How Modern and Antique Technologies Reveal a Dynamic Cosmos
Glass plates taken at the Armagh-Dunsink-Harvard Telescope in Bloemfontein, South Africa, in 1950 and 1951 were annotated by hand.
1950 年和 1951 年在南非布隆方丹的阿马-邓辛克-哈佛望远镜拍摄的玻璃板经过手工注释。
I n early 2007, René Hudec was in Building D of the Harvard-Smithsonian Center for Astrophysics , thumbing through roomfuls of floor-to-ceiling cabinets that look more like a vast record collection than an academic archive.
2007 年初，雷内·邬达克在哈佛-史密森天体物理中心 D 楼翻阅满屋子的落地柜，这些柜子看起来更像是一个巨大的记录收藏，而不是学术档案。
Each paper sleeve holds a glass plate, most of which are 8 by 10 inches, a historic photographic record of the cosmos from before the age of sophisticated digital detectors.
每个纸套都装有一块玻璃板，其中大部分尺寸为 8 x 10 英寸，这是复杂数字探测器时代之前宇宙的历史照片记录。
Hudec, an astrophysicist at the Astronomical Institute of the Czech Academy of Sciences in Ondřejov, was searching for a specific pattern of stars that he had memorized, a region that features a binary system of mammoth yet compact objects.
邬达克是位于翁德热约夫的捷克科学院天文研究所的天体物理学家，他正在寻找他所记住的一种特定的恒星模式，该区域的特征是一个由庞大而致密的天体组成的双星系统。
There, two supermassive black holes and their surrounding accretion disks are locked in a dance that will eventually merge them into one.
在那里，两个超大质量黑洞和它们周围的吸积盘被锁定在一场舞蹈中，最终将它们合并成一个。
Hudec was tracking when this system, known as OJ 287, flared in brightness.
当这个被称为 OJ 287 的系统发出亮度耀斑时，邬达克正在追踪。
Hudec’s archival detective work has been a success: He has found the black hole pair on more than 2,000 glass plates.
邬达克的档案侦探工作取得了成功：他在 2000 多块玻璃板上发现了黑洞对。
The earliest with usable data was from 1896.
最早的可用数据来自 1896 年。
With a magnifying glass, he examined each plate to estimate the system’s luminosity as compared to other stars in the field of view.
他用放大镜检查了每块板，以估计系统的光度与视野中其他恒星的光度相比。
Astronomers knew about a 1913 flare and more recent events, but Hudec ended up discovering multiple flares that were unknown to astronomy, including a major one in 1900.
天文学家知道 1913 年的耀斑和最近发生的事件，但邬达克最终发现了天文学未知的多个耀斑，其中包括 1900 年的一次重大耀斑。
Around the world, glass photographic plates from old telescopes are at risk.
在世界各地，旧望远镜的玻璃底片都面临着危险。
On them lies a history of our ever-changing cosmos.
它们承载着我们不断变化的宇宙的历史。
With this new — well, old — data, Hudec and his colleagues could better model the system and begin to understand the physics that leads to the flares.
有了这些新的——呃，旧的——数据，邬达克和他的同事们可以更好地对系统进行建模，并开始了解导致耀斑的物理原理。
“The discoveries and exact timing of historical outbursts,” he said, help to “tune the model parameters.” One of the black holes is substantially more massive than the other.
“历史爆发的发现和确切时间，”他说，有助于“调整模型参数”。其中一个黑洞比另一个黑洞质量大得多。
As the less massive one passes through the other’s accretion disk, it creates fireworks that coincide with the historical flares he spotted.
当质量较小的一颗穿过另一个吸积盘时，它会产生与他发现的历史耀斑相一致的烟花。
OJ 287 and other active black holes are just one type of celestial object or system that varies in brightness over time.
OJ 287 和其他活跃黑洞只是一种亮度随时间变化的天体或系统。
But the universe is full of objects that fluctuate periodically or that quickly burst forth and then disappear.
但宇宙中充满了周期性波动或快速爆发然后消失的物体。
The night sky, for all its apparent consistency, simmers and sparks.
夜空虽然表面上看起来很一致，但仍然沸腾着，火花四溅。
In fact, “every astrophysical object can be considered a transient or a variable in a different timescale,” said Rosaria Bonito , an astrophysicist at the Palermo Astronomical Observatory of the National Institute for Astrophysics in Italy.
