Publications
of the
MPIfR Optical & Infrared Interferometry Group

Weigelt, G., Balega, Y., Hofmann, K.-H., Scholz, M.

First diffraction-limited speckle masking observations of the Mira variable R Cas with the 6m SAO telescope

Astronomy and Astrophysics 316, L21-L24 (1996)

We present the first diffraction-limited speckle masking observations of a Mira star with the Russian 6m SAO telescope. At 700 and 714nm wavelength a resolution of 30 milli-arcsec was achieved. The reconstructed true images are the images with the highest resolution obtained up to now in this wavelength region. The speckle interferograms of R Cas were recorded through interference filters with center wavelength/ bandwidth of 714nm/6nm (strong TiO band absorption) and 700nm/6nm (moderate TiO absorption). The two reconstructed images show that the azimuthally averaged 700 and 714nm uniform-disk diameters of R Cas are 36mas +/- 2mas and 49mas +/- 2mas, respectively. In the 700nm and 714nm images the disks of R Cas are non-uniform and elongated along position angle 52 +/- 7 degrees and 57 +/- 7 degrees, respectively. The size (elliptical uniform disk fit) of the elongated disks is about 33.3mas x 38.7mas (axial ratio 0.86) in the 700nm pseudo-continuum filter and 42.3mas x 55.6mas (axial ratio 0.76) in the 714nm TiO absorption band filter. We discuss briefly theoretical aspects of these and previous observations.

You can get this publication ...

... by following this link to the ADS website