| LONG BEACH. CALIFORNIA—Planets appear to be everywhere astronomers look, even in orbit around white dwarf stars—the compacted and slowly cooling "corpses" of stars like our own sun. At the 221st meeting of the American Astronomical Society here, researchers reported the discovery of a planetary system around a white dwarf in the famous Hyades star cluster. This cluster is only 150 light-years from Earth and easily visible to the naked eye on a bright winter night. It's only the second time planets have been found in a cluster similar to the one that probably gave birth to our own sun. It's circumstantial evidence, though: The planets apparently stir up the rocky asteroid belt of the system, and as a result, the white dwarf's outer layers become "polluted" with asteroid dust, which in turn is detectable with sensitive spectroscopes. This may be the ultimate fate of our own solar system, after the sun sheds its gaseous mantle into space and condenses into a white dwarf. |
加州長(zhǎng)灘消息：天文學(xué)家們觀察到的地方到處是行星，甚至在白矮星周?chē)加行行恰０装鞘穷?lèi)似我們太陽(yáng)的恒星在塌縮后慢慢冷卻的“死尸”。美國(guó)天文學(xué)會(huì)在這里舉行的第221屆會(huì)議上，研究人員報(bào)道：他們發(fā)現(xiàn)在著名的畢星團(tuán)周?chē)嬖谝粋€(gè)行星系統(tǒng)。畢星團(tuán)距離地球僅僅150光年，在冬季晴朗的夜晚，人們用肉眼能夠很容易地看到。行星在類(lèi)似于誕生太陽(yáng)的星團(tuán)中被發(fā)現(xiàn)，這僅僅是第二次。然而，有充分的證據(jù)表明，這些行星顯然攪亂了系統(tǒng)中的巖石小行星帶，結(jié)果這顆白矮星的外層受到了小行星塵的“污染”，而小行星塵可以被敏感的分光鏡探測(cè)到。這有可能就是我們太陽(yáng)系的最終命運(yùn)，到那時(shí)太陽(yáng)的氣體外圍會(huì)流入太空，并凝縮成白矮星。 |
