STELLAR ATMOSPHERES CECILIA PAYNE PDF

Cecilia Payne began school in Wendover at a private school run by Elizabeth Edwards. There she was urged by Gustav Holst , who taught music at the school, to pursue a career in music, but preferred to focus on science and the following year won a scholarship that paid all her expenses at Newnham College , Cambridge University , where she initially read botany, physics, and chemistry but dropped botany after her first year. After being introduced to Harlow Shapley , the Director of the Harvard College Observatory , where he had just established a graduate program in astronomy, she left England in Adelaide Ames had become the first student on the fellowship in ; the second was Payne. Doctoral thesis[ edit ] Shapley persuaded Payne to write a doctoral dissertation, and so in she became the first person to earn a PhD in astronomy from Radcliffe College of Harvard University. She showed that the great variation in stellar absorption lines was due to differing amounts of ionization at different temperatures, not to different amounts of elements.

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It is also a story of persistence against the odds, whether they were low expectations of women or academic infighting. The story has resonance for those beginning careers today, in a very different academic environment. It also provides an overview of the development of the astrophysics of stellar composition over a long and fruitful career. It was during that tumultuous year after the end of the Great War of — that Cecilia Helena Payne won a scholarship for entry to Newnham College, Cambridge.

She went to Newnham with the intention of reading botany as her principal subject, but the attraction of physics and astronomy soon dominated her life. She took her part I natural sciences examinations in botany, physics and chemistry, and went on to do part II in physics in a further two years, gaining second class honours. The year was the worst of times because of the problems of recovery from the war years and of political and economic turmoil in Europe, particularly in Germany, Austria, France and Belgium.

At Cambridge, the undergraduate population was largely made up of former servicemen, but Cecilia seems to have survived any social problems that might have arisen. It was the best of times because of a spirit of reaching out into new fields of human endeavour, in politics, in the arts, in science and engineering, and in the application of electricity and of the internal combustion engine.

This included the beginnings of commercial aviation. Alcock and Brown first flew across the Atlantic Ocean in and air-mail services began. In astronomy, the inch Mount Wilson telescope and the 74 inch telescope at Victoria, British Columbia, were newly commissioned. At Cambridge, Sir Arthur Eddington, Plumian Professor of Astronomy and director of Cambridge Observatory, was able to announce in November the successful results of the Greenwich and Cambridge expeditions to observe the total eclipse the previous May.

In the same month, Eddington described the work involved in a special lecture in Cambridge which was avidly attended by Cecilia Payne.

She received one of only four tickets for the lecture assigned to Newnham College, when one of the first recipients dropped out. She had a very retentive memory. In choosing astronomy she was considerably frustrated because in the Cambridge tradition astronomy was strongly linked to mathematics and she did not regard herself qualified as a mathematician. All were pioneers in branches of nuclear physics and Cambridge was frequently visited by many world figures in physics such as Niels Bohr.

Eddington became a perfect hero to Cecilia Payne and he helped her to spend hours away from the physics laboratories by allowing her use of the observatory library.

One can imagine her cycling out the short distance between Newnham and the observatory against a cold east wind and entering with enthusiasm the elegant drive and portico of the observatory building, as it became increasingly familiar to her.

In her final undergraduate year of —23 and with the active encouragement of L J Comrie, who later became superintendent of the Nautical Almanac Office, she considered the possibility of studying astronomy in the United States.

It happened that Harlow Shapley, with a background that included journalism, had recently become director of Harvard College Observatory. He visited Britain and spoke at the centenary celebrations of the Royal Astronomical Society in May Comrie introduced Cecilia to Shapley and she immediately found him to be refreshingly encouraging and open, whereas at Cambridge she had received scant encouragement to apply for research assistantships or for study grants. In , the year of her graduation, she secured enough support to travel across the Atlantic as a putative graduate student at Harvard.

It must be reckoned that she left Cambridge, England, for Cambridge, Massachusetts, with few regrets other than her separation from the stimulating influence of Eddington and from her family and home. In England, F J M Stratton, though kindly enough, had thought that she could never hope to be other than an amateur astronomer. Sir Arthur Eddington, after giving the matter some thought, decided that there was no insuperable difficulty in her making a career in astronomy and indeed he did a great deal to help her.

He proposed her for RAS membership and he provided her with a favourable letter of introduction to Harlow Shapley in , it being a full year since she had met him in London. With some funds at his disposal, Shapley was able to award her a small stipend to see her through the first year or two at Harvard, where she shared accommodation with other women working at the observatory. College officers both in and in were fairly exhausted and perhaps depressed through the difficulties in keeping university life going through the war years and would understandably tend to react adversely to starry-eyed aspirations from new students just up from school.

It is the case that she left Cambridge for Harvard with the support of Eddington, the outstanding British astrophysicist of the time, and with friendly acquaintance of E A Milne, W M Smart and L J Comrie, all well-known figures in astronomy in the s and s. It might be difficult to do as well as that now! In there was still no regular graduate astronomy programme at Harvard Observatory. Shapley started one and Cecilia Payne was one of the first students. Women assistants had for long been employed at Harvard and some of these, such as Annie Cannon and Henrietta Leavitt, had become internationally known for their work in astronomy.

Generally, at Harvard, women were employed on the routine work of, for instance, the Henry Draper Catalogue of positions, magnitudes and spectral types. In this way a large body of material on stellar spectra had been accumulated at Harvard.

The Henry Draper Catalogue has remained a standard all-sky resource ever since, only now being replaced in principle by the Tycho catalogue of the Hipparcos programme. This was astrophysics at the frontier of contemporary knowledge. The prospect of materially advancing the subject through the copious resource of the Harvard collection of thousands of spectra enthused her so greatly that she determined to make this the subject of her PhD thesis — the first such thesis produced from Harvard Observatory.

