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مصطلح في المعجم: خط الاستواء السماوي

الوصف: خط الاستواء السماوي هو دائرة عظمى على الكرة السماوية، يقع مستواها بزاوية قائمة على محور دوران الأرض. بمعنى آخر، هو الامتداد أو الإسقاط لخط الاستواء الأرضي على الكرة السماوية.

يمثل هذا الخط مرجعاً أساسياً في أنظمة الإحداثيات الفلكية، إذ يُستخدم لتحديد مواقع الأجرام السماوية بالنسبة لاتجاهات الشمال والجنوب السماويين.

مصطلحات ذات صلة:



اطّلع على هذا المصطلح بلغات أخرى

حالة المصطلح والتعريف: تمت الموافقة على التعريف الأصلي لهذا المصطلح باللغة الإنجليزية من قبل فلكي باحث ومعلم
ترجمة هذا المصطلح وتعريفه ما تزال بانتظار الموافقة

يُعد معجم OAE متعدد اللغات مشروعا تابعا لـ مكتب الاتحاد الفلكي الدولي لتعليم الفلك (OAE) بالتعاون مع مكتب الاتحاد الفلكي الدولي للتواصل الفلكي (OAO). تم اختيار وكتابة ومراجعة المصطلحات والتعاريف ضمن جهد جماعي من قبل OAE ومراكز وعُقد OAE، والمنسقين الوطنيين لتعليم الفلك (NAECs)، بالإضافة إلى متطوعين آخرين. يمكنك العثور على قائمة كاملة بالاعتمادات هنا. جميع المصطلحات والتعاريف الخاصة بالمعجم متاحة بموجب ترخيص Creative Commons CC BY-4.0 ويجب نسبها إلى "IAU OAE".

If you notice a factual or translation error in this glossary term or definition then please get in touch.

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الرسوم التوضيحية المرتبطة


Ophiuchus appears as a headless stick figure

Ophiuchus Constellation Map

الشرح: The constellation Ophiuchus along with its bright stars and its surrounding constellations. Ophiuchus is surrounded by (going clockwise from the top): Hercules, Serpens Caput, Scorpius, Sagittarius and Serpens Cauda. Ophiuchus is not part of the traditional twelve zodiac constellations but it lies on the ecliptic (shown here as a blue line), this is the path the Sun appears to take across the sky over the course of a year. The Sun is in Ophiuchus from late November to mid December. The other planets of the Solar System can often be found in Ophiuchus. Ophiuchus spans the celestial equator and thus part of the constellation is visible across the whole of the earth at some point in the year. However during the time it is most visible in the evenings (the southern hemisphere winter and northern hemisphere summer) much of the arctic is in perpetual daylight making the stars in the constellation impossible to see. The whole constellation is visible from equatorial and temperate regions of both hemispheres. As Ophiuchus lies close to the galactic center it contains many globular clusters such as M9, M10, M12, M14, M19, M62, and M107. These are marked as yellow circles with plus symbols superimposed. The y-axis of this diagram is in degrees of declination with north as up and the x-axis is in hours of right ascension with east to the left. The sizes of the stars marked here relate to the star's apparent magnitude, a measure of its apparent brightness. The larger dots represent brighter stars. The Greek letters mark the brightest stars in the constellation. These are ranked by brightness with the brightest star being labeled alpha, the second brightest beta, etc., although this ordering is not always followed exactly. The dotted boundary lines mark the IAU's boundaries of the constellations and the solid green lines mark one of the common forms used to represent the figures of the constellations. Neither the constellation boundaries, nor the line marking the ecliptic, nor the lines joining the stars appear on the sky.
المصدر: Adapted by the IAU Office of Astronomy for Education from the original by IAU/Sky & Telescope

License: CC-BY-4.0 المشاع الإبداعي نَسب المُصنَّف 4.0 دولي (CC BY 4.0) أيقونات


Canis Major is shaped like a stick figure drawing of a dog tilted up by 45 degrees. Sirius lies at the dog’s shoulder

Canis Major Constellation Map

الشرح: The constellation Canis Major along with its bright stars and its surrounding constellations. Canis Major is surrounded by (going clockwise from the top): Monoceros, Lepus, Columba and Puppis. The constellation is dominated by Sirius, the star which appears brightest in the night sky, which far outshines all of the other stars in the constellation. Canis Major lies just south of the celestial equator and is visible from all of the southern hemisphere as well as equatorial and temperate regions of the northern hemisphere. Sirius is visible from all but the most arctic regions. Canis Major is most visible in the evenings in late winter in the northern hemisphere and late summer in the southern hemisphere. The open star clusters M41, NGC 2360 and NGC 2362 lie in the constellation. These are marked with yellow circles. The y-axis of this diagram is in degrees of declination with north as up and the x-axis is in hours of right ascension with east to the left. The sizes of the stars marked here relate to the star's apparent magnitude, a measure of its apparent brightness. The larger dots represent brighter stars. The Greek letters mark the brightest stars in the constellation. These are ranked by brightness with the brightest star being labeled alpha, the second brightest beta, etc., although this ordering is not always followed exactly. The dotted boundary lines mark the IAU's boundaries of the constellations and the solid green lines mark one of the common forms used to represent the figures of the constellations. Neither the constellation boundaries, nor the lines joining the stars appear on the sky.
المصدر: Adapted by the IAU Office of Astronomy for Education from the original by IAU/Sky & Telescope

