%R 1998A&AS..133..149M
%J-162
%A Martin C., Mignard F., Hartkopf W.I., McAlister H.A.
%T Mass determination of astrometric binaries with Hipparcos. III. New results for 28 systems.
%M ds7641
%F 1998.11.27
%B This paper is the third of a series devoted to the determination of stellar masses from Hipparcos data. This is a continuation of Martin et al. (1997A&AS..122..571M), who introduced the theory and assessed the performance of the method from simulated data, and of a second paper with the first results for 46 systems, (Martin & Mignard, 1998A&A...330..585M). The orbit file maintained by the CHARA group and new publications of orbital elements made the processing of 70 additional candidate systems
possible, including 28 of the 145 systems already tested in the previous work. Significant results were obtained on 22 systems, with relative accuracy better than 25% for the masses of 17 binaries. New estimates are also given for 6 systems previously investigated, thanks to reliable values of the magnitude difference from the Hipparcos catalogue (ESA, 1997HIP...C......0E). New orbital elements are proposed for HIP 12623 (12 Persei) from speckle/spectroscopic measurements. Results are
discussed for each system, alongside the mass-luminosity relation based on Hipparcos magnitudes and distances.
%K stars: fundamental parameters - binaries: visual - astrometry

%R 1998A&AS..133..163F
%J-169
%A Fan J.H., Adam G., Xie G.Z., Cao S.L., Lin R.G., Qin Y.P., Copin Y., Bai J.M., Zhang X., Li K.H.
%T The infrared and optical variability of OJ 287.
%M ds7613
%F 1998.11.27
%B In this paper, the long-term historical optical (UBVRI) and near-infrared (JHK) data are presented with some new observations in the optical (February 1994-January 1995) and near-infrared (November 1995) bands included for BL Lac object OJ 287. The new optical data in V-band are in agreement with the results reported by other authors (Sillanpaa et al., 1996, ASP Conf. Ser. 110, 74; Arimoto et al., 1997PASP..109..300A), a close correlation between the color index of B-V and the magnitude V has been obtained from
our new observations. The new infrared observations presented here indicate that the source was at a high level in the infrared band during the observation period. From the available literature, we have got that the largest variations for UBVRIJHK bands are respectively: {Delta}U=4.72mag ; {Delta}B=5.93mag; {Delta}V=5.18mag; {Delta}R=4.45mag; {Delta}I=4.07mag; {Delta}J=3.87mag; {Delta}H=3.78mag; {Delta}K=3.54mag. A strong correlation is found between the
optical and near-infrared bands when the DCF method is used, which suggests that these two bands have the same emission mechanism.
%K BL Lacertae objects: individual: OJ 287; general - infrared: galaxies

%R 1998A&AS..133..171S
%J-179
%A Surace C., Comte G.
%T The Marseille Schmidt survey for active star-forming galaxies. I. Data on 92 emission line objects in two fields.
%M ds7499
%F 1998.11.27
%B We present data from a moderately deep spectroscopic Schmidt survey (B_lim_ = 17.5) of ``active galaxies'' selected by the presence of emission lines in their spectra and/or their UV excess. The redshift, magnitudes, color and diameter reduction methods have been discussed in a previous paper. Here we explain the emission line equivalent width determination method.
92 emission line objects have been found in two adjacent fields (approximately 50{deg}^2^) in the direction of the southern extension of the Virgo cluster. We give a catalog containing positions, photographic R and B magnitudes, U-R colors, effective diameters, redshifts, equivalent widths and intensity ratios of the [OIII]{lambda}{lambda}4959,5007, H_{beta}_ and [OII]{lambda}3727 emission lines. On these fields, we evaluate the completeness limit of the survey at a pseudo B
magnitude value of 15.7. A more elaborate astrophysical analysis will appear in a forthcoming paper.
%K surveys - galaxies: general - galaxies: starburst - methods: data analysis

