Astronomy Picture of the Day

Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

February 11, 1998

Ultra-Fast Pulsar
Credit: E. V. Gotthelf (LHEA, GSFC) Q. D. Wang (Northwestern Univ.), ASCA


脈衝星是旋轉的中子星,誕生於超新星爆炸的猛烈洪爐中。 就像一座座的宇宙燈塔一樣,從脈衝星表面熱點發出的輻射束,掃過我們的視角,形成脈衝並透露出這些極高密度恆星孑遺體的旋轉速率。 在脈衝星之中,最著名者為位於鄰近超新星遺跡內的蟹狀星雲。 蟹狀星雲的年輕脈衝星轉速很快。 它每秒旋轉33次,並輻射能量化激發周圍的恆星殘骸氣體。 從軌道X射線望遠鏡的觀測檔案資料庫裡,天文學家最近找到了另一顆類似蟹狀星雲波霎、但轉速更高的脈衝星。 這顆新發現的脈衝星,位於大麥哲倫星系(LMC)的超新星遺跡N157B裡,其X射線脈衝顯示其轉速更快,每秒高達62次,讓它成為已知與超新星遺跡關聯的最快脈衝星。 這張假色的等高線X射線影像,呈現了大麥哲倫星系裡N157B的位置、鄰近熾熱星團R136的核心、和另一顆類蟹狀星脈衝星SNR 0540-69.3的位置(每秒僅旋轉20次)。 此影像的跨幅約為1500光年。

Pulsars are rotating neutron stars, born in the violent crucibles of supernova explosions. Like cosmic lighthouses, beams of radiation from surface hotspots sweep past our viewpoint creating pulses which reveal the rotation rates of these incredibly dense stellar corpses. The most famous pulsar of all is found in the nearby supernova remnant, the Crab Nebula. The Crab's young pulsar is fast. Rotating at 33 times a second, its radiation energizes the surrounding gaseous stellar debris. But using archival observations from orbiting X-ray telescopes, astronomers have recently identified another "Crab-like" pulsar that is even faster. Located in the Large Magellanic Cloud (LMC), X-ray pulses from this newly discovered pulsar, in the supernova remnant N157B, indicate an even faster rotation rate - 62 times a second - making it the fastest known pulsar associated with a supernova remnant. This contoured, false color X-ray image of a portion of the LMC shows the location of N157B along with the core of the nearby hot star cluster R136, and the site of another Crab-like pulsar in SNR 0540-69.3 (rotating a mere 20 times a second). The image is about 1,500 light-years across.

Tomorrow's picture: In A Grand Canyon

< Archive | Index | Search | Calendar | Glossary | Education | About APOD >

Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (USRA)
NASA Technical Rep.: Jay Norris. Specific rights apply.
A service of: LHEA at NASA/ GSFC
&: Michigan Tech. U.