事实上，“每个天体物理物体都可以被认为是不同时间尺度的瞬态或变量，”意大利国家天体物理研究所巴勒莫天文台的天体物理学家罗莎里亚·博尼托说。
Any attempt to understand what we see in the cosmos relies on knowing how it changes, night after night.
任何理解我们在宇宙中看到的东西的尝试都依赖于了解它夜复一夜的变化。
Glass plates from the Bruce Telescope at Harvard are annotated with different colors, markings, and stickers that indicate different types of imagery, kind of plate, and plates of interest.
哈佛大学布鲁斯望远镜的玻璃板标有不同的颜色、标记和贴纸，表示不同类型的图像、板的类型和感兴趣的板。
The plate on the left contains annotations by the first Curator of Astronomical Photographs, Williamina Fleming, while the one on the right shows the Orion Nebula.
左边的图版包含第一任天文摄影馆长威廉米娜·弗莱明 (Williamina Fleming) 的注释，右边的图版显示了猎户座星云。
The Harvard Plate Stacks also contain contact prints made from glass plates, so a single image could be annotated in a variety of ways.
哈佛印版堆栈还包含由玻璃板制成的接触印刷品，因此可以通过多种方式对单个图像进行注释。
These show the Magellanic Clouds.
这些显示了麦哲伦星云。
The Harvard Plate Stacks contains a variety of card catalogs and archival materials maintained by individual astronomers that refer to plates in the collection.
哈佛板块堆栈包含由个别天文学家维护的各种卡片目录和档案材料，引用了馆藏中的板块。
Wooden crates were used to ship and transport plates from Harvard to observatories, libraries and universities.
木箱被用来将盘子从哈佛运送到天文台、图书馆和大学。
The plates here date to 1897, and depict the Orion Nebula and the Andromeda Galaxy.
这里的盘子可追溯至 1897 年，描绘了猎户座星云和仙女座星系。
The collection includes a lantern slide collection used for teaching at the Harvard College Observatory.
该收藏包括用于哈佛大学天文台教学的灯笼幻灯片收藏。
Drawers here are labeled by astronomical subjects: galaxies, nebulae, sun, planets, and the moon.
这里的抽屉上标有天文主题：星系、星云、太阳、行星和月亮。
This notion that the sky above is ever-changing led to the development of the newest large astronomical observatory.
这种天空不断变化的观念导致了最新大型天文台的发展。
The Vera C.
维拉 C.
Rubin Observatory , high in the Chilean Andes, is beginning, in early 2026, a 10-year survey that will monitor all things that change and move, to reveal what astronomers call the time-domain universe.
位于智利安第斯山脉高处的鲁宾天文台将于 2026 年初开始一项为期 10 年的调查，该调查将监测所有变化和移动的事物，以揭示天文学家所说的时域宇宙。
With data from previous telescopes — in both digital form and on glass — the project promises a brilliantly dynamic view.
借助以前望远镜的数据（无论是数字形式还是在玻璃上），该项目有望获得绚丽的动态视图。
The value of the Rubin telescope lies not just in the reams of data it will create , but in its potential to connect today’s observations to more than a century of meticulous work.
鲁宾望远镜的价值不仅在于它将创造大量数据，还在于它有可能将今天的观测与一个多世纪的细致工作联系起来。
Within vast analog collections, many of which are at risk of disappearing, lie unexplored connections to today’s changing cosmos.
在大量的模拟收藏中，其中许多都面临着消失的风险，其中隐藏着与当今不断变化的宇宙的未经探索的联系。
Pulling together the modern and the historical could reveal a century-long movie of the sky above us.
将现代和历史结合起来可以揭示我们头顶上空长达一个世纪的电影。
Far from light-polluted cities, one can see meteors racing across the night sky.
远离光污染的城市，人们可以看到流星划过夜空。
Jupiter and Mars move faster than distant stars on that same nightly view.
在同一个夜景中，木星和火星的移动速度比遥远的恒星还要快。
There are many, many other changes that human eyes aren’t sensitive enough to perceive.
还有很多很多其他变化，人眼不够敏感，无法察觉。
“Everything in the cosmos is changing, nothing is static,” said Elizabeth Griffin , an astronomer at the Herzberg Astronomy and Astrophysics Research Center in Victoria, Canada.
“宇宙中的一切都在变化，没有什么是静止的，”加拿大维多利亚赫茨伯格天文学和天体物理学研究中心的天文学家伊丽莎白格里芬说。
“The changes may be quite quick, quite periodic; may be explosive, may be sudden; or they may be terribly, terribly slow.”
