Submillimetre images of dusty debris around nearby stars
Submillimetre images of dusty debris around nearby stars
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DOI：
10.1038/33874
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发表时间：
1998-04-23
期刊：
影响因子：
64.8
通讯作者：
Robson, I
中科院分区：
文献类型：
--
作者：
Holland, WS;Greaves, JS;Robson, I
最近有报道称，间接探测到围绕类太阳恒星运行的大质量（可能是类木星）行星(1,2)。岩石状的类地行星更难探测到，但它们可能存在的线索仍然可以通过观察它们形成的星周尘埃碎片盘来获得。这种圆盘的存在是从过量的远红外发射中推断出来的(3)，但是，除了β绘架座(4)之外，事实证明很难直接对这些结构进行成像，因为星光主导了尘埃散射的微弱光(5)。一种更有前途的方法是尝试对亚毫米波长的尘埃颗粒的热发射进行成像 (6,7)。在这里，我们展示了北落师门、绘架座β和织女星周围此类发射的图像。对于每颗恒星，都会从与太阳彗星柯伊伯带相当的区域检测到尘埃排放。每颗恒星周围的尘埃总质量只有几个月球质量，因此任何存在的类地行星必定已经形成。我们在北落师门的发射中检测到的中央空腔的存在，大约有海王星轨道的大小，这可能确实是此类行星的特征。
Indirect detections of massive - presumably Jupiter-like - planets orbiting nearby Sun-like stars have recently been reported(1,2). Rocky, Earth-like planets are much more difficult to detect, but clues to their possible existence can nevertheless be obtained from observations of the circumstellar debris disks of dust from which they form. The presence of such disks has been inferred(3) from excess far-infrared emission but, with the exception of beta Pictoris(4), it has proved difficult to image these structures directly as starlight dominates the faint Light scattered by the dust(5). A more promising approach is to attempt to image the thermal emission from the dust grains at submillimetre wavelengths(6,7). Here we present images of such emission around Fomalhaut, beta Pictoris and Vega. For each star, dust emission is detected from regions comparable in size to the Sun's Kuiper belt of comets. The total dust mass surrounding each star is only a few lunar masses, so any Earth-like planets present must already have formed. The presence of the central cavity, approximately the size of Neptune's orbit, that we detect in the emission from Fomalhaut may indeed be the signature of such planets.