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3D mapping of the dense interstellar gas around the Local Bubble
We present intermediate results from a long-term program of mapping theneutral absorption characteristics of the local interstellar medium,motivated by the availability of accurate and consistent parallaxes fromthe Hipparcos satellite. Equivalent widths of the interstellar NaID-line doublet at 5890 Å are presented for the lines-of-sighttowards some 311 new target stars lying within ~ 350 pc of the Sun.Using these data, together with NaI absorption measurements towards afurther ~ 240 nearby targets published in the literature (for many ofthem, in the directions of molecular clouds), and the ~ 450lines-of-sight already presented by (Sfeir et al. \cite{sfeir99}), weshow 3D absorption maps of the local distribution of neutral gas towards1005 sight-lines with Hipparcos distances as viewed from a variety ofdifferent galactic projections.The data are synthesized by means of two complementary methods, (i) bymapping of iso-equivalent width contours, and (ii) by densitydistribution calculation from the inversion of column-densities, amethod devised by Vergely et al. (\cite{vergely01}). Our present dataconfirms the view that the local cavity is deficient in cold and neutralinterstellar gas. The closest dense and cold gas ``wall'', in the firstquadrant, is at ~ 55-60 pc. There are a few isolated clouds at closerdistance, if the detected absorption is not produced by circumstellarmaterial.The maps reveal narrow or wide ``interstellar tunnels'' which connectthe Local Bubble to surrounding cavities, as predicted by the model ofCox & Smith (1974). In particular, one of these tunnels, defined bystars at 300 to 600 pc from the Sun showing negligible sodiumabsorption, connects the well known CMa void (Gry et al. \cite{gry85}),which is part of the Local Bubble, with the supershell GSH 238+00+09(Heiles \cite{heiles98}). High latitude lines-of-sight with the smallestabsorption are found in two ``chimneys'', whose directions areperpendicular to the Gould belt plane. The maps show that the LocalBubble is ``squeezed'' by surrounding shells in a complicated patternand suggest that its pressure is smaller than in those expandingregions.We discuss the locations of several HI and molecular clouds. Usingcomparisons between NaI and HI or CO velocities, in some cases we areable to improve the constraints on their distances. According to thevelocity criteria, MBM 33-37, MBM 16-18, UT 3-7, and MBM 54-55 arecloser than ~ 100 pc, and MBM 40 is closer than 80 pc. Dense HI cloudsare seen at less than 90 pc and 85 pc in the directions of the MBM 12and MBM 41-43 clouds respectively, but the molecular clouds themselvesmay be far beyond. The above closest molecular clouds are located at theneutral boundary of the Bubble. Only one translucent cloud, G192-67, isclearly embedded within the LB and well isolated.These maps of the distribution of local neutral interstellar NaI gas arealso briefly compared with the distribution of both interstellar dustand neutral HI gas within 300 pc.Tables 1 and 2 are 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/411/447
| Observations of recently recognized candidate Herbig Ae/Be stars
The results of multicolor photometric and low-resolution spectroscopicobservations of 9 Herbig Ae/Be candidate stars are reported. This sampleincludes two newly recognized objects, MQ Cas and BD+11degr829 , whichwere found by means of cross-correlation of the IRAS Point SourceCatalogue and the catalogue of the galactic early-type emission-linestars (Wackerling \cite{wack}). Near-IR excesses were detected in twostars (AS 116 and BD+11degr829 ) for the first time. Algol-typevariability, which is not common in Herbig Ae/Be stars, was detected inMQ Cas and V1012 Ori. Spectral types are determined for MQ Cas, GSC1811-0767, HDE 244604, BD+11degr829 , V1012 Ori, AS116, AS117, and HDE290380 from low-resolution spectroscopy. Analysis of our and previouslypublished data suggests that 8 of the 9 objects are pre-main-sequencestars, while the last one, Hen 938, is more likely a B[e] supergiant.Based on observations collected at the Astrophysical National Laboratory(LNA -- Brazil), the South--African Astronomical Observatory, the DarkSky Observatory (USA), and the Tien--Shan Observatory (Kazakhstan)
| Stars with ISM Polarization Observed with HPOL
Polarization data are given for stars whose polarizations are mostlyinterstellar which were observed for various programs with theUniversity of Wisconsin spectropolarimeter (HPOL) during 1989-1994.
| Ultraviolet Imaging Telescope Near-Ultraviolet Bright Object Catalog
We present a photometric catalog of 2244 objects detected by theUltraviolet Imaging Telescope in the near-ultraviolet (NUV; 1650A <λ < 2900 A) during the Astro Space Shuttle mission. Sources inthe catalog are as faint as m_nuv_ ~ 18.8, or f_nuv_ ~ 1.1 x 10^16^ ergss^-1^ cm^-2^ A^-1^, but the survey is not complete to this level.Optical catalogs were used to cross identify sources and derive NUV - Vcolors. A majority of the objects (88%) do indeed have proposed opticalidentifications from catalogs, and most are stars. Our purpose increating the catalog is to form a database useful for identifying veryblue objects and performing Galactic UV stellar population studies.
| Observations of emission-line stars with IR excesses. II. Multicolor photometry of B[e] stars.
UBVRIJHK and UBVRI photometry of 10 peculiar Be stars obtained in1989-1994 using the 1-meter telescope of the Assy Observatory inKazakhstan is presented. The observed properties of the objects arebriefly described. This paper summarizes a part of an observationalprogram on early-type stars with emission-line spectra and infraredexcesses.
| A Continuation of Quasi-Periodic Behaviour for HD 45677 = FS CMa
Not Available
| Hyades and Sirius supercluster members brighter than magnitude (V) 7.1. II - Right ascension six to twelve hours
The present star sample is contained in the Bright Star Catalogue andits Supplement, augmented with a further supplement of 788 stars foundduring various observing programs over the past 40 years. Accurate,four-color and H-beta, or (RI), photometry is available for most of thesupercluster members. The criteria for membership are the comparisons ofthe proper motion, radial velocity, and luminosity obtained from thesupercluster parameters with the observed motions and the luminosityderived from the photometric parameters. New proper motions, based onall available catalogs, have been derived for the additional 788 starsdiscussed here, as well as all supercluster members.
| Variations in the U, B, V and u, v, b, Y magnitudes of the peculiar Be star HD 45677
Abstract image available at:http://adsabs.harvard.edu/abs/1976A&A....51..269F
| Ubvy photometry of some southern field stars.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1975A&AS...22..323H&db_key=AST
| Photoelectric UBV observations made on the Palomar 20-inch telescope
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1973MNRAS.164..133P&db_key=AST
| Is HD 45677 a variable star?
Abstract image available at:http://adsabs.harvard.edu/abs/1972A&A....17..142S
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Группы:
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Наблюдательные данные и астрометрия
| Созвездие: | Большой Пёс |
| Прямое восхождение: | 06h27m59.03s |
| Склонение: | -13°09'38.1" |
| Видимая звёздная величина: | 7.059 |
| Расстояние: | 166.667 парсек |
| Собственное движение RA: | -7.6 |
| Собственное движение Dec: | -1.7 |
| B-T magnitude: | 7.034 |
| V-T magnitude: | 7.057 |
Каталоги и обозначения:
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