%R 1998A&AS..133..181M
%J-196
%A Makarova L.N., Karachentsev I.D.
%T CCD imaging of twenty nearby isolated irregular galaxies.
%M ds1565
%F 1998.11.27
%B We present B, V and I CCD stellar photometry for a sample of 20 field irregular dwarf galaxies. Their corrected radial velocity is V_0_<500km/s. Most of them have been resolved into stars for the first time. Based on photometry of their brightest blue stars we have derived the following distances: 5.9Mpc (UGC 685), 5.4Mpc (UGC 1281), 7.2Mpc (UGC 3303), 7.0Mpc (UGC 3476), 7.3:Mpc (UGC 3600), 7.2:Mpc (UGC 3698), 7.9Mpc (NGC 2337), 8.6Mpc (UGC 3817), 5.7Mpc
(UGC 3860), 5.6Mpc (UGC 4426), >=7.9Mpc (F 565-v1), 7.4:Mpc (UGC 5086), 7.1Mpc (UGC 5272), 5.9Mpc (UGC 5340), 7.1Mpc (UGC 5427), 2.7:Mpc (UGC 5456), 6.6Mpc (NGC 3274), 9.3Mpc (UGC 5889), 5.2Mpc (NGC 5238), and 8.0Mpc (UGC 9405). Our sample exhibits diverse morphological properties evidently caused by their different starburst activity. The galaxy sample has a median integral absolute magnitude M_B_=-14.6 and a median integral colour (B-V)_T_=+0.47. One dwarf,
UGC 5340, stands out by its very blue colour, (B-V)_T_=+0.18, and by its high M(HI)/L ratio, as expected for young galaxies. Four objects of the sample are IRAS sources. Being well isolated systems, the considered galaxies may be used to estimate a local value of the Hubble parameter, H=V_0_/D. For half of the sample galaxies their individual H- values are concentrated within [58-68]km/s/Mpc with a median of 65km/s/Mpc.
%K galaxies: distances - galaxies: stellar content - galaxies: dwarf; irregular

%R 1998A&AS..133..197A
%J-200
%A Adelman S.J., Pi C.-L.M., Rayle K.E.
%T uvby photometry of 33 Tauri, HD 50169, and HR 7786 and an assessment of FCAPT comparison stars.
%M ds1566
%F 1998.11.27
%B Differential Stroemgren uvby photometric observations from the Four College Automated Photoelectric Telescope are presented for the ellipsoidal variable 33 Tauri, and the magnetic Chemically Peculiar stars HD 50169 and HR 7786. We confirm that Hube's period of 2.975272 days for 33 Tau is correct. HD 50169 is a constant MCP star. HR 7786 is a large amplitude class member confirming Winzer's discovery, but its period is 8.5297 days. Its comparison star, HR 7721, a
spectroscopic binary B7 V star, is variable with an amplitude of order 0.1mag, but of indeterminant period. In addition Hipparcos photometry of the comparison and check stars for early type stars whose photometry is being obtained with the FCAPT is reviewed to ascertain the stability of these stars.
%K stars: individual: 33 Tau, HR 7786, HD 50169 - stars: chemically peculiar

%R 1998A&AS..133..201I
%J-209
%A Iyengar K.V.K., MacConnell D.J.
%T Spectral classification of unidentified IRAS sources with F_{nu}_(12{mu}m)>=F_{nu}_(25{mu}m).
%M ds1490
%F 1998.11.27
%B Spectral types of a large number of unidentified IRAS Point Sources with F_{nu}_(12{mu}m)>=F_{nu}_(25{mu}m) were determined; the majority are faint, oxygen-rich (M-type) or carbon-rich giant stars. The Guide Star Catalog has been used to find the photographic magnitudes of the newly classified IRAS sources with quality-3 flux densities at 12{mu}m in order to determine their B_j_-[12] colour index. The dependence of this and of the IRAS indices on spectral type is
determined and discussed. The mean [12]-[25] colour of the M-type stars is found to increase monotonically from M3 to M6 and then levels off. Comparison of the [12]-[25] colours of these faint IRAS M stars with those of Bright Star Catalog M stars indicates that, at all types, the mean [12]-[25] index of the former group is higher than that of the latter by at least 0.2 magnitude, and this is found to be significant at the 95% confidence level. Comparison of the quality-3,
mean [25]-[60] colours of the newly-classified, faint M stars with those of BSC stars over the same spectral type also shows the same trend. Possible reasons for this difference are discussed. The percentage of variable sources as a function of spectral type is seen to sharply increase from a nearly constant value of about 25% for sources of spectral type M3 to M7 to a value of about 50% at M10. The mean [12]-[25] colours of the IRAS unidentified sources (within the limits of
the errors on their mean values) appear to be rather insensitive to the degree of variability.
%K stars: AGB - stars: carbon - stars: late-type - stars: mass-loss - infrared: stars

