Secondary Spectrum Of Hydrogen Research Articles

The spectroscopic triple system Eta Orionis A

view Abstract Citations (10) References (20) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS The spectroscopic triple system eta Orionis A. Zizka, E. R. ; Beardsley, W. R. Abstract Radial velocity measures from plates made at five observatories are combined in a reinvestigation of the spectroscopic triple system Eta Ori A, from which short-period and long-period orbits of 7.989 268 days and 9.219 years, respectively, are derived. The spectrum is found to be double-lined, and a weakening of the secondary hydrogen spectrum is seen when redshifted. It is suggested that a large external error for the secondary orbit may offer evidence for rapid pulsation. Minimum masses for the triple system are 14.9, 12.3, and 13.6 solar masses, respectively, for the primary, secondary and, assuming coplanarity, third star. Publication: The Astronomical Journal Pub Date: December 1981 DOI: 10.1086/113077 Bibcode: 1981AJ.....86.1944Z Keywords: A Stars; B Stars; Radial Velocity; Stellar Motions; Stellar Spectra; Curve Fitting; Orbital Elements; Orion Constellation; Red Shift; Astronomy; Periods:Spectroscopic Binaries; Radial Velocities:Spectroscopic Binaries; Spectroscopic Binaries:Triple Stars full text sources ADS | data products SIMBAD (1)

Interferometer Wave-Lengths of Certain Lines in the Secondary Spectrum of Hydrogen

Interferometer Wave-Lengths of Certain Lines in the Secondary Spectrum of Hydrogen

A Note on the Stark-effect of secondary Spectrum of Hydrogen

A Note on the Stark-effect of secondary Spectrum of Hydrogen

Structure of H of Hydrogen

THE structure of the lines of the Balmer spectrum of hydrogen was investigated in this laboratory some years ago. Recently we have attacked the problem again, using two Lummer plates, not crossed as in the investigations of Kent, Taylor and Pearson1, but dispersing in the same plane. With this arrangement, the microphotometer curves of the resultant pattern reveal clearly four distinct components of Hα with intensities and positions roughly as given by theory. There are no ghosts in the Lummer plates and the interference of lines of the secondary spectrum of hydrogen has been eliminated.

Interferometer Wave-Lengths in the Secondary Spectrum of Hydrogen

Interferometer Wave-Lengths in the Secondary Spectrum of Hydrogen

VII.—The Mathematical Representation of the Energy Levels of the Secondary Spectrum of Hydrogen.—III

In a recent communication (Sandeman, 1935) some problems arising out of the attempt to obtain accurate values of the molecular constants in applying the results of the wave mechanics to the secondary spectrum of hydrogen have been discussed, and an analysis of the two molecular states Is2s3∑ and Is2p1∑ on the basis of Dunham's (1932) solution of the Schrödinger equation for the molecular rotating vibrator has been carried out and compared with the previous calculations of Richardson and Davidson and Richardson and Das. In the present paper an analysis of the ground state (IsIs1∑) of the hydrogen molecule—made possible by recent advances in the measurement and allocation of the band lines —has been attempted. For comparison a similar analysis of the ground state of the molecular ion H2+(Is2∑) is included. Although the spectrum of the molecular ion is not known, the fact that the variables in the Schrödinger equation are separable enables an analysis to be built up from theoretical considerations.

V.—The Mathematical Representation of the Energy Levels of the Secondary Spectrum of Hydrogen.—II.

In a recent paper (Sandeman, 1933) the question of the mathematical representation of the energy levels of the hydrogen molecule by methods based on the old mechanics has been considered. In view of the fact that the wave mechanics has supplanted the older theory, the further application of newer methods to this spectrum is desirable. Richardson and Davidson (1929 b, p. 45) worked out the potential energy function U(ξ) (ξ is denned on p. 51) for the state IsσЗpπ3Π on the old quantum mechanics and on the wave mechanics with the following results: U(ξ) = 5·50ξ2(1 – 1·556ξ + 1·58ξ2 – 1·56ξ3) volts on the old quantum mechanics and U(ξ) = 5·71ξ2(1 – 1·55ξ + 1·58ξ2 – 1·59ξ3) volts on the wave mechanics. They also (loc. cit., pp. 30 and 31) gave the U(ξ)'s for the states Isσ2pσ1∑, Isσ2sσ3∑, and IsσЗdπ1Πb, and on p. 45 they gave the formulæ, based on Fues's (1926) results, for transcribing the old quantum mechanics into the wave mechanics series. Richardson and Das (1929, pt. ii) gave similar data for the state IsσЗpσ3∑.

