Uvby Photometry of the Magnetic CP Stars 20 Eridani, HR 1297, 12 Canis Majoris, and HD 134214?
ASTRONOMY & ASTROPHYSICS OCTOBER I 2000,PAGE13 SUPPLEMENT SERIES Astron. Astrophys. Suppl. Ser. 146, 13–17 (2000) uvby photometry of the magnetic CP stars 20 Eridani, HR 1297, 12 Canis Majoris, and HD 134214? Saul J. Adelman Department of Physics, The Citadel, 171 Moultrie Street, Charleston, SC 29409, U.S.A. Received May 2; accepted June 15, 2000 Abstract. Differential Str¨omgren uvby observations from magnetic field measures, but lacked photometry around its the Four College Automated Photoelectric Telescope cycle of variability while HD 134214 is a rapidly oscillating (FCAPT) are presented for the mCP stars 20 Eri, Ap star. HR 1297, 12 CMa, and HD 134214. Adelman & The emergent energy distributions, photospheric abun- Boyce found suggestions that the light curves of dances, and magnetic field strengths of mCP stars depend 20 Eri change between observing seasons. Observations upon photospheric position. A distant observer observes for two additional seasons confirm this behavior and lead photometric, spectrum, and/or magnetic variability due to an improved period of 1.928890 days. For HR 1297 a to rotation when the geometry is favorable and the sur- new period of 15.7490 days was derived. The uvby light face ranges in abundance and in magnetic field strength curves now appear to be the same for different observing are sufficient since the magnetic and rotational axes often seasons. 12 CMa is found to be a photometric variable make a large angle with each other. Diffusion and grav- with the 2.18010 day period determined from magnetic itational settling and other hydrodynamical processes in measurements by Bohlender et al.
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