Exploding Binary Stars Will Light up the Sky in 2022

爆發的雙星將會點亮2022年的夜空

在初一的凌晨看到了這篇報道，感到非常高興，遂翻譯之。原文連結：

Exploding Binary Stars Will Light up the Sky in 2022

原文作者Matt Williams 題圖來自NASA/Casey Reed

Stellar collisions are an amazingly rare thing。 According to our best estimates， such events only occur in our galaxy （within globular clusters） once every 10，000 years。 It’s only been recently， thanks to ongoing improvements in instrumentation and technology， that astronomers have been able to observe such mergers taking place。 As of yet， no one has ever witnessed this phenomena in action – but that may be about to change！

恆星碰撞是一種極其少見的事件。我們的最好估計是：這種事件在我們的星系中每一萬年會發生一次。直到最近，在儀器和科技不斷進步的幫助下，天文學家們已經能夠觀察到這種合併發生了。到目前為止，沒有人曾目睹這種現象發生，但是這（一事實）有可能要改變了。

According to study from a team of researchers from Calvin College in Grand Rapids， Michigan， a binary star system that will likely merge and explode in 2022。 This is an historic find， since it will allow astronomers to witness a stellar merger and explosion for the first time in history。 What’s more， they claim， this explosion will be visible with the naked-eye to observers here on Earth。

根據一組來自凱爾文學院（坐落於密歇根州大急流市）的研究者的研究，一個雙星系統有可能會在2022年合併並爆發。這是一個歷史性的發現，鑑於這是天文學家在歷史上第一次能夠看到恆星合併與爆發。更棒的是，他們聲稱這一爆發將在地球上肉眼可見。

The findings were presented last week at the 229th Meeting of the American Astronomical Society （AAS）。 In a presentation titled “A Precise Prediction of a Stellar Merger and Red Nova Outburst“， Professor Lawrence Molnar and his team shared findings that indicate how this binary pair will merge in about six years time。 This event， they claim， will cause an outburst of light so bright that it will become the brightest object in the night sky。

這一發現在第229次美國天文學會（AAS）大會上被公佈。在題為“對於恆星合併和紅新星爆發的一次精準預測”的演講中，勞倫斯·莫爾納教授和他的團隊分享了這一表明六年後這一雙星系統將會如何合併的發現。他們聲稱這一事件將會引發一次光爆，使得其會成為夜空中最明亮的物體。

Professor Lawrence Molnar of the Calvin College’s Dept。 of Physics and Astronomy。 He predicts KIC 9832227 will collide and explode in 2022。 - Image Credit： Calvin College 勞倫斯·莫爾納教授來自於凱爾文大學物理與天文系。他預言了KIC 9832227將在2022年合併、爆發。圖源：凱爾文大學

This binary star system， which is known as KIC 9832227， is one that Prof。 Molnar and his colleagues – which includes students from the Apache Point Observatory and the University of Wyoming – have been monitoring since 2013。 His interest in the star was piqued during a conference in 2013 when Karen Kinemuchi （an astronomers with the Apache Point Observatory） presented findings about brightness changes in the star。

這一代號為KIC 9832227的雙星系統從2013年就開始被莫爾納教授及同事觀測了，這些同事包括了來自阿帕契點天文臺的學生和來自懷俄明大學的學生。在2013年的一次會議上，Karen Kinemuchi（一名阿帕契點天文臺的天文學家）展示了這一恆星系統的亮度正在變化中，莫爾納教授對於它的興趣便被點燃了。

This led to questions about the nature of this star system – specifically， whether it was a pulsar or a binary pair。 After conducting their own observations using the Calvin observatory， Prof。 Molnar and his colleagues concluded that the star was a contact binary – a class of binary star where the two stars are close enough to share an atmosphere。 This brought to mind similar research in the past about another binary star system known as V1309 Scorpii。

