The Discovery of the Existence of White Dwarf Stars: 1862 to 1930

Hearnshaw J. B. , The analysis of starlight: One hundred and fifty years of astronomical spectroscopy (Cambridge, 1986), 352–60. Other reviews include Luyten W. J. , “White dwarfs and degenerate stars”, Vistas in astronomy, ii (1956), 1956–59, and Schatzman E. , White dwarfs (Amsterdam, 1958), 1–4.

Herschel William , “Account of the changes that have happened, during the last twenty-five years, in the relative situation of double-stars; with an investigation of the cause to which they are owing”, Philosophical transactions of the Royal Society of London, xciii (1803), 339–82.

Herschel William , “Catalogue of double stars”, Philosophical transactions of the Royal Society of London, lxxv (1785), 40–126, p. 73.

The system is star no. II.80 in Herschel's second catalogue and Σ 518 in Struve's catalogue. Its modern designation is ADS 3093.

Heintz W. D. , “Astrometric study of four visual binaries”, Astronomical journal, lxxix (1974), 819–25.

Bessel Friedrich Wilhelm , “On the variation of proper motions of Procyon and Sirius”, Monthly notices of the Royal Astronomy Society, vi (1844), 136–44.

Holberg J. B. Wesemael F. , “The discovery of the companion of Sirius and its aftermath”, Journal for the history of astronomy, xxxviii (2007), 161–74.

Bond G. P. , “On the companion of Sirius”, American journal of science, xxxiii (1862), 286–7, p. 287. “Its faintness would lead us to attribute to it a much smaller mass than would suffice to account for the motions of Sirius, unless we suppose it to be an opaque body or only feebly self-luminous”.

Struve Otto W. , “On the satellite of Sirius”, Monthly notices of the Royal Astronomical Society, xxiv (1864), 149–51.

Le Verrier U.-J. J. , “Rapport sur l'Observatoire Impérial de Paris et projet d'organisation”, Annales de l'Observatoire Impérial de Paris, i (1855), 1–68, p. 7.

Struve Otto W. , “On the satellite of Sirius”, Monthly notices of the Royal Astronomical Society, xxvi (1866), 268–71, p. 270. “Admitting then that the observed satellite is identical with Bessel's obscure body, the above given relation of d = 3.087, indicates that its mass must be estimated approximately half that of Sirius itself. If both bodies had the same physical constitution, this relation of the masses would assign to the globe of the satellite a diameter of only 1.26 times smaller than that of the principal body, and therefore, considering the extraordinary brightness of the large star, we would be induced to place also the satellite in the first class of magnitude. With this conclusion the observed brightness of the companion forms a manifest contradiction. It is commonly said to be of the 9th or 10th magnitude; and only in the Spring of 1864 I have noted it once as of 8th magnitude, probably on account of an extraordinary favourable state of the atmosphere. Hence it follows that, to maintain the identity, we must admit that both bodies are of a very different physical constitution”.

Knott George , “On the companion to Sirius”, Monthly notices of the Royal Astronomical Society, xxvi (1866), 243.

Crossley E. Gledhill J. , and Wilson J. M. , A handbook of double stars (London, 1879), 230.

Clerke Agnes M. , The system of the stars, 2nd edn (London, 1905), 156.

Gore J. E. , “A catalogue of binary stars for which orbits have been computed. With notes”, Proceedings of the Royal Irish Academy, i (1891), 571–89.

Lockyer J. Norman , The meteoritic hypothesis (London, 1890).

FitzGerald A. P. , “John Ellard Gore (1845–1910)”, The Irish astronomical journal, vii (1966), 213–19.

Gore J. E. , “The companion of Sirius”, Journal of the British Astronomical Association, vi (1891), 318–19.

Flammarion Camille , Popular astronomy, transl. by Gore J. E. (London, 1894), 634.

Clerke Agnes M. Fowler A. Gore J. Ellard , Astronomy (London, 1898), 438.

Clerke , op. cit. (ref. 20), 156–7: “… its secondary member is a body abnormally massive proportionately to its light. Sirius shines like four thousand, it gravitates like two of its companions. There must be an enormous disparity of temperature between them, with a probably correspondingly difference in mean density. Yet they are presumably of contemporaneous origin…. Thus the contrast between the components of this binary star could scarcely among visible objects be more pronounced. And its significance is accentuated by its essential repetition in Procyon, the lesser dog star”.