License: CC-BY-4.0 المشاع الإبداعي نَسب المُصنَّف 4.0 دولي (CC BY 4.0) أيقونات


Aquila looks like a simplified arrow shape with the head pointing to the lower right (the south west). Altair is in the tail

Aquila Constellation Map

الشرح: The constellation Aquila with its bright stars and surrounding constellations. Aquila is surrounded by (going clockwise from the top): Sagitta, Hercules, Ophiuchus, Serpens Cauda, Scutum, Sagittarius, Capricornus, Aquarius and Delphinus. Aquila is most notable for its brightest star Altair. This forms one vertex of the prominent Summer Triangle asterism that is visible in northern hemisphere summer evenings. Aquila spans the celestial equator and thus some part of it is visible from all of the Earth at some point in the year. It is most visible in the evenings in the late northern hemisphere summer and late southern hemisphere winter. The y-axis of this diagram is in degrees of declination with north as up and the x-axis is in hours of right ascension with east to the left. The sizes of the stars marked here relate to the star's apparent magnitude, a measure of its apparent brightness. The larger dots represent brighter stars. The Greek letters mark the brightest stars in the constellation. These are ranked by brightness with the brightest star being labeled alpha, the second brightest beta, etc., although this ordering is not always followed exactly. The dotted boundary lines mark the IAU's boundaries of the constellations and the solid green lines mark one of the common forms used to represent the figures of the constellations. The blue line in the lower right of the diagram is the ecliptic. Neither the constellation boundaries, nor the line marking the ecliptic, nor the lines joining the stars appear on the sky.
المصدر: Adapted by the IAU Office of Astronomy for Education from the original by IAU/Sky & Telescope

License: CC-BY-4.0 المشاع الإبداعي نَسب المُصنَّف 4.0 دولي (CC BY 4.0) أيقونات


Canis Minor appears as a straight line extending north west from Procyon which lies in the center of the constellation

Canis Minor Constellation Map

الشرح: The constellation Canis Minor with its bright stars and surrounding constellations. Canis Minor is surrounded by (going clockwise from the top): Gemini, Monoceros, Hydra and Cancer. Canis Minor has relatively few bright stars but its brightest star Procyon is the eight brightest star in the sky. Canis Minor spans the celestial equator and thus part of the constellation is visible from the whole Earth at some point during the year. The whole constellation is visible to all but the most arctic and antarctic regions. The y-axis of this diagram is in degrees of declination with north as up and the x-axis is in hours of right ascension with east to the left. The sizes of the stars marked here relate to the star's apparent magnitude, a measure of its apparent brightness. The larger dots represent brighter stars. The Greek letters mark the brightest stars in the constellation. These are ranked by brightness with the brightest star being labeled alpha, the second brightest beta, etc., although this ordering is not always followed exactly. The dotted boundary lines mark the IAU's boundaries of the constellations and the solid green lines mark one of the common forms used to represent the figures of the constellations. The blue line in the top right of the diagram marks the ecliptic. Neither the constellation boundaries, nor the line marking the ecliptic, nor the lines joining the stars appear on the sky.
المصدر: Adapted by the IAU Office of Astronomy for Education from the original by the IAU and Sky & Telescope

License: CC-BY-4.0 المشاع الإبداعي نَسب المُصنَّف 4.0 دولي (CC BY 4.0) أيقونات


Delphinus looks like a diamond with an additional small line extending to the south

Delphinus Constellation Map

الشرح: The constellation Delphinus with its brighter stars and surrounding constellations. Delphinus is surrounded by (going clockwise from the top): Vulpecula, Sagitta, Aquila, Aquarius, Equuleus and Pegasus. Delphinus is a relatively small constellation with few bright stars. Delphinus lies just north of the celestial equator and thus the whole constellation is visible at some point in the year to all but the most antarctic regions. The constellation is best viewed in the evenings in the early northern hemisphere autumn and early southern hemisphere spring. The globular cluster NGC 6934 lies in Dephinus. It is marked here with a yellow circle with a plus sign superimposed on it. The y-axis of this diagram is in degrees of declination with north as up and the x-axis is in hours of right ascension with east to the left. The sizes of the stars marked here relate to the star's apparent magnitude, a measure of its apparent brightness. The larger dots represent brighter stars. The Greek letters mark the brightest stars in the constellation. These are ranked by brightness with the brightest star being labeled alpha, the second brightest beta, etc., although this ordering is not always followed exactly. The dotted boundary lines mark the IAU's boundaries of the constellations and the solid green lines mark one of the common forms used to represent the figures of the constellations. Neither the constellation boundaries, nor the lines joining the stars appear on the sky.
المصدر: Adapted by the IAU Office of Astronomy for Education from the original by the IAU and Sky & Telescope

License: CC-BY-4.0 المشاع الإبداعي نَسب المُصنَّف 4.0 دولي (CC BY 4.0) أيقونات