An epoxy-coated flux collector for stellar seismology

Most of what we know about the Universe has been gleaned from the study of stars, and a major achievement of 20th-century science was to understand how stars work and their lifecycles from birth to death. ‘Stars’ describes this lifecycle beginning with star formation when a cloud of interstellar gas suffers a runaway of its central density. It then considers nuclear fusion, key stellar masses, and life after the main sequence when the star burns its core helium. The surfaces of stars are described along with stellar coronae and exploding stars—both core-collapse and deflagration supernovae. Finally, globular star clusters, solar neutrinos, stellar seismology, and binary stars are discussed.

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The Whole Earth Telescope: An International Adventure in Asteroseismology

International Astronomical Union Colloquium ◽

10.1017/s0252921100078532 ◽

2001 ◽

Vol 183 ◽

pp. 3-12

Author(s):

Steven D. Kawaler

Keyword(s):

Time Series ◽

Global Networks ◽

Pulsating Stars ◽

New Science ◽

Delta Scuti ◽

Stellar Seismology ◽

Ap Stars ◽

Scuti Stars ◽

Whole Earth

AbstractToday, we are beginning to probe the interior of stars through the new science of stellar seismology. Certain stars, ranging from our own Sun to white dwarfs, undergo natural vibrations that can be detected with sensitive time-series photometry and/or spectroscopy. Since the signal we seek is an unbroken time-series to allow determination of the vibration frequencies, data from a single-site is usually incapable of uniquely identifying the pulsation modes, no matter how large the telescope being used. In many cases, the observational goals can be achieved using small-ish telescopes in well-coordinated global networks. Here, I briefly describe the work of one such international network of observatories and scientists known as the Whole Earth Telescope (WET). With the WET, we have sounded out the interiors of a large number of nonradially pulsating stars. Over the past 14 years, WET has observed dozens of stars in 20 separate observing campaigns. Our team has wide span of interests, and has observed several other classes of objects such as delta Scuti stars, CV stars, pulsating sdB stars, and rapidly oscillating Ap stars.

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E.V.R.I.S. on Board Mars 94: The First Space Experiment Devoted to Stellar Seismology

International Astronomical Union Colloquium ◽

10.1017/s0252921100018820 ◽

1993 ◽

Vol 137 ◽

pp. 758-760

Author(s):

A. Baglin ◽

W. Weissg ◽

G. Bisnovatyi-Kogan

Keyword(s):

Space Experiment ◽

Stellar Seismology ◽

Exploratory Mission

AbstractThe EVRIS experiment is an exploratory mission devoted to stellar seismology. It will observe approximately ten bright stars, for 20 days each, during the cruise of the Russian “MARS 94” mission. The photometer will be able to detect amplitudes of modes as small as a few 10−6 magnitude.

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Near Continuous Photometry with the Whole Earth Telescope (WET)

Open Astronomy ◽

10.1515/astro-2017-0065 ◽

2003 ◽

Vol 12 (4) ◽

Author(s):

J. E. Solheim

Keyword(s):

World Wide ◽

Theoretical Models ◽

Variable Stars ◽

Theoretical Interpretation ◽

Periodic Oscillations ◽

University Of Texas ◽

Scientific Goal ◽

Stellar Seismology ◽

Astronomical Instrument ◽

Whole Earth

AbstractThe Whole Earth Telescope (WET) saw first light in 1988. It was invented by scientists from the Astronomy Department, University of Texas at Austin. The idea was to generate a world-wide network of cooperating astronomical observatories to obtain uninterrupted time-series measurements of some variable stars. The technological goal was to resolve the multi-periodic oscillations in these objects into their individual components; the scientific goal was to construct accurate theoretical models of the target objects, constrained by their observed behavior, from which fundamental astrophysical parameters could be derived. This approach has been extremely successful, and has placed stellar seismology at the forefront of stellar astrophysics. The network is run as a single astronomical instrument with many operators, and the collaboration includes scientists from all continents on our planet, taking part in the observations, data reduction, analysis and theoretical interpretation. The expertise of Lithuanian astronomers in photometry, and their access to the observing station Mt. Maidanak in Uzbekistan, has been important for the success of the network.

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Rapid Oscillations of CP2-Stars

International Astronomical Union Colloquium ◽

10.1017/s0252921100091569 ◽

1986 ◽

Vol 90 ◽

pp. 219-231

Author(s):

Werner W. Weiss

Keyword(s):

Frequency Spectrum ◽

Sufficient Data ◽

Reliable Analysis ◽

Stellar Seismology

With the announcement in 1978 (Kurtz, 1978) of short periodic photometric variations of HD 101065, the first member of a subgroup of CP2 stars was found. This gained attention due to the possibility of applying the methods of stellar seismology to late A to early F type stars. However, the extremely low photometric amplitude of these stars, which is typically few millimagnitudes in B, and the short periods, ranging from few minutes to about 15 minutes, make these stars difficult to discover and a considerable amount of telescope time is required to accumulate sufficient data for a reliable analysis of the frequency spectrum. As a consequence aliasing imposes serious problems. Synchronous observations from observatories well separated in longitude could overcome this dilemma, and have indeed proven to be sucessful (Kurtz and Seeman, 1983; Kurtz and Balona, 1984; Kurtz, Schneider and Weiss, 1985; Kurtz and Kreidl, 1985).

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Is Delta Scuti Star Seismology Possible?

International Astronomical Union Colloquium ◽

10.1017/s0252921100011799 ◽

1989 ◽

Vol 111 ◽

pp. 271-271

Author(s):

G. Kovacs

Keyword(s):

Sampling Rate ◽

Efficient Tool ◽

Scuti Star ◽

Delta Scuti Star ◽

Delta Scuti ◽

Stellar Seismology ◽

Ap Stars ◽

Scuti Stars ◽

Δ Scuti Stars ◽

Nonradial Pulsation

AbstractThe direct fit of theoretical pulsation frequencies to the observations (i.e. stellar seismology) proved to be a very efficient tool in the study of solar oscillations. In the case of other multiperiodic variables, like δ Scuti stars, Ap stars and white dwarfs the method suffers from the disturbing abundance of possible nonradial modes. Colour and/or radial velocity (or line profile) measurements can narrow down the number of possibilities, but these kinds of data are not often available with the desired accuracy and sampling rate. Since pulsational frequencies are the most readily and accurately computed and measured quantities of pulsation, we address the question of the accurate fit of the nonradial pulsation frequencies to the observations in the case of δ Scuti stars.

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Evris

International Astronomical Union Colloquium ◽

10.1017/s0252921100026518 ◽

1994 ◽

Vol 147 ◽

pp. 512-516

Author(s):

A. Baglin

Keyword(s):

Stellar Seismology ◽

Exploratory Mission

AbstractThe EVRIS experiment is an exploratory mission devoted to stellar seismology. It will observe approximately ten bright stars, for 20 days each, during the cruise of the Russian MARS 94 mission. The photometer will be able to detect amplitudes of modes as small as a few 10−6 magnitude. Some objects of masses lower than the solar one will allow to test the thermodynamics.

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