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Observations of Star-Forming Regions with the Midcourse Space Experiment
We have imaged seven nearby star-forming regions, the Rosette Nebula,the Orion Nebula, W3, the Pleiades, G300.2-16.8, S263, and G159.6-18.5,with the Spatial Infrared Imaging Telescope on the Midcourse SpaceExperiment (MSX) satellite at 18" resolution at 8.3, 12.1, 14.7, and21.3 μm. The large angular scale of the regions imaged (~7.2-50deg2) makes these data unique in terms of the combination ofsize and resolution. In addition to the star-forming regions, twocirrus-free fields (MSXBG 160 and MSXBG 161) and a field near the southGalactic pole (MSXBG 239) were also imaged. Point sources have beenextracted from each region, resulting in the identification over 500 newsources (i.e., no identified counterparts at other wavelengths), as wellas over 1300 with prior identifications. The extended emission from thestar-forming regions is described, and prominent structures areidentified, particularly in W3 and Orion. The Rosette Nebula isdiscussed in detail. The bulk of the mid-infrared emission is consistentwith that of photon-dominated regions, including the elephant trunkcomplex. The central clump, however, and a line of site toward thenorthern edge of the cavity show significantly redder colors than therest of the Rosette complex.
| Differential uvby Photometry of 13 Mon (A0 Ib)
Differential uvby photometry of the A0 Ib supergiant 13 Mon obtainedduring three successive observing seasons shows that it is a lowamplitude photometric variable, but no definite period is found. Thevariations in each filter are crudely in the phase. Further, the meanmagnitude in each filter has slowly decreased in the course of the lastthree years.
| Catalogue of Apparent Diameters and Absolute Radii of Stars (CADARS) - Third edition - Comments and statistics
The Catalogue, available at the Centre de Données Stellaires deStrasbourg, consists of 13 573 records concerning the results obtainedfrom different methods for 7778 stars, reported in the literature. Thefollowing data are listed for each star: identifications, apparentmagnitude, spectral type, apparent diameter in arcsec, absolute radiusin solar units, method of determination, reference, remarks. Commentsand statistics obtained from CADARS are given. The Catalogue isavailable in electronic form at the CDS via anonymous ftp tocdsarc.u-strasbg.fr (130.79.128.5) or viahttp://cdsweb.u-strasbg.fr/cgi-bin/qcar?J/A+A/367/521
| New Perspectives on AX Monocerotis
AX Moncerotis is a 232d, noneclipsing, interacting binary star thatconsists of a K giant, a Be-like giant, and large amounts ofcircumstellar material. The K star is almost certainly a synchronousrotator and is probably in contact with its critical lobe. The Be starwas believed to be a rapid rotator based on extremely wide absorptionlines, but new spectra show that these lines arise from thecircumstellar environment. Hydrogen emission, also circumstellar, ismany times stronger than the continuum. Near-ultraviolet light curvesexhibit a 0.5 mag dip near phase 0.75, but there is no such variabilityat longer wavelengths. Gas flow trajectories from the cusp of the K startoward the Be star provide a simple explanation for the photometric andspectroscopic behavior. We may have found a decreasing orbital period,but more data are necessary to confirm this result. We present severalmodels for AX Mon based on (1) new and archival visible photometry, (2)archival ultraviolet spectroscopy, (3) new and archival visiblespectroscopy, (4) new visible polarimetry, and (5) new radio photometry.Future observations, including optical interferometry, are proposed.
| Vitesses radiales. Catalogue WEB: Wilson Evans Batten. Subtittle: Radial velocities: The Wilson-Evans-Batten catalogue.
We give a common version of the two catalogues of Mean Radial Velocitiesby Wilson (1963) and Evans (1978) to which we have added the catalogueof spectroscopic binary systems (Batten et al. 1989). For each star,when possible, we give: 1) an acronym to enter SIMBAD (Set ofIdentifications Measurements and Bibliography for Astronomical Data) ofthe CDS (Centre de Donnees Astronomiques de Strasbourg). 2) the numberHIC of the HIPPARCOS catalogue (Turon 1992). 3) the CCDM number(Catalogue des Composantes des etoiles Doubles et Multiples) byDommanget & Nys (1994). For the cluster stars, a precise study hasbeen done, on the identificator numbers. Numerous remarks point out theproblems we have had to deal with.
| Far-ultraviolet stellar photometry - A field in Monoceros
FUV photometry of stars in a field in Monoceros in the wavelength rangefrom 1230 to 1600 A has been carried out using data from anelectrographic Schmidt camera carried on a sounding rocket. Ultravioletmagnitudes were extracted for 602 objects in the field. Fifty-eightpercent were tentatively identified with visible stars using the SIMBADdata base while another 25 percent are blends of objects too closetogether to separate with our resolution. Eleven of the UV objectscoincide with parts of the star clusters NGC 2169, NGC 2244, and NGC2264 in which individual stars cannot be resolved. As in previousstudies, the majority of the identified ultraviolet sources areidentified with early-stars. However, there are a significant number forwhich no such identification was possible, and we suggest that many ofthese are nearby white dwarfs.
| An Einstein Observatory SAO-based catalog of B-type stars
About 4000 X-ray images obtained with the Einstein Observatory are usedto measure the 0.16-4.0 keV emission from 1545 B-type SAO stars fallingin the about 10 percent of the sky surveyed with the IPC. Seventy-fourdetected X-ray sources with B-type stars are identified, and it isestimated that no more than 15 can be misidentified. Upper limits to theX-ray emission of the remaining stars are presented. In addition tosummarizing the X-ray measurements and giving other relevant opticaldata, the present extensive catalog discusses the reduction process andanalyzes selection effects associated with both SAO catalog completenessand IPC target selection procedures. It is concluded that X-rayemission, at the level of Lx not less than 10 exp 30 ergs/s, is quitecommon in B stars of early spectral types (B0-B3), regardless ofluminosity class, but that emission, at the same level, becomes lesscommon, or nonexistent, in later B-type stars.
| Spectroscopic binary orbits from ultraviolet radial velocities. Paper 2: Plaskett's Star
Not Available
| Catalog of BV magnitudes and spectral classes of 6000 stars
The present catalog, compiled at the Abastumani Observatory, contains BVmagnitudes and spectral classes of about 6000 stars up to V(lim) = 13.0min five circular areas of 18 sq deg located near the salactic-equatorplane. The catalog is intended for star-statistics studies ofstar-formation regions.
| Study of the AX MON system
The manner in which the common envelope of the AX Mon binary affects thespectral composition and spectral variation is studied, along with theinfluence of orbital motion on the envelope's absorption strength. Thecontinuous decrease in the envelope's extent during an 11-yearobservation period is noted. It is shown that periods of maximumextension coincide with periods of maximum emission. Photometricvariations are studied in three time-scales.
| Polarization in NGC2244
Not Available
| La mesure des vitesses radiales au prisme objectif - X - 4e liste de vitesses radiales déterminées au prisme objectif à vision directe
Not Available
| Not Available
Not Available
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Besorolás csoportokba:
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Pozíciós és asztrometriai adatok
| Csillagkép: | Egyszarvú |
| Rektaszcenzió: | 06h32m07.14s |
| Deklináció: | +06°02'08.4" |
| Vizuális fényesség: | 6.702 |
| Távolság: | 260.417 parszek |
| RA sajátmozgás: | -3 |
| Dec sajátmozgás: | 2.1 |
| B-T magnitude: | 6.65 |
| V-T magnitude: | 6.698 |
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