Monday, the 15 of August, 2022 ~ 07:11:46 UTC (31) Euphrosyne occult UCAC4 444-002494 (mag 12.67)


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  • Legend for each body
    • green line is the central line
    • blue lines show the estimate size
    • red lines the 1-sigma error for the path
Event
  • Date : Monday, the 15 of August, 2022 ~ 07:11:46 UTC
  • Max duration : 66.25 seconds
  • Shadow velocity : 4.1 km/s
  • Barycenter prediction : Astorb2021
  • Genoide's reference solution : 2021-11-18T02:49:45.645 (Fomc:1.45 mas)
Asteroidal system
  • Name : (31) Euphrosyne
  • Mag : 12.07
  • Geocentric distance : 2.4054 AU
  • Number of Components : 2
  • Component : Euphrosyne
  • Diameter : 255.9 km
  • Max duration : 62.42 sec
  • Component : S2019-31-1
  • Diameter : 6.0 km
  • Max duration : 1.47 sec
Occulted Star
  • Name : UCAC4 444-002494
  • Used RA   :   02h00m57s3 J2000
  • Used DEC : -01d14m10s6 J2000
  • Mb : 13.03
  • Mv : 12.67
  • Mr : 12.15
  • VizieR - Aladin
Historic
  • 2021-11-26 : Create prediction
Prediction for (31) Euphrosyne system. (wide views)

Euphrosyne

Euphrosyne

S2019-31-1

S2019-31-1

Ephemerides from IMCCE

Ephemeris for Euphrosyne

Ephemeris for S2019-31-1

Ephemeris from Miriade for the date of occultation and geocenter frame. For more specific ephemeris please use the documentation of Miriade.

Orbitography for the (31) Euphrosyne system

S2019-31-1

S2019-31-1

Astrometric observations of S2019-31-1 centered on (31) Euphrosyne.
Dot represents one observed position. The vector shows ephemeris position from observed position.

All components on the tangent plane

Propagation of the solutions

We use all the orbits at 1, 2 and 3-σ uncertainties to predict the location of the satellite (relatively to the primary) at the epoch of the occultation. The figure is oriented with North up and East right.

  • The primary is centered at coordinates 0,0, and the arrow shows the direction of the motion of the shadow
  • The black dots show the best orbit at the date of the occultation
  • The green, blue and red dots represent the positions of the satellite within, respectively, 1, 2 and 3-σ uncertainties

S2019-31-1

S2019-31-1
This figure displays the orbits of the components of the system at the date of the occultation. Positive x are toward East, and positive y are toward North. Probable positions of the components are displayed with colors depending of its uncertainty: green for 1-σ, blue for 2-σ and red for 3-σ. The largest region where the component should be located is, in kilometers:
  • 1-σ error = 1111 km
  • 2-σ error = 1119 km
  • 3-σ error = 1135 km

Accuracy for timing

The date of the event presented at the top of this page concerns the barycenter of the system. The occultation by the satellite, however, does not occur exactly at this date. If we consider all the 3-σ uncertainties, we can define a time span of the probable occurring of the event. A negative value corresponds to a time prior the date of the main event.

1-σ 2-σ 3-σ
Minimum time offset -98 sec -99 sec -100 sec
Maximum time offset 99 sec 100 sec 102 sec

Accuracy for position

The black arrow shows the direction of the motion of the shadow. The uncertainty of the position of the satellite at the time of the occultation is defined by the clusters of green (1-σ), blue (2-σ) and red (3-σ) dots. The green lines materialize the lower and upper limits of the 1-σ cluster in the direction of the motion of the shadow. The following table shows the uncertainties on the position of the satellite relatively to its best predicted position. A positive value indicates an offset on the position toward : North-West

1-σ 2-σ 3-σ
Minimum orthogonal projection -30 km -34 km -40 km
Maximum orthogonal projection 1081 km 1085 km 1095 km

More graphics

Contents
  • Orbital solution fitted by Genoid project (Vachier F., Berthier J., Carry B.) IMCCE/CNRS
  • Ephemeris has made available with Miriade Project (Berthier J. & Vachier F.) IMCCE/CNRS
  • Occultation Prediction by Vachier F. using Occult (Occultation Prediction Software by D.Herald)
  • Ephemeris and offset for the barycenter are based on ASTORB (Edward Bowell)