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Coordinates and Identifications of Harvard Variables
Coordinates and identifications are presented for 726 Harvard Variablestars and suspected variables, discovered or studied by D. Hoffleit andannounced in Harvard Bulletins 874, 884, 887, 901, and 902; plus 141others, previously known, lying in the same fields.
| Oxygen-rich semiregular and irregular variables. A catalogue of circumstellar CO observations
Using the SEST, the Onsala 20 m telescope, the JCMT, and the IRAM 30 mtelescope we have carried out a survey of circumstellar CO(J=1-0, 2-1,3-2, and 4-3) emission on a large sample of oxygen-rich semiregular (SRaand SRb) and irregular variables (Lb). A total of 109 stars wereobserved in at least one CO line: 66 were shown to have circumstellar COline emission (7 SRa, 36 SRb, and 23 Lb variables), ~ 60% of thesemiregulars and all but one of the irregulars were detected for thefirst time. Most stars were observed in at least two transitions. Thereis a total of 138 detected CO lines. For twelve stars stronginterference from interstellar CO emission precluded detection. Wepresent here a catalogue of all observational data and the spectra ofall detections, as well as brief discussions on detection statistics(including its dependence on variability type, period, IRAS-colour, IRASLRS-class, and M-subclass), line profiles (including line shapeasymmetry, multi-component line shapes, and line intensity ratios), gasexpansion velocity distributions, and correlations between CO line andIR continuum fluxes (including implications for the mass-lossmechanism). Based on observations collected using at the EuropeanSouthern Observatory, La Silla, Chile, the Onsala Space Observatory,Chalmers Tekniska Högskola, Sweden, the James Clerk MaxwellTelescope, Hawaii and the IRAM 30~m telescope, Pico Veleta, Spain.
| Catalogue of H-alpha emission stars in the Northern Milky Way
The ``Catalogue of Stars in the Northern Milky Way Having H-alpha inEmission" appears in Abhandlungen aus der Hamburger Sternwarte, Band XIin the year 1997. It contains 4174 stars, range {32degr <= l() II< 214degr , -10degr < b() II < +10degr } having the Hαline in emission. HBH stars and stars of further 99 lists taken from theliterature till the end of 1994 were included in the catalogue. We givethe cross-identification of stars from all lists used. The catalogue isalso available in the Centre de Données, Strasbourg ftp130.79.128.5 or http://cdsweb.u-strasbg.fr and at the HamburgObservatory via internet.
| The Infrared Spectral Classification of Oxygen-rich Dust Shells
This paper presents infrared spectral classifications for a flux-limitedsample of 635 optically identified oxygen-rich variables includingsupergiants and sources on the asymptotic giant branch (AGB). Severalclasses of spectra from oxygen-rich dust exist, and these can bearranged in a smoothly varying sequence of spectral shapes known as thesilicate dust sequence. Classification based on this sequence revealsseveral dependencies of the dust emission on the properties of thecentral star. Nearly all S stars show broad emission features fromalumina dust, while most of the supergiants exhibit classic featuresfrom amorphous silicate dust. Mira variables with symmetric light curvesgenerally show broad alumina emission, while those with more asymmetriclight curves show classic silicate emission. These differences may arisefrom differences in the photospheric C/O ratio.
| New detections of H_2O maser sources on the 13.7 M radio telescope of Purple Mountain Observatory
Observations of H_2O maser sources on the 13.7 m radio telescope ofPurple Mountain Observatory from 1990 Aug. to 1994 Jan. are summarized.For searching new water masers, the total number of search candidates isabout 360, with 110 objects detected. Among them are 96 new detections.A list of the new detections and their spectra are presented. Table 1and Fig. 1 are only available in electronic form at the CDS viaanonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsweb.u-strasbg.fr/Abstract.html
| Classification and Identification of IRAS Sources with Low-Resolution Spectra
IRAS low-resolution spectra were extracted for 11,224 IRAS sources.These spectra were classified into astrophysical classes, based on thepresence of emission and absorption features and on the shape of thecontinuum. Counterparts of these IRAS sources in existing optical andinfrared catalogs are identified, and their optical spectral types arelisted if they are known. The correlations between thephotospheric/optical and circumstellar/infrared classification arediscussed.
