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2020-03-18 / 4UC 461-003255 / (304) Olga

#OBSObserverOccMeth.Instr.CC TSRCUT1UT2UT3UT4UT2EUT3EDur.Chrd
1 show Pierre Le Cam O+ CCD M250 FR GPS++ 19:26:30 19:28:21.60 19:28:23.35 19:30:30 0.13 0.38 1.75 78.4
2 show Lionel Rousselot O+ CCD M250 FR GPS++ 19:26:00 19:28:21.85 19:28:23.25 19:30:02 0.20 0.40 1.40 62.7
3 show Stefan Meister O+ CCD M500 CH GPS 19:27:39 19:28:23.77 19:28:24.90 19:29:09 0.13 0.25 1.13 50.6
UT1/UT4: Begin/End of observation | UT2/UT3: Begin/End of occultation | Dur: Reported duration in seconds | Chrd: Corresponding chord length in km | More

3 observations found in db: euraster

Available (probably) matching predictions (click on the link to switch):
JPL#74 : 28d9fcfd-facb-4f9d-a0d6-19983ab62068 [db: observed]

Using prediction 28d9fcfd-facb-4f9d-a0d6-19983ab62068 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:
Ellipse profile fit was not successful. Trying circular fit.

Circular diameter = 78 km

From 3 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).

Check SiMDA for size and mass data.

Check Johnston Archive for satellites.

Sky projection (artificial light) for occ. time: 2020-03-18, 19:27 UT (JD = 2458927.310)

DAMITQP (h)λ, βJD0JD-JD0φ0VersionModifiedVol-equiv DCmnt
# 50861.018.201 38°, 37° 2.457229e61698.30.0° None2020-10-05 not scaled 2019-10-23
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] : 28d9fcfd-facb-4f9d-a0d6-19983ab62068 [observed]

 Occultation Date + Time   : 2020-03-18 at 19:26:19 UT +/- 0.0 min  [1]
 Object Designation        : (304) Olga
 Orbit Class               : MBA
 Star Designation          : GDR3 2513704106192295680
 Star Coordinates (ICRF)   : RA = 02 20 44.1553, DE = +02 08 40.164  [2]
 Star Magnitudes           : G = 12.58 mag, RP = 11.93 mag, BP = 13.06 mag
 Object Magnitude          : V = 15.04 mag
 Estimated Magnitude Drop  : 2.6 mag
 Estimated Max. Duration   : 1.5 sec
 Object Mean Diameter      : 68 km  (src: astorb)
 Speed of the shadow       : 44.8 km/s
 Elongation to Moon & Sun  : 96° (sunlit = 26%), Sun = 36°
 Cross-track uncertainty   : 0.3 mas = 0 km = 0.01 path-width (1-sig)
 RUWE and duplicate source : 1.12 mas, dup.src = 0  (0:false, 1:true)

 Ephemeris Reference       : JPL#74

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

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