Summary of 2014 - 2015 Asteroidal Occultations in North America July, 2014 through September 30, 2015 Brad Timerson

Asteroidal Occultation Observations

Asteroidal Occultations by Number of Chords

Best Observed Events July 2014 through September 2015 24 August 2014 393 Lampetia – 5 chords 6 September 2014 93 Minerva – 9 chords, model, satellite 18 September 2014 82 Alkmene – 4 chords, model 20 November 2014 3 Juno – 2 chords, model 10 December 2014 127 Johanna – 2 chords, model 10 January 2015 489 Comacina – 5 chords 10 January 2015 786 Bredichina – 4 chords 20 January 2015 702 Alauda – 4 chords 30 January 2015 166 Rhodope – 5 chords, model 18 February 2015 71 Niobe – 5 chords 7 March 2015 506 Marion – 10 chords! 2 April 2015 90 Antiope – 14 chords, model, double star

Best Observed Events July 2014 through September 2015 15 April 2015 595 Polyxena – 5 chords, model 6 May 2015 107 Camilla – 3 chords, model 20 June 2015 426 Hippo – 4 chords 17 July 2015 679 Pax – 3 chords, 2 model fit 23 August 2015 107 Camilla – 6 chords, model 4 September 2015 409 Aspasia – 5 chords, model

Chord 3 duration well known, but absolute time in question. 24 August 2014 – 393 Lampetia Chord 3 duration well known, but absolute time in question.

6 September 2014 – 93 Minerva

6 September 2014 – 93 Minerva

Light Curve from Steve Messner’s campground remote station, closest to the predicted central line – “A lucky hit” The blue dots are for the target star; the count at the bottom is in video frames (each 1/30th sec.). The green line in the middle is a comparison star in the FOV that was not occulted. The thick red vertical lines mark the D and R by Minerva. But notice 20s after the main event, there is another brief drop lasting 0.6 seconds. This turned out to be an occultation by Minerva’s inner moon, Gorgoneion.

Plot by Frédéric Vachier, IMCCE, Paris shows that Steve Messner’s secondary occultation observation fits the orbit of Gorgoneion very well. The moon’s orbit is known, but not the position in the orbit, but IMCCE found that the new point is consistent with earlier observations. The position of the outer satellite Aegis is shown but its occultation was not observed. Messner’s chord is 6.5 km, larger than the expected 3.2 km size expected from the earlier data.

18 September 2014 – 82 Alkmene

20 November 2014 – 3 Juno

10 December 2014 – 127 Johanna

10 January 2015 – 489 Comacina

10 January 2015 – 786 Bredichina

20 January 2015 – 702 Alauda

30 January 2015 – 166 Rhodope

18 February 2015 – 71 Niobe

7 March 2015 – 506 Marion

2 April 2015 – 90 Antiope

Northern Component with Double Star

Southern Component with Double Star

15 April 2015 – 595 Polyxena

6 May 2015 – 107 Camilla

20 June 2015 – 426 Hippo

17 July 2015 – 679 Pax

17 July 2015 – 679 Pax

23 August 2015 – 107 Camilla

4 September 2015 – 409 Aspasia

Questions? Comments?