Nebular abundances of southern symbiotic stars
We have calculated relative element abundances for a sample of 43symbiotic stars. Helium abundances and the relative elemental abundancesN/O, Ne/O, Ar/O were derived from new spectra collected in the opticalrange through low dispersion spectroscopy. The He ionic abundances werederived taking into account self-absorption effects in Balmer lines. Wefound that the symbiotic stars in the galactic bulge have heavy elementabundances showing the same wide distribution as other bulge objects. Inthe galactic disk, the symbiotic stars follow the abundance gradient asderived from different kinds of objects.
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A catalogue of symbiotic stars
We present a new catalogue of symbiotic stars. In our list we include188 symbiotic stars as well as 30 objects suspected of being symbiotic.For each star, we present basic observational material: coordinates, Vand K magnitudes, ultraviolet (UV), infrared (IR), X-ray and radioobservations. We also list the spectral type of the cool component, themaximum ionization potential observed, references to finding charts,spectra, classifications and recent papers discussing the physicalparameters and nature of each object. Moreover, we present the orbitalphotometric ephemerides and orbital elements of known symbioticbinaries, pulsational periods for symbiotic Miras, Hipparcos parallaxesand information about outbursts and flickering.
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Raman scattering in symbiotic stars. I. Spectropolarimetric observations.
We present high signal-to-noise, high-dispersion linearspectropolarimetry of the Raman-scattered λλ6825, 7082Aemission lines in 27 southern-hemisphere symbiotic systems. We givecontinuum polarization measurements for all the targets (together withestimates of the foreground interstellar polarization), and newestimates of the red-giant spectral types in 23 systems. We confirmcontinuum-polarization variability in five out of eight systems withprevious high-quality photopolarimetry. The Raman lines are fullyresolved; although they display a wide variety of morphologies, both theintensity and polarization profiles appear basically to betriple-peaked. Spectra of five systems observed in both 1992 and 1994show stable Raman-line intensity profiles, but with significantvariations in the polarization structure.
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ROSAT Observations of Symbiotic Binaries and Related Objects
Not Available
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Spectral classification and HR diagram for symbiotic stars in the galactic bulge
Abstract image available at:http://adsabs.harvard.edu/abs/1995AJ....109.1770M
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A highly sensitive radio survey of symbiotic stars at 3.6 centimeters
Results of a new highly sensitive radio survey of about 100 symbioticstars at 3.6 cm are reported. The survey has led to the detection ofabout half of all the symbiotic stars searched, effectively doubling thenumber of known radio detections. The analysis shows that the radioemission is correlated strongly with emission in the mid-IR (12 and 25microns) and less strongly with IR emission at both shorter and longerwavelengths. A comparison between the radio and UV continua (1300 A)indicates that the ionized nebula in nearly all symbiotic stars isoptically thick and/or density bounded. In particular, there is evidencethat S-types are more optically thick in the radio wavelength range thanD-types.
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Strasbourg - ESO catalogue of galactic planetary nebulae. Part 1; Part 2
Not Available
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The collective radio properties of symbiotic stars
Radio measurements of symbiotic stars are reported which extend thesearch for radio emission and provide multifrequency and multiepochmeasurements of previously detected stars. The results show no evidencethat there are time variations in excess of about 30 percent over aperiod of several years in the detected stars. The radio flux densitiesare correlated with brightness in the IR, especially at the longer IRwavelengths where dust emission dominates. It is confirmed thatsymbiotics with the latest red giant spectral types are the mostluminous radio emitters. The D-types are the most radio-luminous.Virtually all detected stars with measurements at more than onefrequency exhibit a positive spectral index, consistent with opticallythick thermal bremsstrahlung. The binary separation for a number ofradio-emitting symbiotics is estimated, and it is found that thedistribution of inferred binary separations is dramatically differentfor IR D-types than for S-types.
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Far-infrared data for symbiotic stars. II - The IRAS survey observations
IRAS survey data for all known symbiotic binaries are reported. S typesystems have 25 micron excesses much larger than those of single redgiant stars, suggesting that these objects lose mass more rapidly thando normal giants. D type objects have far-IR colors similar to those ofMira variables, implying mass-loss rate of about 10 to the -6th solarmasses/yr. The near-IR extinctions of the D types indicate that theirMira components are enshrouded in optically thick dust shells, whiletheir hot companions lie outside the shells. If this interpretation ofthe data is correct, then the very red near-IR colors of D typesymbiotic stars are caused by extreme amounts of dust absorption ratherthan dust emission. The small group of D prime objects possesses far-IRcolors resembling those of compact planetary nebulae or extreme OH/IRstars. It is speculated that these binaries are not symbiotic stars atall, but contain a hot compact star and an exasymptotic branch giantwhich is in the process of ejecting a planetary nebula shell.
