scholarly journals Etoiles Multiples Et Amas Ouverts

1977 ◽  
Vol 33 ◽  
pp. 67-72
Author(s):  
J. Dommanget
Keyword(s):  
Frequency Distribution ◽  
Basic Difference ◽  
Multiple Systems ◽  
Number Of Components ◽  
Double Stars ◽  
Dense Part ◽  
Galactic Clusters

AbstractIt is generally suspected that multiple systems and galactic clusters are objects of different kinds. Their frequency distribution as a function of the number of components, n, as well as their sizes and their masses, show important differences between both categories and also the probable existence of a limit lying between n = 10 and n = 20 components. The basic difference between these objects seems to be that the multiple systems finally appear to be components of the stellar medium in th same way as single and double stars, whereas the galactic clusters are groups of components of a particularly dense part of this medium.

scholarly journals Observational Programme for Classical and CCD Photometry of Visual Double and Multiple Systems

1992 ◽  
Vol 135 ◽  
pp. 339-342
Author(s):  
E. Oblak ◽  
P. Lampens
Keyword(s):  
Photometric Data ◽  
European Network ◽  
Ccd Photometry ◽  
Multiple Systems ◽  
Double Stars ◽  
Visual Double Stars ◽  
Astrometric Data ◽  
Input Catalogue ◽  
Colour Indices

Complementary accurate photometric data with astrophysical content are needed for a well-chosen sample of binaries and multiple systems for which good-quality astrometric data already exist or will soon be available. The observational programme, started in the context of the European Network of Laboratories “Visual Double Stars” (Oblak et al. 1992), is therefore based on samples extracted from the “Catalogue des Composantes d’Etoiles Doubles et Multiples” (CCDM, Dommanget, 1989) and reported in Annex 1 (Double and Multiple Systems) of the HIPPARCOS Input Catalogue (C. Turon et al. 1992).Systems with components in the HIPPARCOS Input Catalogue are selected for which the present photometric information is poor, i.e. not all components have been observed or they have colour indices and/or magnitudes of insufficient quality for extraction of astrophysical quantities (Figure 1).Observations, performed in various observatories located in both hemispheres, must yield both classical and CCD photometric campaigns.

scholarly journals The Catalogue of the Components of Double and Multiple Stars (CCDM) - First Edition

1995 ◽  
Vol 166 ◽  
pp. 395-395 ◽  
Author(s):  
J. Dommanget ◽  
O. Nys
Keyword(s):  
Data Base ◽  
Multiple Star ◽  
Multiple Systems ◽  
Double Stars ◽  
Multiple Stars ◽  
Double And Multiple Stars ◽  
General Data ◽  
Input Catalogue ◽  
Better Than

The Hipparcos mission required the realisation of an Input Catalogue giving the positions of 100.000 stars (single or components of double and multiple systems) to an accuracy better than 1″5. At the start of this work (1981) no specific catalogue of double and multiple stars provided these data. The only general data base on double stars available to us, giving positions to ±1′, was the Index (1961,0) updated at the USNO by C. E. Worley till 1976,5 and of which a copy was communicated by P. Muller of the Observatoire de Meudon. It has then been decided to reformat this Catalogue in such a way as to allow the introduction of all necessary information for the mission. This permitted a correct cross-identification with the Hipparcos Input Catalogue (of finally 118.000 stars). It was later called: the Catalogue of the Components of Double and Multiple stars (CCDM). Since then, it has been developed and its aim remains to furnish the best accurate locations and descriptions of the double and multiple systems on the sky for all double and multiple star research.

scholarly journals Gaia DR2 distances to Collinder 419 and NGC 2264 and new astrometric orbits for HD 193 322 Aa,Ab and 15 Mon Aa,Ab

2019 ◽  
Vol 630 ◽  
pp. A119 ◽  
Author(s):  
J. Maíz Apellániz
Keyword(s):  
Total Mass ◽  
Binary Systems ◽  
Orbit Space ◽  
The Sun ◽  
Spatial Covariance ◽  
Multiple Systems ◽  
Star Catalog ◽  
Stellar Group ◽  
Galactic Clusters ◽  
The One

Context. On the one hand, the second data release of the Gaia mission (Gaia DR2) has opened a trove of astrometric and photometric data for Galactic clusters within a few kiloparsecs of the Sun. On the other hand, lucky imaging has been an operational technique to measure the relative positions of visual binary systems for a decade and a half. This time is sufficient to apply the results of the technique to the calculation of orbits of some massive multiple systems within ∼1 kpc of the Sun. Aims. As part of an ambitious research program to measure distances to Galactic stellar groups (including clusters) containing O stars, I start with two of the nearest examples: Collinder 419 in Cygnus and NGC 2264 in Monoceros. The main ionizing source for each cluster is a multiple system with an O-type primary: HD 193 322 and 15 Mon, respectively. For each of the two multiple systems, I aim to derive new astrometric orbits for the Aa,Ab components. Methods. First, I present a method that uses Gaia DR2 G + GBP + GRP photometry, positions, proper motions, and parallaxes to obtain the membership and distance of a stellar group and applied these values to Collinder 419 and NGC 2264. Second, I present a new code that calculates astrometric orbits by searching the whole seven-parameter orbit space and apply it to HD 193 322 Aa,Ab and 15 Mon Aa,Ab using, as input, literature data from the Washington Double Star Catalog and the AstraLux measurements recently presented by our group in another paper published this year. Results. I obtain Gaia DR2 distances of 1006+37−34 pc for Collinder 419 and 719 ± 16 pc for NGC 2264; the main contribution to the uncertainties comes from the spatial covariance of the parallaxes. The two NGC 2264 subclusters are at the same distance (within the uncertainties) and show a significant relative proper motion. The distances are shown to be robust. HD 193 322 Aa,Ab follows an eccentric (e = 0.58+0.03−0.04) orbit with a period of 44 ± 1 a and the three stars it contains have a total mass of 76.1+9.9−7.4M⊙. The orbit of 15 Mon Aa,Ab is even more eccentric (e = 0.770+0.023−0.030); it has a period of 108 ± 12 a and a total mass of 45.1+3.6−3.3M⊙ for its two stars.

