天文學(xué)家們發(fā)現(xiàn)了一種奇特的新型恒星，它只在一側(cè)脈動

天文學(xué)家們發(fā)現(xiàn)了一種奇特的新型恒星，它只在一側(cè)脈動

The Universe has yielded another surprise, and this time, it's practically under our very noses. Just 1,500 light-years away, astronomers have found a star that pulsates - but only on one side. Although such an object was predicted decades ago, this is the first time we've actually seen it.

宇宙帶來了另一個驚喜，而這一次，它就在我們的眼皮底下。就在1500光年遠的地方，天文學(xué)家們發(fā)現(xiàn)了一顆跳動的恒星，但它只在一邊。盡管早在幾十年前就有人預(yù)測到這樣一個天體，但這是我們第一次真正看到它。

"We've known theoretically that stars like this should exist since the 1980s," said astronomer Don Kurtz of the University of Central Lancashire in the UK.

英國中央蘭開夏大學(xué)的天文學(xué)家唐·庫爾茲說:“從理論上講，我們從20世紀80年代就知道這種恒星應(yīng)該存在。”

The star is called HD74423, an A-type main-sequence star about 1.7 times the mass of the Sun, and younger, too (although it's hard to age it precisely).

這顆恒星被稱為HD74423，是一顆A型主序恒星，質(zhì)量約為太陽的1.7倍，而且也更年輕(盡管很難精確地確定年齡)。

Its strange pulsing behaviour was first spotted by citizen scientists poring over data from NASA's exoplanet-hunting space telescope TESS, looking for anomalies.

它奇怪的脈沖行為最初是由平民科學(xué)家發(fā)現(xiàn)的，他們仔細研究了NASA的外行星搜尋太空望遠鏡TESS的數(shù)據(jù)，尋找異常現(xiàn)象。

Unsure of what they were seeing, they took their findings to professional astronomers, ultimately looping in Kurtz and astronomer Gerald Handler of the Nicolaus Copernicus Astronomical Centre in Poland.

由于不確定自己看到了什么，他們把自己的發(fā)現(xiàn)交給了專業(yè)天文學(xué)家，最終在庫爾茨和波蘭哥白尼天文中心的天文學(xué)家杰拉德·漢德勒(Gerald Handler)那里得到了證實。

Pulsations within a star aren't unusual. Many stars - maybe even all stars - oscillate in rhythmic patterns, caused by waves bouncing around inside the star. These waves are thought to be created by convection and the star's magnetic field; like earthquakes can be used to probe Earth's guts, the waves can reveal what's going on in stellar interiors.

恒星內(nèi)部的脈動并不罕見。許多恒星——甚至可能是所有的恒星——都在有節(jié)奏地振動，這是由恒星內(nèi)部的波動引起的。這些波被認為是由對流和恒星磁場產(chǎn)生的;就像地震可以用來探測地球內(nèi)部一樣，這些波也可以揭示恒星內(nèi)部的情況。

But in all other stars prior to HD74423, these oscillations could be detected globally; that is, over the entire surface of the star. So why is HD74423 such a weirdo?

但在HD74423之前的所有其他恒星中，這些振蕩可以在全球范圍內(nèi)被探測到;也就是說，在恒星的整個表面。那么，為什么HD74423如此古怪呢?

Well, it has a friend. A really close friend. The pulsating star's binary companion is a red dwarf, and the two are locked in a super-tight orbit of just 1.6 days. At that proximity, the gravity of the red dwarf is distorting HD74423, pulling it into more of an egg or teardrop shape.

嗯，因為它有一個朋友，一個非常親密的朋友。這顆脈動恒星的雙星伴侶是一顆紅矮星，這兩顆星被鎖定在一個超緊密的軌道上，周期只有1.6天。在這個距離上，紅矮星的引力使HD74423變形，使它更像一個雞蛋或淚滴形狀。

But that's not the only thing weird about HD74423. As researchers started examining the object more closely, astronomer Simon Murphy of the University of Sydney in Australia was noticing some unusual chemical abundances.

但這并不是HD74423唯一奇怪的地方。當研究人員開始更仔細地研究這個物體時，澳大利亞悉尼大學(xué)的天文學(xué)家西蒙墨菲(Simon Murphy)發(fā)現(xiàn)了一些不尋常的化學(xué)物質(zhì)豐度。

"What first caught my attention was the fact it was a chemically strange star," Murphy said. "Stars like this are usually fairly rich with metals - but this is metal poor, making it a rare type of hot star."

墨菲說:“首先引起我注意的是，這是一顆化學(xué)性質(zhì)奇特的恒星。”“像這樣的恒星通常含有豐富的金屬，但這顆恒星缺乏金屬，這使得它成為一種罕見的熱恒星。”