Document Type

Article

Publication Date

9-25-2015

Keywords

Circumstellar matter, Magnetic fields, Stars: individual (HD 345439; HD 23478), Stars: massive, Stars: pre-main sequence

Abstract

The SDSS III APOGEE survey recently identified two new σ Ori E type candidates, HD 345439 and HD 23478, which are a rare subset of rapidly rotating massive stars whose large (kGauss) magnetic fields confine circumstellar material around these systems. Our analysis of multi-epoch photometric observations of HD 345439 from the Kilodegree Extremely Little Telescope, Wide Angle Search for Planets, and ASAS surveys reveals the presence of a ~0.7701 day period in each data set, suggesting the system is among the faster known σ Ori E analogs. We also see clear evidence that the strength of Hα, H i Brackett series lines, and He i lines also vary on a ~0.7701 day period from our analysis of multi-epoch, multi-wavelength spectroscopic monitoring of the system from the APO 3.5 m telescope. We trace the evolution of select emission line profiles in the system, and observe coherent line profile variability in both optical and infrared H i lines, as expected for rigidly rotating magnetosphere stars. We also analyze the evolution of the H i Br-11 line strength and line profile in multi-epoch observations of HD 23478 from the SDSS-III APOGEE instrument. The observed periodic behavior is consistent with that recently reported by Sikora and collaborators in optical spectra.

Publication Title

The Astrophysical Journal Letters

Volume

811

Issue

2

DOI

10.1088/2041-8205/811/2/L26

Required Publisher's Statement

Copyright by the American Astronomical Society

http://iopscience.iop.org/article/10.1088/2041-8205/811/2/L26?fromSearchPage=true

https://doi.org/10.1088/2041-8205/811/2/L26

Subjects - Topical (LCSH)

Stellar dynamics; Supergiant stars; Stars--Evolution; Stars--Atmospheres

Genre/Form

articles

Type

Text

Language

English

Format

application/pdf

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