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Pulkovo compilation of radial velocities for 35495 stars in a common system.
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| CaII K interstellar observations towards early-type disc and halo stars - distances to intermediate- and high-velocity clouds
We compare existing high spectral resolution(R=λ/Δλ~ 40000) CaII K observations(λair= 3933.66 Å) towards 88 mainly B-typestars, and new observations taken using the Intermediate dispersionSpectrograph and Imaging System (ISIS) on the William Herschel Telescopeat R~ 10000 towards three stars taken from the Palomar-Green Survey,with 21-cm HI emission-line profiles, in order to search for opticalabsorption towards known intermediate- and high-velocity cloudcomplexes. Given certain assumptions, limits to the gas phase abundanceof CaII are estimated for the cloud components. We use the data toderive the following distances from the Galactic plane (z). (i)Tentative lower z-height limits of 2800 and 4100 pc towards complex Cusing lack of absorption in the spectra of HD341617 and PG0855+294,respectively. (ii) A weak lower z-height of 1400 pc towards complexWA-WB using lack of absorption in EC09470-1433 and a weak lower limit of2470 pc using lack of absorption in EC09452-1403. (iii) An upperz-height of 2470 pc towards a southern intermediate-velocity cloud (IVC)with vLSR=-55 km s-1 using PG2351+198. (iv)Detection of a possible IVC in CaII absorption at vLSR=+52 kms-1 using EC20104-2944. No associated HI in emission isdetected. At this position, normal Galactic rotation predicts velocitiesof up to ~+25 km s-1. The detection puts an upper z-height of1860 pc to the cloud. (v) Tentative HI and CaII K detections towards anIVC at ~+70 km s-1 in the direction of high-velocity cloud(HVC) complex WE, sightline EC06387-8045, indicating that the IVC may beat a z-height lower than 1770 pc. (vi) Detection of CaII K absorption inthe spectrum of PG0855+294 in the direction of IV20, indicating thatthis IVC has a z-height smaller than 4100 pc. (vii) A weak lowerz-height of 4300 pc towards a small HVC with vLSR=+115 kms-1 at l, b= 200°, + 52°, using lack of absorption inthe CaII K spectrum of PG0955+291.
| CaII K interstellar observations towards early-type disc and halo stars
We present high-resolution (R=λ/Δλ~ 40000) CaII Kinterstellar observations (λair= 3933.66Å)towards 88 mainly B-type stars, of which 74 are taken from theEdinburgh-Cape or Palomar-Green surveys, and 81 have |b| > 25°.The majority of the data come from previously existing spectroscopy,although also included are 18 new observations of stars with echellespectra taken with UVES on the Very Large Telescope UT2 (Kueyen). Some49 of the sample stars have distance estimates above the Galactic plane(|z|) >= 1 kpc, and are thus good probes of the halo interstellarmedium. Of the 362 interstellar Ca K components that we detect, 75 (21per cent) have absolute values of their LSR velocity values exceeding 40km s-1. In terms of the deviation velocity for the sightlineswith distance estimates, 46/273 (17 per cent) of components havevelocity values exceeding those predicted by standard Galactic rotationby more than 40 km s-1. Combining this data set with previousobservations, we find that the median value of the reduced equivalentwidth (REW) of stars with |z| >= 1 kpc (EW×sin|b|) is ~115mÅ (n= 80), similar to that observed in extragalactic sightlinesby Bowen. Using data of all z distances, the REW at infinity is found tobe ~130 mÅ, with the scaleheight (l) of the CaII K column densitydistribution being ~800 pc (n= 196) and reduced column density atinfinity of log[N(CaII K) cm-2]~12.24. This implies that ~30per cent of CaII K absorption occurs at distances exceeding ~1 kpc. Fornine sightlines with distance exceeding 1 kpc and with a companionobject within 5°, we find that all but two have values of CaIIreduced equivalent width the same to within ~20 per cent, when the REWof the nearest object is extrapolated to the distance of the further ofthe pair, and assuming l= 800 pc. For 29 of our sightlines with |z|>= 1 kpc and a HI detection from the Leiden-Dwingeloo survey(beamsize of 0.5°), we find log(N(CaII K)/N(HI)) ranging from -7.4to -8.4. Values of the CaII K abundance relative to neutral hydrogen(log[N(CaIIK)cm-2]-log[N(HI)cm-2]) are found to bemore than ~0.5dex higher in stars with distances exceeding ~100 pc, whencompared with the (log[N(CaII K) cm-2]-log[N(Htot) cm-2]) values found in nearbysightlines such as those in Wakker & Mathis (2000). Finally, stellarCaII K equivalent widths of the sample are determined for 26 objects.
| BVR Photometry of Northern Hemisphere Luminous Stars. III. LS and HD Stars
CCD-based BVR photometry of 48 previously unobserved stars drawn fromvolumes V and VI of the Luminous Stars in the Northern Milky Way,Luminous Stars in the Southern Milky Way, and HD catalogs is reported.
| Radial velocities. Measurements of 2800 B2-F5 stars for HIPPARCOS
Radial velocities have been determined for a sample of 2930 B2-F5 stars,95% observed by the Hipparcos satellite in the north hemisphere and 80%without reliable radial velocity up to now. Observations were obtainedat the Observatoire de Haute Provence with a dispersion of 80Ä,mm(-1) with the aim of studying stellar and galactic dynamics.Radial velocities have been measured by correlation with templates ofthe same spectral class. The mean obtained precision is 3.0 km s(-1)with three observations. A new MK spectral classification is estimatedfor all stars. Based on observations made at the Haute ProvenceObservatory, France and on data from The Hipparcos Catalogue, ESA.Tables 4, 5 and 6 are only available in electronic form at the CDS viaanonymous ftp to cdsarc.u-strasbg.fr or viahttp://cdsweb.u-strasbg.fr/Abstract.htm
| Radial velocity measurements. I - Ground-based observations of the program stars for the HIPPARCOS satellite
The radial velocities of 272 stars brighter than m(pg) = 8.5 aredetermined by digital microphotometric measurement of plates obtainedwith dispersion 80 A/mm using the Marly slit spectrograph on the 120-cmtelescope of the Observatoire de Haute Provence. The objects wereselected as probable members of the input catalog for the ESA Hipparcosastrometric satellite. The measurement techniques and data-reductionprocedures are described in detail, and the results are presented inextensive tables and graphs and briefly characterized.
| The galactic reddening law - The evidence from uvby-beta photometry of B stars
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1985A&A...142..189T&db_key=AST
| Four-colour photometry of B stars north of B = + 45 deg and comparison with the south
Four-color photometry of 33 Henry Draper B stars north of b = + 45 degis presented. Most are little-reddened B or intermediate-A stars. A newAm star is discovered. The new measures essentially complete uvbyphotometry of all HD B stars within 45 deg of either galactic pole. Thenorthern and southern cones of HD B stars are compared, and selectioneffects deduced. Far from the galactic plane, it appears that B starsmay be equally distributed north and south of the plane; closer to thesun, an asymmetry associated with Gould's Belt is evident.
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Pozíciós és asztrometriai adatok
| Csillagkép: | Oroszlán |
| Rektaszcenzió: | 11h15m48.32s |
| Deklináció: | -02°17'57.5" |
| Vizuális fényesség: | 8.892 |
| Távolság: | 469.484 parszek |
| RA sajátmozgás: | -8.1 |
| Dec sajátmozgás: | -2.2 |
| B-T magnitude: | 8.764 |
| V-T magnitude: | 8.882 |
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