“这些变化可能非常快，相当周期性；可能是爆炸性的，可能是突然的；或者它们可能非常非常慢。”
All these variations comprise the dynamic universe that astronomers are working to reveal.
所有这些变化构成了天文学家正在努力揭示的动态宇宙。
Matthew Graham , an astronomer at the California Institute of Technology, separates the objects studied by time-domain astronomy into two groups: things that go bang, and things that fluctuate.
加州理工学院的天文学家马修·格雷厄姆将时域天文学研究的物体分为两类：爆炸物体和波动物体。
The former are also known as transients, and they change quickly.
前者也称为瞬态，它们变化很快。
These include the largest blasts in the universe, such as supernova explosions and gamma-ray bursts.
其中包括宇宙中最大的爆炸，例如超新星爆炸和伽马射线爆发。
A photographic plate at the Neils Bohr Institute in Copenhagen captures the 1919 solar eclipse that was used to confirm Einstein’s theory of general relativity.
哥本哈根尼尔斯·玻尔研究所的一个底片捕捉到了 1919 年的日食，该日食被用来证实爱因斯坦的广义相对论。
Niels Bohr Institute, Copenhagen University
哥本哈根大学尼尔斯玻尔研究所
The second category, variable objects, includes a wide variety of solo stars including the Cepheids, which fluctuate at a rate that reveals their intrinsic brightness (making them very valuable for measuring galactic distances).
第二类是可变天体，包括各种单独的恒星，包括造父变星，它们的波动速度揭示了它们的固有亮度（使它们对于测量银河系距离非常有价值）。
Systems of binary stars also fall into this category, as their observed brightness changes depending on where each star is, if one is passing in front of the other, and if one is siphoning material from the other.
双星系统也属于这一类，因为它们观测到的亮度变化取决于每颗恒星的位置、一颗恒星是否从另一颗恒星前面经过，以及一颗恒星是否从另一颗恒星吸取物质。
The actively accreting black holes at the cores of galaxies also vary over time, “across all wavelengths and across all sorts of timescales,” said Graham, who studies this variability.
研究这种变化的格雷厄姆说，星系核心积极吸积的黑洞也会随着时间的推移而变化，“跨越所有波长和各种时间尺度”。
These phenomena can tell astronomers and astrophysicists how physics operates within the most extreme environments.
这些现象可以告诉天文学家和天体物理学家物理学家在最极端的环境中是如何运作的。
Any theoretical model that describes how those active galactic nuclei (AGNs) emit flares and produce other brightness variations must match the actual observations.
任何描述这些活动星系核（AGN）如何发出耀斑并产生其他亮度变化的理论模型都必须与实际观测结果相匹配。
That’s where time-domain astronomy comes in: Tracking the changes over a year, a decade, or a century gives astrophysicists specific markers for a model to match.
这就是时域天文学的用武之地：跟踪一年、十年或一个世纪的变化，为天体物理学家提供了模型匹配的特定标记。
The full scope of celestial changes helps set boundaries on astronomers’ theoretical understanding: Exploding stars help cosmologists measure extragalactic distances, while variations in stellar brightness can reveal details of how stars evolve.
天体变化的全部范围有助于为天文学家的理论理解设定界限：爆炸的恒星帮助宇宙学家测量河外距离，而恒星亮度的变化可以揭示恒星如何演化的细节。
Astronomer Percival Lowell peers through the eyepiece of the telescope at the observatory that bears his name in Flagstaff, Arizona.
天文学家珀西瓦尔·洛厄尔通过望远镜的目镜观察亚利桑那州弗拉格斯塔夫以他的名字命名的天文台。
It was there that, in 1930, Clyde Tombaugh found Pluto in a time series of photographs.
1930 年，克莱德·汤博 (Clyde Tombaugh) 在一系列时间照片中发现了冥王星。
To find these changes across time, astronomers use software to quickly scour data captured via modern telescopes and their powerful digital cameras.
为了发现这些随时间的变化，天文学家使用软件快速搜索通过现代望远镜及其强大的数码相机捕获的数据。
This has been the method of choice for some 40 years.
大约 40 年来，人们一直选择这种方法。
But prior to the development of digital imaging detectors, astronomers used analog photography and glass plates.
但在数字成像探测器开发之前，天文学家使用模拟摄影和玻璃板。
To find changes in the dynamic sky, human eyes carefully compared plate images captured at different times.