The λ 4502 Band of NH

From a consideration of the possible electron configurations in the NH molecule Mulliken predicted a stable 1 Ʃ + state lying about 1·9 volts above the ground state 3 Ʃ - . It is therefore to be anticipated that tran­sitions to this level from the known 1 II level will be observed simultaneously with the known 1 II → 1 ∆ transition. Mulliken estimated the shape of the potential energy curve for the 1 Ʃ + state; this corresponds to the existence of a 1 II → 1 Ʃ + band degraded to the red and lying in the neighbourhood of λ 4100. The plates from which the 1 II → 1 ∆ band was analysed were therefore examined for evidence of the 1 II → 1 Ʃ + band. After eliminating the numerous lines of the intense secondary spectrum of hydrogen which occurs in this region there remained only five unidentified lines. These are now seen to be the most intense lines of the Q branch of the λ 4502 band. The plates record the spectrum of a heavy current discharge in hydrogen containing a trace of nitrogen.

The stark effect in the molecular spectrum of hydrogen

In considerations of the effect of electric fields on band spectra one finds attention focussed on the secondary spectrum of hydrogen, which alone shows appreciable Stark effect. Following some rather limited observations by early writers, Kiuti has given a more extensive analysis under low dispersion but high fields. This has remained the standard reference in all but the blue and violet regions where MacDonald has given better resolutions, and has succeeded in correlating some of the observed patterns with theory. The rapid advances made by Richardson and others in the classification of the normal H 2 spectrum together with the recent publication by MacDonald of a complete theory for the Stark effect in H 2 have increased enormously the interest attached to further experimental information. In addition, the Stark patterns have been shown to depend upon the rotational quantum numbers, so that the possibility of obtaining new information which may be of assistance in the analysis of the spectrum must not be overlooked.

XXIII.—The Mathematical Representation of the Energy Levels of the Secondary Spectrum of Hydrogen

I. Term Representation of Diatomic Spectra.The mathematical symbolism now employed by the practical spectroscopist for the representation of the energy term F(J) of the diatomic molecule has recently been fixed with precision as a result of the labours of Mulliken and others. The formula employed to represent the rotational term iswhere J is the quantum number and Be, De, … are constants. BeJ(J + 1) is the kinetic energy, expressed in wave-numbers, which the molecule would have if it were a rigid rotator; and the remaining small correction terms in powers of J(J + 1) correspond to the expansion of the rotator under centrifugal force.

XVI.—Pressure Effects in the Secondary Spectrum of Hydrogen

This paper is an account of an experimental investigation which was made on the behaviour of the secondary spectrum of hydrogen as affected by the pressure of the luminous gas. It was conjectured that the classification of the lines of the spectrum according to their behaviour in this respect should be of value in the problem of accounting for their origin in terms of the quantum theory. There can be no doubt, on the evidence given below, that the method is of some importance. For this reason it has been considered worth while bringing the results already obtained to the notice of workers in this field by publishing tables of intensities.

LXVI.New bands in the Secondary Spectrum of Hydrogen

(1931). LXVI. New bands in the Secondary Spectrum of Hydrogen. The London, Edinburgh, and Dublin Philosophical Magazine and Journal of Science: Vol. 11, No. 71, pp. 761-786.

XCIX.New bands in the secondary spectrum of hydrogen. Part III

XCIX.<i>New bands in the secondary spectrum of hydrogen. Part III</i>

EVIDENCE FOR THE EXISTENCE OF THE SECONDARY SPECTRUM OF HYDROGEN IN THE SUN-SPOT SPECTRUM

EVIDENCE FOR THE EXISTENCE OF THE SECONDARY SPECTRUM OF HYDROGEN IN THE SUN-SPOT SPECTRUM

V.New bands in the secondary spectrum of hydrogen.— Part II

V.<i>New bands in the secondary spectrum of hydrogen</i>.— Part II

Some additional lines in the secondary spectrum of hydrogen

The author had measured about 1000 lines in the hydrogen spectrum between λ 4735 and λ 4018 when the similar work of Gale, Monk and Lee was published in 1928. The author's list included, however, about 280 lines not given in the prior list, and these are published in the present paper.

