Circumstellar matter, Magnetic fields, Stars: individual (HD 345439; HD 23478), Stars: massive, Stars: pre-main sequence
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.
The Astrophysical Journal Letters
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Wisniewski, J. P.; Chojnowski, S. D.; Davenport, James R. A.; Bartz, J.; Pepper, J.; Whelan, D. G.; Eikenberry, S. S.; Lomax, J. R.; Majewski, S. R.; and Richardson, N. D., "Characterizing the Rigidly Rotating Magnetosphere Stars HD 345439 and HD 23478" (2015). Physics & Astronomy. 29.