%R 1999A&AS..134....1S %J-19 %A Simon V. %T Variations of the orbital periods in semi-detached binary stars with radiative outer layers. %M ds1524 %F 1999.01.07 %B A detailed analysis of the period changes of sixteen semi-detached binaries which contain only stars with radiative outer layers (ET-systems) has been performed and their respective O-C diagrams are brought and discussed. It was found that the course of the period variations is monotonic and in some systems the period is even constant. This detailed analysis of extensive sets of timings covering several decades brings a strong support to an earlier finding of Hall (1989) and develops it further. We show that all systems with the orbital periods shorter than nine days display constant period or its increase, with the exception of an uncertain case of V337 Aql. The course of the period variations in TT Aur appears more complex but the cyclic term can be plausibly explained by the third body. A search for general relations between the parameters of the systems and the period changes was undertaken. The mass ratio q appears to play a role in the period variations. Clear changes in systems with orbital periods shorter than 9 days were detected only for q>0.4 while constant periods are common in systems with q<0.4 in this period range. The sense of the secular changes in most systems is in accordance with the dominant conservative mass transfer in evolved binary and corresponds to the slow phase. The role of the evolutionary scenarios (case A versus B) and the influence of changes of the rotational angular momenta of the components are discussed. %K stars: activity - binaries: eclipsing - binaries: close - circumstellar matter - stars: early- type - stars: evolution %R 1999A&AS..134...21G %J-37 %A Georgiev L., Borissova J., Rosado M., Kurtev R., Ivanov G., Koenigsberger G. %T The Local Group dwarf irregular galaxy IC 1613. I. The young stellar content. %M ds7636 %F 1999.01.07 %B We obtained U-band photometry of 1500 stars and BV-band photometry of 3100 stars in a field centred on the HII regions of the northeast sector of the dwarf irregular galaxy IC 1613 - a member of the Local Group. The ages of the stellar populations were determined from the ((B-V)_0_,M_V_) color-magnitude using the isochrones from Padua's library. The stellar populations were split into three groups: the group of the youngest stars with ages of between 5 and 20Myr, the group of intermediate stars with ages of 200-300 Myr and the group of old stars with ages up to 10 Gyr. The slope of the Stellar Initial Mass Function (IMF) for blue stars is {Gamma}=-2.0+/-0.1 which is similar to that of other nearby galaxies. We investigated the stellar content of nine Hodge associations as well as that of seven new OB associations determined by cluster analysis. The total U, B and V magnitudes of eight Hodge open clusters and two new cluster candidates are given and there are six new possible nonstellar objects reported. The latter are most probably distant galaxies visible through the disk of IC 1613, which confirms the original suggestion of Baade that IC 1613 contains no bright globular clusters. %K galaxies: individual: IC 1613 - galaxies: stellar content - galaxies: star clusters and associations %R 1999A&AS..134...39S %J-52 %A Sumiyoshi K., Ibanez J.M., Romero J.V. %T Thermal history and structure of rotating protoneutron stars with relativistic equation of state. %M ds7607 %F 1999.01.07 %B We study the properties of general relativistic, slowly rotating, protoneutron stars. We explore the structure of rotating protoneutron stars with a wide range of the entropy per baryon, the lepton fraction and the baryonic mass in order to study the evolutionary history of protoneutron stars during the cooling epoch. We adopt the relativistic equation of state for dense matter derived within the relativistic mean field theory, which is based on the microscopic nuclear many-body framework, and checked by the experimental data of many nuclei. We provide broad information on the effect of rotation, temperature and lepton trapping of protoneutron stars with various baryonic masses. The evolutionary track of rotating protoneutron stars is examined and its implications are addressed. %K dense matter - stars: interiors - stars: neutron - stars: rotation %R 1999A&AS..134...53A %J-57 %A Adelman S.J. %T uvby photometry of the chemically peculiar stars. HD 15980, HR 1094, 33 Gem, and HD 115708. %M ds1595 %F 1999.01.07 %B Differential Stroemgren uvby photometry obtained with the Four College Automated Photoelectric Telescope shows that the hot HgMn star 33 Gem is photometrically constant. The Si star HD 15980 is found to be a variable whose period is significantly greater than 2 years. The unusual magnetic chemically peculiar Co star HR 1094 is discovered to be a low amplitude photometric variable with the magnetic field period of Hill & Blake (1996MNRAS.278..183H), 2.9761 days. The ephemeris for the magnetic chemically peculiar star HD 115708 of Wade et al. (1996A&A...307..500W) is confirmed with the error in its period of 5.07622 days being greatly reduced. The u, v, b, and y light curves for both HR 1094 and HD 115708 exhibit differences which indicate complex elemental photospheric abundance distributions. %K stars: individual: HD 15890, HR 1094, 33 Gem, HD 115708 - stars: chemically peculiar %R 1999A&AS..134...59H %J-73 %A Hilker M., Kissler-Patig M., Richtler T., Infante L., Quintana H. %T The central region of the Fornax cluster. I. A catalog and photometric properties of galaxies in selected CCD fields. %M ds1557 %F 1999.01.07 %B We present a photometric catalog (based on V and I photometry) of galaxies in the central regions of the Fornax galaxy cluster. Our 11 CCD fields cover 0.17 square degrees in total. The limiting surface brightness is around 24mag/arcsec^2^, similar to that of Ferguson's (1989) catalog, whereas our limiting total magnitude is around V=~22mag, about two magnitudes fainter. It is the surface brightness limit, however, that prevents us from detecting the counterparts of the faintest Local Group dwarf spheroidals. The photometric properties of all objects are presented as a catalog (Appendix A). The properties and fit parameters of the surface brightness profiles for a sub-sample are presented as a second catalog (Appendix B). We can only add 4 new dwarf galaxies to Ferguson's catalog. However, we confirm that the dwarf galaxies in Fornax follow a similar surface brightness - magnitude relation as the Local Group dwarfs. They also follow the color (metallicity) - magnitude relation seen in other galaxy clusters. A formerly suspected excess of dwarf galaxies surrounding the central giant cD galaxy NGC 1399 can finally be ruled out. An enhanced density of objects around NGC 1399 can indeed be seen, but it appears displaced with respect to the central galaxy and is identified as a background cluster at z=0.11 in Paper II of these series, which will discuss spectroscopic results for our sample. %K galaxies: clusters: individual: Fornax cluster - galaxies: fundamental parameters - galaxies: photometry - catalogs - galaxies: dwarf %R 1999A&AS..134...75H %J-86 %A Hilker M., Infante L., Vieira G., Kissler-Patig M., Richtler T. %T The central region of the Fornax cluster. II. Spectroscopy and radial velocities of member and background galaxies. %M ds7625 %F 1999.01.07 %B Radial velocities of 94 galaxies brighter than about V_tot_ = 20 mag in the direction of the central Fornax cluster have been measured. Except for 8 Fornax members, all galaxies lie in the background. Among the 8 members, there are 5 nucleated dwarf ellipticals that are already listed in the FCC (Ferguson's 1989). Two of the 3 ``new'' members are very compact and have surface brightnesses comparable to globular clusters, however their luminosities are in the range of dwarf elliptical nuclei. The measured line indices (especially Mg2, H{beta}, and iron) of the brighter of the compact objects suggest a solar metallicity, whereas the fainter compact object as well as the dE, Ns have line indices that are similar to those of old metal-poor globular clusters (GCs). However, with these data it is not possible to clearly classify the compact objects either as very bright globular clusters, isolated nuclei of dE, Ns, or even compact ellipticals. A background galaxy cluster at z=0.11 has been found just behind the center of the Fornax cluster. This explains the excess population of galaxies reported in Paper I. The brightest galaxy of the background cluster lies only 