scholarly journals Archives of Photometric Data

1992 ◽  
Vol 9 ◽  
pp. 725-726 ◽  
Author(s):  
J.-C. Mermilliod
Keyword(s):  
Data Retrieval ◽  
Photometric Data ◽  
Multiple Systems ◽  
Double Stars ◽  
Definition Of

The process of archiving photometric data and compiling catalogues is in principle easy to solve, but, in practice, does not appear so simple. Data retrieval may become difficult and inefficient if sufficient care is not taken to solve the general problems which are encoutered: (i) the lack of definition of fundamental identificators; (ii) the lack of coordinates for thousands of faint stars; (iii) the innacuracy of the identification and description of the components observed in double stars or multiple systems: A, B, C, AB, or BC; (iv) the fact that the number of observations is often not published.

scholarly journals HIPPARCOS First Results in the Double Star Photometry

1992 ◽  
Vol 135 ◽  
pp. 421-428
Author(s):  
F. Mignard ◽  
J.L. Falin ◽  
M. Froeschlé
Keyword(s):  
Double Star ◽  
Multiple Systems ◽  
Double Stars ◽  
Multiple Stars ◽  
Accuracy And Precision ◽  
First Results ◽  
Main Detector ◽  
Input Catalogue ◽  
Magnitude Difference ◽  
Better Than

AbstractIn addition to its astrometric capabilities the HIPPARCOS main detector proves to be a good phototometer. The main features of the photometric reduction applied to double stars are outlined. We show how it is possible to discriminate single stars from multiple stars from the photometric signal. Results presented are based on about 16000 stars recognized as non-single, of which 8000 were not known to be double in the HIPPARCOS Input Catalogue. Magnitudes for multiple systems as a whole are derived with a precision usually better than 0.005 mag while the magnitude of each component is recovered up to magnitude difference of 3 mag, but with less accuracy and precision.

scholarly journals An Improved Method of Photographic Measures of Double Stars

1988 ◽  
Vol 98 ◽  
pp. 122-127
Author(s):  
D. Rodriguez ◽  
J.A. Bernedo ◽  
D. Valls-Gabaud
Keyword(s):  
Statistical Analysis ◽  
High Accuracy ◽  
Double Star ◽  
Improved Method ◽  
Ccd Cameras ◽  
Multiple Systems ◽  
Double Stars ◽  
Fine Grain ◽  
A New Technique ◽  
Number Of Segments

We present a new technique in double star photography leading to high accuracy measurements in amateur-size instruments. The trailing method has been improved by the use of a chopper that cuts the trail into a number of segments. The chopper period is accurately known, so it is the length of each segment on the plate. In this way the scale factor is measured in each exposure. Fine-grain films, such as hyper-sensitized Kodak 2415, are used and all measurements are performed at the microscope. The same technique may also be applied to CCD cameras. A statistical analysis of errors shows that Δθ ≤ 30′ and Δρ/ρ ≈ 0.01 for most binaries with ρ ≥ 3″. This method has been applied to professional-amateur joint programs dealing with multiple systems with variable components and a survey of poorly-observed wide binaries.

scholarly journals Micrometer and CCD measurements of double stars (Series 51)

1998 ◽  
pp. 67-71
Author(s):  
G.M. Popovic ◽  
R. Pavlovic
Keyword(s):  
Multiple Systems ◽  
Double Stars

36 micrometric measurements of 20 double or multiple systems carried out with the Zeiss 65/1055 cm Refractor of Belgrade Observatory are communicated. Also 35 CCD measurements of 15 double or multiple systems are included.

scholarly journals Trapezium Type Multiple Systems and Formation of Stars

1982 ◽  
Vol 69 ◽  
pp. 109-113
Author(s):  
G.N. Salukvadze
Keyword(s):  
Observational Data ◽  
Common Multiple ◽  
Multiple Star ◽  
Multiple Systems ◽  
Trapezium Type ◽  
Double Stars ◽  
Spectral Class ◽  
Multiple Stars ◽  
Stellar Associations

AbstractBy a comparison of Trapezium-type multiple star systems in the Abastumani Catalogue and the famous Catalogue of Stellar Associations and Clusters, it is confirmed that the great number of Trapezium-type multiple stars, which belong mostly to spectral classes 0-B2, are found in associations and clusters.In 13 T-associations, 120 Trapezium-type multiple systems and 182 common multiple and double stars could be detected.Based on present-day observational data and the author's photographic observations, the kinematic of Trapezium-type multiple stars of spectral class 0-B2 is studied.

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