Browsing by Author "Matthews, J. M."

Browsing by Author "Matthews, J. M."

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    Asteroseismic analysis of the pre-main-sequence stars in NGC 2264 
    Guenther, David B.; Kallinger, T.; Zwintz, K.; Weiss, W. W.; Kuschnig, R.; Casey, M. P.; Matthews, J. M.; Moffat, A. F. J.; Rucinski, S. M.; Sasselov, D.; Walker, G. A. H. (American Astronomical Society, 2009-10-20)
    NGC 2264 is a young open cluster lying above the Galactic plane in which six variable stars have previously been identified as possible pre-main-sequence (PMS) pulsators. Their oscillation spectra are relatively sparse ...

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    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 ...

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    [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 ...

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    Detection of long-period variations in the subdwarf B star PG 0101+039 on the basis of photometry from the MOST satellite 
    Randall, S. K.; Matthews, J. M.; Fontaine, G.; Rowe, J.; Kuschnig, R.; Green, E. M.; Brassard, P.; Chayer, P.; Guenther, David B.; Moffat, A. F. J. (American Astronomical Society, 2005-11-01)
    We report the detection of three discrete pulsation frequencies in the long-period variable subdwarf B star PG 0101+039 on the basis of ~400 hr of MOST wide-band photometry. The periodicities uncovered lie at 7235, 5227, ...

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    Detection of solar-like oscillations in the red giant star [Epsilon] Ophiuchi by MOST spacebased photometry 
    Barban, C.; Matthews, J. M.; De Ridder, J.; Baudin, F.; Kuschnig, R.; Mazumdar, A.; Samadi, R.; Guenther, David B.; Moffat, A. F. J.; Rucinski, S. M. (EDP Sciences, 2007-06)
    Context. Solar-like oscillations have been discovered in a few red giants, including e Oph, through spectroscopy. Acoustic modes around 60 μHz were clearly seen in this star, but daily aliasing of the groundbased data ...

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    Discovery of the new slowly pulsating B star HD 163830 (B5 II/III) from MOST space-based photometry 
    Guenther, David B.; Aerts, C.; De Cat, P.; Kuschnig, R.; Matthews, J. M.; Moffat, A. F. J.; Rucinski, S. M.; Sasselov, D.; Walker, G. A. H.; Weiss, W. W. (American Astronomical SocietyIOP Publishing, 2006-05-10)
    We report the discovery of a new slowly pulsating B star, with the largest number of detected frequencies to date by more than a factor of 3, based on 37 days of MOST (Microvariability and Oscillations of STars) satellite ...

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    HR 5907: discovery of the most rapidly rotating magnetic early B-type star by the MiMeS collaboration 
    Guenther, David B.; Grunhut, J. H.; Rivinius, Th.; Wade, G. A.; Townsend, R. H. D.; Marcolino, W. L. F.; Bohlender, D. A.; Szeifert, Th.; Petit, V.; Matthews, J. M. (Oxford University Press, 2012-01)
    We report the discovery and analysis of a very strong magnetic field in the rapidly rotating early B-type star HR 5907, based on observations obtained as part of the Magnetism in Massive Stars (MiMeS) project. We infer a ...

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    MOST detects g- and p-modes in the B supergiant HD 163899 (B2 Ib/II ) 
    Saio, H.; Kuschnig, R.; Gautschy, A.; Cameron, Chris; Walker, G. A. H.; Matthews, J. M.; Guenther, David B.; Moffat, A. F .J.; Rucinski, S. M.; Sasselov, D. (American Astronomical Society, 2006-10-20)
    The Microvariability and Oscillations of Stars (MOST ) satellite observed the B supergiant HD 163899 (B2 Ib/ II ) for 37 days as a guide star and detected 48 frequencies [less than tilde] 2.8 cycles day [superscript minus ...

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    MOST detects SPBe pulsations in HD 127756 and HD 217543: asteroseismic rotation rates independent of v sin i[superscript 1] 
    Guenther, David B.; Cameron, Chris; Saio, H.; Kuschnig, R.; Walker, G. A. H.; Matthews, J. M.; Moffat, A. F. J.; Rucinski, S. M.; Sasselov, D.; Weiss, W. W. (American Astronomical Society, 2008-09)
    The MOST (Microvariability and Oscillations of Stars ) satellite has discovered SPBe (slowly pulsating Be) oscillations in the stars HD 127756 (B1/B2 Vne) and HD 217543 (B3 Vpe). For HD 127756, 30 significant frequencies ...

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    MOST finds no coherent oscillations in the hot carbon-rich Wolf-Rayet star HD 165763 (WR 111) 
    Guenther, David B.; Moffat, A. F. J.; Marchenko, S. V.; Zhilyaev, B. E.; Rowe, J. F.; Muntean, V.; Chene, A.-N.; Matthews, J. M.; Kuschnig, R.; Rucinski, S. M. (American Astronomical SocietyIOP Publishing, 2008-05-20)
    We have photometrically monitored the V = 8 mag Galactic Population I WC5 star WR 111 for 3 weeks nonstop using the MOST microsatellite. Each of the ∼27,000 data points has a precision of ∼3 mmag. We find no coherent Fourier ...