为了发现动态天空的变化，人眼仔细比较不同时间拍摄的板块图像。
Both collecting the data and discovering celestial variations took a great deal more time during the century of analog astrophotography.
在模拟天文摄影的世纪里，收集数据和发现天体变化都花费了更多的时间。
The Vera C.
维拉 C.
Rubin Observatory will study nearly the entire sky visible from atop Cerro Pachón in Chile with its wide-angle camera system.
鲁宾天文台将利用其广角摄像系统研究从智利帕雄山山顶可见的几乎整个天空。
Its aim is to reveal millions of new objects, both in the solar system and much farther beyond, by comparing images taken at different times.
其目的是通过比较不同时间拍摄的图像来揭示太阳系内和更远的地方的数百万个新物体。
It is the same technique that Clyde Tombaugh used to discover Pluto at the Lowell Observatory in Arizona nearly 100 years ago.
近 100 年前，克莱德·汤博 (Clyde Tombaugh) 在亚利桑那州洛厄尔天文台发现冥王星时也使用了同样的技术。
Tombaugh took thousands of hourlong photographs over the course of months and examined them visually to document the faint object on the edge of the solar system.
汤博在几个月的时间里拍摄了数千张长达一小时的照片，并对它们进行目视检查，以记录太阳系边缘的微弱物体。
The Rubin Observatory, on the other hand, boasts a camera that is the largest ever built for any purpose .
另一方面，鲁宾天文台拥有有史以来最大的相机。
In one 15-second exposure, Rubin can reveal objects more than 2,500 times fainter than what the Pluto scope saw, and some 40 million times fainter than what unaided human eyes can see.
在一次 15 秒的曝光中，鲁宾可以显示比冥王星望远镜看到的暗淡超过 2,500 倍的物体，比肉眼看到的暗淡约 4000 万倍。
Its Legacy Survey of Space and Time (LSST) project will tile the sky, repeatedly moving from each 3.5-degree-wide field (seven full moons side by side) to the next.
其遗留的时空勘测 (LSST) 项目将平铺天空，反复从每个 3.5 度宽的视野（七个满月并排）移动到下一个。
Over the next 10 years, it will image the southern sky some 1,000 times in six color filters, from ultraviolet through visible light and into infrared, bringing ever-fainter objects into view.
在接下来的 10 年里，它将使用六种滤色镜对南部天空进行约 1,000 次成像，从紫外线到可见光再到红外线，将越来越暗的物体带入视野。
Rubin will show a constantly changing cosmos, filled with moving objects, stars that vary in brightness, and stellar explosions.
鲁宾将展示一个不断变化的宇宙，其中充满了移动的物体、亮度不同的恒星以及恒星爆炸。
Comparing the view of the sky before Rubin to after, Bonito likens it to music, “from a single note to chords.”
博尼托将鲁宾前后的天空景象进行比较，将其比作音乐，“从单个音符到和弦”。
The Vera C.
维拉 C.
Rubin Observatory (top) is about to begin a 10-year survey that will image the entire southern sky 1,000 times.
鲁宾天文台（上）即将开始一项为期 10 年的调查，将对整个南方天空进行 1,000 次成像。
Early images from its telescope (bottom) are already leading to discoveries.
来自其望远镜（底部）的早期图像已经带来了新的发现。
NSF–DOE Rubin Observatory/P.J.
NSF-DOE 鲁宾天文台/P.J.
Assuncao Lago (top); NSF–DOE Vera C.
Assuncao Lago（上）； NSF-DOE 维拉 C.
Rubin Observatory
鲁宾天文台
Once the survey has ramped up, the Rubin team estimates that the observatory will collect 20 terabytes of data every evening.
一旦调查加大力度，鲁宾团队估计天文台每天晚上将收集 20 TB 的数据。
Software automatically compares the just-captured images to previous ones of the same location.
软件会自动将刚刚捕获的图像与同一位置之前的图像进行比较。
If anything has changed, it sends an alert within a minute.
如果有任何变化，它会在一分钟内发送警报。
“It’s basically a small packet of information that [tells] you when, where, and by how much a source has changed its luminosity,” said Igor Andreoni , an astrophysicist at the University of North Carolina, Chapel Hill who co-chairs the Rubin variable stars and transients group.
北卡罗来纳大学教堂山分校的天体物理学家、鲁宾变星和瞬变小组的联合主席伊戈尔·安德烈奥尼 (Igor Andreoni) 表示：“它基本上是一小包信息，可以告诉你光源在何时、何地以及改变了多少光度。”
Pulling together the modern and the historical could reveal a century-long movie of the sky above us.