%R 1998A&AS..133..211H
%J-216
%A Hric L., Petrik K., Urban Z., Hanzl D.
%T Photometry of the dust nova V705 Cassiopeiae.
%M ds7679
%F 1998.11.27
%B We present the results of our UBV photoelectric photometry of V705 Cas (Nova Cassiopeiae 1993) obtained at the Skalnate Pleso, Stara Lesna, Hlohovec and Brno Observatories. The observations cover the light curve development of this nova over its stages of dust formation and disappearance of the envelope. The results of the light curve analysis are presented. We have also used the visual brightness estimates of V705 Cas by the members of the VSNET network as an auxiliary
data set in order to determine the nova's brightness behaviour as accurately as possible. The basic parameters of the brightness decline of the nova t_2,B_=40d, t_2,V_=33d, t_3,B_=63d, t_3,V_=61d, with the accuracy not worse than one day, were obtained on the basis of our light curves. The relevant value of M_B_=(-7.27+/-0.3)mag and the value M_V_=(-7.32+/-0.22)mag in the maximum of brightness were derived. The corresponding value of the mass of the white
dwarf component of the presumable underlying nova binary is M_WD_=(0.79+/-0.06)M_{sun}_. The colour excess at brightness maximum is E_B-V_=0.56mag and the corresponding value of the distance r=(1.67+/-0.34)kpc. This value of the distance is very probably underestimated due to the strong extinction by the dust envelope of the nova. The general problem of the use of statistical calibrations as well as that of the distance determination for dust novae is discussed.
%K stars: novae, cataclysmic variables - stars: individual: V705 Cas

%R 1998A&AS..133..217F
%J-220
%A Fan J.H., Xie G.Z., Lin R.G., Qin Y.P.
%T Infrared variability of BL Lacertae.
%M ds7295
%F 1998.11.27
%B In this paper, the historic light curves of BL Lacertae in the infrared (JHK) bands have been constructed from the published literature. Maximum variations of {Delta}J=2.29mag , {Delta}H=2.42mag , and {Delta}K=2.93mag and average color indices of J-H=0.78+/-0.11, H-K=0.78+/-0.12, and J-K=1.55+/-0.13 have been found. The relation between the color index and the brightness of the source and the correlation of color-color indices have been investigated. Our
analysis shows that there is no clear correlation between the color index and the brightness, and the emission mechanism is non-thermal in the near-infrared.
%K infrared: galaxies - BL Lacertae objects: individual: BL Lac

%R 1998A&AS..133..221S
%J-226
%A Soubiran C., Katz D., Cayrel R.
%T On-line determination of stellar atmospheric parameters T_eff_, logg, [Fe/H] from ELODIE echelle spectra. II. The library of F5 to K7 stars.
%M ds1567
%F 1998.11.27
%B A library of 211 echelle spectra taken with ELODIE at the Observatoire de Haute-Provence is presented. It provides a set of spectroscopic standards covering the full range of gravities and metallicities in the effective temperature interval [4000K, 6300K]. The spectra are straightened, wavelength calibrated, cleaned of cosmic ray hits, bad pixels and telluric lines. They cover the spectral range [440nm, 680nm] with an instrumental resolution of 42000. For each star,
basic data were compiled from the Hipparcos catalogue and the Hipparcos Input Catalogue. Radial velocities with a precision better than 100m/s are given. Atmospheric parameters (T_eff_, logg, [Fe/H]) from the literature are discussed. Because of scattered determinations in the bibliography, even for the most well-known stars, these parameters were adjusted by an iterative process which takes account of common or different spectral features between the standards, using
our homogeneous set of spectra. Revised values of effective temperature, gravity and metallicity are proposed. They are still consistent with the literature, and also lead to the self-consistency of the library, in the sense that similar spectra have similar atmospheric parameters. This adjustment was performed by using step by step a method based on the least square comparison of carefully prepared spectra, which was originally developed for the on-line estimation of the
atmospheric parameters of faint field stars (companion paper in the main journal).
%K atlases - stars: abundances - stars: atmospheres - stars: fundamental parameters

%R 1998A&AS..133..227D
%J-228
%A Dimitrijevic M.S., Sahal-Brechot S.
%T Stark broadening of spectral lines of multicharged ions of astrophysical interest. XXII. K VIII and K IX spectral lines.
%M ds1585
%F 1998.11.27
%B By using the semiclassical-perturbation formalism, we have calculated electron-, proton-, and He III-impact line widths and shifts for 4 K VIII and 30 K IX multiplets, of interest for analysis, investigation and modeling of different plasmas in solar and stellar subphotospheric layers research and plasma physics. The obtained results are presented as a function of temperature and perturber density. Results are compared with other theoretical estimates, based on
regularities and systematic trends.
%K lines: profile - atomic data