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    MOST light-curve analysis of the [gamma] Doradus pulsator HR8799, showing resonances and amplitude variations 
    Sodor, A.; Chene, A. -N.; De Cat, P.; Bognar, Zs.; Wright, D. J.; Marois, C.; Walker, G. A. H.; Matthews, J. M.; Kallinger, T.; Rowe, J. F.; Guenther, David B. (EDP Sciences, 2014-08)
    Context. The central star of the HR 8799 system is a γ Doradus-type pulsator. The system harbours four planetary-mass companions detected by direct imaging, and is a good solar system analogue. The masses of the ...

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    MOST observations of [sigma] Ori E: challenging the centrifugal breakout narrative 
    Guenther, David B.; Townsend, R. H. D.; Rivinius, Th.; Rowe, J. F.; Moffat, A. F. J.; Matthews, J. M.; Bohlender, D.; Neiner, C.; Telting, J. H.; Kallinger, T. (American Astronomical SocietyIOP Science, 2013-05-20)
    We present results from three weeks’ photometric monitoring of the magnetic helium-strong star [sigma] Ori E using the Microvariability and Oscillations of Stars microsatellite. The star’s light curve is dominated by ...

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    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 ...

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    MOST observations of the roAp stars HD 9289, HD 99563, and HD 134214 
    Guenther, David B.; Gruberbauer, Michael; Huber, D.; Kuschnig, R.; Weiss, W. W.; Matthews, J. M.; Moffat, A. F. J.; Rowe, J. F.; Rucinski, S. M.; Sasselov, D. (EDP Sciences, 2011-06)
    We report on the analysis of high-precision space-based photometry of the roAp (rapidly oscillating Ap) stars HD 9289, HD 99563, and HD 134214. All three stars were observed by the MOST satellite for more than 25 days, ...

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    MOST photometry and modeling of the rapidly oscillating (roAp) star [gamma] Equulei 
    Guenther, David B.; Gruberbauer, Michael; Saio, H.; Huber, D.; Kallinger, T.; Weiss, W. W.; Kuschnig, R.; Matthews, J. M.; Moffat, A. F. J.; Rucinski, S. (EDP Sciences, 2008)
    Aims. Despite photometry and spectroscopy of its oscillations obtained over the past 25 years, the pulsation frequency spectrum of the rapidly oscillating Ap (roAp) star [gamma] Equ has remained poorly understood. Better ...

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    MOST photometry of the roAp star 10 Aquilae 
    Guenther, David B.; Huber, D.; Saio, H.; Gruberbauer, Michael; Weiss, W. W.; Rowe, J. F.; Hareter, M.; Kallinger, T.; Reegen, P.; Matthews, J. M. (EDP Sciences, 2008-05)
    Context. We present 31.2 days of nearly continuous MOST photometry of the rapidly oscillating Ap star 10 Aql. Aims. The goal was to provide an unambiguous frequency identification for this little studied star, as well as ...

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    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 ...

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    New slowly pulsating B stars in the field of the young open cluster NGC 2244 discovered by the MOST photometric satellite 
    Guenther, David B.; Gruber, D.; Saio, H.; Kuschnig, R.; Fossati, L.; Handler, G.; Zwintz, K.; Weiss, W. W.; Matthews, J. M.; Moffat, A. F. J. (Oxford University Press, 2012-02)
    During two weeks of nearly continuous optical photometry of the young open cluster NGC 2244 obtained by the Microvariability and Oscillations of STars (MOST) satellite,we discovered two new slowly pulsating B (SPB) stars, ...

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    Nonradial p-modes in the G9.5 giant [epsilon] Ophiuchi? Pulsation model fits to MOST photometry 
    Kallinger, T.; Guenther, David B.; Matthews, J. M.; Weiss, W. W.; Huber, D.; Kuschnig, R.; Moffat, A. F. J.; Rucinski, S. M.; Sasselov, D. (European Southern ObservatoryEDP Sciences, 2008)
    The G9.5 giant [epsilon] Oph shows evidence of radial p-mode pulsations in both radial velocity and luminosity. We re-examine the observed frequencies in the photometry and radial velocities and find a best model fit to ...

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    Observations of Cepheids with the MOST satellite: contrast between pulsation modes 
    Evans, N. R.; Szabo, R.; Derekas, A.; Szabados, L.; Cameron, C.; Matthews, J. M.; Sasselov, D.; Kuschnig, R.; Rowe, J. F.; Guenther, David B. (Oxford University Press, 2015-02)
    The quantity and quality of satellite photometric data strings is revealing details in Cepheid variation at very low levels. Specifically, we observed a Cepheid pulsating in the fundamental mode and one pulsating in the ...