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
Required Publisher's Statement
Copyright by the American Astronomical Society
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.
Subjects - Topical (LCSH)
Stellar dynamics; Supergiant stars; Stars--Evolution; Stars--Atmospheres