Absolute Dimensions and Apsidal Motions of Three Binary Systems in the Large Magellanic Cloud

2019 ◽  
Vol 158 (5) ◽  
pp. 185
Author(s):  
Kyeongsoo Hong ◽  
Jae Woo Lee ◽  
Seung-Lee Kim ◽  
Jae-Rim Koo ◽  
Jang-Ho Park ◽  
...  
Keyword(s):  
Binary Systems ◽  
Large Magellanic Cloud ◽  
Magellanic Cloud ◽  
Absolute Dimensions

Massive Binaries in the Magellanic Clouds

2005 ◽  
Vol 13 ◽  
pp. 463-463
Author(s):  
Virpi S. Niemela
Keyword(s):  
Binary Stars ◽  
Present Status ◽  
Binary Systems ◽  
Massive Stars ◽  
Large Magellanic Cloud ◽  
Magellanic Cloud ◽  
Magellanic Clouds ◽  
Stellar Winds ◽  
Multiple Systems ◽  
Orbital Parameters

We present results of our ongoing observing program on search and studies of massive stars (O and WR type) in binary systems in our neighbor galaxies, the Magellanic Clouds. Radial velocity orbits are presented for two new binaries, one in the Small Magellanic Cloud and another in the Large Magellanic Cloud, and improved orbits for previously known systems. We compare orbital parameters of selected binaries containing O and WR type components. We also discuss the present status of knowledge for massive binary stars in the Magellanic Clouds and the problems encountered in their orbital studies such as stellar winds the ubiquitous tendency to be born in multiple systems.

scholarly journals A precise and accurate distance to the Large Magellanic Cloud from late-type eclipsing-binary systems

2012 ◽  
Vol 8 (S289) ◽  
pp. 169-172
Author(s):  
G. Pietrzyński ◽  
W. Gieren ◽  
D. Graczyk ◽  
I. Thompson ◽  
B. Pilecki ◽  
...  
Keyword(s):  
Binary Systems ◽  
Zero Point ◽  
Large Magellanic Cloud ◽  
Magellanic Cloud ◽  
Distance Scale ◽  
Late Type ◽  
Eclipsing Binary ◽  
Extragalactic Distance Scale

AbstractWe present a precise and accurate measurement of the distance to the Large Magellanic Cloud based on late-type eclipsing-binary systems. Our results provide curently the most accurate zero point for the extragalactic distance scale.

scholarly journals The Tarantula Massive Binary Monitoring

2020 ◽  
Vol 634 ◽  
pp. A119 ◽  
Author(s):  
L. Mahy ◽  
L. A. Almeida ◽  
H. Sana ◽  
J. S. Clark ◽  
A. de Koter ◽  
...  
Keyword(s):  
Binary Systems ◽  
Large Magellanic Cloud ◽  
Magellanic Cloud ◽  
Light Curves ◽  
Spectroscopic Binaries ◽  
Systematic Analysis ◽  
Orbital Parameters ◽  
The Individual ◽  
30 Doradus ◽  
Dynamical Masses

Context. A high fraction of massive stars are found to be binaries but only a few of them are reported as photometrically variable. By studying the populations of double-lined spectroscopic binaries in the 30 Doradus region, we found a subset of them that have photometry from the OGLE project and that display variations in their light curves related to orbital motions. Aims. The goal of this study is to determine the dynamical masses and radii of the 26 binary components in order to investigate the mass-discrepancy problem and to provide an empirical mass-luminosity relation for the Large Magellanic Cloud (LMC). Methods. We use the PHOEBE programme to perform a systematic analysis of the OGLE V and I light curves obtained for 13 binary systems in the 30 Doradus region. We adopt the effective temperatures, and orbital parameters derived previously to obtain the inclinations of the systems and the parameters of the individual components. Results. Three systems display eclipses in their light curves, while the others only display ellipsoidal variations. We classify two systems as over-contact, five as semi-detached, and four as detached. The two remaining systems have uncertain configurations due to large uncertainties on their inclinations. The fact that systems display ellipsoidal variations has a significant impact on the inclination errors. From the dynamical masses, luminosities, and radii, we provide LMC-based empirical mass-luminosity and mass-radius relations, and we compare them to other relations given for the Galaxy, the LMC, and the Small Magellanic Cloud. These relations differ for different mass ranges, but do not seem to depend on the metallicity regimes. We also compare the dynamical, spectroscopic, and evolutionary masses of the stars in our sample. While the dynamical and spectroscopic masses agree with each other, the evolutionary masses are systematically higher, at least for stars in semi-detached systems. This suggests that the mass discrepancy can be partly explained by past or ongoing interactions between the stars.

scholarly journals Spectroscopic Binaries in the LMC

1986 ◽  
Vol 116 ◽  
pp. 85-86
Author(s):  
Virpi S. Niemela
Keyword(s):  
Binary Systems ◽  
Large Magellanic Cloud ◽  
Magellanic Cloud ◽  
Spectroscopic Binaries ◽  
Preliminary Results ◽  
Spectroscopic Binary ◽  
Stellar Masses

