第2242期:Nova Explosion to Be ‘Once-in-Lifetime’ Event in Night Sky

The American space agency NASA says a huge star explosion is expected to light up the night sky later this year. NASA describes it as a “once-in-a-lifetime” event.
美国航天局NASA表示，预计今年晚些时候会有一次巨大的恒星爆炸，将照亮夜空。NASA将其描述为“一生一次”的事件。

The event is known as a nova. It happens when changes to a star cause it to release a large amount of energy and it becomes very bright. This activity is only temporary and such stars usually return to their normal state after experiencing a nova event.
这一事件被称为新星。当恒星发生变化导致其释放大量能量并变得非常明亮时，就会出现新星。这种活动只是暂时的，经历新星事件后，这些恒星通常会恢复到正常状态。

Astronomers have predicted the nova is likely to happen by September 2024. The expected event will involve a two-star system – called a binary system – in the constellation Corona Borealis, also known as the Northern Crown. This constellation is about 3,000 light years from Earth. A light year is the distance light travels in a year – about 9.5 trillion kilometers.
天文学家预测，这次新星事件可能会在2024年9月之前发生。预计的事件将涉及一个由两颗恒星组成的双星系统，位于被称为北冕座的星座中。这个星座距离地球大约3000光年。一光年是光在一年内行进的距离，大约为9.5万亿公里。

The binary system is called T Coronae Borealis. It contains two gravitationally linked stars – a white dwarf and a red giant.
这个双星系统被称为T Coronae Borealis。它包含两颗通过引力连接的恒星——一颗白矮星和一颗红巨星。

NASA describes a white dwarf as the remains of an Earth-sized star that died. A white dwarf is formed when the star burns off all its central nuclear fuel and loses its outer layers.
NASA将白矮星描述为一颗死亡的地球大小的恒星残骸。当恒星燃尽所有核心核燃料并失去其外层时，就会形成白矮星。

A red giant forms when a star releases large amounts of hydrogen at its center. This loss of energy causes the star to begin to collapse. But the process also increases the red giant’s temperature and pressure, leading to new releases of energy that can affect nearby objects.
当恒星在其中心释放大量氢气时，就会形成红巨星。这种能量的损失导致恒星开始塌缩。但这一过程也会增加红巨星的温度和压力，导致新的能量释放，从而影响附近的天体。

Astronomers say a red giant’s release of hydrogen in a binary system causes a heavy buildup of pressure and heat on the white dwarf. Over time, such buildup can cause a “thermonuclear explosion” large enough to blast away the material the white dwarf had collected.
天文学家表示，双星系统中红巨星释放的氢气会在白矮星上造成巨大的压力和热量积聚。随着时间的推移，这种积聚可能导致“热核爆炸”，足以炸飞白矮星积聚的物质。

This process differs from a supernova. NASA describes a supernova as an “extremely bright, super-powerful explosion of a star.” The main difference is that a supernova is the final destruction that happens at the end of a particular star’s life. In a nova, the white dwarf remains active after the event.
这一过程与超新星不同。NASA将超新星描述为“极其明亮、超强力的恒星爆炸”。主要区别在于，超新星是特定恒星生命终结时的最终毁灭。而在新星中，白矮星在事件后仍然活跃。

Scientists believe novas appear to repeat, on average, about every 80 years. NASA notes that nova events can keep happening “for tens of hundreds or thousands of years.” That is why the space agency called the upcoming nova a “once-in-a-lifetime event.”
科学家认为，新星平均大约每80年重复一次。NASA指出，新星事件可能会持续“数百年甚至数千年”。这就是为什么航天局将即将到来的新星称为“一生一次”的事件。

Scientists say the nova explosion will be so bright, people should be able to see the resulting light without telescopes or other special equipment. The bright light can make it appear as though a new star has formed in the sky.
科学家表示，新星爆炸将非常明亮，人们不需要望远镜或其他特殊设备就能看到产生的光亮。这道亮光会让人感觉天空中好像形成了一颗新星。

It will be at least the third time humans have witnessed a nova, the French news agency AFP reports. The event was first discovered by Irish astronomer John Birmingham in 1866 and then reappeared in 1946.
据法国新闻社AFP报道，这将是人类至少第三次目睹新星事件。1866年，爱尔兰天文学家约翰·伯明翰首次发现了这一事件，然后在1946年再次出现。

Sumner Starrfield is a professor of astrophysics at Arizona State University. He told AFP he was very excited to see the nova event. He has studied the T Coronae Borealis star system at different times since the 1960s.
萨姆纳·斯塔菲尔德是亚利桑那州立大学的天体物理学教授。他告诉AFP，他对看到这次新星事件感到非常兴奋。自20世纪60年代以来，他在不同时间研究了T Coronae Borealis星系。

Starrfield is currently working on a scientific paper to predict what astronomers will learn about the repeating nova, whenever it shows up. "It could be today... but I hope it's not," he joked.
斯塔菲尔德目前正在撰写一篇科学论文，预测天文学家将在重复新星事件中学到什么。他打趣道：“可能是今天……但我希望不是今天。”

Rebekah Hounsell is a research scientist specializing in nova events at NASA’s Goddard Space Flight Center in Maryland. She said that interest in the event may “create a lot of ... astronomers out there.” She hopes this can give young people “a cosmic event they can observe for themselves, ask their own questions, and collect their own data.”
丽贝卡·豪塞尔是NASA位于马里兰州的戈达德太空飞行中心研究新星事件的科学家。她说，对这次事件的兴趣可能会“培养出很多……天文学家”。她希望这能给年轻人“一个他们可以自己观察、提出问题并收集数据的宇宙事件”。

She added that the nova event might even be helpful to “fuel the next generation of scientists.”
她补充说，这次新星事件甚至可能有助于“激发下一代科学家”。