1.1' south of NGC 1399 and is comparable in absolute luminosity with the central Fornax galaxy itself. %K galaxies: clusters: individual: Fornax cluster - galaxies: distances and redshifts - galaxies: abundances - galaxies: dwarf %R 1999A&AS..134...87J %J-87 %A Jasinta D.M.D., Raharto M., Soegiartini E. %T Photographic observations of visual double stars. %M ds1578 %F 1999.01.07 %B The photographic observations of 72 visual double stars are presented. The observations were made in the years 1992-1997 with the 60-cm double refractor of the Bosscha Observatory at Lembang. %K astrometry - binaries: visual %R 1999A&AS..134...89T %J-101 %A Tuerler M., Paltani S., Courvoisier T.J.-L., Aller M.F., Aller H.D., Blecha A., Bouchet P., Lainela M., McHardy I.M., Robson E.I., Stevens J.A., Teraesranta H., Tornikoski M., Ulrich M.-H., Waltman E.B., Wamsteker W., Wright M.C.H. %T 30 years of multi-wavelength observations of 3C 273. %M ds7889 %F 1999.01.07 %B We present a wide multi-wavelength database of most observations of the quasar c obtained during the last 30 years. This database is the most complete set of observations available for an active galactic nucleus (AGN). It contains nearly 20000 observations grouped together into 70 light curves covering 16 orders of magnitude in frequency from the radio to the {gamma}-ray domain. The database is constituted of many previously unpublished observations and of most publicly available data gathered in the literature and on the World Wide Web (WWW). It is complete to the best of our knowledge, except in the optical (UBV) domain where we chose not to add all observations from the literature. In addition to the photometric data, we present the spectra of c obtained by the International Ultraviolet Explorer (IUE) satellite. In the X-ray domain, we used the spectral fit parameters from the literature to construct the light curves. Apart from describing the data, we show the most representative light curves and the average spectrum of c. The database is available on the WWW in a homogeneous and clear form and we wish to update it regularly by adding new observations. %K astronomical data bases: miscellaneous - quasars: general - quasars: individual: 3C 273 - radio continuum: galaxies - ultraviolet: galaxies - X-rays: galaxies %R 1999A&AS..134..103C %J-113 %A Cassisi S., Castellani V., Degl'Innocenti S., Salaris M., Weiss A. %T Galactic globular cluster stars: From theory to observation. %M h0955 %F 1999.01.07 %B We use evolutionary calculations presented in a recent paper (Cassisi et al. 1997a, hereinafter Paper I) to predict B, V, I magnitudes for stars in galactic globulars. The effect of the adopted mixing length on stellar magnitudes and colors is discussed, showing that the uncertainty on such a theoretical parameter prevents the use of MS stars as bona fide theoretical standard candles. However, comparison with Hipparcos data for field subdwarfs discloses a substantial agreement between theory and observation. Present predictions concerning the magnitude of TO and of HB stars are compared with similar results appeared in the recent literature. We find that our predictions about the dependence on metallicity of ZAHB magnitudes appear in good agreement with observational constraints as recently discussed by Gratton et al. (1997c). We present and discuss a theoretical calibration of the difference in magnitude between HB and TO as evaluated with or without element sedimentation. The effect of a variation of the original helium content on the magnitude of MS, TO and HB stars is explored and discussed. Finally we use theoretical HB magnitudes to best fit the CM diagram of M 68 and M 5, taken as representative of metal poor and intermediate metallicity galactic globulars, deriving an age of 11+/-1.0Gyr and 10+/-1.0Gyr, respectively, for the adopted chemical compositions, plus an additional uncertainty of +/-1.4Gyr if the uncertainty on the chemical composition is taken into account. This result is discussed on the basis of current evaluations concerning cluster ages and distance moduli. %K stars: evolution - HR diagram - horizontal-branch - Population II %R 1999A&AS..134..115S %J-128 %A Slysh V.I., Val'tts I.E., Kalenskii S.V., Voronkov M.A., Palagi F., Tofani G., Catarzi M. %T The Medicina survey of methanol masers at 6.7GHz. %M ds1575 %F 1999.01.07 %B A survey of Class II methanol masers at 6.7GHz was made in the Northern hemisphere with the 32-m Medicina radio telescope. 