Occultation observations from around the world Jan 2011 to Jun 2012 Dave Herald

Part 1 Lunar Occultations Summary of observations Jan – Jun. 2012

# Observations by region Nth America357 Australasia1201 Japan928 Europe2082 MiddleEast88

# Reported Grazes by region Nth America2 Australasia10 Japan12 Europe10 Middle East2 Total36

Grazes with 5 or more observers 2011 Apr 23 – Australia (5) 2011 Aug 24 – Europe (5) 2011 Sep 17 – Australia (6) 2012 Jan 29 – Japan (6)

Grazes by number of events (>10) Date# eventsRegion (# observers) 2011 Sep 1742Australia (5) 2011 Apr 836Australia (3) 2011 Nov 336Japan (4) 2011 Aug 2234USA (2) 2011 Aug 2431Europe (5) 2011 Oct 330Japan (3) 2012 Jan 2928Japan (6) 2011 Mar 1327Japan (2) 2011 Mar 1120Europe (2) 2011 Dec 1016Japan (2) 2012 Feb 414Japan (1) 2012 Apr 114USA (1) 2012 Apr 2913Europe (1) 2011 May 712Japan (1) 2011 Jun 2312Australia (1) 2012 Jan 2912Europe (1)

Double star observations # positive measures94 # doubtful doubles30 # definite not double58 # wide doubles22 Reports collected and analysed by Brian Loader, New Zealand

Some double star solutions R3287 S96610 S97067 S76152

Part 2 Asteroidal Occultations Summary of the best events Jan 2011 – June 2012

The number of events has flattened off…

Number of successful events by region, and max # sites: 2011/ /06 Australasia (7 sites) Europe (19 sites) Japan (25 sites) US (57 sites) 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

7 double stars discovered since Jan 2011 Star number Sep (mas) P.A. Date Asteroid HIP ± ± Jan Una u Sep Irma ± Jan Vinifera HIP Jan Agamemnon Feb Irma ± ± Mar Mnemosyne Mar Nysa

90 Antiope how good does it get!

Star diameter from 90 Antiope Dia from 61 light curves : mas For complex occultations, correct interpretation of a light curve may depend on results from adjacent chord => need to ensure data is available for re-analysis.

212 Medea 2011 Jan 8, Japan

144 Vibilia 2011 Jan 25, Europe

(11) Parthenope 2011 Jan 26, USA

(554) Perega 2011 Mar 08, Europe

(360) Carlova 2011 Aug 15, USA

(156) Xanthippe 2011 Dec 26, ES + US

(329) Svea 2011 Dec 28, Japan

(705) Erminia 2012 Jan 2, Japan

(654) Zelinda 2012 Jan 6, Japan

(266) Aline 2012 Jan 17, Japan

(57) Mnemosyne 2012 Mar 11, USA

(128) Nemesis 2012 Mar 30, Australia

(1030) Vitja 2012 Apr 28, CA + US

Any questions?