Variable Stars and the Cosmic Distance Scale

For three quarters of a century pulsating variable stars have lain at the foundation of the extragalactic distance scale. The construction of larger telescopes, advances in detector technology, hard work by observers, and our understanding of stellar structure have all contributed to the expansion of the realm of the Cepheids to the distance of M101. Now, with the advent of Hubble Space Telescope (HST), we can look forward to the detection of Cepheids in the Virgo cluster and the removal of much of the remaining uncertainty in the Hubble constant.

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The Virgo Cluster

Proceedings of the International Astronomical Union ◽

10.1017/s1743921312021527 ◽

2012 ◽

Vol 8 (S289) ◽

pp. 262-268

Author(s):

Jeremy Mould

Keyword(s):

Hubble Space Telescope ◽

Hubble Constant ◽

Virgo Cluster ◽

Distance Scale ◽

Wilkinson Microwave Anisotropy Probe ◽

Traditional Role ◽

Distance Measurements ◽

Redshift Surveys ◽

Extragalactic Distance Scale

AbstractIn the era of precision cosmology, the Virgo cluster takes on a new role in the cosmic distance scale. Its traditional role of testing the consistency of secondary distance indicators is replaced by an ensemble of distance measurements within the Local Supercluster, united by a velocity-field model obtained from a reconstruction based on redshift surveys. The Wilkinson Microwave Anisotropy Probe (WMAP) leads us to see the Hubble constant as one of six parameters in a standard model of cosmology with considerable covariance among parameters. Independent experiments, such as WMAP, the Hubble Space Telescope Key Project on the Extragalactic Distance Scale, and their successors constrain these parameters.

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The Hubble Space Telescope Key Project to Measure the Hubble Constant

Symposium - International Astronomical Union ◽

10.1017/s007418090013205x ◽

1999 ◽

Vol 183 ◽

pp. 17-30 ◽

Cited By ~ 13

Author(s):

Wendy L. Freedman ◽

Jeremy R. Mould ◽

Robert C. Kennicutt ◽

Barry F. Madore

Keyword(s):

Hubble Space Telescope ◽

Hubble Constant ◽

Distance Scale ◽

General Assembly ◽

Host Galaxies ◽

Space Telescope ◽

Type Ia Supernova ◽

Type Ia ◽

Extragalactic Distance Scale

A Joint Discussion on the extragalactic distance scale and the Hubble constant took place fifteen years ago, at the 1982 XVIIIth General Assembly of the IAU, held in Patras, Greece. At that time, the newest applications of infrared photometers to Tully-Fisher measurements (Aaronson 1983) and Cepheid distances (Madore 1983) were reported. CCDs were just coming into use and had not yet been applied to extragalactic distance determinations; all of the extragalactic Cepheid distances were based on photographic Argelander (eye-estimated) photometry (Tammann and Sandage 1983 and references therein). No Cepheid distances to type Ia supernova-host galaxies were available.

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Cepheid and Long – Period Variables in Virgo Cluster Galaxies

International Astronomical Union Colloquium ◽

10.1017/s0252921100116938 ◽

1993 ◽

Vol 139 ◽

pp. 81-89

Author(s):

M.J. Pierce ◽

R.D. McClure ◽

D.L. Welch ◽

R. Racine ◽

S. van den Bergh

Keyword(s):

High Resolution ◽

Hubble Constant ◽

Variable Stars ◽

Virgo Cluster ◽

Distance Scale ◽

Cluster Galaxies ◽

Cluster Distance ◽

Resolution Imaging ◽

Extragalactic Distance Scale

AbstractWe are currently undertaking a ground-based imaging survey which attempts to discover and determine periods for variable stars in Virgo Cluster galaxies. Such a survey is now feasible thanks to the high resolution imaging (FWHM ≤ 0.50 arcsec) routinely obtained with the High Resolution Camera on the Canada-France-Hawaii Telescope. The Virgo Cluster has long been considered a crucial “stepping-stone” in the extragalactic distance scale problem given that the cluster is at a “cosmologically interesting” distance and that there is little controversy in the relative distance between Virgo and more distant clusters, such as Coma. Consequently, much of the controversy regarding the extragalactic distance scale and the Hubble Constant can be eliminated with a determination of the Virgo Cluster distance. Some preliminary results and the prospects for establishing the distance to the Virgo Cluster using Cepheids and LPVs are discussed.