%R 1998A&AS..133..229T
%J-244
%A Terzi N., Sahal-Brechot S., Ben Lakhdar Z.
%T Stark profiles of infrared helium lines.
%M ds7702
%F 1998.11.27
%B We have calculated Stark widths and shifts of some infrared helium lines that are missing and that are important for modellisation of the atmospheres of hot early-type stars. These calculations are based on the impact and quasistatic theory and semi-classical approximation. The provided data are displayed for a grid of temperatures (10^4^ to 10^5^K) and electron densities (10^10^ to 10^13^cm^-3^) typical of hot early-type stars. We also discuss the conditions of use of
our data for astrophysical purposes.
%K stars: early-type - infrared: general - atomic data - lines: profiles

%R 1998A&AS..133..245G
%J-248
%A Galavis M.E., Mendoza C., Zeippen C.J.
%T Atomic data from the IRON Project. XXXII. On the accuracy of the effective collision strength for the electron impact excitation of the quadrupole transition in Ar III.
%M ds1564
%F 1998.11.27
%B Since Burgess et al. (1997, J. Phys. B 30, 33) have recently questioned the accuracy of the effective collision strength calculated in the IRON Project for the electron impact excitation of the 3s^2^3p^4^ ^1^D-^1^S quadrupole transition in Ar III, an extended R-matrix calculation has been performed for this transition. The original 24-state target model was maintained, but the energy regime was increased to 100 Ryd. It is shown that in order to ensure convergence of the partial wave
expansion at such energies, it is necessary to take into account partial collision strengths up to L=30 and to ``top-up'' with a geometric series procedure. By comparing effective collision strengths, it is found that the differences from the original calculation are not greater than 25% around the upper end of the common temperature range and that they are much smaller than 20% over most of it. This is consistent with the accuracy rating (20%) previously assigned to
transitions in this low ionisation system. Also the present high-temperature limit agrees fairly well (15%) with the Coulomb-Born limit estimated by Burgess et al., thus confirming our previous accuracy rating. It appears that Burgess et al., in their data assessment, have overextended the low-energy behaviour of our reduced effective collision strength to obtain an extrapolated high-temperature limit that appeared to be in error by a factor of 2.
%K atomic and molecular data

%R 1998A&AS..133..249D
%J-255
%A Donnelly D., Bell K.L., Keenan F.P.
%T Photoionization cross sections for Fe XVIII.
%M h0926
%F 1998.11.27
%B A sophisticated R-matrix calculation is performed for the photoionization of the fine-structure levels of the ground state of Fe XVIII. High resolution total and partial cross sections are obtained with the later restricted to the cases of the Fe XVIII ion being left in one of the fine-structure levels corresponding to the energetically lowest 11 LS states of Fe XIX after ionization. Both sets of cross sections are obtained using the Breit-Pauli R-matrix approximation
which allows for the possibility of fine structure splitting in both resonances and thresholds. We find extensive resonance structure in the 99 to 113 Ryd photon energy range, a high percentage of which arises from 2p photoionization leaving the ion in the 2s^2^2p^4^ ^3^P_2_ state while the background cross section is constructed almost exclusively of 2p and 2s photoionization with the former dominant in both photoionization cases. Relativistic effects are found to be
important in obtaining accurate threshold positions as well as being responsible for a significant drop in the background cross section in comparison with various calculations done in LS coupling. We believe that this is the first relativistic calculation for this ion.
%K atomic data - atomic processes

%R 1998A&AS..133..257K
%J-269
%A Kisielius R., Storey P.J., Davey A.R., Neale L.T.
%T Recombination coefficients for NeII lines at nebular temperatures and densities.
%M ds7807
%F 1998.11.27
%B We calculate total recombination coefficients for Ne^2+^ + e^-^ and effective recombination coefficients for the formation of selected lines of NeII. New photoionization data are calculated which accurately map the near threshold resonances and are used to derive recombination coefficients for principal quantum numbers, n<=15, including radiative and dielectronic recombination. Cascading from higher states is included, allowing for the effects of finite electron density
in a hydrogenic approximation. The effects of population in the excited states of the recombining ion are investigated.
%K atomic data - H II regions - planetary nebulae: general

