Astronomy and Astrophysics Supplement Series

https://aas.aanda.org/

List of Papers (Total 1,079)

Light curves and periods of Mira variables

Good distance indicators are needed in studies of the galactic structure. Pulsating variables can be used, but the problem is to find a homogenous sample obeying a period-luminosity relation with low scatter. In this paper, we show how such a sample can be produced using the Terzan catalogue of Variables and available Schmidt plates. We have selected 150 large amplitude variables...

Optical structure and star formation in blue compact dwarf galaxies. I. Observations and profile decomposition

We present new B and R CCD surface photometry for a sample of 4 Blue Compact Dwarf Galaxies (BCDs) and 2 higher luminosity starburst galaxies. We find that the BCD surface brightness profiles (SBPs) can be generally well fitted by the sum of the light of 3 distinct components: 1) an exponential component at large radii, with or without a central flattening which describes the...

A spatial and spectral maximum entropy method as applied to OVRO solar data

We present first results of applying a Maximum Entropy Method (MEM) algorithm that acts in both the spatial and spectral domains to data obtained with the frequency-agile solar interferometer at Owens Valley Radio Observatory (OVRO) taken at 45 frequencies in the range . The traditional MEM algorithm does not exploit the spatial information available at adjacent frequencies in...

Absolute transition probabilities for the a6D y6P° multiplet (#8) of Fe II

We report the first laboratory measurement of absorption oscillator strengths (f-values) for 6 VUV () transitions of the multiplet (#8) in Fe II. We have also reconfirmed a recent measurement of the f-value of the Fe II resonance line at . These measurements are made with the high sensitivity absorption experiment at the University of Wisconsin-Madison. Measurements are also made...

TT Arietis: Photometric variability from 1985 to 1994

Results of photoelectric observations of TT Ari during the 1985–1994 interval are presented. Observations were carried out at the Rozhen and Belogradchik observatories as part of our programme for the study of anti-dwarf novae. The long-term light curve in the standard UBV system is constructed and peculiarities of the long-term behaviour of the star in this time interval are...

Multicolour deep CCD photometric study of the moderately young southern open star clusters NGC 3228, NGC 4103, NGC 5662 and NGC 6087

CCD observations in the U, B, V, R and I passbands have been used to generate colour-colour and deep colour-magnitude diagrams for the young open star clusters NGC 3228, NGC 4103,  NGC 5662 and NGC 6087. The sample consists of about 2000 stars reaching down to . The interstellar extinction across the face of the imaged cluster regions seems to be uniform with average values of...

Two-band spectral filtering in instruments for measuring solar magnetic fields

In this paper we formulate the basic concept of a bichromatic image technique. Specific examples of its application are analyzed in the context of research into solar plasma characteristics by pinpointing its merits and demerits. Specialized requirements to the spectral devices are set forth, which may be summarized as: a) the presence of two nearby identical spectral passbands...

CLEAN and WIPE

Clean is a matching pursuit process which has two weak points: in situations of astrophysical interest, the "clean map

Optical positions and proper motions of radio stars

The optical positions of 31 radio stars were obtained with the 40 cm astrograph at Zô–Sè Section, Shanghai Observatory from 1985 to 1988. The observational positions and the proper motions of these radio stars in the FK5 system are given in this paper.

New theoretical yields of intermediate mass stars

We present theoretical yields of H, 4He, 12C, 13C, 14N, and 16O for stars with initial masses between 0.8 and 8 and initial metallicities , 0.004, 0.008, 0.02, and 0.04. We use the evolutionary tracks of the Geneva group up to the early asymptotic giant branch (AGB) in combination with a synthetic thermal-pulsing AGB evolution model to follow in detail the chemical evolution and...

Library of high and mid-resolution spectra in the Ca ii H & K, H∝, , Hβ, Na i D1, D2, and He i D3 line regions of F, G, K and M field stars

In this work we present spectroscopic observations centered in the spectral lines most widely used as optical indicators of chromospheric activity (, , Ca ii H & K, and He i ) in a sample of F, G, K and M chromospherically inactive stars. The spectra have been obtained with the aim of providing a library of high and mid-resolution spectra to be used in the application of the...

A stellar coronograph for the COME-ON-PLUS adaptive optics system - I. Description and performance

The detection of faint emissions very close to much brighter objects is required in several different fields of astrophysics, for example in the search for planetary disks. We present here a coronograph that we built to work with , the ESO adaptive optics system, high angular resolution being of key importance in allowing observations close to a central, occulted object. The...

Active region effects on solar irradiance at Na I D lines

The possibility to detect solar oscillations in the low frequency domain depends crucially on the power contrast among the oscillation signal and other time dependent signals in the same frequency range. The signal to noise ratio is increased by our ability to understand and remove solar sources of noise. In measurements of the mean Doppler velocity shift of the integrated solar...

