Browsing Articles by Subject "Variable stars"

Now showing items 1-17 of 17

Asteroseismology of hybrid pulsators made possible: simultaneous MOST space photometry and ground-based spectroscopy of [gamma] PEG

Handler, G.; Matthews, J. M.; Eaton, J. A.; Daszynska-Daszkiewicz, J.; Kuschnig, R.; Lehmann, H.; Rodriguez, E.; Pamyatnykh, A. A.; Zdravkov, T.; Lenz, P.; Guenther, David B. (American Astronomical Society, 2009-06-10)

We have acquired simultaneous high-precision space photometry and radial velocities of the bright hybrid [beta] Cep/Slowly Pulsating B pulsator [gamma] Peg. Frequency analyses reveal the presence of six gravity (g) modes ...
[delta] Ceti is not monoperiodic: seismic modeling of a [beta] Cephei star from MOST space-based photometry

Guenther, David B.; Aerts, C.; Marchenko, S. V.; Matthews, J. M.; Kuschnig, R.; Moffat, A. F. J.; Rucinski, S. M.; Sasselov, D.; Walker, G. A. H.; Weiss, W. W. (American Astronomical Society, 2006-05)

The [beta] Cephei star [delta] Ceti was considered one of the few monoperiodic variables in its class. Despite (or perhaps because of) its apparently simple oscillation spectrum, it has been challenging and controversial ...
A digitally synthesized classroom variable star

DuPuy, David L. (American Association of Physics Teachers, 1978-11)

There is no abstract available for this article.
The Kepler characterization of the variability among A- and F-type stars

Uytterhoeven, K.; Moya, A.; Grigahcene, A.; Guzik, J. A.; Gutierrez-Soto, J.; Smalley, B.; Handler, G.; Balona, L. A.; Niemczura, E.; Fox Machado, L.; Gruberbauer, Michael (EDP Sciences, 2011-10)

Context. The Kepler spacecraft is providing time series of photometric data with micromagnitude precision for hundreds of A-F type stars. Aims. We present a first general characterization of the pulsational behaviour of ...
Kepler observations of rapidly oscillating Ap, [delta] Scuti and [gamma] Doradus pulsations in Ap stars

Balona, L. A.; Cunha, M. S.; Kurtz, D. W.; Brandao, I. M.; Gruberbauer, Michael; Saio, H.; Ostensen, R.; Elkin, V. G.; Borucki, W. J.; Christensen-Dalsgaard, J. (Wiley-Blackwell, 2011-01-01)

Observations of the A5p star KIC 8677585 obtained during the Kepler 10-d commissioning run with 1-min time resolution show that it is a rapidly oscillating Ap (roAp) star with several frequencies with periods near 10 min. ...
Modeling convective core overshoot and diffusion in Procyon constrained by asteroseismic data

Guenther, David B.; Demarque, P.; Gruberbauer, Michael (IOP Publishing Limited, 2014-06-01)

We compare evolved stellar models, which match Procyon’s mass and position in the HR diagram, to current groundbased asteroseismic observations. Diffusion of helium and metals along with two conventional core overshoot ...
MOST observations of the Herbig Ae [delta]-Scuti star HD 34282

Guenther, David B.; Casey, M. P.; Zwintz, K.; Weiss, W. W.; Amado, P. J.; Diaz-Fraile, D.; Rodriguez, E.; Kuschnig, R.; Matthews, J. M.; Moffat, A. F. J. (Royal Astronomical SocietyOxford University Press, 2013-01)

Microvariability and Oscillations of STars observations and model analysis of the Herbig Ae star HD 34282 (V1366 Ori) reveal [delta] Scuti pulsations. 22 frequencies are observed, 10 of which confirm those previously ...
MOST photometry and DDO spectroscopy of the eclipsing (white dwarf + red dwarf) binary V471 Tau

Guenther, David B.; Kaminski, Krzysztof Z.; Rucinski, Slavek M.; Matthews, Jaymie M.; Kuschnig, Rainer; Rowe, Jason F.; Moffat, Anthony F. J.; Sasselov, Dimitar; Walker, Gordon A. H.; Weiss, Werner W. (American Astronomical Society, 2007-09)

The Hyades K2 V + WD system 471 Tau is a prototype post-common envelope system and a likely cataclysmic binary progenitor. We present 10 days of nearly continuous optical photometry by the MOST (Microvariability and ...
The nature of p-modes and granulation in Procyon: new MOST photometry and new Yale convection models