這便引向了一個關於這一恆星系統性質的問題：它是一個脈衝星還是雙星。在凱爾文天文臺進行自己的觀測後，莫爾納教授和同事們得出結論：這是相接雙星——一類兩顆恆星近得共享大氣的雙星系統。這便使得我們想起了之前關於被稱為天蠍座V1309的另一個雙星系統。

This binary pair also had a shared atmosphere； and over time， their orbital period kept decreasing until （in 2008） they unexpectedly collided and exploded。 Believing that KIC 9832227 would undergo a similar fate， they began conducting tests to see if the star system was exhibiting the same behavior。 The first step was to make spectroscopic observations to see if their observations could be explained by the presence of a companion star。

這一雙星系統也擁有共享的大氣；隨著時間流逝，他們的軌道週期持續縮短直到它們出乎意料地碰撞並爆發（在2008年）。相信KIC 9832227將會有相似的命運，他們開始進行檢測這一恆星系統是否展示（與天蠍座V1309）相同表現的測試。第一步是進行光譜測試，檢驗他們的觀測結果是否可以用一個伴星的存在（也就是存在三顆恆星）來解釋。

As Cara Alexander， a Calvin College student and one of the co-authors on the team’s research paper， explained in a college press release：

“We had to rule out the possibility of a third star。 That would have been a pedestrian， boring explanation。 I was processing data from two telescopes and obtained images that showed a signature of our star and no sign of a third star。 Then we knew we were looking at the right thing。 It took most of the summer to analyze the data， but it was so exciting。 To be a part of this research， I don’t know any other place where I would get an opportunity like that； Calvin is an amazing place。”

在（凱爾文）大學學報上，一位凱爾文大學學生卡拉·亞歷山大和該團隊研究論文的合作作者是如此解釋的：

“我們必須排除有第三顆恆星存在的可能性。不然這就是一個平淡、無趣的現象了。我處理來自兩個望遠鏡的資料並且獲取了關於目標恆星的圖片，這些圖片顯示並沒有第三顆恆星的跡象。那時我們便知道我們沒有白費時間。我們用了大半個夏天處理資料，但這真是一顆賽艇（令人激動）。我不知道有任何別的地方能給我一個參加像這樣研究的機會。凱爾文大學棒極了。”

Diagram showing the summer constellations of Cygnus and Lyra and the position of KIC 9832227 （shown with a red circle）。 - Image Credit： calvin。edu 圖中展示了夏季星座天鵝座和天琴座以及KIC 9832227的位置（用紅圈標出） 圖源：calvin。edu

The next step was to measure the pair’s orbital period， to see it was in fact getting shorter over time – which would indicate that the stars were moving closer to each other。 By 2015， Prof。 Molnar and his team determined that the stars would eventually collide， resulting in a kind of stellar explosion known as a “Red Nova”。 Initially， they estimated this would take place between 2018 and 2020， but have since placed the date at 2022。

下一步是測量雙星的軌道週期，檢測週期是否的確在逐漸縮短——這意味著兩顆恆星正在靠近彼此。到2015年的時候，莫爾納教授和團隊證實了兩顆恆星最終會相撞，導致一種被稱為“紅新星”的恆星爆發。一開始，他們估計這將會在2018到2020年發生，但最近他們把日期推遲到了2022年。

In addition， they predict that the burst of light it will cause will be bright enough to be seen from Earth。 The star will be visible as part of the constellation Cygnus， and it appear as an addition star in the familiar Northern Cross star pattern （see above）。 This is an historic case， since no astronomer has ever been able to accurately predict when and where a stellar collision would take place in the past。

同時，他們預測該事件的亮度將使得其可在地球上看到。它將成為天鵝座的一部分，併成為我們熟悉的北十字星型的新成員（在上圖中可見）。這是一個歷史性的事件，鑑於在過去沒有天文學家曾經有機會準確地預測一次恆星合併在何時何地發生。

What’s more， this discovery is immensely significant because it represents a break with the traditional discovery process。 Not only have small research institutions and universities not been the ones to take the lead on these sorts of discoveries in the past， but student-and-teacher teams have also not been the ones who got to make them。 As Molnar explained it：