The Washington Double Star Catalog (WDS, 1996.0)

A major revision of the Washington Double Star (WDS) catalog containing data for the components of 78 100 systems is now available from the data centers and via the World Wide Web (http://aries.usno.navy.mil/ad/wds/).

photometric sequences for nine selected dark globules

Using a CCD detector, BVRI photometry has been carried out in the vicinity of nine Lynds dark nebulae. In conjunction with spectroscopic data which could be obtained at a later stage, the data listed herein could be used for possible distance determinations of the nine nebulae.

Spatial distribution of neutral and ionic constituents in comet P/Halley

Multislit spectra of comet P/Halley were obtained on April 10, 1986, using a focal reducer with a field of angular diameter. The number and arrangement of the slits allowed a reconstruction of the spatial distribution of principal neutral and ionic coma constituents within a frame of about at the comet. Radial profiles and two-dimensional maps for the dust continuum, CN, , CH...

A list of new nearby dwarf galaxy candidates

To increase completeness of the distance limited sample of nearby galaxies from the the Kraan-Korteweg & Tammann (1979) catalogue we undertook a search for small companions of larger known galaxies which have corrected radial velocities within 500 km/s. Based primarely on the POSS-II and ESO/SERC films we found 260 nearby dwarf galaxy candidates with angular diameters  arcmin...

The revised GB/GB2 sample of extragalactic radio sources

This paper presents the revised sample of 373 extragalactic radio sources brighter than 0.2 Jy at 1.4 GHz. These sources, selected from the finding Green Bank surveys, were mapped at 1465 MHz using the VLA at different configurations. The biases introduced into the original GB and GB2 catalogues by confusion as well as partial resolution by the VLA at A-configuration, are...

Hipparcos photometry of 24 variable massive stars (α Cygni variables)

The photometric variability of 24 α Cyg variables, i.e. variable super–and hypergiants, observed by the Hipparcos satellite is described. Three of the selected stars are situated in the SMC, 12 in the LMC and the remaining 9 in the Galactic plane. Four of them are hot S Dor–type variables, or LBVs (luminous blue variables) and two are possible members of this class. Light curves...

A photometric catalogue of galaxies in the cluster Abell 85

We present two catalogues of galaxies in the direction of the rich cluster ABCD 85. The first one includes 4232 galaxies located in a region from the cluster centre. It has been obtained from a list of more than 25000 galaxy candidates detected by scanning a Schmidt photographic plate taken in the BJ band. Positions are very accurate in this catalogue but magnitudes are not. This...

Numerical simulation of observations with GOLF on board SOHO

The main objective of the GOLF Experiment (Global Oscillations at Low Frequencies) on-board the SOHO (Solar and Heliospheric Observatory) space mission is the quantitative knowledge of the internal structure of the Sun by measuring the spectrum of its global oscillations in a wide frequency range (30 nHz to 6 mHz). There is special interest in detecting the low p- and g-modes...

Achromatic lens systems for near infrared instruments - II. Performances and limitations of standard Flint glasses

This paper investigates which normal Flint glasses are best suited for the design of lens systems working in the infrared up to about 1.7 μm, and possibly up to 2.5 μm. Between 0.9 and 2.5 μm the best known achromatic pairs are -2 and -3 and, to a lesser extent, -7 (Oliva & Gennari 1995). Unfortunately, Schott will most probably stop the production of these very little used and...

A deep λ20 cm radio continuum survey of M 31

We present a survey of the total and linearly polarized radio continuum emission of the Andromeda galaxy at 20 cm wavelength with the VLA-D array. 7 fields were observed with 45 angular resolution. The missing large-scale total emission observed with the Effelsberg telescope was inserted. This survey is the most sensitive radio continuum survey of M 31 so far and the first one in...

Structure and stellar content of dwarf galaxies - I. B and R photometry of dwarf galaxies in the M 81 group

We have carried out CCD photometry in the Cousins B and R bands of 25 dwarf galaxy members and suspected members of the M 81 group of galaxies. Based on azimuthally averaged brightness profiles we have derived total magnitudes, effective radii, effective surface brightnesses, as well as galaxy diameters at various isophotal levels in both photometric bands. Best-fitting...

Loose groups of galaxies in the Perseus–Pisces survey

We present a large catalog of loose groups of galaxies in the Southern Galactic Hemisphere, selected from the Perseus–Pisces redshift Survey (PPS). Particular care is taken in order to obtain group samples as homogeneous as possible to previously published catalogs. All our catalogs contain about 200 groups, significantly more than in most previous studies where group samples...