42 objects were detected, 20 of them are new detections at 6.7GHz. Our results show that the detection rate of 6.7GHz masers toward the inner part of the Galaxy is higher than in other directions. It is confirmed that most of the methanol masers are associated with faint compact HII regions. The 6.7GHz methanol masers show large velocity dispersion and large velocity offset from the velocity of parent molecular clouds. %K masers - ISM: molecules; HII regions - radio lines: ISM %R 1999A&AS..134..129K %J-133 %A Kohoutek L., Mayer P., Lorenz R. %T Photometry and spectroscopy of the central star of the Trifid nebula. %M ds1495 %F 1999.01.07 %B UBV photometry of the central star of the Trifid nebula - HD 164492, which has so far been suspected of photometric as well as of radial velocity variability - is presented. The results of our photometry do not confirm any variability. Moreover, based on new high resolution CCD spectra any radial velocity variability can be discarded. Photometry of several other members of the multiple stellar system is included; according to this photometry, the system is a physical one. Equivalent widths for the main component of HD 164492 are given. Positions measured on CCD exposures are presented too. %K binaries: visual - stars: early-type - stars: individual: HD 164492 - ISM: Trifid nebula %R 1999A&AS..134..135S %J-148 %A Starck J.L., Abergel A., Aussel H., Sauvage M., Gastaud R., Claret A., Desert X., Delattre C., Pantin E. %T ISOCAM data processing. %M ds1478 %F 1999.01.07 %B The ISOCAM infrared camera is one of the four instruments on board the ISO (Infrared Space Observatory) spacecraft which was launched successfully on 1995 November 17. It operates in the 2.5-18{mu}m range, and was developed by the ISOCAM consortium lead by the French Service d'Astrophysique of CEA Saclay. This paper presents different algorithms which can be used for the calibration of ISOCAM data. Advantages and limitations of each method are also outlined. A range of examples illustrates the results. %K methods: data analysis - instrumentation: interferometers - infrared: general %R 1999A&AS..134..149D %J-159 %A Donati J.-F., Catala C., Wade G.A., Gallou G., Delaigue G., Rabou P. %T A dedicated polarimeter for the MuSiCoS echelle spectrograph. %M ds7787 %F 1999.01.07 %B We present in this paper the technical characteristics of a new polarimetric unit dedicated to the MuSiCoS echelle spectrograph. The first test runs indicate that our instrument is very good at measuring polarisation or depolarisation structures in line profiles. It is therefore one of the very few facilities worldwide for studying magnetic topologies of active and chemically peculiar stars through rotational modulation of linearly and circularly polarised Zeeman signatures in line profiles. It is also a very interesting tool for investigating geometries of non-axisymmetric circumstellar environments through depolarisation of spectral lines formed within the scattering envelope. %K stars: magnetic fields - stars: circumstellar matter - line: profiles - polarization - instrumentation: polarimeters %R 1999A&AS..134..161M %J-172 %A Marks R.D., Vernin J., Azouit M., Manigault J.F., Clevelin C. %T Measurement of optical seeing on the high antarctic plateau. %M ds7288 %F 1999.01.07 %B Results from the 1995 season of site-testing experiments at the South Pole are presented, in which the seeing was measured using balloon-borne microthermal probes. Our analysis shows a marked division of the atmosphere into two characteristic regions: (i) a highly turbulent boundary layer (0-220m) associated with a strong temperature inversion and wind shear, and (ii) a very stable free atmosphere. The mean seeing, averaged over 15 balloon flights, was measured to be 1.86", of which the free atmosphere component was only 0.37". The seeing from ~200 m upward is superior to the leading mid-latitude sites (e.g. Fuchs 1995; Roddier et al. 1990) by almost a factor of two. The results are in good agreement with optical seeing data obtained by a differential image motion monitor on three of the five