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Glossary term: 变星

Redirected from 激变变星

Description: 变星是指对观测者而言亮度随时间发生明显变化的恒星。实际上,由于恒星的演化,所有恒星的亮度都会在数百万年或数十亿年内发生变化。而变星一词通常是指那些发生亮度变化的时间尺度远远短于其演化时标的恒星。

产生光变有几种可能的物理机制。有些恒星,如仙王座变星或天琴座RR型变星,它们是不稳定的,且会发生脉动,使得其大小和亮度发生变化。

其他恒星会喷射出明亮的物质,从而增加观测到的总体亮度("爆发变星")。有一类被称为灾变变星或新星的恒星,它们的亮度会突然增加,然后又恢复到以前的水平。这类系统通常由一对恒星组成,其中一颗恒星的物质流向另一颗恒星,一旦达到某个临界点,就会发生核聚变反应。其中一个伴星或另一个伴星发生大爆炸并变亮。

还有一些恒星看起来变化是因为它们在旋转,交替地向我们展示亮度较高和亮度较低的一面,或者是由于双星系统绕着彼此运行,其中一颗恒星周期性地被另一颗遮挡。后一类双星被称为食双星。

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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".

Related Diagrams


猎户座呈沙漏状,两串恒星分别向东北和西北方延伸

猎户座星图

Caption: 猎户座及其明亮的恒星和周围的星座。猎户座被金牛座、波江座、天兔座、麒麟座和双子座环绕(从上往下顺时针依次排列)。猎户座最亮的恒星参宿四和参宿七分别位于星座的北端(图中上部)和南端(图中下部),中间是著名的三星 "腰带"。 猎户座横跨天赤道,因此在一年中的某些时候,从地球上的任何地方都能看到它。在世界上最北极或最南极地区,可能看不到猎户座的某些部分。猎户座在北半球冬季和南半球夏季的晚上最为明显。猎户座上方的蓝线标志着黄道,即太阳在一年中划过天空的轨迹。太阳从不经过猎户座,但人们偶尔会在猎户座发现太阳系的其他行星和月球。 在猎户座腰带的正南方,有两个梅西叶天体M42(猎户座星云)和M43,用绿色方框标出。这些星云和M78(腰带左边的绿色方框)是巨大的猎户座分子云团的一部分。它覆盖了猎户座的大部分区域,包括这些分子云正在坍缩形成新星的区域。 该图的 y 轴表示赤纬,单位为度数,以北为上,x 轴表示赤经,单位为小时,以东为左。这里标注的恒星大小与恒星的视星等有关,视星等是衡量恒星视亮度的标准。较大的点代表较亮的恒星。希腊字母表示星座中的亮星。这些恒星按亮度排序,最亮的恒星被标记为α星,第二亮的为β星,等等,不过并不总是完全遵循这种排序。围绕着参宿四的圆圈表示它是一颗变星。虚线是国际天文学联合会划定的星座边界,绿色实线是表示星座的常用形式之一。星座边界和连接恒星的线条都不会出现在实际天空中。
Credit: 由国际天文学联合会天文教育办公室根据国际天文学联合会/《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


Scorpius appears as a letter T joined to a letter J. The ecliptic runs ESE to WNW and clips one arm of the T

Scorpius Constellation Map

Caption: The constellation Scorpius (often commonly called Scorpio) along with its bright stars and surrounding constellations. Scorpius is surrounded by (going clockwise from the top) Ophiuchus, Serpens Caput, Libra, Lupus, Norma, Ara, Corona Australis and Sagittarius. Scorpius’s brightest star Antares appears in the heart of the constellation with the famous tail of Scoprius in the south-east (lower left). Scorpius 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 only spends a short amount of time in late November in Scorpius. The other planets of the Solar System can often be found in Scorpius. Scorpius lies south of the celestial equator. The whole constellation is not visible from the most arctic regions of the world with parts of Scorpius obscured for observers in northern parts of Asia, Europe and North America. Scorpius is most visible in the evenings in the northern hemisphere summer and southern hemisphere winter. The yellow circles mark the positions of the open clusters M6, M7 & NGC 6231 while the yellow circles with plus signs superimposed on them mark the globular clusters M4 and M80. The y-axis of this diagram is in degrees of declination and 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 circle around Antares indicates that it is a variable star. 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. The blue line marks the ecliptic, the path the Sun appears to travel across the sky over the course of one year.
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