Frederic Vachier ' web page

Thursday, the 17 of March, 2022 ~ 04:09:06 UTC (3749) Balam occult UCAC4 547-039642 (mag 13.17)

Download the Google Earth File KMZ
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 : Thursday, the 17 of March, 2022 ~ 04:09:06 UTC
Max duration : 9.10 seconds
Shadow velocity : 7.9 km/s
Barycenter prediction : JPL#75:2021-Nov-09
Genoide's reference solution : 2021-11-27T10:09:20.333 (Fomc:34.26 mas)

Asteroidal system

Name : (3749) Balam
Mag : 16.87
Geocentric distance : 1.4034 AU
Number of Components : 2

Component : Balam
Diameter : 14.0 km
Max duration : 1.78 sec

Component : S2002-3749-1
Diameter : 6.0 km
Max duration : 0.76 sec

Occulted Star

Name : UCAC4 547-039642
Used RA : 07h21m33s9 J2000
Used DEC : +19d21m49s2 J2000
Mb : 13.48
Mv : 13.17
Mr : 12.70
VizieR - Aladin

Historic

2021-11-29 : Create prediction

Prediction for (3749) Balam system. (wide views)

Balam

S2002-3749-1

Ephemerides from IMCCE

Ephemeris for Balam

Ephemeris for S2002-3749-1

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

Orbitography for the (3749) Balam system

S2002-3749-1

Astrometric observations of S2002-3749-1 centered on (3749) Balam.
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

S2002-3749-1

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 = 285 km
2-σ error = 313 km
3-σ error = 352 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	-8 sec	-16 sec	-17 sec
Maximum time offset	40 sec	41 sec	43 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/North-East

	1-σ	2-σ	3-σ
Minimum orthogonal projection	-178 km	-195 km	-203 km
Maximum orthogonal projection	108 km	118 km	149 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 JPL Horizons