“Most big scientific projects are done in enormous groups with thousands of people and billions of dollars。 This project is just the opposite。 It’s been done using a small telescope， with one professor and a few students looking for something that is not likely。 Nobody has ever predicted a nova explosion before。 Why pay someone to do something that almost certainly won’t succeed？ It’s a high-risk proposal。 But at Calvin it’s only my risk， and I can use my work on interesting， open-ended questions to bring extra excitement into my classroom。 Some projects still have an advantage when you don’t have as much time or money。”

此外，之所以這一發現十分顯著是因為這代表了傳統發現過程被顛覆了。在過去，不僅僅師生小團隊無法在這類（偉大）發現中拔得頭籌，就連小型研究機構和大學也無法做到。莫爾納是這樣說的：

“大部分大型科學專案都是由一個幾千人的大型團隊在幾十億美元的經費下完成的。而這一專案恰恰相反。一個教授帶著幾個學生，用著一個小望遠鏡就把一些看似不可能的事情給做了。沒人曾預測過新星爆發。為什麼要花錢讓一些人去做幾乎是不可能的事呢？這是一個高風險的提議。但是在凱爾文大學，所有風險都由我承擔，而且透過利用我在一些有趣的、開放答案的問題下做的工作，我能為我的課堂帶來額外的樂趣。在沒有足夠時間和經費的條件下，有一些專案仍具有優勢。”

The model Prof。 Molnar and his team constructed of the double star system KIC 9832227， which is a contact binary （i。e。 two stars that are touching）。 Image Credit： Calvin College 莫爾納教授和團隊關於KIC 9832227雙星系統的模型——一個相接雙星（兩顆接觸的恆星）。圖源：Calvin College

Over the course of the year， Molnar and his colleagues will be monitoring KIC 9832227 carefully， and in multiple wavelengths。 This will be done with the help of the NROA’s Very Large Array （VLA）， NASA’s Infrared Telescope Facility at Mauna Kea， and the ESA’s XMM-Newton spacecraft。 These observatories will study the star’s radio， infrared and X-ray emissions， respectively。

在接下來的一年中，莫爾納和他的同事們將會細心地用各種波長觀測KIC 9832227。（他們的工作）將得到美國國家射電天文臺（NROA）的甚大天線陣（VLA）、NASA在冒納凱阿火山的紅外望遠鏡設施和歐洲空間局的牛頓X射線多鏡面衛星的協助。這些望遠鏡將會分別研究該恆星的無線電、紅外線、X射線訊號。

Molnar also expects that amateur astronomers will be able to monitor the pair’s orbital timing and variations in brightness。 And if he and his team’s predictions are correct， every student and stargazer in the northern hemisphere – not to mention people who just happen to be out for a walk – will be privy to the amazing light show。 This is sure to be a once-in-a-lifetime event， so stay tuned for more information。

莫爾納也希望業餘天文愛好者能夠觀測該雙星的軌道週期和亮度變化。而且如果他和他的團隊是對的話，每個在北半球的學生、觀星者，更不用提那些碰巧外出的人將會目睹到一場棒極了的星光表演。這一定會成為一次一生一次的大事件，所以敬請期待更多訊息。

Interestingly enough， this historic discovery is also the subject of a documentary film。 Titled “Luminous“， the documentary – which is directed by Sam Smartt， a Calvin professor of communication arts and sciences – chronicles the process that led Prof。 Molnar and his team to make this unprecedented discovery。 The documentary will also include footage of the Red Nova as it happens in 2022， and is expected to be released sometime in 2023。

有趣的是，這一歷史性的發現也是一部紀錄片的主體。這部紀錄片名為“Luminous”，由薩姆·斯瑪特執導，他是一位凱爾文大學的傳播藝術與科學教授（此處譯文存疑）。這一紀錄片記錄了莫爾納教授和他的團隊完成這一前所未有的發現的全過程。這一記錄片將包含在2022年發生的紅新星事件，所以預計會在2023年的某個時候釋出。