| Identification of IRAS Sources in the Outer Disk of the Galaxy
Near infrared imaging and photometric observations at J, H and K (or K')bands were performed toward 95 IRAS sources in the outer disk of theGalaxy most of which had been searched for SiO maser emission and arecandidates for variable late-type stars with cold circumstellarenvelopes. Low resolution optical spectroscopic observations were madeto 19 stars of them for classifying the spectral types. Thirty-eight ofthem, for which counterparts were not found at I band brighter than19mag, were taken near infrared images for identification. All areidentified in the near-infrared images brighter than 16 mag at K' bandexcept two that could be in the faint phase of variation when observed.So most of the IRAS late-type stars perhaps have a near-infraredcounterpart although many have no optical counterpart. In thenear-infrared color-color diagram, the stars with O-rich and C-richcircumstellar envelopes(CSEs) are separated from each other. The starswith C-rich CSE are redder than those with O-rich CSE in general butthere are three very red stars in this sample being SiO maser sources,i.e. with O-rich CSE. By combining the near-infrared colors and IRAScolor, the two types of circumstellar envelopes are discriminated. 48percent are stars with C-rich CSE in the entire sample and the numberratios of C-rich to O-rich stars are 14:43 and 32:6 for the opticallyidentified and unidentified groups respectively. This indicates anincreasing proportion of C-rich stars with galacto-centric distance andstellar evolutionary stage. The result is applied to explain the lowdetection rate of SiO maser emission in a similar and bigger sample inthe outer disk of the Galaxy.
| Catalogue of stars in the northern Milky Way having H-alpha in emission
Not Available
| SiO Maser Sources in the Outer Disk of the Galaxy
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1996ApJS..106..463J&db_key=AST
| Mainline OH detection rates from blue circumstellar shells.
We identified 240 accessible circumstellar shells with water and/or SiOmasers, and used the Arecibo and Nancay radio telescopes to search formainline OH emission from them. Our targets are often Mira variableswithout previously known mainline masers. This search results in 89detections, of which 77 are new. The probability of detecting a maser islarger once a water maser is known, and becomes progressively larger thethicker and redder the shell. Nevertheless, almost all of our examplesof solitary 1665MHz masers, rather than the joint occurrence of both1665 and 1667MHz masers, are in the bluest shells. The IRAS lowresolution spectral type is the strongest factor correlating with themainline detection rate. We find that 67% of objects with a silicateemission feature exhibit masers, whereas only 27% of objects with acomparatively featureless 1n type do. These rates are colourinsensitive. We ascribe this clearcut difference to differing UVextinction properties of the two grain types, which is likely to resultfrom differing grain-size distributions. The IR colour sensitivity ofthe overall mainline detection rate is thus almost entirely anincidental artifact of the changing proportion of the two grain typeswith colour. Inferentially, since 90% of the sample exhibit watermasers, and the proportion of blue sources with silicate features issubstantially larger than an unbiased selection from the IRAS PointSource Catalog would give, the incidence of water masers is similarlysensitive to spectral type.
| New OH/IR stars from color-selected IRAS sources. 3: A complete survey
We present the results of 1612 MHz observations conducted at the AreciboObservatory of 571 color-selected sources from the IRAS Point SourceCatalog. Of these sources we detect 132, 113 for the first time. This isthe third part of an Arecibo survey of color-selected IRAS sources. Theearlier two parts together detected a total of 268 sources of 1612 MHzemission. An analysis of the properties of the OH/IR stars detected inall three parts of the survey is included. In particular we compute thelimiting 1612 MHz peak flux of the entire survey to be approximately 40mJy. The correlation between the IRAS infrared fluxes and the 1612 MHzflux of the 132 sources detected in part III of the survey is smallerthan that found in the earlier parts of the survey. This is to beexpected from the intrinsic variability of OH/IR stars and the longertime gap between the 1612 MHz observations and the IRAS measurements. Weidentify a subset of 54 stars as being near the tangent point of thegalactic rotation curve. Using the kinematical distances to these starswe find that the efficiency of momentum transfer varies exponentiallywith the (25 - 12) micrometer color, consistent with the stellar outflowbeing driven by radiation pressure. Further the IR pump efficiencyincreases with increasing optical depth of the circumstellar shell, asexpected for radiative pumping. The bolometric luminosity function isfound to decrease sharply above LBol = 5600 solar luminosity,and the 1612 MHz luminosity function shows a corresponding falloff aboveL1612 = 1.8 x 10-8 solar luminosity. We also finddirect confirmation of the expectation that sources with large expansionvelocity are more luminous than sources with small expansion velocity.
