کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1782097 1022318 2008 6 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Instrumental and digital coronagraphy for the observation of the Uranus satellites’ upcoming mutual events
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات فیزیک زمین (ژئو فیزیک)
پیش نمایش صفحه اول مقاله
Instrumental and digital coronagraphy for the observation of the Uranus satellites’ upcoming mutual events
چکیده انگلیسی

Ground-based observations of faint satellites nearby their planets with 1–2 m class telescopes usually do not allow for high quality astrometry and photometry, due to saturation by the primary or to poor S/N ratio on the satellite images, generally embedded on the scattered light of the planet. Earth-based observations of the Uranus satellites’ upcoming mutual events in 2007–2008 are no exception. In most cases, the event will take place at 4 arcs or less from the planet, with “planet minus satellite” brightness differences of 10 magnitudes. So as to make feasible the observations of these important phenomena, we have developed a prototype of a coronagraph of simple design making use of good quality commercial optical systems. Pilot tests made with this coronagraph with a telescope of D=1.6m show that it is possible to obtain S/N ratios of 50 or higher for 10 s exposures, for satellites as close as 2 Uranus radii from the planet center. We have also developed numerical algorithms which perform digital coronagraphy in the images, with the elimination of the influence of the planets’ scattered light. This procedure considerably improves the S/N ratio of the satellite images (with or without a coronagraph instrument) and shall be applied in the reduction of the observations of the Uranus events so as to achieve the highest possible photometric and astrometric quality.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Planetary and Space Science - Volume 56, Issue 14, November 2008, Pages 1882–1887
نویسندگان
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