scholarly journals Eclipsing Binaries: Tools for Calibrating the Extragalactic Distance Scale

2006 ◽  
Vol 2 (S240) ◽  
pp. 79-87 ◽  
Author(s):  
Alceste Z. Bonanos
Keyword(s):  
Local Group ◽  
Hubble Constant ◽  
Magellanic Clouds ◽  
Distance Scale ◽  
Eclipsing Binaries ◽  
Fundamental Parameters ◽  
Andromeda Galaxy ◽  
Formation And Evolution ◽  
Extragalactic Distance Scale ◽  
Distance Indicators

AbstractIn the last decade, over 7000 eclipsing binaries have been discovered in the Local Group through various variability surveys. Measuring fundamental parameters of these eclipsing binaries has become feasible with 8 meter class telescopes, making it possible to use eclipsing binaries as distance indicators. Distances with eclipsing binaries provide an independent method for calibrating the extragalactic distance scale and thus determining the Hubble constant. This method has been used for determining distances to eclipsing binaries in the Magellanic Clouds and the Andromeda Galaxy and most recently to a detached eclipsing binary in the Triangulum Galaxy by the DIRECT Project. The increasing number of eclipsing binaries found by microlensing and variability surveys also provide a rich database for advancing our understanding of star formation and evolution.

scholarly journals Distance Indicators in the Magellanic Clouds

1983 ◽  
Vol 6 ◽  
pp. 209-216 ◽  
Author(s):  
J.A. Graham
Keyword(s):  
Chemical Evolution ◽  
Comparative Studies ◽  
Hubble Constant ◽  
Magellanic Clouds ◽  
Distance Scale ◽  
Stellar Systems ◽  
Age Range ◽  
Distance Indicators ◽  
The Universe

In talking about the overall distance scale of the Universe and the Hubble Constant, the Magellanic Clouds are good places to start. They are stellar systems large enough to contain stars, clusters and nebulae of all types, covering a wide age range. With modern telescopes and detectors, we are able to observe stars from the very bright down to those fainter intrinsically than our own Sun. From comparative studies, we may thus establish our basic calibrations of bright objects before moving out to measure the Universe at large. At the same time, the fact that both Magellanic Clouds are independently evolving galaxies, enables us to separate the effects of stellar age and chemical evolution on the calibrations that we make.

scholarly journals A survey of the most massive stars in the Magellanic Clouds

2008 ◽  
Vol 4 (S256) ◽  
pp. 343-348
Author(s):  
Alceste Z. Bonanos
Keyword(s):  
Star Formation ◽  
Massive Star ◽  
Massive Stars ◽  
Magellanic Clouds ◽  
Eclipsing Binaries ◽  
Large Impact ◽  
Massive Star Formation ◽  
Fundamental Parameters ◽  
Precise Data ◽  
Formation And Evolution

AbstractDespite the large impact very massive stars (>30 M⊙) have in astrophysics, their fundamental parameters remain uncertain. I present results of a survey aiming to characterize the most massive stars in the Magellanic Clouds. The survey targets the brightest, blue, eclipsing binaries discovered by the OGLE microlensing survey, for which masses and radii are measured to 5%. Such precise data are rare and provide constraints for theories of massive star formation and evolution at low metallicities.

scholarly journals TheHubble Space TelescopeKey Project on the Extragalactic Distance Scale. XXVI. The Calibration of Population II Secondary Distance Indicators and the Value of the Hubble Constant

2000 ◽  
Vol 529 (2) ◽  
pp. 745-767 ◽  
Author(s):  
Laura Ferrarese ◽  
Jeremy R. Mould ◽  
Robert C. Kennicutt, Jr. ◽  
John Huchra ◽  
Holland C. Ford ◽  
...  
Keyword(s):  
Hubble Constant ◽  
Distance Scale ◽  
Extragalactic Distance Scale ◽  
Distance Indicators

scholarly journals MEASURING THE HUBBLE CONSTANT WITH THE HUBBLE SPACE TELESCOPE

2009 ◽  
Vol 5 (H15) ◽  
pp. 1-16 ◽  
Author(s):  
W. L. Freedman ◽  
R. C. Kennicutt ◽  
J. R. Mould
Keyword(s):  
Hubble Space Telescope ◽  
Hubble Constant ◽  
Distance Scale ◽  
Space Telescope ◽  
Peculiar Velocities ◽  
Extragalactic Distance Scale ◽  
Distance Indicators

AbstractTen years ago our team completed the Hubble Space Telescope Key Project on the extragalactic distance scale. Cepheids were detected in some 25 galaxies and used to calibrate four secondary distance indicators that reach out into the expansion field beyond the noise of galaxy peculiar velocities. The result was H0 = 72 ± 8 km s−1 Mpc−1 and put an end to galaxy distances uncertain by a factor of two. This work has been awarded the Gruber Prize in Cosmology for 2009.