Preliminary results are presented of an observing programme aimed to obtain estimates of the stellar masses from studies of spectroscopic binary systems in the Large Magellanic Cloud. These are the first steps with the final purpose to determine an empirical mass-luminosity relation in a galaxy other than our own.

scholarly journals THE ARAUCARIA PROJECT. DETERMINATION OF THE LARGE MAGELLANIC CLOUD DISTANCE FROM LATE-TYPE ECLIPSING BINARY SYSTEMS. I. OGLE-051019.64-685812.3

2009 ◽  
Vol 697 (1) ◽  
pp. 862-866 ◽  
Author(s):  
Grzegorz Pietrzyński ◽  
Ian B. Thompson ◽  
Dariusz Graczyk ◽  
Wolfgang Gieren ◽  
Andrzej Udalski ◽  
...  
Keyword(s):  
Binary Systems ◽  
Large Magellanic Cloud ◽  
Magellanic Cloud ◽  
Late Type ◽  
Eclipsing Binary

scholarly journals Cepheid Variables in the LMC and SMC

1999 ◽  
Vol 190 ◽  
pp. 513-516
Author(s):  
D.L. Welch ◽  
Keyword(s):  
Recent Work ◽  
Binary Systems ◽  
Large Magellanic Cloud ◽  
Magellanic Cloud ◽  
Small Magellanic Cloud ◽  
Eclipsing Binary ◽  
Classical Cepheids ◽  
Cepheid Variables

In this paper, we will review major new results regarding classical Cepheids, in the Large Magellanic Cloud (LMC) and Small Magellanic Cloud (SMC). Specifically, we discuss recent work regarding multimode Cepheids and describe new observations of a W Vir star (HV 5756) and a Cepheid which are each in eclipsing binary systems. An additional interesting pulsating supergiant in an eclipsing system is also identified. Ephemerides for eclipses for the three systems are provided.

scholarly journals Observations of Two Binary Systems with 04f Type Components

1992 ◽  
Vol 151 ◽  
pp. 505-508
Author(s):  
V. S. Niemela ◽  
M. A. Cerruti ◽  
N. I. Morrell ◽  
H. G. Luna
Keyword(s):  
Linear Polarization ◽  
Binary Systems ◽  
Large Magellanic Cloud ◽  
Magellanic Cloud

We present linear polarization observations of two binary systems with early Of type components, namely Sk-67°105 in the Large Magellanic Cloud, and LSS 3074 in our Galaxy. Both binaries show phase-locked polarization variations, from which we determined orbital inclinations for the systems.

Distance to SN 1987A and the LMC

1999 ◽  
Vol 190 ◽  
pp. 549-554
Author(s):  
Nino Panagia
Keyword(s):  
Angular Size ◽  
Large Magellanic Cloud ◽  
Magellanic Cloud ◽  
Light Curves ◽  
Distance Modulus ◽  
Absolute Size ◽  
Sn 1987A

Using the new reductions of the IUE light curves by Sonneborn et al. (1997) and an extensive set of HST images of SN 1987A we have repeated and improved Panagia et al. (1991) analysis to obtain a better determination of the distance to the supernova. In this way we have derived an absolute size of the ringRabs= (6.23 ± 0.08) x 1017cm and an angular sizeR″ = 808 ± 17 mas, which give a distance to the supernovad(SN1987A) = 51.4 ± 1.2 kpc and a distance modulusm–M(SN1987A) = 18.55 ± 0.05. Allowing for a displacement of SN 1987A position relative to the LMC center, the distance to the barycenter of the Large Magellanic Cloud is also estimated to bed(LMC) = 52.0±1.3 kpc, which corresponds to a distance modulus ofm–M(LMC) = 18.58±0.05.

Novae in the Magellanic Clouds

1979 ◽  
Vol 46 ◽  
pp. 96-101
Author(s):  
J.A. Graham
Keyword(s):  
Large Magellanic Cloud ◽  
Magellanic Cloud ◽  
Magellanic Clouds ◽  
University Of Michigan ◽  
The Past ◽  
Spectroscopic Information ◽  
Objective Prism ◽  
The University ◽  
Small Cloud ◽  
Low Dispersion

During the past several years, a systematic search for novae in the Magellanic Clouds has been carried out at Cerro Tololo Inter-American Observatory. The Curtis Schmidt telescope, on loan to CTIO from the University of Michigan is used to obtain plates every two weeks during the observing season. An objective prism is used on the telescope. This provides additional low-dispersion spectroscopic information when a nova is discovered. The plates cover an area of 5°x5°. One plate is sufficient to cover the Small Magellanic Cloud and four are taken of the Large Magellanic Cloud with an overlap so that the central bar is included on each plate. The methods used in the search have been described by Graham and Araya (1971). In the CTIO survey, 8 novae have been discovered in the Large Cloud but none in the Small Cloud. The survey was not carried out in 1974 or 1976. During 1974, one nova was discovered in the Small Cloud by MacConnell and Sanduleak (1974).

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