occasions when the two measurements were performed simultaneously. The boundary layer winds are of katabatic origin, and so we may consider the possibility of exceptional seeing conditions from surface level at other locations on the plateau such as Domes A and C, where there is little or no katabatic wind. In addition, the proximity of the optical turbulence to the focus of a telescope situated at ground level is a highly favourable situation for the use of adaptive optics, since the wavefront spatial coherence scale is related to the altitude of the turbulent layers producing the image distortion. Some comparisons are made between the relevant adaptive optics parameters measured at the South Pole and Cerro Paranal, one of the best mid-latitude sites. %K atmospheric effects - balloons - instrumentation: miscellaneous - methods: observational - site testing %R 1999A&AS..134..173V %J-186 %A Viateau B., Requieme Y., Le Campion J.F., Benevides-Soares P., Teixeira R., Montignac G., Mazurier J.M., Monteiro W., Bosq F., Chauvet F., Colin J., Daigne G., Desbats J.M., Dominici T.P., Perie J.P., Raffaelli J., Rapaport M. %T The Bordeaux and Valinhos CCD meridian circles. %M ds7937 %F 1999.01.07 %B A first CCD 512 x 512 camera working in scan mode (declination field 14') was mounted in 1994 on the Bordeaux CCD meridian circle. After a testing period, this camera was installed on the Valinhos CCD meridian circle (near Sao Paulo, Brazil), as part of a collaboration between Bordeaux Observatory and the Instituto Astronomico e Geofisico of Sao Paulo. A second improved CCD 1024 x 1024 camera, with a declination field of 28', was installed on the Bordeaux instrument in June 1996. The mean internal precision of a single observation is about 0.04'' in both coordinates for 9<=V<=14. In the same magnitude range, magnitudes can also be obtained with an internal precision of about 0.05 mag. Both instruments can participate efficiently in extending the Hipparcos- Tycho frame, during the next decade. Among other duties, the Bordeaux CCD meridian circle is being used since January 1997 for completing the Meridien 2000 project. The characteristics of both instruments and some results obtained with them are presented in this paper. %K astrometry - reference systems - instrumentation: miscellaneous %R 1999A&AS..134..187B %J-192 %A Bellucci G. %T Imaging spectroscopy of planetary surfaces: Improving the spatial contrast. %M ds1504 %F 1999.01.07 %B A method to improve the spatial contrast of planetary images acquired by means of push-broom imaging spectrometers is presented. The technique allows to better recognize the boundaries of spatially coherent units with different mineralogic composition. We have analyzed the case of a surface observed by means of an imaging spectrometer from a ground-based telescope. It is assumed that image degradation is mainly due to the atmosphere placed between the surface remotely sensed and the instrumentation. A possible extension to space born imaging spectrometers affected by random errors of the pointing system is also discussed. An example relative to the observation of the Moon is given. %K instrumentation: spectrographs - techniques: spectroscopic - planets and satellites: general - space vehicles - methods: statistical %R 1999A&AS..134..193F %J-200 %A Fusco T., Veran J.-P., Conan J.-M., Mugnier L.M. %T Myopic deconvolution method for adaptive optics images of stellar fields. %M ds1570 %F 1999.01.07 %B The atmospheric turbulence severely limits the angular resolution of ground based telescopes. When using Adaptive Optics compensation, the wavefront sensor data permit the estimation of the residual PSF. Yet, this estimation is imperfect. A ``myopic'' deconvolution method which takes into account this estimation and its associated noise is presented. This technique is applied to adaptive optics corrected images of star fields. It is based on a stochastic approach which uses the available information about the object and about the PSF. This technique allows the simultaneous restoration of star parameters (position with sub-pixel precision and accurate photometry) and of the PSF. The algorithm is successfully applied both to simulated and to experimental data. %K techniques: adaptive optics - methods: image processing