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天文学家发现“灾难性变量”系统:证实了几十年前的预测_我的网站

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A |     Dharmendra is being remembered as one of the most iconic actors of Bollywood. He has given Hindi cinema some of its rarest gems and his movies and songs still remain fresh in the memories of the audience. He has sadly passed away earlier in the morning today and his fans and followers have been sharing their heartfelt condolences in person and on social media.His family, including Hema Malini and Esha Deol have arrived at the crematorium. Many of his industry colleagues including Amitabh Bachchan, Salman Khan and more have also attended his last rites. Karan Johar, Kajol and more made special posts for the veteran actor to remember his contributions to Indian cinema.In one of his previous interviews, while talking to a leading daily about his 85th birthday, Dharmendra said, “I have lived my life to the fullest, and life has kept me young."          He had further revealed that he doesn’t like to celebrate his birthday in a big way and often spends time at his farm. He had added that he often cries alone on his birthday as he misses his late mother a lot.Also Read: President Droupadi Murmu and PM Modi Mourn Veteran Bollywood Actor Dharmendra’s DemiseDharmendra made his debut in 1960 and quickly became a superstar. He was known for his versatility, mastering roles from the romantic hero to the tough action star. His career boasts over 300 films, many of which are considered classics today.Some of his most memorable performances include the iconic role of Veeru in the cult classic Sholay, as well as memorable performances in Phool Aur Patthar, Seeta Aur Geeta, Chupke Chupke, Dharam Veer, and Pratigya. His natural charm and powerful screen presence earned him millions of fans worldwide.Also Read: Bobby Deol: I wanted to work with Aryan Khan even without hearing the script - Exclusive。    需要说明的是,这并不是科学记者的夸张之词。天文学家称这些系统为灾难性变星是一个恰当的描述。这个术语描述了一个白矮星和一个次级“正常”恒星的配对,前者是一颗曾经强大的恒星的密集残余物,后者跟太阳类似但质量可能较小。在这对组合的紧密轨道上,白矮星由于其极端的引力而从较大的恒星上吸走恒星物质。周三发表在《自然》上的新灾难性变量的发现其特点是一颗大小为太阳1/100的白矮星和一颗更大的恒星--约是太阳质量的10%并挤在一个木星大小的球体中。这对恒星距离地球约3000光年,其被标记为ZTF J1813+4251。它是在兹威基瞬变设施拍摄的图像中被发现,这是一项广域调查,其使用加州帕洛玛天文台的一台望远镜并依次拍摄数百张天空图像。

B | 兹威克瞬变设施目录使天文学家能寻找恒星亮度的快速变化。这就是研究人员发现这对奇特的星体的方式。“这是一个特殊的系统,”麻省理工学院的天体物理学家Kevin Burdge说道。他指出,这是已知的行为最优美的灾难性变数之一。Burdge和他的同事们搜索了茨威基的数据以试图在深黑的太空中找到灯塔。他们希望看到有规律的眨眼特征--Burdge通常在寻找快速的眨眼,这是因为它们往往是一对恒星快速运行的信号。研究小组看到ZTF J1813+4251每51分钟闪烁一次。据悉,这是其中一颗恒星从另一颗恒星前面经过并使其光线变暗。闪烁的时间跟迄今为止发现的灾难性变星的最短轨道相吻合。通过用夏威夷和西班牙的其他望远镜以及天基望远镜进行观测,这使得研究人员对恒星变得更加集中,并能更准确地测量它发出的光线。

C | 不过这引发了一个难题。Burdge在一份新闻稿中指出:“有一颗恒星看起来像太阳,但是太阳无法进入一个短于8小时的轨道。”太阳的质量使它无法拥有如此紧密的轨道。那么为什么这颗木星大小的恒星会这样做呢?Burdge和研究小组已经确定的解释是,这颗白矮星一直在吞噬其伙伴星的一大块氢。这留下了一个更密集的氦气核心,而这有助于稳定紧密的轨道。简而言之,研究小组是在这一过程的中间阶段观察这对恒星的,当时白矮星已经剥去了大部分的氢。剥离后的白矮星留下了一个吸积盘,它像土星环一样围绕着核心。“这是一个罕见的案例,我们在从氢到氦的吸积过程中抓住了其中的一个系统,”Burdge说道。

D | 在12亿颗恒星中,该算法挑出了我们迄今发现的最有趣的灾难性变数之一。这一幸运的发现有助于支持早先提出的关于大灾变体过渡到超短轨道的理论,该理论是在近四十年前提出的--现在我们知道这确实发生了。该小组还进行了模拟以确定ZTF J1813+4251的最终命运。他们预测,在约7000万年后,这对天体将更快地围绕对方运行,每18分钟做一次完整的循环。尽管人们不会看到它,但一旦激光干涉仪空间天线(LISA)在2030年代末的某个时候进入轨道,那么研究人员将能更详细地研究这个灾难性的变量。这一系列卫星将被用来探测引力波--这些恒星舞伴将产生引力波。

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