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Full-Text Articles in Physical Sciences and Mathematics
Parallaxes And Distance Estimates For 14 Cataclysmic Variable Stars, John R. Thorstensen
Parallaxes And Distance Estimates For 14 Cataclysmic Variable Stars, John R. Thorstensen
Dartmouth Scholarship
I used the 2.4 m Hiltner Telescope at MDM Observatory in an attempt to measure trigonometric parallaxes for 14 cataclysmic variable stars. Techniques are described in detail. In the best cases the parallax uncertainties are below 1 mas, and significant parallaxes are found for most of the program stars. A Bayesian method that combines the parallaxes together with proper motions and absolute magnitude constraints is developed and used to derive distance estimates and confidence intervals. The most precise distance derive here is for WZ Sge, for which I find 43: 3.1:6 1:5 pc. Six Luyten Half-Second stars with previous precise …
0937+2931_Opt_Lris, Adam J. Burgasser
0415-0935_Opt_Lris, Adam J. Burgasser
Grb 021004: A Possible Shell Nebula Around A Wolf‐Rayet Star Gamma‐Ray Burst Progenitor, N. Mirabal, J. P. Halpern, Ryan Chornock, Alexei V. Filippenko, D. M. Terndrup, E. Armstrong, J. Kemp, J. R. Thorstensen, M. Tavarez, C. Espaillat
Grb 021004: A Possible Shell Nebula Around A Wolf‐Rayet Star Gamma‐Ray Burst Progenitor, N. Mirabal, J. P. Halpern, Ryan Chornock, Alexei V. Filippenko, D. M. Terndrup, E. Armstrong, J. Kemp, J. R. Thorstensen, M. Tavarez, C. Espaillat
Dartmouth Scholarship
The rapid localization of GRB 021004 by the HETE-2 satellite allowed nearly continuous monitoring of its early optical afterglow decay, as well as high-quality optical spectra that determined a redshift of z3 = 2.328 for its host galaxy, an active starburst galaxy with strong Ly emission and several absorption lines. Spectral observations show multiple absorbers at z3A = 2.323, z3B= 2.317, and z3C = 2.293 blueshifted by ~450, ~990, and ~3155 km s-1, respectively, relative to the host galaxy Lyα emission. We argue that these correspond to a fragmented shell nebula that has …