Magellanic Cloud Eclipsing Binaries: Primary Distance Indicators

1999 ◽  
Vol 190 ◽  
pp. 563-566
Author(s):  
J. D. Pritchard ◽  
W. Tobin ◽  
J. V. Clausen ◽  
E. F. Guinan ◽  
E. L. Fitzpatrick ◽  
...  
Keyword(s):  
New Zealand ◽  
Magellanic Cloud ◽  
Eclipsing Binaries ◽  
Fundamental Parameters ◽  
Distance Indicators

Our collaboration involves groups in Denmark, the U.S.A. Spain and of course New Zealand. Combining ground-based and satellite (IUEandHST) observations we aim to determine accurate and precise stellar fundamental parameters for the components of Magellanic Cloud Eclipsing Binaries as well as the distances to these systems and hence the parent galaxies themselves. This poster presents our latest progress.

scholarly journals A Comparison of Chemical Evolution between the Milky Way and M31 Galaxy

2006 ◽  
Vol 2 (S235) ◽  
pp. 313-313
Author(s):  
J. Yin ◽  
J.L. Hou ◽  
R.X. Chang ◽  
S. Boissier ◽  
N. Prantzos
Keyword(s):  
Star Formation ◽  
Chemical Evolution ◽  
Milky Way ◽  
Local Group ◽  
Spiral Galaxies ◽  
Star Formation History ◽  
Milky Way Galaxy ◽  
Andromeda Galaxy ◽  
Formation History ◽  
Formation And Evolution

Andromeda galaxy (M31,NGC224) is the biggest spiral in the Local Group. By studying the star formation history(SFH) and chemical evolution of M31, and comparing with the Milky Way Galaxy, we are able to understand more about the formation and evolution of spiral galaxies.

scholarly journals Direct DEBs in M31 and M33

2005 ◽  
Vol 13 ◽  
pp. 452-453
Author(s):  
Lucas M. Macri
Keyword(s):  
Galaxy Formation ◽  
Eclipsing Binaries ◽  
Stepping Stones ◽  
Current Effort ◽  
Systematic Uncertainties ◽  
Galaxy Formation And Evolution ◽  
Nearby Galaxies ◽  
Formation And Evolution ◽  
Extragalactic Distance Scale ◽  
Early Galaxy

The DIRECT project (as in “direct distances”) started in 1996 with the long-term goal of obtaining distances to two important galaxies in the cosmological distance ladder – M31 and M33 – using detached eclipsing binaries (DEBs) and Cepheids. These two nearby galaxies are the stepping stones in most of the current effort to understand the evolving universe at large scales. Not only are they essential to the calibration of the extragalactic distance scale, but they also constrain population synthesis models for early galaxy formation and evolution. However, accurate distances are essential to make these calibrations free from large systematic uncertainties.

TheHubble Space TelescopeKey Project on the Extragalactic Distance Scale. XXVIII. Combining the Constraints on the Hubble Constant

2000 ◽  
Vol 529 (2) ◽  
pp. 786-794 ◽  
Author(s):  
Jeremy R. Mould ◽  
John P. Huchra ◽  
Wendy L. Freedman ◽  
Robert C. Kennicutt, Jr. ◽  
Laura Ferrarese ◽  
...  
Keyword(s):  
Hubble Constant ◽  
Distance Scale ◽  
Extragalactic Distance Scale

scholarly journals Radial velocities, metallicities, and distances of Cepheids in M31 and M33

2004 ◽  
Vol 193 ◽  
pp. 99-102
Author(s):  
Amy D. Forestell ◽  
Thomas G. Barnes ◽  
Christopher Sneden ◽  
Thomas J. Moffett
Keyword(s):  
High Resolution ◽  
Surface Brightness ◽  
Local Group ◽  
Variable Stars ◽  
Radial Velocities ◽  
Distance Scale ◽  
Distance Measurements ◽  
Using Data ◽  
Extragalactic Distance Scale

AbstractCepheid variable stars are fundamental to the calibration of the extragalactic distance scale. We present radial velocities, preliminary metallicities, and preliminary surface brightness distances of Cepheids in Local Group galaxies M31 and M33 using data obtained with the High Resolution Spectrograph on the Hobby-Eberly Telescope at McDonald Observatory. These data are the first step toward surface brightness distance measurements and metallicity calibrations of these extragalactic Cepheids.

scholarly journals Magellanic Cloud Eclipsing Binaries: Primary Distance Indicators

1999 ◽  
Vol 190 ◽  
pp. 563-566
Author(s):  
J. D. Pritchard ◽  
W. Tobin ◽  
J. V. Clausen ◽  
E. F. Guinan ◽  
E. L. Fitzpatrick ◽  
...  
Keyword(s):  
New Zealand ◽  
Magellanic Cloud ◽  
Eclipsing Binaries ◽  
Fundamental Parameters ◽  
Distance Indicators

Our collaboration involves groups in Denmark, the U.S.A. Spain and of course New Zealand. Combining ground-based and satellite (IUE and HST) observations we aim to determine accurate and precise stellar fundamental parameters for the components of Magellanic Cloud Eclipsing Binaries as well as the distances to these systems and hence the parent galaxies themselves. This poster presents our latest progress.

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