7 Months of Asteroidal Occultations in North America

7 Months of Asteroidal Occultations in North America September 2017 through March 31, 2018 Brad Timerson

Asteroidal Occultation Observations Extrapolated values for 2018: Positives, 176; Misses, 420; Total Observations, 596

Asteroidal Occultations by Number of Chords Extrapolated Values for 2018: 1 chord, 88; 2 chords, 44; 3 chords, 8; 4 chords, 24; >4 chords, 16

Best Observed Events September 2017 through March 31, 2018 n n n n n n 10 September 2017 9 October 2017 23 October 2017 3 November 2017 6 December 2017 10 December 2017 21 December 2017 26 December 2017 28 January 2018 4 February 2018 7 February 2018 9 February 2018 10 February 2018 21 February 2018 4 March 2018 5 March 2018 7 March 2018 9 March 2018 12 March 2018 18 March 2018 357 Ninina – 8 chords 44 Nysa – 4 chords, model 154 Bertha – USA/Europe, 7 chords, 2 models 509 Iolanda – 2 chords, model 464 Magaira – 3 chords 151 Abundantia – USA/Europe, 7 chords, poor fit 980 Anacostia – 3 chords 65 Cybele – 3 chords, model 259 Aletheia – 4 chords 192 Nausikaa – 5 chords, model 50 Virginia – 11 chords 191 Kolga – 8 chords, new double 175 Andromache – 4 chords 303 Josephina – 8 chords 372 Palma – 4 chords, model 505 Cava – 4 chords, model 79 Eurynome – 2 chords, model 32 Pomona – 2 chords, model 2207 Antenor – 2 chords 117 Lomia – 2 chords, model 444 Gyptis – 4 chords

10 September 2017 – 357 Ninina Graze -> Chord 3 duration well known, but absolute time in question.

9 October 2017 – 44 Nysa Notice rotation of +8° for best fit.

23 October 2017 – 154 Bertha USA only model fit to chords

23 October 2017 – 154 Bertha Europe only model fit to chords

3 November 2017 – 509 Iolanda Miss chord picks up the model shape well! 24 Positive observations!

6 December 2017 – 464 Magaira

10 December 2017 – 151 Abundantia European fit to chords requires elongated asteroid.

10 December 2017 – 151 Abundantia USA chord fit isn’t as good and requires a different shape. Model supplied by Josef Durech via email

21 December 2017 – 980 Anacostia

26 December 2017 – 65 Cybele

28 January 2018 – 259 Aletheia

4 February 2018 – 192 Nausikaa

7 February 2018 – 50 Virginia

9 February 2018 – 191 Kolga Double Star Aligned Fit

9 February 2018 – 191 Kolga Chord Fit to Primary

9 February 2018 – 191 Kolga Chord Fit to Secondary

9 February 2018 – 175 Andromache

10 February 2018 – 303 Josephina

21 February 2018 – 372 Palma

4 March 2018 – 505 Cava

5 March 2018 – 79 Eurynome

7 March 2018 – 32 Pomona

9 March 2018 – 2207 Antenor

12 March 2018 – 117 Lomia

18 March 2018 – 444 Gyptis

Nice work by Everyone Involved !