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Glossary term: 天赤道

Description: 天赤道被定义为天球上所在平面垂直于地球自转轴的大圆。实质上,它是地球赤道在天球上的投影。

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Term and definition status: The original definition of this term in English have been approved by a research astronomer and a teacher
The translation of this term and its definition is still awaiting approval

The OAE Multilingual Glossary is a project of the IAU Office of Astronomy for Education (OAE) in collaboration with the IAU Office of Astronomy Outreach (OAO). The terms and definitions were chosen, written and reviewed by a collective effort from the OAE, the OAE Centers and Nodes, the OAE National Astronomy Education Coordinators (NAECs) and other volunteers. You can find a full list of credits here. All glossary terms and their definitions are released under a Creative Commons CC BY-4.0 license and should be credited to "IAU OAE".

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Related Diagrams


蛇夫座看起来像一个无头人形。

蛇夫座星图

Caption: 蛇夫座及其明亮恒星与周边星座示意图。从顶部开始沿顺时针方向,蛇夫座周边的星座依次为:武仙座、巨蛇头、天蝎座、人马座和巨蛇尾。蛇夫座并不属于传统的黄道十二星座,但它也位于黄道上。从地球看来,太阳以一年为周期在天球上移动,所经过的路径称为黄道,在图中以蓝色实线标注。太阳在每年十一月下旬到十二月中旬位于蛇夫座。太阳系中的其他行星也经常出现在蛇夫座。 蛇夫座横跨天赤道,因此在一年中的某些时候,整个地球都能看到蛇夫座的一部分。蛇夫座在北半球的夏季和南半球的冬季夜晚最适宜观测——不过此时,北极的大部分地区正处于极昼,因此无法看到蛇夫座的恒星。在赤道地区和南北两个半球的温带地区都能看到整个蛇夫座。 由于蛇夫座靠近银河系中心,因此包含了许多球状星团,如M9、M10、M12、M14、M19、M62和M107。这些球状星团在图中以叠加了十字符号的黄色圆圈标注。 该图的纵轴为赤纬,横轴为赤经,方向为上北下南左东右西。图中标注的恒星大小对应其视星等——衡量天体视亮度的标准,较大的圆点代表着较亮的恒星。图中的希腊字母标注着星座中最亮的恒星。这些恒星按亮度排序,最亮的一般被标记为α星,第二亮的一般为β星,等等,不过这种字母排序并不总是和实际亮度排序完全一致。图中虚线标注的是国际天文学联合会划定的星座边界,绿色实线则是一种常见的星座形象连线。需要注意的是,在实际观测时,这些边界与连线都不会出现在天空中。
Credit: 国际天文学联合会天文教育办公室(IAU OAE)根据国际天文学联合会和《天空与望远镜》的原文改编

License: CC-BY-4.0 Creative Commons 署名 4.0 国际 (CC BY 4.0) icons


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

Caption: 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.
Credit: Adapted by the IAU Office of Astronomy for Education from the original by IAU/Sky & Telescope

License: CC-BY-4.0 Creative Commons 署名 4.0 国际 (CC BY 4.0) icons


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

Caption: 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.
Credit: Adapted by the IAU Office of Astronomy for Education from the original by IAU/Sky & Telescope

License: CC-BY-4.0 Creative Commons 署名 4.0 国际 (CC BY 4.0) icons


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

Canis Minor Constellation Map

Caption: 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.
Credit: Adapted by the IAU Office of Astronomy for Education from the original by the IAU and Sky & Telescope

License: CC-BY-4.0 Creative Commons 署名 4.0 国际 (CC BY 4.0) icons


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

Delphinus Constellation Map

Caption: 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.
Credit: Adapted by the IAU Office of Astronomy for Education from the original by the IAU and Sky & Telescope

License: CC-BY-4.0 Creative Commons 署名 4.0 国际 (CC BY 4.0) icons