%R 1998A&AS..133..271G
%J-284
%A Greve A., Kramer C., Wild W.
%T The beam pattern of the IRAM 30-m telescope. (a reflector with several surface error distributions)
%M ds1442
%F 1998.11.27
%B Total power scans across the Moon around New Moon (mostly day time) and Full Moon (night time) at 3.4mm (88GHz), 2.0mm (150GHz), 1.3mm (230GHz), and 0.86mm (350GHz) wavelength are used to derive the beam pattern of the IRAM 30-m telescope to a level of approximately -30dB (0.1%) and, dependent on wavelength, to a full width of 1000-1400''. From the reflector surface construction and application of the antenna tolerance theory we find that the measurable beam
consists of the diffracted beam, two underlying error beams which can be explained from the panel dimensions, and a beam deformation mostly due to large-scale transient residual thermal deformations of the telescope structure. In view of the multiple beam structure of the 30-m telescope, and of other telescopes with a similar reflector construction of (mini-)panels and panel frames, we summarize the antenna tolerance theory for the influence of several independent
surface/wavefront deformations. This theory makes use of different correlation lengths, which in essence determine the independent error distributions, and of the wavelength-scaling of the diffracted beam and of the error beams. From the Moon scans we derive the parameters for calculation of the 30-m telescope beam in the wavelength range 3mm to 0.8mm as required for the reduction of astronomical observations, in particular of extended sources. The parameters of the beam
are primarily for the time after July 1997 when the reflector was re-adjusted and improved to the illumination weighted surface precision of {sigma}_T_ = 0.065 - 0.075 mm. In the Appendix we explain the choice for this analysis of scans taken around New Moon and Full Moon.
%K telescopes

%R 1998A&AS..133..285M
%J-292
%A Mathew S.K., Bhatnagar A., Prasad C.D., Ambastha A.
%T Fabry-Perot filter based solar video magnetograph.
%M ds1569
%F 1998.11.27
%B A tunable Lithium Niobate (LiNbO_3_) Fabry-Perot filter (FP) (passband 165m{AA} at 6122{AA}) based video magnetograph has been designed and fabricated. This instrument is capable of providing near simultaneous observations of photospheric longitudinal magnetic field, chromospheric H{alpha}, and photospheric CaI pictures using the same telescope and back-end set-up. The magnetic field measurements are made by using the polarization properties of the Zeeman components of
the photospheric CaI line at 6122{AA} (Lande g factor of 1.75). The CaI line has been chosen due to its low temperature sensitivity and no blend with other solar or atmospheric lines. A variable electro-optic quarter wave retarder, KD^*^P (Potassium di-Deuterium Phosphate) along with a linear polarizer is used for analyzing the circular polarization of the Zeeman components. The filter tuned at 140 m{AA} away from the line center in the blue wing is found to give the best
linear response for the field strength up to 1500 Gauss. A field of view (FOV) of ~4x3arcmin on the solar disk is imaged using a 699 x 288 pixel Cohu CCD camera in synchronous with the KD^*^P modulation. The {lambda}/4 modulation is achieved by applying +/-2100 volts to the KD^*^P to obtain alternate frames of oppositely circular polarized images. These images are stored in separate frame buffers of an image acquisition system. To achieve high signal to noise ratio, a
large number of images (maximum 256) are added in the respective frame buffers and then the difference between the left and the right circularly polarized images is obtained. This difference is related to the magnetic field strength. On comparing the video magnetograms (VMG) obtained at Udaipur Solar Observatory (USO) on 09 April 1997 at 09:32 UT with those taken by SOHO/MDI at 09:41 UT, it was found that all the magnetic features matched very well in both the magnetograms.
In this paper we present the details of the instrument and examples of observations.
%K instruments: polarimeter - Sun: activity; flares; magnetic fields

%R 1998A&AS..133..293B
%J-297
%A Bratsolis E., Bellas-Velidis I., Kontizas E., Pasian F., Dapergolas A., Smareglia R.
%T Automatic detection of objective prism stellar spectra.
%M ds1550
%F 1998.11.27
%B Object detection is a common problem in image processing and particularly in astronomy and astrophysics, when a huge number of objects are to be processed. Such is the case of objective prism plates, where thousands of spectra are recorded. We present a new method for automatic detection of stellar spectra on digitally-scanned objective prism plates. Our method is based on signal processing techniques with emphasis on obtaining the maximum signal-to-noise ratio from the
data, as well as on applying a number of morphological criteria of one-dimensional stellar spectra images. It uses only the prism plate image without the need of the corresponding direct plate. This fully automated method gives inpressive results in the detection of stellar spectra.
%K methods: data analysis; image processing - stars: objective prism spectra