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Full-Text Articles in Physical Sciences and Mathematics

A Study Of Hα Line Profile Variations In Β Lyr, Richard Ignace, Sharon K. Gray, Macno A. Magno, Gary D. Henson, Derek Massa Aug 2018

A Study Of Hα Line Profile Variations In Β Lyr, Richard Ignace, Sharon K. Gray, Macno A. Magno, Gary D. Henson, Derek Massa

ETSU Faculty Works

We examine over 160 archival Hα spectra from the Ritter Observatory for the interacting binary β Lyr obtained between 1996 and 2000. The emission is characteristically double-peaked, but asymmetric, and with an absorption feature that is persistently blueshifted. Using a set of simplifying assumptions, phase varying emission line profiles are calculated for Hα formed entirely in a Keplerian disk, and separately for the line formed entirely from an off-center bipolar flow. However, a dynamic spectrum of the data indicates that the blueshifted feature is not always present, and the data are even suggestive of a drift of the …


An L Band Spectrum Of The Coldest Brown Dwarf, Caroline V. Morley, Andrew J. Skemer, Katelyn N. Allers, Mark S. Marley, Jacqueline K. Faherty, Channon Visscher, Samuel A. Beiler, Brittany E. Miles, Roxana Lupu, Richard S. Freedman, Jonathan J. Fortney, Thomas R. Geballe, Gordon L. Bjoraker Apr 2018

An L Band Spectrum Of The Coldest Brown Dwarf, Caroline V. Morley, Andrew J. Skemer, Katelyn N. Allers, Mark S. Marley, Jacqueline K. Faherty, Channon Visscher, Samuel A. Beiler, Brittany E. Miles, Roxana Lupu, Richard S. Freedman, Jonathan J. Fortney, Thomas R. Geballe, Gordon L. Bjoraker

Faculty Work Comprehensive List

The coldest brown dwarf, WISE 0855, is the closest known planetary-mass, free-floating object and has a temperature nearly as cold as the solar system gas giants. Like Jupiter, it is predicted to have an atmosphere rich in methane, water, and ammonia, with clouds of volatile ices. WISE 0855 is faint at near-infrared wavelengths and emits almost all its energy in the mid-infrared. Skemer et al. (2016) presented a spectrum of WISE 0855 from 4.5–5.1 µm (M band), revealing water vapor features. Here, we present a spectrum of WISE 0855 in L band, from 3.4–4.14 µm. We present a set of …


Rr Lyrae Calibration Using Sdss, Single-Epoch Spectroscopy, Stacy Long Jan 2018

Rr Lyrae Calibration Using Sdss, Single-Epoch Spectroscopy, Stacy Long

Theses and Dissertations--Physics and Astronomy

I use single-epoch, SDSS spectroscopy of RR Lyraes identified in the Catalina survey to separate the spectra into same-temperature groups. Then I draw temperature-phase diagrams of the groups. I find shocked stars, improperly phased stars, low amplitude stars, and a few that are more likely eclipsing binaries. The RR Lyraes are then given precise metallicities by measurements of the CaII K and H-β, H-γ, and H-δ lines. This leads to better distance measurements, which allow me to confirm a distinction between the inner and outer galactic halo.