New PDF release: B[e] Stars: Proceedings of the Paris Workshop held from 9–12

By D. De Winter, M. E. Van Den Ancker, M. R. Pérez (auth.), Anne Marie Hubert, Carlos Jaschek (eds.)

ISBN-10: 9048150809

ISBN-13: 9789048150809

ISBN-10: 9401590141

ISBN-13: 9789401590143

The inspiration of getting a gathering got here to the Editors whilst engaged on numerous points of galactic Be and B[e] stars. they discovered common precis of the homes of B[e] stars used to be lacking, in order that the organiza­ tion of a primary assembly on those gadgets seemed as very worthwhile. B[e] stars have hydrogen line emission and forbidden [Fe eleven] and [0 I] emission traces of their spectra; also they are characterised by means of a robust IR extra as a result of circumstellar dirt. Having a large number of extinction within the UV and the visible they've been much less usually saw than different emission line gadgets. even supposing approximately 100 galactic items were categorized as B[e], merely fif­ teenager or so were studied in a few aspect. along with this, the evolutionary prestige of those gadgets is rat her debatable, are they pre-main series or stars with a purpose to develop into nUclei of planetary nebulae? different tough difficulties seem while contemplating the kin of those stars with different comparable teams, like Herbig AeBe stars, Be, luminous blue variables and the superluminous B[e] stars saw within the Magellanic Clouds. The convention turns out well timed when you consider that huge surveys like DENIS and 2Mass, plus new area and new tools for the micron, millimeter and cen­ timeter wavelength zone will lead to the invention of extra stars of this group.

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Extra info for B[e] Stars: Proceedings of the Paris Workshop held from 9–12 June, 1997

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For some cluster properties estimates are given with the error between parentheses. 3 0 6611 6611 Total dW+PT2 Hil Notes: *) Taken from Luiken-Miller (1982). **) Taken from Sagar & Joshi (1978). ) survival time is ~107 yrs. The latter is supported by the detection of Hester et al. (1996) that dusty regions in NGC 6611 suffer from erosion due to the intense UV radiation fields of nearby 0 & B stars. This might work also as disk erosion of young stars in such clusters (Perez et al. 1998). In fact their calculations show that in these crowded regions the disk survival time is less than the pre-main sequence time of a few Myrs for the studied stars, which explains the lack of detected HAeBe stars, see Table 1.

Depending on the authors, these stars are consid- ered as extreme emission li ne stars, undassified B[e] stars or as supergiants of the type of dusty B[e] supergiants of Magellanic Clouds described by Zickgraf (1993), Zickgraf et al. (1996). In this group we consider MWC 314 and HD 316285. MWC 314 was recently studied by Miroshnichenko (1996), who determined the effective temperature we used in the present calculation. In this star there is no evidence for a DCE. The reddening vector of this object sc ales with Rism = 2.

1988), it ean be shown that stars of Table 3, exeepting the HAeBe's, are not associated with moleeular clouds. Our program B[e] stars globally follow the spaee distribution of young star associations and young clusters (Humphreys 1979). They also closely follow the distribution of 09-B5 supergiants (Humphreys 1979) and that of long-period Cepheids (Humphreys 1970). The rough, first-order kinematie indications obtained in the preeeding section and comparison of distributions made in the paragraph above lead us to conclude that stars with the B[e] phenomenon have a galactie distribution resembling that of extreme Population I objeets.

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B[e] Stars: Proceedings of the Paris Workshop held from 9–12 June, 1997 by D. De Winter, M. E. Van Den Ancker, M. R. Pérez (auth.), Anne Marie Hubert, Carlos Jaschek (eds.)


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