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MEASURING THE HUBBLE CONSTANT WITH THE HUBBLE SPACE TELESCOPE

Proceedings of the International Astronomical Union ◽

10.1017/s1743921310008148 ◽

2009 ◽

Vol 5 (H15) ◽

pp. 1-16 ◽

Cited By ~ 1

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.

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The Hubble Space Telescope extragalactic distance scale key project. 2: Photometry of WFC images of M81

The Astrophysical Journal ◽

10.1086/174227 ◽

1994 ◽

Vol 428 ◽

pp. 143 ◽

Cited By ~ 9

Author(s):

Shaun M. G. Hughes ◽

Peter B. Stetson ◽

Anne Turner ◽

Robert C., Jr. Kennicutt ◽

Robert Hill ◽

...

Keyword(s):

Hubble Space Telescope ◽

Distance Scale ◽

Space Telescope ◽

Extragalactic Distance Scale

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The Extragalactic Distance Scale Key Project. III. The Discovery of Cepheids and a New Distance to M101 Using the Hubble Space Telescope

The Astrophysical Journal ◽

10.1086/177221 ◽

1996 ◽

Vol 463 ◽

pp. 26 ◽

Cited By ~ 88

Author(s):

Daniel D. Kelson ◽

Garth D. Illingworth ◽

Wendy F. Freedman ◽

John A. Graham ◽

Robert Hill ◽

...

Keyword(s):

Hubble Space Telescope ◽

Distance Scale ◽

Space Telescope ◽

Extragalactic Distance Scale

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The H0 Key Project: Cepheids in NGC925, M101 and M100

International Astronomical Union Colloquium ◽

10.1017/s0252921100037076 ◽

1995 ◽

Vol 155 ◽

pp. 258-259

Author(s):

S. M. G. Hughes

Keyword(s):

Standard Model ◽

Hubble Space Telescope ◽

Big Bang ◽

Distance Scale ◽

Space Telescope ◽

The Standard Model ◽

Age Of The Universe ◽

Extragalactic Distance Scale ◽

The Big Bang ◽

The Universe

AbstractAs part of the Extragalactic Distance Scale Key Project, the Hubble Space Telescope has been used to identify Cepheids in M100, M101 and NGC925, and to measure distances derived from the Cepheid PL relation. For M100, the distance of 17.1 ± 1.8 Mpc has been used to infer a preliminary value for H0 of ~ 80 km/s/Mpc, which brings the age of the Universe derived from the standard model of the Big Bang into conflict with the ages of the oldest stars.

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Progress in Measuring the Hubble Constant

Australian Journal of Physics ◽

10.1071/ph951093 ◽

1995 ◽

Vol 48 (6) ◽

pp. 1093 ◽

Cited By ~ 1

Author(s):

Jeremy Mould

Keyword(s):

Vacuum Energy ◽

Hubble Space Telescope ◽

Hubble Constant ◽

Variable Stars ◽

Space Telescope ◽

Open Universe ◽

Physical Cosmology ◽

Distance Indicators

The Hubble Space Telescope is breaking a long-standing impasse in physical cosmology. The distances of galaxies sufficiently remote for their random velocities to be negligible can now be measured in two steps, the first using Cepheid variable stars as standard candles to approximately 20 Mpc, the second using a variety of secondary distance indicators to distances 10 times larger. The present key project on the Hubble Constant aims to measure Ho to 10%. Current results with approximately 20% uncertainty suggest that cosmologists will be offered a dilemma: an open Universe or a vacuum energy dominated Universe.

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