将现代和历史结合起来可以揭示我们头顶上空的长达一个世纪的电影。
There will be a lot of alerts; the Rubin team expects to send more than 20 billion of them over the 10-year survey.
会有很多警报； Rubin 团队预计在为期 10 年的调查中将发送超过 200 亿条信息。
Anyone can receive them, but no one can expect to comb through them all.
任何人都可以收到它们，但没有人能指望将它们全部梳理一遍。
To manage the torrent, researchers are writing their own code to sort the alerts.
为了管理种子，研究人员正在编写自己的代码来对警报进行排序。
For example, Andreoni is looking for anything that has shown brightness changes in at least three images in a row, and specifically cases of a star that’s stretched and changed by getting too close to a black hole — a tidal disruption event.
例如，安德烈奥尼正在寻找任何在至少连续三幅图像中显示出亮度变化的物体，特别是一颗恒星因太靠近黑洞而被拉伸和改变的情况——潮汐破坏事件。
The Rubin Observatory will capture these changes over hours and days and eventually a decade.
鲁宾天文台将在数小时、数天乃至十年内捕捉到这些变化。
But many cosmic variations happen over much longer time spans, and there have certainly been countless transients in decades past that were unnoticed or undocumented in their time.
但许多宇宙变化发生的时间跨度要长得多，而且在过去的几十年里肯定有无数的瞬变在当时未被注意到或没有记录。
If researchers want to access time-domain astronomy beyond the past few decades, the antique technology Tombaugh used remains vital.
如果研究人员想要了解过去几十年之后的时域天文学，汤博使用的古董技术仍然至关重要。
But there are no alerts for glass photographic plates.
但没有关于玻璃照相底片的警报。
Astronomical photography before around 1980 looked very different than it does in the digital age.
1980 年左右之前的天文摄影看起来与数字时代有很大不同。
Scientists such as Tombaugh imaged the sky on rectangular panes of glass coated on one side in a biochemical emulsion.
汤博等科学家在一侧涂有生化乳剂的矩形玻璃板上拍摄了天空图像。
As starlight passed through a telescope, it hit the emulsion on the plate.
当星光穿过望远镜时，它照射到板上的乳剂上。
When scientists developed the plates, any spots where starlight hit the emulsion would be dark.
当科学家开发出这些板时，星光照射到乳剂上的任何斑点都会变暗。
The density of the darkness corresponded to brighter starlight.
黑暗的密度与更明亮的星光相对应。
This 1934 plate of Andromeda, captured at the Oak Ridge Observatory at Harvard, was so heavily marked up because it was used to count galaxies.
这幅 1934 年的仙女座图是在哈佛大学橡树岭天文台拍摄的，它被标记得很重，因为它被用来计算星系。
Plate MC27415.
板 MC27415。
September 11, 1934.
1934 年 9 月 11 日。
Harvard Plate Stacks.
哈佛板栈。
Center for Astrophysics | Harvard & Smithsonian, Cambridge, Mass.
天体物理学中心|哈佛大学和史密森尼学会，剑桥，马萨诸塞州。
Hudec, the Czech astrophysicist, who has visited more than 70 plate collections across the world, estimates that there could be 10 million plates still in existence.
捷克天体物理学家邬达克参观了世界各地 70 多个板块收藏，估计现存的板块可能有 1000 万块。
If all those plates were carefully digitized, they would amount to thousands of terabytes of data.
如果所有这些车牌都经过仔细的数字化，它们的数据量将达到数千 TB。
They hold more than a century of astronomical observations.
他们拥有一个多世纪的天文观测。
And though they are scattered around the world and unwieldy to work with, they’ve provided today’s researchers with more than 100 modern discoveries.
尽管它们分散在世界各地并且难以操作，但它们为当今的研究人员提供了 100 多项现代发现。
The collection at the Harvard-Smithsonian Center for Astrophysics is the largest and best-studied astronomical plate archive in the world, with some 550,000.
哈佛-史密森天体物理中心的馆藏是世界上最大、研究最透彻的天文板块档案馆，约有 550,000 个。
The collection covers both the northern and southern skies, with observations from 1849 through 1992.
该集合涵盖了北部和南部的天空，包括 1849 年至 1992 年的观测数据。
And some 430,000 of these are now in digital and searchable form thanks to a 20-year digitization project led by Jonathan Grindlay, an astrophysicist at Harvard University.
