Asteroidal Occultations around the world Summary of the best events in last 2 years
The number of events continues to grow…
Number of successful events by region, and max # observers Australasia50(5 obs, 6 stns) Europe51(231 obs) Japan25(34 obs) US106(14 obs, 18 stns) Japan has a much smaller land area than the other regions; Australasia has a much smaller population
Double stars discovered in asteroidal occultations New double stars can be discovered in an asteroidal occultation Separations are usually in the range 0.1 to If several observers, the uncertainty in separation can be less than 1 milli- arcsecond
9 double stars discovered in last 24 months Star number Sep ( ) P.A. Date Asteroid ± ± Apr Lacadiera ± ± Jul Pretoria ± ± Jul Tjilaki HIP Sep Arabia ± Nov 9 79 Eurynome ± ± Jun Bohemia Aug Bella 2U ± ± Oct Ludmilla HIP ± ± Jan Una
An odd-shaped asteroid - or – (234) Barbara has a heart 2009 Nov 21, Florida + Germany 28 stations – but only 13 observers – Degenhardt – 7 stations – Dunham – 4 stations – Maley – 5 stations – Venable – 3 stations
Issues with Barbara Asteroid may be a contact binary asteroid There were timing issues with a couple of critical observations – which were resolved.
Roma occults δ Oph 2010 Jul 08 Path crossed Europe Star mag 2.9 => naked eye event Star has a significant diameter Over 230 separate observations - most ever.
Star had a large diameter… Star dia : Asteroid dia : All events were gradual
Roma – sample light curve
Roma – fit is poor because of inconsistent light levels used for event times
Roma profile using good observations
Other well-observed events A selection of the best observed events that show the profile of the asteroid.
709 Pretoria
(449) Hamburga
(216) Kleopatra (the dog-bone asteroid)
(81) Terpsichore
(80) Sappho
(16) Psyche (timing issue with one chord)
(695) Bella
(96) Aegle
(93) Minerva
(212) Medea
(160) Una
(11) Parthenope (timing issues)