Forum Springer Astron. Astrophys.
Forum Whats New Search Orders

Astron. Astrophys. 357, 548-552 (2000)

Previous Section Next Section Title Page Table of Contents

4. HD 86592

Bidelman (1981) classified HD 86592 as a SrEu star. Babel & North (1997) discovered a very strong magnetic field of 15 to 16 kG, estimated v sin i = 16[FORMULA]2 km s-1, and found photometric variability from 24 photometric measurements in the Geneva system:

HJD (max. flux Geneva B mag.)
= 2446896.801 + (2.886669[FORMULA]0.00030)E.

Forty-five and 77 sets of good Strömgren differential observations were made with the FCAPT during the 1997-98 and 1998-99 observing seasons, respectively (Table 4). The period finding techniques yield the same period as Babel & North whose photometry covers a much long time period, but whose coverage is far sparser. The new photometry defines more subtle variations in the light curves. These values are plotted in Fig. 3. The B light curve of Babel & North shows the same minimum as those of u , b , and v which are in phase. It will require another set of observations to improve the ephemeris.

[FIGURE] Fig. 3. Differential FCAPT uvby photometry of HD 86592 (filled circles) plotted with the ephemeris HJD (max Geneva B mag.) = 2446896.801 + 2.886669 E. Note the variation of y is crudely out of phase with those of u , v , and b .

HD 86582 is a large amplitude variable in v (0.13 mag.) while in u , b , and y the amplitudes are 0.04, 0.04, and 0.018 mag., respectively. The variability in y is very crudely, but not perfectly in antiphase with those of u , v , and b as its maximum occurs near phase 0.5 rather than 0.35. Thus there must be an approximately non-variable wavelength region between the mean wavelengths of b and y . The halt in the rise of the rising branch of the light curve near phase 0.75 which is seen in v may also weakly occur in b .

Previous Section Next Section Title Page Table of Contents

© European Southern Observatory (ESO) 2000

Online publication: June 5, 2000