| OH/IR star color mimics
IR color criteria are used to select potential OH/IR stars from the IRASPoint Source Catalog. These OH/IR star color mimics, despite oftenhaving thick and demonstrably O-rich dust shells to shield theirmolecules against interstellar UV, have no 1612 MHz masers. The mostlikely reason for this is that these stars have degenerate companions,which collect an accretion disk from the red giant wind, which in turnprovides them with a local source of UV to dissociate molecules fromwithin their dust shells. In some cases this self-generated UV issufficient to excise all molecules from a shell, as happens withsymbiotic novae; in some cases it merely reduces their number and theability of a shell to support a maser. It is suggested that D-typesymbiotic stars can be identified among sources with thick opaque dustshells by a persistent absence of appropriate masers: these are theOH/IR color mimics.
| Lunar occultations of IRAS point sources, 1991-2000
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1989ApJS...69..651C&db_key=AST
| 55 emission stars discovered during observations of the Galactic anticenter at Abastumani
Not Available
| On the contribution of interstellar extinction to the 10 micron dust feature in OH/IR stars
The IRAS Low Resolution Spectra of 467 sources with the 10 micron dustfeature are analyzed. The strengths of the dust feature are determinedby the ratio of the flux at 9.7 micron to the fitted continuum level.Color temperatures are derived from the fluxes of the four IRASphotometric bands after correcting for the effect of the 10 micronfeature on the fluxes of the 12 micron band. A definite correlationbetween the strength of the feature and the color temperature of thecontinuum is found, implying that the 10 micron dust feature is largelycircumstellar in origin. A reexamination of the strength of the silicatefeature for seven of the OH/IR star used by Gehrs and colleagues in 1985has failed to reproduce the optical depth-distance relationship found bythese authors. It is concluded that interstellar extinction does notplay a major role in the formation of the 10 micron absorption feature.
| Lunar occultations of IRAS point sources, 1986-1990
A complete listing is given for objects in the IRAS Point Source Catalogwhich will be occulted by the moon over the course of 1986-1990. A totalof 14,148 ASCII card images is encompassed by the complete listing ofobjects having geocentric events during this period. The resultscontained in this complete listing are illustrated in two of the presenttables for the brightest objects at 12 and 100 micron wavelengths.
| IRAS catalogues and atlases - Atlas of low-resolution spectra
Plots of all 5425 spectra in the IRAS catalogue of low-resolutionspectra are presented. The catalogue contains the average spectra ofmost IRAS poiont sources with 12 micron flux densities above 10 Jy.
| The stellar component of the galaxy as seen by the AFGL infrared sky survey
The noise-limited magnitudes for the Air Force Geophysical Laboratory(AFGL) Infrared Sky Survey have been estimated by direct comparison withground-based observations. Using these limiting magnitudes, 'pruned'versions of the AFGL catalog have been generated. Infrared observationsof all the stellar objects seen at 11, 20, or 27 microns and astatistical sample of the stars seen only at 4 microns are reported.Analysis of the observations leads to estimates of the absolute 4 and 10microns magnitudes and space densities for the two clases of objects.The expected results from the Infrared Astronomical Satellite arereexamined.
| Classification of 831 two-micron sky survey sources south of +5 degrees.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1975AJ.....80.1011H&db_key=AST
| The Distribution of the BD M-Type Stars Along the Galactic Equator.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1958ApJ...128..510N&db_key=AST
| Bright Late M-Type Stars Near the Galactic Equator.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1954ApJ...120..118N&db_key=AST
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Наблюдательные данные и астрометрия
| Созвездие: | Телец |
| Прямое восхождение: | 05h38m32.63s |
| Склонение: | +25°00'06.8" |
| Видимая звёздная величина: | 10.092 |
| Собственное движение RA: | -7.2 |
| Собственное движение Dec: | -15.9 |
| B-T magnitude: | 11.731 |
| V-T magnitude: | 10.228 |
Каталоги и обозначения:
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