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Physical Sciences and Mathematics Commons

Open Access. Powered by Scholars. Published by Universities.®

Astrophysics and Astronomy

Dartmouth Scholarship

2014

Eclipse

Articles 1 - 2 of 2

Full-Text Articles in Physical Sciences and Mathematics

Optical Counterparts Of Two Fermi Millisecond Pulsars: Psr J1301+0833 And Psr J1628–3205, Miao Li, Jules P. Halpern, John R. Thorstensen Oct 2014

Optical Counterparts Of Two Fermi Millisecond Pulsars: Psr J1301+0833 And Psr J1628–3205, Miao Li, Jules P. Halpern, John R. Thorstensen

Dartmouth Scholarship

Using the 1.3 m and 2.4 m Telescopes of the MDM Observatory, we identified the close companions of two eclipsing millisecond radio pulsars that were discovered by the Green Bank Telescope in searches of Fermi Gamma-ray Space Telescope sources, and measured their light curves. PSR J1301+0833 is a black widow pulsar in a 6.5 hr orbit whose companion star is strongly heated on the side facing the pulsar. It varies from R = 21.8 to R > 24 around the orbit. PSR J1628–3205 is a "redback," a nearly Roche-lobe-filling system in a 5.0 hr orbit whose optical modulation in the range …


Magnetic Inhibition Of Convection And The Fundamental Properties Of Low-Mass Stars. Ii. Fully Convective Main-Sequence Stars, Gregory A. Feiden, Brian Chaboyer Jun 2014

Magnetic Inhibition Of Convection And The Fundamental Properties Of Low-Mass Stars. Ii. Fully Convective Main-Sequence Stars, Gregory A. Feiden, Brian Chaboyer

Dartmouth Scholarship

We examine the hypothesis that magnetic fields are inflating the radii of fully convective main-sequence stars in detached eclipsing binaries (DEBs). The magnetic Dartmouth stellar evolution code is used to analyze two systems in particular: Kepler-16 and CM Draconis. Magneto-convection is treated assuming stabilization of convection and also by assuming reductions in convective efficiency due to a turbulent dynamo. We find that magnetic stellar models are unable to reproduce the properties of inflated fully convective main-sequence stars, unless strong interior magnetic fields in excess of 10 MG are present. Validation of the magnetic field hypothesis given the current generation of …