由于哈佛大学天体物理学家乔纳森·格林德利 (Jonathan Grindlay) 领导的为期 20 年的数字化项目，其中约 430,000 个现已以数字形式呈现并可搜索。
“It seemed like a very obvious thing to do,” he said.
“这似乎是一件非常明显的事情，”他说。
The Digital Access to a Sky Century at Harvard , or DASCH, has been cited in close to 100 scientific papers and talks, for discoveries covering all areas of time-domain astronomy.
哈佛大学的数字访问天空世纪 (DASCH) 已被近 100 篇科学论文和演讲引用，其发现涵盖了时域天文学的所有领域。
And that was the point, Grindlay said: “to be able to do time-domain astrophysics in a way that’s never been done before.”
格林德利说，这就是重点：“能够以前所未有的方式进行时域天体物理学。”
The Photographic Plate Archive at Harvard College Observatory in the 1890s.
1890 年代哈佛大学天文台的摄影底片档案。
It would grow for another century.
它将继续增长一个世纪。
While most of Harvard’s plates are digitized, most plates in other archives are not.
虽然哈佛的大部分车牌都是数字化的，但其他档案馆中的大多数车牌都没有。
In addition, some astronomers who study those plates prefer to use the physical, tangible objects, so they can be sure that there are no artifacts from the scanning process.
此外，一些研究这些板块的天文学家更喜欢使用物理的、有形的物体，这样他们就可以确定扫描过程中没有任何伪影。
Time-domain differences can be subtle.
时域差异可能很微妙。
Rajka Jurdana-Šepić , an astrophysicist at the University of Rijeka in Croatia, always begins her plate searches with a set of 10 or more “wish-list” objects.
Rajka Jurdana-Šepić 是克罗地亚里耶卡大学的天体物理学家，她总是从一组 10 个或更多“愿望清单”物体开始她的盘子搜索。
While some astronomers, such as Hudec and Graham, might be looking for a few specific, active, variable supermassive black holes, others such as Jurdana-Šepić study bursting stars.
虽然邬达克和格雷厄姆等一些天文学家可能正在寻找一些特定的、活跃的、可变的超大质量黑洞，但尤尔达纳-塞皮奇等其他天文学家则研究爆发的恒星。
The goal is to better understand the physical processes and mechanisms that cause brightness to change.
目标是更好地了解导致亮度变化的物理过程和机制。
At plate stacks, such as the collection at the Asiago Astrophysical Observatory in Italy and the one at Harvard, Jurdana-Šepić pulls the plates she has targeted off the shelf.
在盘堆中，例如意大利阿夏戈天体物理天文台和哈佛大学的藏品，尤尔达娜-塞皮奇从架子上取下了她所瞄准的盘。
She carefully removes them from their paper jackets and places one plate at a time on a light table.
她小心翼翼地将它们从纸套中取出，一次将一个盘子放在一张轻便的桌子上。
Then comes the hard part: peering through a microscope to find her half-inch-wide field among thousands of black dots.
接下来是最困难的部分：通过显微镜观察，在数千个黑点中找到她半英寸宽的视野。
Usually she can find the area within 20 minutes.
通常她可以在 20 分钟内找到该区域。
Then she begins measuring.
然后她开始测量。
She prefers opera for this part: “Puccini, Verdi, or something in my ears, and thousands of plates on the table,” she said.
她更喜欢歌剧这个部分：“普契尼，威尔第，或者我耳朵里的东西，还有桌子上的数千个盘子，”她说。
Her measurements involve comparing, by eye, her stellar target and bright stars of known magnitude in that same tiny field.
她的测量包括通过肉眼比较她的恒星目标和同一微小区域中已知星等的明亮恒星。
“For example, seven grades from A, three grades from B,” she said.
“例如，A 成绩为 7 分，B 成绩为 3 分，”她说。
At the end of several weeks, she’ll have recorded a few hundred magnitude measurements across hundreds or even thousands of plates to build up a light curve for the object that spans decades.
几周后，她将在数百甚至数千个板上记录数百个星等测量结果，以建立该物体跨越数十年的光曲线。
René Hudec has visited more than 70 plate collections around the world, and estimates there could be 10 million surviving glass plates.
勒内·邬达克参观了世界各地 70 多个玻璃板收藏馆，估计现存的玻璃板可能有 1000 万块。
Bradley Schaefer , an astronomer at Louisiana State University, focuses on cataclysmic variable stars, objects that vary in brightness over time due to some type of major turmoil.
