Thursday 9th of November 2017 ~ 18:21:48 UTC (87) Sylvia occult TYC 6392-00874-1(mag 11.6)


  • Download the Google Earth File KMZ
  • green line is the central line of (87) Sylvia
  • blue lines show the estimate size of (87) Sylvia
  • red lines the 1-sigma error for the path
  • white lines show Romulus
Event
  • Max duration : 25.2 seconds
  • Mag drop : 1.4
  • Shadow velocity : 10.4 km/s
  • Ingress Earth : 2017-11-09 18h12
  • Egress Earth  : 2017-11-09 18h32
  • Moon illumination : 62%
  • Moon phase : Waning gibbous
Asteroidal system
  • Name : (87) Sylvia
  • Mag : 12.6
  • Asteroid Diameter : 263 km
  • Geocentric distance : 2.752 AU
  • Number of satellite : 2
  • Satellite : Romulus
  • Diameter : 18 km
  • Max duration : 1.7 sec
  • Satellite : Remus
  • Diameter : 7 km
  • Max duration : 0.7 sec
Occulted Star
  • Name : TYC 6392-00874-1
  • Used RA   :   22:40:28.8585 J2000
  • Used DEC : -21:47:32.675 J2000
  • Mv : 11.6
  • VizieR - Aladin
Historic
  • 2016-07-12 : Create prediction
Prediction for (87) Sylvia and Romulus (wide views)

Sylvia

Sylvia

Romulus

Romulus

Remus

Remus

Ephemerides from IMCCE

Ephemeris for (87) Sylvia

Ephemeris for Romulus

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

Orbitography for the (87) Sylvia system

Romulus

Romulus

Astrometric observations centered on (87) Sylvia.
Dot represents one observed position. The vector shows ephemeris position from observed position.

Romulus

Romulus

Geometry of orbit for the (87) Sylvia system view from Earth
  • Cyan circle show the position of the satellite Romulus at the occultation date.
  • The black dots show next positions during almost a period
  • In the center, (87) Sylvia represented by an ellipsoid
  • Remus

    Remus

    Astrometric observations centered on (87) Sylvia.
    Dot represents one observed position. The vector shows ephemeris position from observed position.

    Remus

    Remus

    Geometry of orbit for the (87) Sylvia system view from Earth
  • Cyan circle show the position of the satellite Remus at the occultation date.
  • The black dots show next positions during almost a period
  • In the center, (87) Sylvia represented by an ellipsoid
  • Propagation of the solutions
    We use all orbits from 1,2 and 3 sigma issued from Genetical algorithm, and we see where the satellite is for the occultation date. North on top, and East on right.
    • Center at coordinates 0,0 is Primary
    • Black dots show the orbit with the best solution at the date of occultation
    • Green zone show orbits covering 1-sigma error
    • Blue zone for 2-sigma
    • Red zone for 3-sigma

    Remus

    Remus
    This figure represent 2117378 orbits computed to the occultation date. Each orbit is classify throw its performance, given an accuracy in kilometer :
    • 1-σ error = 293 km
    • 2-σ error = 320 km
    • 3-σ error = 347 km

    Romulus

    Romulus
    This figure represent 2119901 orbits computed to the occultation date. Each orbit is classify throw its performance, given an accuracy in kilometer :
    • 1-σ error = 113 km
    • 2-σ error = 127 km
    • 3-σ error = 135 km
    Contents
    • Orbital solution fitted by Genoid project (Vachier F., Berthier J., Carry B. & Pajuelo M.) 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 based on ASTORB (Edward Bowell)