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天文学家在系外行星的大气层中发现已知最重元素_我的网站

美丽人生

一 | 这一意外的发现提出了关于这些异域大气可能是什么样的问题。

二 | PHILADELPHIA -- Spencer Strider could not watch Nick Castellanos' second home run off him in Game 4. The 20-game winner simply accepted his fate — he gave the ball to Atlanta Braves manager Brian Snitker and awaited a reception almost as rude as the homers.Strider put his head down and walked toward the dugout as 45,000 fired-up, towel-waving Phillies fans — that had heckled and derisively chanted his name since he warmed up — pointed fingers at the pitcher and gave him the business one more time.Strider never broke stride, never looked up. If he had, Strider might have read the sign that read “Bye-Bye Strider.”It was soon bye-bye Braves — once again an October departure in Philly.When the bats in a lineup that hit 307 homers this season fell silent, so did Atlanta in a 3-1 loss to Philadelphia in Game 4 of the National League Division Series on Thursday night.“You look at the playoff format, you don't need to be a great team all year,” Strider said. “You need to get to the playoffs and then it's a different game.”One the Braves haven't yet mastered.A year after the 101-win Braves were eliminated in Game 4 in Philly, this season's 104-win edition suffered the same cruel fate. They scored a total of eight runs in the series.“Pretty much just told them they have nothing to hang their heads about. It stinks what just happened,” Braves manager Brian Snitker said. “We wanted to go deep into this postseason, but I said it my first meeting every year, it’s like we want to check the first box, win the division because you never know what might happen. And we hit 300 some homers and didn’t happen in this playoff series.”Maybe it was the short break from the regular season to the start of the NLDS that cooled off the Braves. Ronald Acuña Jr., one of the front-runners for NL MVP, was 2 for 14 in the four games. Marcell Ozuna and Orlando Arcia each went 2 for 13. Michael Harris II went hitless in 13 at-bats.Austin Riley homered in the fourth inning of Game 4, but that was it for the Braves.Trailing 3-1 in the seventh, Atlanta loaded the bases on three two-out walks. Craig Kimbrel then retired Acuña on a deep fly ball that was run down by rookie center fielder Johan Rojas.Rally, over.Strider allowed two homers to Castellanos, a go-ahead shot to Trea Turner — who entered 0 for 17 lifetime against Strider — struck out seven and threw 96 pitches in 5 2/3 innings.“They didn't have a cheat code,” Strider said. “If you ask them, I'm sure they'll tell you I hung a couple of sliders.”Just one month earlier, the Braves took three of four and clinched their sixth straight NL East title in Philadelphia. The Braves went 8-5 against the Phillies in the regular season.Those numbers were as empty as the Braves offense.The franchise that put together an unprecedented streak of 14 straight division titles in the 1990s and 2000s tried for one more memorable run just two seasons removed from winning a World Series.But outside of a fantastic Game 2 rally, little went right for the Braves.Phillies fans had saved the worst for Strider, who is 8-0 in the regular season against the Phillies and a disaster in the postseason against them. Phillies fans chanted “We Want Strider” in Game 3, and then reserved their loudest pregame boos for him in Game 4.Strider, perhaps tongue-in-cheek, had said in an interview “there should be no fans” at the ballgame.“Get rid of the fans, it’s too loud,” he told MLB Fits. “It’s too loud, everybody be quiet. We don’t need the cheering, we know you’re watching. I don’t need the fans.”Joking or not, the Phillies needed little incentive to jump all over the ace right-hander. Some fans wore T-shirts that read “Is This Too Loud For You Spencer?” and others held signs with the same message.It was part of quirky series overall for the Braves.The social media user behind the account for the mascot Blooper oddly took aim on the Phillie Phanatic, writing “his last highlight was recorded with a flash.” Phillies fans spent the rest of the remaining games roasting Blooper.But Blooper was far from the only error.After Philadelphia star Bryce Harper committed a baserunning blunder that closed out Atlanta's Game 2 win, Arcia cracked “Attaboy, Harper!” inside of the Braves' jubilant clubhouse. Harper responded with two homers in Game 3, staring at the shortstop as he rounded the bases after each drive.Atlanta joins this year's list of playoff teams that tore through the regular season only to flop in October. The teams with the five best regular-season records — the Braves, Baltimore (101 wins), Dodgers (100), Tampa Bay (99) and Milwaukee (92) — all failed to reach the LCS.“We got beat and didn’t play good enough to win the series. It’s as simple as that,” Snitker said. “We got beat by a really good club that has a penchant for it this time of year.”___AP MLB: https://apnews.com/hub/mlb。这一发现是利用欧洲南方天文台的超大型望远镜(ESO's VLT)得到。来自波尔图大学和葡萄牙天体物理研究所(IA)的博士生Tomás Azevedo Silva表示：“令人费解和反直觉的部分是：为什么在这些行星的大气层上层会有如此重的元素？”Silva领导了这项研究，该研究于10月13日发表在《Astronomy & Astrophysics》上。WASP-76 b和WASP-121 b不是普通的系外行星。

三 | 这两颗行星都被称为超热木星，因为它们的大小跟木星相当，同时具有极高的表面温度，可以飙升到1000℃以上。这是由于它们非常接近它们的主星，这也意味着围绕每颗恒星的轨道只需要一到两天的时间。这使这些行星具有相当奇特的特征。比如，天文学家怀疑WASP-76 b上会下铁雨。但即便如此，天文学家们还是惊讶地发现，在WASP-76 b和WASP-121 b的高层大气中发现了比铁重1.5倍的钡。“鉴于这些行星的高重力，我们预计像钡这样的重元素会迅速落入大气层的下层，”研究论文共同作者Olivier Demangeon指出。他也是来自波尔图大学和IA的研究人员。Azevedo Silva说道：“这在某种程度上是一个‘意外’的发现。

四 | 我们并没有特别期待或寻找钡，并且必须交叉检查这是否真的来自该行星，因为之前从未在任何系外行星上看到过。”在这两颗超热木星的大气中检测到钡的事实表明，这类行星可能比以前认为的还要奇怪。尽管我们在自己的天空中确实偶尔会看到钡，就像烟花中绚丽的绿色一样，但科学家们的问题是什么自然过程会导致这种重元素在这些系外行星中处于如此高的高度。“目前我们不确定机制是什么，”Demangeon说道。在研究系外行星的大气层时，超高温的木星是非常有用的。

五 | 正如Demangeon解释的那样--“由于是气态并呈现高温，它们的大气层非常宽广，因此比那些较小或较冷的行星更容易观察和研究。”确定一颗系外行星大气层的组成需要非常专业的设备。研究小组利用智利欧空局VLT上的ESPRESSO仪器来分析经过WASP-76 b和WASP-121 b大气层过滤的星光，这使得他们有可能清楚地探测到其中的几种元素，包括钡。这些新结果表明，我们人类只是触及了系外行星之谜的表面。