路易斯安那州立大学的天文学家布拉德利·谢弗（Bradley Schaefer）专注于灾难变星，即由于某种类型的重大动荡而亮度随时间变化的物体。
His favorites are recurrent novas — binary systems in which a massive white dwarf siphons so much material from its partner that its surface becomes dense enough and hot enough to undergo nuclear fusion, resulting in a dramatic increase in brightness at least twice per century.
他最喜欢的是循环新星——双星系统，其中一颗巨大的白矮星从其伙伴那里吸走大量物质，使其表面变得足够致密、足够热，足以进行核聚变，导致亮度每世纪至少两次急剧增加。
More common novas work in a similar way, but their white dwarfs are smaller, meaning their bursts are much less frequent.
更常见的新星以类似的方式工作，但它们的白矮星较小，这意味着它们的爆发频率要低得多。
Scientists think there could be a connection between recurrent novas and Type Ia supernovas.
科学家认为复发新星和 Ia 型超新星之间可能存在联系。
These supernovas are critically important for measuring the expansion rate of the universe.
这些超新星对于测量宇宙的膨胀率至关重要。
Schaefer is testing the theory that recurrent novas could evolve into Type Ia supernovas.
谢弗正在测试复发新星可能演化为 Ia 型超新星的理论。
By measuring their brightness over years, potentially over multiple fusion bursts, Schaefer could observe patterns and changes in these orbital systems.
通过多年来测量它们的亮度，可能是多次聚变爆发，谢弗可以观察这些轨道系统的模式和变化。
He’s been able to track the orbital periods of more than a dozen systems, and he has ruled out a few of them as potential precursors to a special type of supernova explosion.
他已经能够追踪十多个系统的轨道周期，并排除了其中一些系统作为特殊类型超新星爆炸的潜在前兆。
For this work, “you need many decades’ worth of data,” Schaefer said.
对于这项工作，“你需要数十年的数据，”谢弗说。
“Archival data [is] the only game in town.”
“档案数据是城里唯一的游戏。”
If and when something in the cosmos goes bang, astronomers want to know its history.
如果宇宙中有什么东西发生爆炸，天文学家就会想知道它的历史。
Older data lets them observe earlier blips, flares, or other activity, and “that then helps the interpretation, and maybe suggests a different model,” Graham said.
较旧的数据让他们能够观察到早期的光点、耀斑或其他活动，“这有助于解释，也许会提出不同的模型，”格雷厄姆说。
The AGNs that Graham studies are active supermassive black holes and their surrounding accretion disks.
格雷厄姆研究的活动星系核是活跃的超大质量黑洞及其周围的吸积盘。
These vary randomly, so describing their brightness changes is complex.
这些是随机变化的，因此描述它们的亮度变化很复杂。
While scientists have 60 years of targeted data and 5 million time series images of AGNs, he said, “we still really don’t understand the mechanisms by which they are variable.”
他说，虽然科学家们拥有 60 年的目标数据和 500 万张活动星系核的时间序列图像，但“我们仍然不明白它们变化的机制。”
Graham is co-leader and project scientist at the Zwicky Transient Facility (ZTF), another sky survey looking for changing cosmic objects.
格雷厄姆是兹威基瞬态设施（ZTF）的联合领导者和项目科学家，这是另一项寻找变化的宇宙物体的天空调查。
ZTF uses the 48-inch Oschin Schmidt telescope at Mount Palomar in California.
ZTF 使用位于加利福尼亚州帕洛玛山的 48 英寸奥辛·施密特望远镜。
The telescope bridges the eras of observational astronomy.
该望远镜架起了观测天文学时代的桥梁。
Today it boasts sophisticated digital detectors, but it was also used for foundational surveys in the days of glass photographic plates.
如今，它拥有先进的数字探测器，但在玻璃照相底片时代，它也被用于基础调查。
Graham recently acquired 20 terabytes of historical data: the digitized versions of the plates captured during the Palomar Observatory Sky Survey (POSS), first conducted in the 1940s and 1950s, and its successor POSS-II, which spanned the 1980s and 1990s.
格雷厄姆最近获取了 20 TB 的历史数据：帕洛马天文台巡天 (POSS) 期间捕获的板块的数字化版本（首次于 20 世纪 40 年代和 1950 年代进行）及其后继者 POSS-II（跨越 1980 年代和 1990 年代）。
This won’t be the first time he has combined data from multiple surveys, although in the past he’s focused on putting together digital surveys only.