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Symbiotic stars according to IRAS observations
Symbiotic stars contained in Allen's catalog are examined with a view toestablishing their coincidence with sources of far infrared radiation inthe catalog of point sources observed with the IRAS satellite.Altogether, 72 symbiotic or suspected symbiotic objects have beenidentified. A list of the identified stars has been compiled, and theenergy distributions in the infrared spectra of selected stars aregiven. It has been found that the presence of dust in symbiotic systemsis a more widespread phenomenon than hitherto believed. Almost 40percent of them are 'dust' systems. Among them, objects with dusttemperature of several tens of degrees K have been found. It is shownthat the only useful two-color diagram is the (K - m12)-(m12 - m25)diagram. Finally, attention is drawn to a type of symbiotic star havingcold components of the spectral class G; these require a specialinvestigation.
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Misclassified planetary nebulae
In this paper 266 objects taken from catalogs and lists of planetarynebulas are discussed. Opinions are based on observations given in theliterature, on the vast photometric information collected by the IRASsatellite, plus on the observations from the ongoing project of aspectroscopic survey of all planetary nebulas. Of the objects, 199 aredefinitely rejected as planetary nebulas, 63 others are possibly notplanetary nebulas.
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Spectroscopic observations of faint and misclassified planetary nebulae
Using low resolution IDS spectra, an attempt is made to clarify theclassification of 264 objects which appeared as planetary nebulae invarious listings, and were originally included in two lists of Sanduleak(1976): (1) misclassified or doubtfully classified planetary nebulae;and (2) faint, suspected planetary nebulae. The new data show that 67percent of the objects can be considered as true planetary nebulae, ofwhich 46 percent present low excitation characteristics. The status ofthe other objects remains quite uncertain, some of them being symbioticstars (14 percent), or various emission-line objects. In four cases, nopositive indication of emission-line objects in the observed areas wasfound.
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A catalogue of symbiotic stars
A catalog of the 100 known symbiotic stars is presented, based on X-ray,ultraviolet, infrared, and radio surveys. The catalog is divided intothree parts: a catalog with positional data; a set of finding charts;and a set of previously unpublished spectral data. A series of notesexplaining particular features of the maps and finding charts isprovided.
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Index and cross-identification of planetary nebulae
The index of 86 discovery lists of planetary nebulae contains all theknown planetary nebulae in the Galaxy, including the probable, possibleand misclassified objects. A cross-identification gives all the names ofthe 1518 PN ordered by increasing galactic longitude.
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Photographic Infrared Observations of Planetary Nebulae
Abstract image available at:http://adsabs.harvard.edu/abs/1983RMxAA...8...39M
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The Infrared Variability and Nature of Symbiotic Stars - Part Five - Seven More Systems
Abstract image available at:http://adsabs.harvard.edu/abs/1983MNRAS.203..373F
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Infrared studies of symbiotic stars
Infrared photometry and spectroscopy of symbiotic stars is reviewed. Itis shown that at wavelengths beyond micron these systems are generallydominated by the cool star's photosphere and, indeed, areindistinguishable from ordinary late-type giants. About 25% of symbioticstars exhibit additional emission due to circumstellar dust. Most of thedusty systems probably involve Mira variables, the dust forming in theatmospheres of the Miras. In a few cases the dust is much cooler and thecool component hotter; the dust must then form in distant gas shieldedfrom the hot component, perhaps by an accretion disk.
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The ESO/Uppsala survey of the ESO(B) Atlas of the Southern Sky. VI.
Abstract image available at:http://adsabs.harvard.edu/abs/1978A&AS...34..285H
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Bibliographical index of planetary nebulae for the period 1965-1976.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1977A&AS...30..217A&db_key=AST
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Objective-prism spectroscopy of planetary nebulae in the southern Milky Way.
Not Available
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Infrared photometry of southern emission-line stars.
Abstract image available at:http://adsabs.harvard.edu/abs/1974MNRAS.167..337A
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A Study of (h - Objects in the Southern Milky way.
Not Available
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Nuevas nebulosas planetarias Y objetos con emision EN la region del centro galactico .
Not Available
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