کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
8141583 | 1523831 | 2018 | 5 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Twilight observation by the naked eye of the dawn sincere at Hail and other areas in Saudi Arabia
ترجمه فارسی عنوان
مشاهده گرگ و میش توسط چشم غم انگیز سپیده دم در حائل و مناطق دیگر عربستان سعودی صادق است
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کلمات کلیدی
تگرگ، مکان های مختلف، منطقه کویر سپیده دم مشاهده چشم بر روی چشم،
موضوعات مرتبط
مهندسی و علوم پایه
فیزیک و نجوم
نجوم و فیزیک نجومی
چکیده انگلیسی
Naked eye observations of morning twilight phenomenon at Hail and other areas of Saudi Arabia are recorded. During the interval from 2014 to 2015, about 80 morning twilight observations were carried out in Hail at longitude λâ¯=â¯41°42â²E and latitude Ïâ¯=â¯27°31â²N for a desert background. The phenomena was followed over azimuth angles ranged from 0° to 20° of solar vertical direction and from 0° to 10° along the altitudinal range. By selecting 32â¯days with a very good visibility, it was found that Sun depression, Do, lies in a range between 13.48° and 14.69° with an average of 14.014°â¯Â±0.317. The difference between our obtained value and that one which is currently applicable in Saudi Arabia is about 4°. The results indicate that dawn (white thread browser) occurs at a sun vertical depression angle Doâ¯=â¯14.66° (meanâ¯+â¯2SD) according to the normal eye estimations. The results at different areas in the deep desert in KSA showed that the beginning of morning twilight and true dawn is at sun vertical depression Doâ¯=â¯14.88° (meanâ¯+â¯1SD). The current study shows significant results, which are comparable with both naked eye observations and photoelectric measurements of true dawn in both Egypt and Libya for desert background.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: NRIAG Journal of Astronomy and Geophysics - Volume 7, Issue 1, June 2018, Pages 22-26
Journal: NRIAG Journal of Astronomy and Geophysics - Volume 7, Issue 1, June 2018, Pages 22-26
نویسندگان
N.S. Khalifa, A.H. Hassan, A.I. Taha,