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Physical Sciences and Mathematics Commons

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2011

Series

Florida Institute of Technology

White Dwarfs

Articles 1 - 3 of 3

Full-Text Articles in Physical Sciences and Mathematics

V344 Lyrae: A Touchstone Su Uma Cataclysmic Variable In The Kepler Field, Matt A. Wood, Martin D. Still, Steve B. Howell, John K. Cannizzo, Alan P. Smale Nov 2011

V344 Lyrae: A Touchstone Su Uma Cataclysmic Variable In The Kepler Field, Matt A. Wood, Martin D. Still, Steve B. Howell, John K. Cannizzo, Alan P. Smale

Aerospace, Physics, and Space Science Faculty Publications

We report on the analysis of the Kepler short-cadence (SC) light curve of V344 Lyr obtained during 2009 June 20 through 2010 March 19 (Q2-Q4). The system is an SU UMa star showing dwarf nova (DN) outbursts and superoutbursts, and promises to be a touchstone for CV studies for the foreseeable future. The system displays both positive and negative superhumps with periods of 2.20 and 2.06 hr, respectively, and we identify an orbital period of 2.11 hr. The positive superhumps have a maximum amplitude of ~0.25 mag, the negative superhumps have a maximum amplitude of ~0.8 mag, and the orbital …


The Chromospheric Activity, Age, Metallicity, And Space Motions Of 36 Wide Binaries, Jingkun Zhao, Terry D. Oswalt, Mark J. Rudkin, Gang Zhao, Yuqin Chen Apr 2011

The Chromospheric Activity, Age, Metallicity, And Space Motions Of 36 Wide Binaries, Jingkun Zhao, Terry D. Oswalt, Mark J. Rudkin, Gang Zhao, Yuqin Chen

Aerospace, Physics, and Space Science Faculty Publications

We present the chromospheric activity (CA) levels, metallicities, and full space motions for 41 F, G, K, and M dwarf stars in 36 wide binary systems. Thirty-one of the binaries contain a white dwarf (WD) component. In such binaries, the total age can be estimated by adding the cooling age of the WD to an estimate of the progenitor's main-sequence lifetime. To better understand how CA correlates to stellar age, 14 cluster member stars were also observed. Our observations demonstrate for the first time that, in general, CA decays with age from 50 Myr to at least 8 Gyr for …


The Period And Amplitude Changes In The Coolest Gw Virginis Variable Star (Pg 1159-Type) Pg 0122+200, Gérard P. Vauclair, Jianning Fu, Jan Erik Solheim, Seunglee Kim, Noël Dolez, M Chevreton, Li Chen, Matt A. Wood, Isaac M. Silver, Zs Bognár, Margit Paparó, Alejandro H. Córsico Jan 2011

The Period And Amplitude Changes In The Coolest Gw Virginis Variable Star (Pg 1159-Type) Pg 0122+200, Gérard P. Vauclair, Jianning Fu, Jan Erik Solheim, Seunglee Kim, Noël Dolez, M Chevreton, Li Chen, Matt A. Wood, Isaac M. Silver, Zs Bognár, Margit Paparó, Alejandro H. Córsico

Aerospace, Physics, and Space Science Faculty Publications

Context: The PG 1159 pre-white dwarf stars experiment a rapidly cooling phase with a time scale of a few 106 years. Theoretical models predict that the neutrinos produced in their core should play a dominant role in the cooling, mainly at the cool end of the PG 1159 sequence. Measuring the evolutionary time scale of the coolest PG 1159 stars could offer a unique opportunity to empirically constrain the neutrino emission rate. Aims. A subgroup of the PG 1159 stars are nonradial pulsators, the GW Vir type of variable stars. They exhibit g-mode pulsations with periods of a few hundred …