A DETACHED DUST SHELL SURROUNDING THE J-TYPE CARBON STAR Y CANUM VENATICORUM
This paper reports the first clear detection of a de- tached dust shell surrounding the prototypical J-type carbon star Y CVn in 90 m and 160 m maps taken with the ISO/ISOPHOT 1 . The projected inner radius of the shell is 180 -190 , corresponding to (6.4-7.1) 10 17 cm at a distance of 250 pc. The shell thickness is obtained to be (2-5) 10 17 cm. The mass-loss rate at the formation of the shell is estimated to be in the range (7-20) 10 6 M yr 1 , about two orders of magni- tude higher than the present-day mass-loss rate derived from CO gas observations. The obtained mass in the shell is (4-14) 10 2 M. It is concluded that the mass-loss rate decreased by two orders of magnitude on a short time scale 1.4 10 4 years ago as- suming an average shell expansion velocity of 15 km s 1 ,a nd that Y CVn has been staying at the low mass-loss state. The duration of the previous higher mass-loss phase would be at most 2 10 4 years even if the asymmetry in the shell geometry is taken into account. The evolutionary status of Y CVn is also discussed.
Circumstellar Dust Shells of Carbon Stars Resolved with ISO
Abstract We present far-infrared images of very extended dust shells of carbon stars observed with ISOPHOT on board the Infrared Space Observatory. A prototypical J-type carbon star Y CVn is surrounded by a very extended, detached dust shell, which shows that once there was a period with an intense mass-loss on the order of 10 −5 M Θ yr −1 followed by a swift switch to a phase with a mass-loss rate lower by two orders of magnitude about (1–2)×10 4 years ago. An N-type carbon star U Ant shows a double shell structure, a compact but resolved dust shell surrounded by a very extended one. The observed structure as well as the previously known thin CO gas shell indicates that this star experienced two cycles of “a high mass-loss phase of the order of 10 −5 M Θ yr −1 followed by a phase with a fainter mass-loss by two orders of magnitude” in the last (1–2)×10 4 years.
The image of the Jew in European liberal culture, 1789-1914
This collection of essays explores the complex articulations and contexts of anti-Semitism in the literature of four cultures — Britain, Germany, France and Italy — in the long nineteenth century. The essays examine the presence both of explicitly anti-Semitic writing and apparently anti-Jewish stereotypes in the work of writers who were not consciously hostile to Jews. The book scrutinizes assumptions about the relative absence of anti-Semitism in Britain, the image of Germany as resistant to Jewish assimilation, and of Italy as particularly hospitable to Jews. The essays are placed in a comparative framework in order to examine the representation of Jews both within particular national cultures and in the context of Western European modernity. The volume considers the ways in which anti-Semitism functioned within liberal culture in the nineteenth century as part of the broader history of oppression with which Western modernity has been complicit.