The structure of the Large Magellanic Cloud from hot binary stars and Classical Cepheids

2013 ◽  
Vol 64 ◽  
pp. 409-410
Author(s):  
T. Muraveva ◽  
G. Clementini ◽  
C. Maceroni ◽  
M.I. Moretti
Keyword(s):  
Binary Stars ◽  
Large Magellanic Cloud ◽  
Magellanic Cloud ◽  
Classical Cepheids

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 Period–luminosity–metallicity relation of classical Cepheids

2020 ◽  
Vol 642 ◽  
pp. A230
Author(s):  
V. Ripepi ◽  
G. Catanzaro ◽  
R. Molinaro ◽  
M. Marconi ◽  
G. Clementini ◽  
...  
Keyword(s):  
Near Infrared ◽  
Data Gathering ◽  
Hubble Constant ◽  
Zero Point ◽  
Total Sample ◽  
Large Magellanic Cloud ◽  
Magellanic Cloud ◽  
Point Of View ◽  
Classical Cepheids ◽  
Metal Abundance

Context. Classical Cepheids (DCEPs) are the most important primary indicators for the extragalactic distance scale. Establishing the dependence on metallicity of their period–luminosity and period–Wesenheit (PL and PW) relations has deep consequences for the estimate of the Hubble constant (H0). Aims. We investigate the dependence on metal abundance ([Fe/H]) of the PL and PW relations for Galactic DCEPs. Methods. We combined proprietary and literature photometric and spectroscopic data, gathering a total sample of 413 Galactic DCEPs (372 fundamental mode, DCEP_F, and 41 first-overtone, DCEP_1O) and constructed new metallicity-dependent PL and PW relations in the near-infrared adopting the astrometry-based luminosity. Results. We find indications that the slopes of the PL(KS) and PW(J, KS) relations for Galactic DCEPs might depend on metallicity on the basis of the comparison with the Large Magellanic Cloud relationships. Therefore we used a generalized form of the PL and PW relations to simultaneously take the metallicity dependence of the slope and intercept of these relations into account. Conclusions. We calculated PL and PW relations that for the first time explicitly include a metallicity dependence of the slope and intercept terms. The quality of the available data is insufficient, however, and we cannot yet present conclusive results, but they are relevant from a methodological point of view. The new relations are linked to the geometric measurement of the distance to the Large Magellanic Cloud and allowed us to estimate a Gaia DR2 parallax zero-point offset Δϖ = 0.0615 ± 0.004 mas from the dataset of DCEPs used in this work.

scholarly journals Two New Massive Binary Stars in the Magellanic Clouds

2002 ◽  
Vol 207 ◽  
pp. 202-204
Author(s):  
Virpi S. Niemela
Keyword(s):  
Binary Stars ◽  
Large Magellanic Cloud ◽  
Magellanic Cloud ◽  
Magellanic Clouds ◽  
Open Clusters ◽  
Small Magellanic Cloud

The discovery and preliminary spectroscopic orbits of two early O type binaries in very young open clusters in the Magellanic Clouds is reported. The binaries are NGC 346–1 in the Small Magellanic Cloud, and HDE 270145 in NGC 2122 in the Large Magellanic Cloud.

scholarly journals Geometry of the Large Magellanic Cloud using multiwavelength photometry of classical Cepheids

2018 ◽  
Vol 478 (2) ◽  
pp. 2526-2540 ◽  
Author(s):  
Sukanta Deb ◽  
Chow-Choong Ngeow ◽  
Shashi M Kanbur ◽  
Harinder P Singh ◽  
Daniel Wysocki ◽  
...  
Keyword(s):  
Large Magellanic Cloud ◽  
Magellanic Cloud ◽  
Classical Cepheids

scholarly journals Classical Cepheids, what else?

2012 ◽  
Vol 8 (S289) ◽  
pp. 116-125 ◽  
Author(s):  
G. Bono ◽  
L. Inno ◽  
N. Matsunaga ◽  
K. Genovali ◽  
B. Lemasle ◽  
...  
Keyword(s):  
Surface Brightness ◽  
Near Infrared ◽  
Large Magellanic Cloud ◽  
Magellanic Cloud ◽  
Distance Modulus ◽  
Period Range ◽  
Classical Cepheids ◽  
Similar Distance ◽  
Distance Indicators ◽  
Zero Points

AbstractWe present new and independent estimates of the distances to the Magellanic Clouds (MCs) using near-infrared (NIR) and optical–NIR period–Wesenheit (PW) relations. The slopes of the PW relations are, within the dispersion, linear over the entire period range and independent of metal content. The absolute zero points were fixed using Galactic Cepheids with distances based on the infrared surface-brightness method. The true distance modulus we found for the Large Magellanic Cloud—(m − M)0 = 18.48 ± 0.01 ± 0.10 mag—and the Small Magellanic Cloud—(m − M)0 = 18.94 ± 0.01 ± 0.10 mag—agree quite well with similar distance determinations based on robust distance indicators. We also briefly discuss the evolutionary and pulsation properties of MC Cepheids.

scholarly journals Mean Magnitudes and Colours of Six Cepheids in Three Red Globular Clusters of the Large Magellanic Cloud

1973 ◽  
Vol 21 ◽  
pp. 150-150
Author(s):  
Serge Demers
Keyword(s):  
Globular Clusters ◽  
Large Magellanic Cloud ◽  
Magellanic Cloud ◽  
Light Curves ◽  
Classical Cepheids ◽  
The Galaxy ◽  
The Mean ◽  
Field Cepheids

AbstractPhotographic B and V light curves are determined for six variables, with periods longer than one day, in and near NGC 1751, NGC 1953, and NGC 2121. New photoelectric sequences are used to calibrate the plates. The mean magnitudes and colours of these variables are similar to the magnitudes and colours of Classical Cepheids of the same period. The photometric properties of these variables are unlike Population II Cepheids in the Galaxy but are comparable to field Cepheids of the Large Magellanic Cloud.

scholarly journals Candidates for non-pulsating stars located in the Cepheid instability strip in the Large Magellanic Cloud based on Strömgren photometry

2019 ◽  
Vol 489 (3) ◽  
pp. 3285-3293 ◽  
Author(s):  
Weronika Narloch ◽  
G Pietrzyński ◽  
Z Kołaczkowski ◽  
R Smolec ◽  
M Górski ◽  
...  
Keyword(s):  
Gravitational Lensing ◽  
Large Magellanic Cloud ◽  
Magellanic Cloud ◽  
Light Curves ◽  
Instability Strip ◽  
Classical Cepheid ◽  
Pulsating Stars ◽  
Giant Stars ◽  
Classical Cepheids ◽  
Astrophysical Research

ABSTRACT We present candidates for non-pulsating stars lying in the classical Cepheid instability strip based on the Optical Gravitational Lensing Experiment (OGLE) photometric maps combined with Strömgren photometry obtained with the 4.1-m Southern Astrophysical Research (SOAR) telescope, and Gaia Data Release 2 data in four fields in the Large Magellanic Cloud. We selected 19 candidates in total. After analysis of their light curves from OGLE surveys we found that all these stars appear to be photometrically stable at the level of a few mmag. Our results show that non-pulsating stars might constitute to about $21\!-\!30\, {\rm per\, cent}$ of the whole sample of giant stars located in the classical instability strip. Furthermore, we identified potential candidates for classical Cepheids with hot companions based on their Strömgren colours.

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