Merged catalogue of reflection nebulae
Several catalogues of reflection nebulae are merged to create a uniformcatalogue of 913 objects. It contains revised coordinates,cross-identifications of nebulae and stars, as well as identificationswith IRAS point sources.The catalogue is only available in electronic form at the CDS viaanonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or viahttp://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/399/141
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The Neutral Envelopes around AGB and Post-AGB Objects Their Structure and Kinematics
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Observational constraints on the ERE interpretation
Empirical relationships on the properties of the Extended Red Emission(ERE) are presented. They are based on published observational data andon new results obtained on reflection nebulae illuminated by cold stars.The plot of the width versus the central wavelength of the ERE band isin agreement with laboratory properties of the materials commonlyproposed as the ERE carriers. But this is not the case for the plot ofthe ERE band width versus the effective temperature of the nebulailluminating star. Partly based on observations made at Observatoire deHaute Provence du CNRS and at European Southern Observatory (ESO), LaSilla (Chile)}
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Li-rich giants: A survey based on IRAS colours
In a previous work we studied the IRAS colours of known Li-rich redgiants and showed that they have flux ratiosF12/F25 and F25/F60 in welldefined ranges. By using this result as a selection criterion, weprepared a list of 280 IRAS Point Source candidates to be Li-rich giantstars. Up to the present we have obtained spectra for 57% of our targetlist. We identified five stars showing a strong LiI 670.079 nm line andsix ones with a Li line of medium strength. Most of the candidates showfeatures typical of normal giants having circumstellar dust, asindicated by their IRAS colours. Observations collected at theLaboratorio Nacional de Astrofisica - LNA, Brazil; Observatoire de HauteProvence - OHP, France; European Southern Observatory - ESO, Chile.
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Circumstellar Molecular Envelopes of AGB and Post-AGB Objects
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Nebulosity around the S-Star Rz-Sagittarii
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1994MNRAS.270L..15W&db_key=AST
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An infrared study of the remarkable dusty M star HR 3126
HR 3126 is a unique M giant star embedded in the bipolar reflectionnebula IC 2220. In this paper we present new photometric andspectroscopic observations of HR 3126 and combine them with existingdata from the literature in an extensive reappraisal of the star'sproperties at infrared wavelengths. The spectral energy distribution isconsistent with an optical classification of M0-3 II with infraredexcess. The dust shell cannot be fitted by a single-temperatureblackbody: at least three components are required, with temperatures inthe range 35-1300 K. On the basis of spectroscopy at 1-4 and 7-25microns, combined with an assessment of various color-color diagrams, weare able to reject the hypothesis that HR 3126 is carbon-rich. Weaksilicate emission features are detected at 10 and 19 microns, and aprevious report of silicon carbide emission at 11.2 microns is notsubstantiated. It seems likely that HR 2136 is in a phase of advancedand rapid postmain-sequence evolution, possibly beginning its ascent ofthe asymptotic giant branch.
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CCD surface photometry of IC 2220
BVRI color-difference measurements are reported for the unusual bipolarreflection nebula IC 2220 which surrounds an early-M giant. The datawere obtained through BVRI imaging with a CCD detector. Analysis of thecolor difference between the nebula and the illuminating star HR 3126indicates that the nebular dust, having formed in the outflow from thestar, is similar to average interstellar dust. No evidence is found forthe presence of extended red emission in this nebula, although there isan indication of nonequilibrium continuum emission. The Milky Wayprovides a significant amount of external illumination to IC 2220 in Band U.
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Observations of the nebulosities near SN 1987A
Direct images of SN 1987A taken during periods of good seeing at LaSilla Observatory are combined with spectra to map the velocity andspatial structure of the dust and gas that surround SN 1987A. The datafrom December 1989 show that the supernova is embedded in a filamentarynebula of mixed gases and dust that is morphologically and kinematicallysimilar to planetary nebulae. The narrowness of the filaments, theirshape, their radial velocities, and the lack of detectable expansion inthe plane of the sky imply that this is a physical structure, not justthe SN 1987A light curve seen reflected from a continuous sheet ofbackground material. This inner, highly structured nebula is immersed inan outer, larger nebula which may be due to reflected light from SK -69deg 202, the progenitor of SN 1987A. Alternatively, if it is due toreflected light from SN 1987A, it must lie in front of the supernova.
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A journey with light. Come on a 12-billion-year journey as the light from a distant quasar travels to earth.
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Multi-wavelength observations of the peculiar red giant HR 3126
Ultraviolet observations of the red giant HR 3126 are combined withmulti-wavelength data in order to provide a firmer basis for explainingthe arc-minute sized nebula surrounding the object. Possibilities as tothe location of HR 3126 on the Hertzsprung-Russel diagram, and to theformation mechanisms of the reflection nebula IC 2220 associated withit, are summarized.
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Über einige unstabile Sterne.
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The Toby Jug nebula /IC 2220/ - A bipolar and biconical nebula
An optical linear polarization map of IC 2220, the nebula surroundingthe cool red giant HD 65750, is presented. The nebula appears to bebipolar and biconical in structure. The mass of the nebula is estimatedto be 0.01 solar masses and is consistent with the nebula being formedfrom the current mass loss stage of the central star.
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Studies of bipolar nebulae. VII - The exciting star of OH 0739-14 /equals OH 231.8 plus 4.2/
A spectral classification for the exciting star of the bipolarreflection nebula OH 0739-14, which has also been observed to be anOH/H2O maser source, is obtained from the spectrum of the nebulosity inthe range 6000-9000 A. Spectrophotometry of the visible nebula wasobtained with the Cassegrain image-tube scanner on the Lick Observatory3-m telescope at a resolution of approximately 7 A. The red spectrum isfound to be distinguished by TiO absorption at the bandheads at 8206,8303, 8432, 8442 and 8452 A and VO in the 7400 and 7900 A regions. Onthe basis of the depths of these bandheads and the K I 7699 A and Ca IIinfrared triplet, OH 0739-14 is determined to be of spectral type M9III. The underlying star thus represents the coolest known star to occurin a bipolar system.
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INHABITED SKY