Gore J. Ellard , “The satellite of Sirius”, The observatory, xxviii (1905), 55–57.

Gore , op. cit. (ref. 15).

Monck W. H. S. , “Some further notes on binary stars”, The observatory, x (1887), 134–5.

Clerke , op. cit. (ref. 20), 176: “The duskiest stars in the [Gore's] list are those composing o₂ Eridani, which revolve in 180 years, and considerably exceed the sun in gravitating power, although claiming respectively only ninth and tenth magnitude rank. Admitting their density to be the same as that of ξ Ursae, they seem to be intrinsically 660 times less luminous”.

DeVorkin David , Henry Norris Russell, dean of American Astronomers (Princeton, 2000), 61–67.

Russell Henry Norris , “Address by Professor Henry Norris Russell”, Novae and white dwarfs, i: The novae (Paris, 1941), 5–6:

The white dwarfs at the time of their discovery presented an apparently insoluble problem. As I happened to be one of the first two or three people who ever heard of them, I may, I hope, be pardoned for introducing a reminiscence which has never before been published. About thirty years ago I was visiting my friend and generous benefactor, Professor Edward C. Pickering. With characteristic kindness, he had volunteered to have the spectra observed for all the stars — Including comparison stars — Which had been observed in the observations for stellar parallax which Hinks and I made at Cambridge, and I discussed. This piece of apparently routine work proved very fruitful — It led to the discovery that all the stars of very faint absolute magnitude were of spectral class M. In conversation on this subject (as I recall it), I asked Pickering about certain other faint stars, not on my list, mentioning in particular omicron² Eridani B. Characteristically, he sent a note the Observatory Office, and before long the answer came (I think from Mrs. Fleming) that the spectrum of this star was A. I knew enough about it, even in those paleozoic days, to realize at once that there was an extreme inconsistency between what we would then have called « possible» values of the surface brightness and the density. I must have shown that I was not only puzzled, but crestfallen, at this exception to what looked like a very pretty rule of stellar characteristics; but Pickering smiled upon me, and said: «It is just these exceptions that lead to an advance in our knowledge, » and so the white dwarfs entered the realm of study!

Russell Henry Norris , “Notes of white dwarfs and small companions”, Astronomical journal, li (1944), 13–17, p. 13:

The first person who knew of the existence of white dwarfs was Mrs. Fleming; the next two, an hour or so later, Professor E. C. Pickering and I. With characteristic generosity, Pickering had volunteered to have the spectra of the stars which I had observed for parallax looked up on the Harvard plates. All those of faint absolute magnitude turned out to be of class G or later. Moved with curiosity I asked him about the companion of 40 Eridani. Characteristically, again, he telephoned to Mrs. Fleming who reported within an hour or so, that it was of Class A. I saw enough of the physical implications of this to be puzzled, and expressed some concern. Pickering smiled and said, “It is just such discrepancies which lead to the increase of our knowledge.” Never was the soundness of his judgment better illustrated.

Russell H. N. , “Giant and dwarf stars”, The observatory, xxxvi (1913), 324–9, p. 325.

Russell Henry Norris , “Relations between the spectra and other characteristics of the stars”, Popular astronomy, xx (1914), 275–94, p. 286.

DeVorkin , op. cit. (ref. 26), 118–19.

Hertzsprung to Adams, 19 Nov. 1914. Folder 19.336 of the Walter Sydney Adams Papers, Huntington Library.

Hertzsprung's “effective wavelengths” refer the method of estimating the effective wavelength of stellar energy distributions from the distance between the densest portions of the positively and negatively dispersed stellar images on objective grating plates. Bluer stars had shorter “effective wavelengths” than red stars.

Hertzsprung Ejnar , “Effective wavelengths of absolutely faint stars”, Astrophysical journal, xlii (1915), 111–19.

Adams Walter S. , “An A-type star of very low luminosity”, Publications of the Astronomical Society of the Pacific, xxvi (1914), 198.

Öpik E. , “The densities of visual binary stars”, Astrophysical journal, xliv (1916), 292–302, pp. 301–2.

