Herbig Haro 32英文原文

    HH 32是恒星形成时向星际空间喷射喷流一类恒星的典型代表。这个距离地球有1000光年远的天体要比哈勃变光星云要老一些,而HH 32的中央恒星的星风已经吹走了大部分中心区域附近的尘埃,因此,可以轻易的看见这颗恒星。很多年轻的恒星,例如HH 32的中央天体,被从周围星云中吸引过来的尘埃和气体组成的“盘”围绕着。组成这个“盘”的物质渐渐的围绕着这些恒星转动,并不断地向这些恒星飞过去,最后终于飞入了这些恒星之中,从而增加了它们地质量。这些气体中的一小部分正被垂直地以每秒200公里地速度向这个“盘”中喷射过去,形成了两个对立地喷流。这两个喷流直冲入周围的星云,产生巨大的冲击波,使得星云在氢原子(红色)和硫离子(蓝色)以及其他几种原子或者离子的波段发出强光;有些时候,活跃恒星发出的辐射也被它周围的气体反射回来了(红色)。


    为了纪念在二十世纪50年代,在这方面做了很多前期工作的天文学家George Herbig和Guillermo Haro,我们将利用这一类的发光机制发光的物体叫做Herbig-Haro天体。这些顶部、最远可以达到0.2光年的喷流,在指向我们方向显得更清晰一点,而相反方向也就是底部的喷流距我们很远,当然,也很暗,因为被围绕着恒星的尘埃挡住了,或者是因为这颗恒星与我们之间的空间中的尘埃很少。


   译自 哈勃网站(http://oposite.stsci.edu

Herbig Haro 32
Chinese Version

  HH 32 is an excellent example of a "Herbig-Haro object," which is formed when young stars eject jets of material back into interstellar space. This object, about 1,000 light-years from Earth, is somewhat older than Hubble's variable nebula, and the wind from the bright central star has already cleared much of the dust out of the central region, thus exposing the star to direct view. Many young stars, like the central object in HH 32, are surrounded by disks of gas and dust that form as additional material is attracted gravitationally from the surrounding nebula. Material in the disk gradually spirals in toward the star and eventually some of it accretes onto the star, increasing its mass. A fraction of the gas, however, is ejected perpendicularly to the disk at speeds near 200 miles per second, and forms two oppositely directed jets. These jets plow into the surrounding nebula, producing strong shock waves that heat the gas and cause it to glow in the light of hydrogen atoms (green) and sulfur ions (blue), several other atoms and ions, and sometimes radiation from the exciting star that is reflected by the surrounding gas (red). This glow is called a Herbig-Haro object, in honor of astronomers George Herbig and Guillermo Haro, who did much of the early work in this area in the 1950's. The jet on the top side, whose furthest extent is about 0.2 light-year from the star, is pointed more nearly in our direction, while the opposite jet on the bottom lies on the far side of the star and is fainter either because it is partially obscured by dust surrounding the star or because there is much less material in front of the star.

  The Hubble Heritage team (NASA/AURA/STScI) made this image from observations of Herbig-Haro 32 acquired by Salvador Curiel, Jorge Cant? Alejandro Raga, (UNAM), Alberto Noriega-Crespo (IPAC), and collaborators.

   From Hubble Web(http://oposite.stsci.edu