Some Peculiar Hydrogen Bands

Photographs of the secondary spectrum of hydrogen as excited by an electrodeless ring discharge were taken at various pressures in the range 0.08 to 0.001 mm. A number of lines were found to be much more intense at low pressures than at high pressures. The more prominent of these were arranged into a band with $P$, $Q$ and $R$ branches corresponding to a $\ensuremath{\Pi}\ensuremath{\rightarrow}\ensuremath{\Sigma}$ type electronic transition; this band was assumed to be a 0\ensuremath{\rightarrow}0 band. The majority of the remaining lines were tentatively arranged into three more bands which appeared to be the 1\ensuremath{\rightarrow}0, 0\ensuremath{\rightarrow}1 and 1\ensuremath{\rightarrow}1 bands corresponding to the same $\ensuremath{\Pi}\ensuremath{\rightarrow}\ensuremath{\Sigma}$ electronic transition. The values of the moments of inertia are ${{I}_{0}}^{\ensuremath{'}}=3.8\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}40}$, ${{I}_{1}}^{\ensuremath{'}}=5.5\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}40}$, ${{I}_{0}}^{\ensuremath{'}\ensuremath{'}}=2.0\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}40}$ and ${{I}_{1}}^{\ensuremath{'}\ensuremath{'}}=2.3\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}40}$. The corresponding values of the nuclear separation "$r$" are ${{r}_{0}}^{\ensuremath{'}}=2.14\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}8}$ cm, ${{r}_{1}}^{\ensuremath{'}}=2.57\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}8}$ cm, ${{r}_{0}}^{\ensuremath{'}\ensuremath{'}}=1.55\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}8}$ cm, and ${{r}_{1}}^{\ensuremath{'}\ensuremath{'}}=1.66\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}8}$ cm. The emitter of these bands is thought to be either ${\mathrm{H}}_{2}^{+}$ or doubly excited hydrogen.

Stark-effect in a violet region of the secondary spectrum of hydrogen

Simultaneously with his examination of the effect of electric fields on the Balmer series in hydrogen, Stark observed some general characteristics of the secondary spectrum. In the latter he noted the comparatively small displacements, which were proportional to the square of the field; the lack of symmetry in the splitting; and an apparently general irregularity in the effect. The work was extended by Takamine and Yoshida, Nitta, and Takamine and Kokubu, whose observations included effects on a total of 54 lines. Kiuti has recently used much higher fields in a far more extensive investigation embracing effects throughout the entire visible spectrum. He found regularities in two groups, each composed of three lines. The members of each group were split in like manner and the original lines were accompanied by “satellites” which were displaced toward the violet without any observed splitting. Within each Fulcher band the displacements were, as a rule, alternately large and small. The bands were further marked by a great increase in intensity for high fields.

The spectrum of H 2 : The bands analogous to the ortho-helium line spectrum

In “Structure in the Secondary Spectrum of Hydrogen—Part V” it was shown that there existed in this spectrum a very extensive series of bands whose null lines were related by a Rydberg-Ritz formula and whose electronic terms were very close to those of the principal series of the so-called helium doublets (orthohelium) showing that the spectrum of H 2 is closely analogous to the line spectrum of He. [It is also very similar to the spectrum of He 2 .] This similarity has since been confirmed by the discovery and investigation of the absorption spectrum of unexcited H 2 by Dieke and Hopfield from which it appears that none of the final 2 states of that spectrum, in which the transitions are from 1 1 S to an upper 2 state, are the same as the final 2 states of these emission bands. On the other hand their 2 1 S states do agree, to the accuracy of the ultra-violet data, with the final states of an entirely different set of band systems in the visible spectrum which are therefore analogous to the parhelium spectrum. The conclusions of Part V were drawn from a study of the Q branches of the bands only. In an earlier paper (Part IV) a preliminary investigation of some of the accompanying P and R branches had been made by a study of the intensity distribution in these bands in the first type discharge. This method enables the lowest rotational quantum number lines of the bands to be picked out with some certainty but the upper lines cannot in general be recognised on account of the faintness of the discharges. These can only be located by finding lines which satisfy some reasonable combination principle. An attempt made by one of us (O. W. R.) in collaboration with Dr. D. B. Deodhar to extend the classification of Part IV led us to the conclusion that the existing data were inadequate, mainly owing to insufficient resolution, to enable a satisfactory decision to be formed as to whether the details of Part IV were correct or ought to be modified.

Intensity measurements in the secondary spectrum of hydrogen.—II

In an earlier publication Prof. Ornstein and the writers gave intensity measurements of a part (4500-4900 A.) of the secondary spectrum of hydrogen. At Prof. Ornstein’s instigation the measurements were later extended to other parts of this spectrum, as such measurements may be valuable for the theoretical investigations of the secondary spectrum and the classification of the lines, about which much uncertainty exists as yet. Only the results of the measurements are given in this paper: the theoretical discussion will be submitted later. For particulars of the experimental methods, readers are referred to the initial publication.