Adams Walter S. , “The spectrum of the companion of Sirius”, Publications of the Astronomical Society of the Pacific, xxvii (1915), 236–7.

Ibid., 237.

Hertzsprung Ejnar , “Zur Strahlungen der Sterne”, Zeitschrift für wissenschaftlich Photographie, iii (1905), 429–42.

Maury Antonia C. Pickering Edward C. , “Spectra of bright stars photographed with the 11-inch Draper telescope”, Annals of the Astronomical Observatory of Harvard College, xxviii/1 (1897), 18.

Adams Walter S. , and Kohlschütter Arnold “Some spectral criteria for the determination of absolute stellar magnitudes”, The astrophysical journal, xl (1914), 385–99.

Lindblad Bertil , “Spectrophotometric methods for determining stellar luminosity”, Astrophysical journal, lv (1922), 85–118.

van Maanen A. , “Two faint stars with large proper motion”, Publications of the Astronomical Society of the Pacific, xxix (1917), 258–9.

Luyten Willem J. , “A study of stars with large proper motions”, Lick Observatory bulletin, xi (1923), 1–32.

Luyten Willem J. , “Note on some faint early type stars with large proper motions”, Publications of the Astronomical Society of the Pacific, xxxiv (1922), 54–55.

Luyten Willem J. , “Additional note on faint early-type stars with large proper-motions”, Publications of the Astronomical Society of the Pacific, xxxiv (1922), 132.

Luyten Willem J. , “Third note on faint early type stars with large proper motions”, Publications of the Astronomical Society of the Pacific, xxxiv (1922), 356–7.

DeVorkin David H. , “Internationalism, Kapteyn and the Dutch pipleline”, in The legacy of J. C. Kapteyn, ed. by van der Kruit P. C. van Berkel K. (Dordrecht, 2000), 129–50.

Hertzsprung Ejnar , “Lists of stars nearer than 5 parsecs”, The bulletin of the Astronomical Institutes of the Netherlands, i (1922), 21–22.

Eddington A. S. Address Presidential , Monthly notices of the Royal Astronomical Society, lxxxii (1922), 432–7, p. 436.

Eddington A. S. , The internal constitution of the stars (Cambridge, 1926), 164–5.

Eddington A. S. , “On the relation between the masses and luminosities of the stars”, Monthly notices of the Royal Astronomical Society, lxxxiv (1924), 308–22, p. 322.

Eddington , op. cit. (ref. 53), 322.

As will be discussed in a subsequent paper, when Eddington first wrote to Walter Adams in January 1924 about the possibility of measuring the gravitational redshift of Sirius B he assumed a temperature of 10,000 K, a value appropriate to an ‘A’ star (see Douglas A. Vibert , The life of Arthur Stanley Eddington (London, 1957), 75). Later, in his correspondence with Adams, Eddington inexplicably adopts an ‘F0’ spectral type and a correspondingly lower temperature for Sirius B. The modern value for the temperature of Sirius B is 25,000 K.

Eddington A. S. , The internal constitution of the stars (Cambridge, 1926), 170:

I do not see how a star which has once got itself in to this compressed condition is ever going to get out of it. So far as we know, the close packing of matter is only possible so long as the temperature is great enough to ionise the material. When the star cools down and regains the normal density ordinarily associated with solids, it must expand and do work against gravity. The star will need energy in order to cool. … We can scarcely credit the star with sufficient foresight to retain more than 90 per cent. in reserve for the difficulty awaiting it. It would seem that the star will be in an awkward predicament when its supply of sub-atomic energy ultimately fails. Imagine a body continually losing heat but with insufficient energy to grow cold!

Fowler R. H. , “On dense matter”, Monthly notices of the Royal Astronomical Society, lxxxvii (1924), 114–22.

Nauenberg Michael , “Edmund C. Stoner and the discovery of the maximum mass of white dwarfs”, Journal for the history of astronomy, xxxix (2008), 297–312.

For opposing discussions of the measurement of the gravitational redshift see: Hetherington N. S. , “Sirius B and the gravitational redshift: An historical review”, Quarterly journal of the Royal Astronomical Society , xxi (1980), 246–52, and Greenstein J. L. Oke J. B. Shipman H. L. , “On the redshift of Sirius B”, Quarterly journal of the Royal Astronomical Society, xxvi (1985), 1985–88.