718376f-6060-4120-8adb-1807ea03020a [db: observed]

Using prediction 3718376f-6060-4120-8adb-1807ea03020a 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:
Size = 143 x 86 km
a',b' = 71.5, 42.9 km
X0,Y0 = 2389.6, 17.2 km
Mean diameter = 111 km

From 3 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: 2019-09-09, 22:48 UT (JD = 2458736.450)

DAMITQP (h)λ, βJD0JD-JD0φ0VersionModifiedVol-equiv DCmnt
# 1169None6.665 144°, 29° 2.443159e615577.50.0° NoneNone not scaled 2016-01-04
# 1170None6.665 329°, 23° 2.443159e615577.50.0° NoneNone 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] : 3718376f-6060-4120-8adb-1807ea03020a [observed]

 Occultation Date + Time   : 2019-09-09 at 22:50:22 UT +/- 0.01 min  [1]
 Object Designation        : (171) Ophelia
 Orbit Class               : MBA
 Star Designation          : GDR3 2543319142649120128
 Star Coordinates (ICRF)   : RA = 00 41 17.7546, DE = +00 40 10.512  [2]
 Star Magnitudes           : G = 12.0 mag, RP = 11.54 mag, BP = 12.29 mag
 Object Magnitude          : V = 13.91 mag
 Estimated Magnitude Drop  : 2.1 mag
 Estimated Max. Duration   : 9.4 sec
 Object Mean Diameter      : 117 km  (src: astorb)
 Speed of the shadow       : 12.4 km/s
 Elongation to Moon & Sun  : 69° (sunlit = 85%), Sun = 157°
 Cross-track uncertainty   : 2.3 mas = 4 km = 0.04 path-width (1-sig)
 RUWE and duplicate source : 1.53 mas, dup.src = 0  (0:false, 1:true)

 Ephemeris Reference       : JPL#141

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