Although he had originally suggested that she follow a more conventional line, Harlow Shapley gave her active support in this work and eventually fought the battle of her becoming the first woman recipient at Harvard-Radcliffe of the PhD degree.

One of the foremost authorities on stellar atmospheres and stellar structure at that time at Princeton was Henry Norris Russell. Menzel was himself keen on using the Harvard spectra for purposes similar to those of Cecilia, but in due course he concentrated on cooler stars, while Cecilia specialized in the early types.

There is the implication in her autobiography that Shapley played Menzel and Cecilia off against each other and it was only when Menzel succeeded Shapley in that Cecilia and Menzel found good common understanding. He strove to improve markedly her salary and status at Harvard — the first time that she received proper recognition as a professor and head of the university astronomy department. I limit myself largely to this work in the remainder of this account.

In , when she started this work, the basic Hertzsprung—Russell diagram, then called the Russell diagram, had been firmly established in terms of visual absolute magnitude against spectral type. Giants and dwarfs were barely differentiated spectroscopically but there had been several calibrations, notably by E S King at Harvard and by Wilsing and Scheiner at Potsdam, of black-body temperature for stars of different spectral type.

The printed version runs to over pages, plus five appendices, and is divided into three parts: The Physical Groundwork, Theory of Thermal Ionisation, Additional Deductions from Ionisation Theory. As well as work by Saha himself, several astronomers had applied the Saha equation of ionization to stellar atmospheres. In particular, contemporaneously with the graduate work on the Harvard spectra by Cecilia, R H Fowler and E A Milne published two long and detailed papers in Monthly Notices 83 and 84 based on the estimated probability of atoms being in different states of ionization and excitation so that absorption lines could be formed.

They produced a diagram with temperature as abscissa, calibrated in Kelvin from to 40 , and with a parallel scale in spectral types. It would seem that these types from O to M were placed according to the black-body temperature estimates for each type. What Cecilia set out to do, and succeeded in doing, was to use the marginal and maximum appearance of the lines according to theory to place the spectral types along the axis.

In this way real information on the stellar atmospheres was obtained and the spectral types were closely identified as a temperature sequence, using the Fraunhofer lines rather than the best black-body continuum.

Hence a maximum occurs in a fairly well-defined range of temperature. This permitted for the first time a detailed comparison of the theory of spectral lines with their appearance over a wide range of spectral types.

It will be understood that these applications of the theory are entirely in terms of a photosphere and an overlying reversing-layer even though, by , when she started this work, the concept of Schuster and of Schwarzschild was already available of an atmosphere where there was no such sharp division wherein atoms responded to the radiation coming up from below by scattering, absorption and re-emission.

The reversing-layer concept collapsed in principle around on the basis that the limb-darkening of the Sun would be quite different from that observed. However, the simplicity of the reversing-layer concept resulted in its being maintained over decades even to the present day. Cecilia Payne, when mentioning solar-spectrum observations, does not emphasize the significance of solar limb-darkening observations.

It would seem that, owing a lot to E A Milne, she did not thoroughly grasp the way emerging radiation ought to be visualized at a time when the concept of the reversing layer was becoming obsolete. I must now pass on to what was in retrospect the greatest achievement of her monograph on stellar atmospheres — but was not recognized at the time, even by herself.

Abundance of the elements A section of part 3 of Stellar Atmospheres contains a discussion of the abundances of elements derived from the marginal appearance of spectral lines.

As previously, this is based upon the concept of the reversing layer and is prior to the emergence of the curve-of-growth method. If then it be assumed that the number of atoms required for marginal appearance is the same for all elements, the reciprocals of the computed fractional concentrations at marginal appearance should give directly the relative abundances of the atoms.

There are, however, large discrepancies in the cases of hydrogen and of helium — up by a factor of or so in number-count of atoms. Probably the result may be considered, for hydrogen, as another aspect of its abnormal behaviour … and helium … possibly deviates for similar reasons. The lines of both atoms appear to be far more persistent, at high and low temperatures, than those of any other element.

Marriage and children In Cecilia visited Europe. She writes of the terrible conditions under which the Pulkova astronomers were working at that time.

On her return she attended the Astronomische Gesellschaft meeting in Gottigen where she met a Russian exile, Sergei Gaposchkin. Back in Washington she successfully pursued the question of his obtaining a visa entry. They were married in With seemingly thoroughly disparate backgrounds and different mother tongues, they formed an astronomical partnership that lasted for four decades and they had a family of three children, reckoned, possibly unfairly, by some visitors to Harvard in the s as among the worst-behaved family they had experienced.

The biographical accounts barely hint at this, referring to a home that was sometimes in domestic chaos, and with a reference to the old Harvard Observatory buildings as a fine play area for active children. Professionally, the Gaposchkins collaborated assiduously and produced definitive studies of variable stars, including Magellanic Cloud cepheids, in extenso.

Numerous books by one or the other, or by both, were produced, as well as annual lists of papers published. From the authentic biographies, I found papers published from —79, including five during , and nine books authored or co-authored with Sergei Gaposchkin. I have to suppose that the accusers had never read any scientific literature. We spend our lives trying to overthrow obsolete ideas and to replace them with something that represents Nature better … Science is a living thing, not a dead dogma.

Haramundanis K ed. Press, — Press, 72— Hoffleit D Journal of the A. Gingerich O et al. Gingerich O Quarterly Journal Roy. Author notes " This paper was presented by the late Prof. Issue Section:.

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