Guenther, David B.; Kallinger, T.; Gruberbauer, Michael; Huber, D.; Weiss, W. W.; Kuschnig, R.; Demarque, P.; Robinson, F.; Matthews, J. M.; Moffat, A. F. J. (American Astronomical Society, 2008-11)

We present new photometry of Procyon, obtained by MOST during a 38 day run in 2007, and frequency analyses of those data. The long time coverage and low point-to-point scatter of the light curve yield an average noise ...
Pulsation analysis of V 588 MON AND V 589 MON observed with the MOST AND CoRoT satellites

Zwintz, K.; Kallinger, T.; Guenther, David B.; Gruberbauer, Michael; Kuschnig, R.; Weiss, W. W.; Auvergne, M.; Jorda, L.; Favata, F.; Matthews, J.; Fischer, M. (American Astronomical SocietyIOP Publishing, 2011-03-01)

The two pulsating pre-main sequence (PMS) stars V 588 Mon and V 589 Mon were observed by CoRoT for 23.4 days in 2008 March during the Short Run SRa01 and in 2004 and 2006 by MOST for a total of ∼70 days. We present their ...
The pulsation mode and distance of the Cepheid FF Aquilae

Turner, David Gerald, 1945-; Kovtyukh, V. V.; Luck, R. E.; Berdnikov, L. N. (IOP Publishing Limited, 2013-07-20)

The determination of pulsation mode and distance for field Cepheids is a complicated problem best resolved by a luminosity estimate. For illustration a technique based on spectroscopic luminosity discrimination is applied ...
Radial stellar pulsation and three-dimensional convection. II. Two-dimensional convection in full amplitude radial pulsation

Deupree, Robert G. (Robert Gaston), 1946-; Geroux, Chris M. (American Astronomical SocietyIOP Science, 2013-07-10)

We have developed a three-dimensional radiation hydrodynamics code to simulate the interaction of convection and radial pulsation in classical variable stars. One key goal is the ability to carry these simulations to full ...
A search for OB associations near southern long-period Cepheids. V. AQ Puppis and V620 Puppis

Turner, David Gerald, 1945-; van den Bergh, S.; Younger, P. F.; Majaess, Daniel J.; Pedreros, M. H.; Berdnikov, L. N. (IOP Publishing Limited, 2012-12)

A photometric UBV survey is presented for 610 stars in a region surrounding the Cepheid AQ Puppis and centered southwest of the variable, based upon photoelectric measures for 14 stars and calibrated iris photometry of ...
Seismology of pre-main-sequence stars in NGC 6530

Guenther, David B.; Kallinger, T.; Zwintz, K.; Weiss, W. W.; Tanner, J. (American Astronomical Society, 2007-12)

Nonradial p-mode oscillation spectra, computed from a dense grid of pre-main-sequence models, are fit to observed oscillation spectra of several stars in the young cluster NGC 6530. The five stars we consider, all previously ...
Spectral and photometric analysis of the eclipsing binary [epsilon] Aurigae prior to and during the 2009–2011 eclipse

Chadima, P.; Harmanec, P.; Bennett, Philip Desmond, 1952-; Kloppenborg, B.; Stencel, R.; Yang, S.; Bozic, H.; Slechta, M.; Kotkova, L.; Wolf, M. (EDP Sciences, 2011-06)

A series of 353 red electronic spectra (from three observatories, mostly from 6300 to 6700 A) obtained between 1994 and 2010, and of 171 UBV photometric observations (from two observatories) of the 2010 eclipse, were ...
A stable quasi-periodic 4.18-d oscillation and mysterious occultations in the 2011 MOST light-curve of TW Hya

Siwak, Michal; Rucinski, Slavek M.; Matthews, Jaymie M.; Guenther, David B.; Kuschnig, Rainer; Moffat, Anthony F. J.; Rowe, Jason F.; Sasselov, Dimitar; Weiss, Werner W. (Oxford University Press, 2014-10-11)

We present an analysis of the 2011 photometric observations of TW Hya by the MOST satellite; this is the fourth continuous series of this type. The large-scale light variations are dominated by a strong, quasi-periodic ...
Stellar modelling of Spica, a high-mass spectroscopic binary with a [beta] Cep variable primary component

Tkachenko, A.; Matthews, J. M.; Aerts, C.; Pavlovski, K.; Papics, P. I.; Zwintz, K.; Cameron, C.; Walker, G. A. H.; Kuschnig, R.; Degroote, P.; Guenther, David B. (Oxford University Press, 2016-05-11)

Binary stars provide a valuable test of stellar structure and evolution, because the masses of the individual stellar components can be derived with high accuracy and in a model-independent way. In this work, we study ...