The Glass Universe: The Hidden History of the Women Who Took the Measure of the Stars. Дава Собел

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СКАЧАТЬ the plates trumped any visual observer’s report, “for in the case of the observer, you have simply his statement of how the object appeared at a given time as seen by him alone, while here you have a photograph in which every star speaks for itself, and which can at any time, now or in the years to come, be compared with any other photographs of the same part of the sky.”

      Early in 1891, after she had identified a new variable in the constellation of the Dolphin, and, with the director’s approval, published her finding in the Sidereal Messenger, two skilled observers from other institutions took it upon themselves to corroborate the discovery. Both contested her claim, declaring the star not variable. When those same two astronomers met to discuss their conclusions, however, they realized they had each been watching a different star, neither of which was in fact Mrs. Fleming’s star. “No such error,” she all but crowed, “could have occurred from the comparison of the photographic charts.”

      Detecting new variable stars had become Mrs. Fleming’s forte. Although fewer than two hundred such inconstant lights were known when she joined the observatory staff, the decade of her employment flushed out a hundred more, of which she personally identified a score. She made her earliest finds while gauging magnitudes by the size of the speck a star created on a photographic plate, and then noting which specks changed size in subsequent pictures. Spectra gave her an easier means. Once she had familiarized herself with the spectral features of a few well-known variables, she could recognize similar traits in other stars, almost at a glance. For example, the presence of a few light hydrogen lines among the black ones signaled a variable star near the height of its brightness.

      As Mrs. Fleming ferreted out new variables, she also kept a close watch on the old. The director was keen to monitor how the spectra of variable stars changed over time, and the ways that variations in brightness correlated with the appearance of the Fraunhofer lines.

      In the spring of 1891, Mrs. Fleming noticed something unusual about the familiar variable called Beta Lyrae. Its changeable nature had been known for a hundred years, but now, looking at its magnified spectrum, she recognized the doubled lines signifying that Beta Lyrae belonged to the newly defined group of spectroscopic binaries—that this star was in fact two stars.

      Miss Maury also took an interest in Beta Lyrae, even a proprietary interest, given that Lyra (the Harp) was a northern constellation, and she had charge of the approximately seven hundred brightest stars of the northern skies. Together with Pickering and Mrs. Fleming, she reviewed twenty-nine Draper Memorial plates that contained images of Beta Lyrae. Her analysis suggested this binary did not comprise identical twins, as was the case for Mizar and Beta Aurigae, but two stars of different classes, each varying at its own rate and for its own reasons. She began to frame a theory about the nature of their relationship.

      Pickering had hoped to publish Miss Maury’s classification of the northern bright stars by the end of 1891, as a sequel to Mrs. Fleming’s 1890 “Draper Catalogue of Stellar Spectra.” Unfortunately, Miss Maury seemed nowhere near ready to release her results. Her two-tiered classification system, which addressed both the identity and the quality of the spectral lines, required a painstaking exactitude. Anything less would deny the complexity of the problem. Although her slow pace disturbed Pickering, he could hardly accuse her of slacking. She had taken on a second job as a teacher in the nearby Gilman School, while still pursuing her observatory work so assiduously that he feared she neglected her health. Mrs. Draper, too, grew impatient with her niece. After a visit to the observatory in early December, she wrote Pickering, “I do hope Antonia Maury will make an effort and finish more satisfactorily what she has in hand.”

      Pickering stopped daily by the computing room to monitor the assistants’ progress. Miss Maury shrank from these encounters. She often went home feeling tired and nervous, and more than once complained to her family that the director’s criticism had shaken her faith in her own ability. Incapable of continuing under such conditions, she quit the observatory early in 1892. Through the next few months she negotiated with Pickering about the fate of her unfinished projects, which she refused to abandon or cede to anyone else.

      “I have had in mind for some time to explain to you,” she wrote on May 7, “how I feel in regard to the closing up of my work at the Observatory. I am willing and anxious to leave it in satisfactory condition, both for my own credit and in honor of my uncle. I do not think it is fair to myself that I should pass the work into other hands until it is in such shape that it can stand as work done by me. I do not mean that I need necessarily complete all the details of the classification, but that I should make a full statement of all the important results of the investigation. I worked out the theory at the cost of much thought and elaborate comparison and I think that I should have full credit for my theory of the relations of the star spectra, and also for my theories in regard to Beta Lyrae. Would it not be fair that I should, at whatever time the results are published, receive credit for whatever I leave in writing in regard to these matters?”

      Pickering stood ever ready to credit her. He just wished he had some idea of when that occasion might arise.

      • • •

      MISS MAURY’S DEPARTURE at the start of 1892 coincided with the long-awaited arrival from France of the Bruce telescope’s glass disks, two of flint and two of crown, each two feet in diameter by three inches thick, weighing in the neighborhood of ninety pounds, and rimmed in a metal hoop. The flawless purity of the glass rendered the disks invisible, and therein lay their beauty. Pickering immediately consigned them to the Clarks for the all-important grinding and polishing. He expected the transformation of the disks into the four-element portrait lens to take at least six months of long days on the Clarks’ steam-powered lathe. First the glasses would be abraded with rough sand, then by ever-finer rouge powders, until they assumed the desired curvature.

      While that process was under way, Pickering drew plans for a freestanding structure in which to assemble and try out the finished instrument. The Bruce telescope must pass his own stringent tests before he could ship it to Arequipa. And Arequipa, in turn, must be readied to receive it. On May 29 he notified William, who had disappointed him, that his term as southern director would expire at the end of the year, at which time Solon Bailey would replace him. William could return in future to observe at the site, if he liked, but he would no longer be in charge.

      William recoiled at the insult. “Without being boastful, I think I’ve accomplished a pretty big thing,” he argued on June 27, 1892, “and if the authorities [the president and fellows of the Harvard Corporation] could see it they would say I had got them a great deal for their money.” The idea of subservience to Bailey particularly rankled William: “As to our coming down here again to Peru and living in a small hut, while the Baileys occupy the Director’s house, it is out of the question. I planned and built that house, and while I am in Peru I expect to live in it. I don’t choose to live in a shanty while one of my subordinates occupies the house I built.”

      All through the summer of 1892, William soothed himself by studying Mars during its close approach. As he reported in Astronomy and Astro-Physics, he observed and drew the red planet every night save one from July 9 to September 24. He collected “considerable data” on the Martian polar caps, the shaded areas “of greenish tint,” and the two large, dark regions that, under favorable conditions, turned blue “presumably due to water.” He referred to these as “seas.” He corroborated the numerous Martian “canals” originally discovered by Giovanni Schiaparelli of Italy, and noted that many of them intersected one another—at junctions he dubbed “lakes.” William communicated these same findings to the editors of the New York Herald, who printed them to sensational effect. An exasperated Edward Pickering complained to William on August 24 that the waters of Mars had generated a “flood” of forty-nine newspaper cuttings in one morning. He admonished William to restrict himself “more distinctly to the facts.”

      Meanwhile Edward and Lizzie Pickering were looking to remodel the “dwelling house” in the observatory’s СКАЧАТЬ