Previous abstract Next abstract
The star P Cygni was discovered on August 18, 1600 AD when it brightened to about the third magnitude.
Several attempts to get informations on size, chemical composition and density distribution of the material around the star have been already done (see for example Leitherer and Zickgraf (1987). Barlow et al. (1994) got [Ni II] narrow band images which show a nearly circular nebula with angular diameter of about 22 arcsec and hint at the presence of nebular rings at circa 6 and 11 arcsec. On the other hand, White and Becker (1982) obtained observations which are consistent with a homogeneous, spherically symmetric, constant velocity, isothermal flow.
Our aim was to analyse the circumstellar regions very close to the star (<6 arcsec) to look for material ejected in the outburst of 1600 AD taking advantage of the use of both adaptive optics and coronography. We have obtained direct CCD images with the Compensated Image System (CIS) installed on the 1.6 m telescope of Air Force Maui Optical Station (AMOS) on Mt. Haleakala, Maui, Hawaii. We have used an occulting mask of about 0.5 arcsec and interference filters centered on the strongest P Cygni and nebular pure-emission lines (H alpha, [NiII], etc ).
Preliminary results obtained in H alpha are presented showing the capabilities Of adaptive optics plus coronograph as tools for analyzing circumstellar envelopes within a few arcseconds of bright stars.
Wednesday program listing