Asteroid 112 rotation period found

BillYeung

This is a cooperation project between amateurs from Germany (Reiner Stoss using remote telescope in Spain) and USA (Bill Yeung using remote telescope from New Mexico). The period was found to be 31.344 hr +/- 18 seconds. Two points:

1. The data processing is done by a Croatian (克羅地亞) student!

2. The old period 15.x hr was wrong!!!!!!!!

112   Iphigenia                  S Ch    I     72.18   M  9.84   I 0.0393   15.783                          0.50 1  N            
                                                                  



Bill

[ 本帖最後由 BillYeung 於 2007-12-25 10:12 編輯 ]

CHYeung

Bravo!

That is a good piece of work. BTW, what is the photographic or visual magnitude of the asteroid at time of measurement?


C. H. Yeung

BillYeung

原帖由 CHYeung 於 2007-12-25 14:18 發表
Bravo!

That is a good piece of work. BTW, what is the photographic or visual magnitude of the asteroid at time of measurement?


C. H. Yeung

Dear Dr. Yeung,

Thanks for your kind words. Asteroid 112 was around mag. 12.0 around the few days that we measured it. Using 60 second expsoure, the S/N is close to 100 and that is why we almost see no error bar (Actually there is error bar, but it is just too short)

Attached below is NOT asteroid 112, but on Dec. 20 when asteroid 444 almost occultate a bright star. When asteroid 444 moved close enough to the target star, I took a series of 120 ten second expsoure and record the light curve, the 0.05 mag. increase in brightness was due to the asteroid light curve and there is no occultation that could be detected at H07. The actual occultation path past South of New mexico Observatory H07 by 800 km. A well documented report had been written and emailed to Hilda, it should be published in March newsletter. Stay tuned.





Reiner is a very careful observer. He did ask me about the few gaps in my portion of the curve (asteroid 112), in case other readers may have the same question. Those gaps are due to at times the asteroid moving too close to a bright "field star", which made accurate photometry difficult, if not impossible. Since this won't affect the calculation of the period and we decide to skip it.

Bill

[ 本帖最後由 BillYeung 於 2007-12-26 07:48 編輯 ]