New Double Periodic Variable stars in the ASAS-SN Catalog

D. The Line Spectrum of Pulsating Variable Stars

Symposium - International Astronomical Union ◽

10.1017/s0074180900019021 ◽

1967 ◽

Vol 28 ◽

pp. 207-244

Author(s):

R. P. Kraft

Keyword(s):

Variable Stars ◽

The Other ◽

Line Spectrum ◽

Afternoon Session ◽

Empirical Information ◽

Pulsating Variable Stars ◽

Almost Continuous ◽

Informal Approach

(Ed. note:Encouraged by the success of the more informal approach in Christy's presentation, we tried an even more extreme experiment in this session, I-D. In essence, Kraft held the floor continuously all morning, and for the hour and a half afternoon session, serving as a combined Summary-Introductory speaker and a marathon-moderator of a running discussion on the line spectrum of cepheids. There was almost continuous interruption of his presentation; and most points raised from the floor were followed through in detail, no matter how digressive to the main presentation. This approach turned out to be much too extreme. It is wearing on the speaker, and the other members of the symposium feel more like an audience and less like participants in a dissective discussion. Because Kraft presented a compendious collection of empirical information, and, based on it, an exceedingly novel series of suggestions on the cepheid problem, these defects were probably aggravated by the first and alleviated by the second. I am much indebted to Kraft for working with me on a preliminary editing, to try to delete the side-excursions and to retain coherence about the main points. As usual, however, all responsibility for defects in final editing is wholly my own.)

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C. The Continuous Spectrum of Pulsating Variable Stars

Symposium - International Astronomical Union ◽

10.1017/s007418090001901x ◽

1967 ◽

Vol 28 ◽

pp. 177-206

Author(s):

J. B. Oke ◽

C. A. Whitney

Keyword(s):

Continuous Spectrum ◽

Variable Stars ◽

Velocity Fields ◽

The Other ◽

Line Spectrum ◽

Direct Information ◽

Thermodynamic Structure ◽

Diagnostic Interpretation ◽

Pulsating Variable Stars ◽

The Continuum

Pecker:The topic to be considered today is the continuous spectrum of certain stars, whose variability we attribute to a pulsation of some part of their structure. Obviously, this continuous spectrum provides a test of the pulsation theory to the extent that the continuum is completely and accurately observed and that we can analyse it to infer the structure of the star producing it. The continuum is one of the two possible spectral observations; the other is the line spectrum. It is obvious that from studies of the continuum alone, we obtain no direct information on the velocity fields in the star. We obtain information only on the thermodynamic structure of the photospheric layers of these stars–the photospheric layers being defined as those from which the observed continuum directly arises. So the problems arising in a study of the continuum are of two general kinds: completeness of observation, and adequacy of diagnostic interpretation. I will make a few comments on these, then turn the meeting over to Oke and Whitney.

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Galactic orbits of stars

Symposium - International Astronomical Union ◽

10.1017/s0074180900105340 ◽

1966 ◽

Vol 25 ◽

pp. 93-97

Author(s):

Richard Woolley

Keyword(s):

Globular Cluster ◽

Potential Field ◽

High Velocity ◽

Velocity Vector ◽

Variable Stars ◽

The Sun ◽

Proper Motions ◽

Rr Lyrae ◽

The Galaxy

It is now possible to determine proper motions of high-velocity objects in such a way as to obtain with some accuracy the velocity vector relevant to the Sun. If a potential field of the Galaxy is assumed, one can compute an actual orbit. A determination of the velocity of the globular clusterωCentauri has recently been completed at Greenwich, and it is found that the orbit is strongly retrograde in the Galaxy. Similar calculations may be made, though with less certainty, in the case of RR Lyrae variable stars.

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Surface Brightness Scale of Galactic Cepheids

Symposium - International Astronomical Union ◽

10.1017/s0074180900118996 ◽

1999 ◽

Vol 190 ◽

pp. 561-562

Author(s):

G. P. Di Benedetto

Keyword(s):

Surface Brightness ◽

Variable Stars ◽

Giant Stars ◽

Near Ir

An accurate calibration of the surface brightness scaleSVas a function of the near-IR color (V–K) has been recently measured for non-variable Galactic dwarf and giant stars. It can be shown that this correlation can be applied to theSVscale of Galactic Cepheid variable stars, which are of major cosmological interest.

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