这并不是他第一次整合多项调查的数据，尽管过去他只专注于整合数字调查。
Combining datasets from multiple telescopes and observations requires calibration to account for different optics, filters, and detectors.
结合多个望远镜和观测的数据集需要进行校准，以考虑不同的光学器件、滤波器和探测器。
A physical plate, or a scanned image of one, adds further complications, Griffin said.
格里芬说，物理板或扫描图像会增加更多的复杂性。
The photographic emulsion’s density — those dark marks — relates in a very specific way to the incoming starlight’s intensity.
照相乳剂的密度（那些黑色标记）以非常特定的方式与入射星光的强度相关。
But the astronomers who know how to read the plates can combine their measurements with ones from more recent surveys for a longer-term view.
但知道如何解读这些板块的天文学家可以将他们的测量结果与最近的调查结果结合起来，以获得更长远的观点。
Schaefer uses data from multiple space telescopes, but they’re not suited to his purpose unless paired with ground-based datasets and the more historical forms of observation.
谢弗使用来自多个太空望远镜的数据，但除非与地面数据集和更具历史意义的观测形式相结合，否则它们并不适合他的目的。
“It’s just one point,” he said of the space telescope images, “where the story is told over the century.”
“这只是一个点，”他在谈到太空望远镜图像时说，“讲述了一个世纪的故事。”
Every telescope that astronomers used to document the sky during the century before 1980 used glass plate photography.
1980 年前的一个世纪里，天文学家用来记录天空的每台望远镜都使用玻璃板摄影。
The plates, if stored in stable conditions and not piled up with weight on top of them, can endure for centuries.
如果这些盘子存放在稳定的条件下，并且上面没有堆放重物，那么这些盘子可以保存几个世纪。
Unfortunately, some collections were misplaced when university departments switched buildings.
不幸的是，当大学院系更换大楼时，一些藏品丢失了。
Others have even been thrown into the garbage.
其他人甚至被扔进垃圾箱。
Of the many that have survived, their condition can be a concern; some glass plates are cracked or little more than shards.
在许多幸存者中，他们的状况可能令人担忧。有些玻璃板破裂或只是碎片。
In other cases, the emulsion is peeling due to humidity swings or growing mold from water exposure.
在其他情况下，乳液由于湿度波动或因接触水而发霉而剥落。
Both Hudec and Griffin are strong proponents of the value in these historical artifacts.
邬达克和格里芬都大力支持这些历史文物的价值。
Both have also seen collections destroyed and data saved.
两者都看到藏品被毁，数据被保存。
Griffin spoke of an experience at a collection overseas.
格里芬谈到了一次在海外收藏的经历。
She reached into a box filled with plate envelopes to pull out a plate with the spectrum of the bright star Arcturus.
她把手伸进一个装满平板信封的盒子里，拿出一个带有明亮恒星大角星光谱的平板。
“The emulsion fell off,” she said.
“乳液脱落了，”她说。
“Only the glass came up.” All the plates in the box were the same.
“只有玻璃升起来了。”盒子里的所有盘子都是一样的。
They had apparently been moved too quickly from high humidity to low humidity.
显然，它们从高湿度转移到低湿度的速度太快了。
Surviving plate collections can be a constant source of discovery.
幸存的盘子收藏可以成为不断发现的源泉。
And with careful scanning, the data they hold can be invaluable, full of hidden surprises from a century of astronomical flares, bursts, and more.
通过仔细扫描，它们所保存的数据可能是无价的，充满了一个世纪以来的天文耀斑、爆发等隐藏的惊喜。
The Rubin Observatory will lead to many incredible discoveries; its early images already have.
鲁宾天文台将带来许多令人难以置信的发现；它的早期图像已经有了。
But the lifetimes of cosmic objects are long, and understanding today’s data relies on yesterday’s, in the form of stacks and stacks of glorious glass.
但宇宙物体的寿命很长，而理解今天的数据依赖于昨天的数据，这些数据以一堆堆光彩夺目的玻璃的形式存在。
That’s why, Griffin said, “it’s so desperately important to keep them.”
格里芬说，这就是为什么“保留它们非常重要”。
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《Quanta》杂志对评论进行审核，以促进知情、实质性、文明的对话。
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辱骂、亵渎、自我推销、误导、语无伦次或偏离主题的评论将被拒绝。
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版主在正常工作时间（纽约时间）有工作人员，并且只能接受英文评论。