The ACS Nearby Galaxy Survey Treasury (2009)
Dalcanton, Julianne J., Williams, Benjamin F., Seth, Anil C., Dolphin, Andrew, Holtzman, Jon, Rosema, Keith, ...
The ACS Nearby Galaxy Survey Treasury (ANGST) is a systematic survey to establish a legacy of uniform multi-color photometry of resolved stars for a volume-limited sample of nearby galaxies (D14...
Bernard, Edouard J., Monelli, Matteo, Gallart, Carme, Drozdovsky, Igor, Stetson, Peter B., Aparicio, Antonio, ...
(abridged) We present the first study of the variable star populations in the isolated dwarf spheroidal galaxies (dSph) Cetus and Tucana. Based on Hubble Space Telescope images obtained with the...
The ACS Nearby Galaxy Survey Treasury I. The Star Formation History of the M81 Outer Disk (2008)
Williams, Benjamin F., Dalcanton, Julianne J., Seth, Anil C., Weisz, Daniel, Dolphin, Andrew, Skillman, Evan, ...
The ACS Nearby Galaxy Survey Treasury (ANGST) is a large Hubble Space Telescope (HST) Advanced Camera for Surveys (ACS) treasury program to obtain resolved stellar photometry for a volume-limited...
Bernard, Edouard J., Gallart, Carme, Monelli, Matteo, Aparicio, Antonio, Cassisi, Santi, Skillman, Evan D., ...
We present a study of the radial distribution of RR Lyrae variables, which present a range of photometric and pulsational properties, in the dwarf spheroidal galaxy Tucana. We find that the fainter...
A Deep HST Study of the Globular Cluster NGC 6397: Reduction Methods (2008)
Anderson, Jay, King, Ivan R., Richer, Harvey B., Fahlman, Gregory G., Hansen, Brad M. S., Hurley, Jarrod, ...
We describe here the reduction methods that we developed to study the faintest red dwarfs and white dwarfs in an outer field of NGC6397, which was observed by \hst for 126 orbits in 2005. The...
Galactic Globular Cluster Metallicity Scale From the Ca (2008)
Triplet Ii, Glen A. Rutledge, James E. Hesser, Peter B. Stetson
We compare our compilation of the W 0 calcium index for 71 Galactic globular clusters to the widely used Zinn and West (1984 ApJS, 55, 45) [Fe/H] scale and to Carretta and Gratton's (1997...
Davis, D. Saul, Richer, Harvey B., Anderson, Jay, Brewer, J. H., Hurley, J., Kalirai, Jasonjot S., ...
Using Hubble Space Telescope observations of the globular cluster NGC 6397, we constrain the cluster's binary fraction. The observations consist of two fields: the primary science field, a single...
Deep advanced camera for surveys imaging in the globular cluster NGC 6397: reduction methods (2008)
Anderson, Jay, King, Ivan R., Richer, Harvey B., Fahlman, Gregory G., Hansen, Brad M. S., Hurley, Jarrod, ...
We describe here the reduction methods that we developed to study the faintest red dwarfs and white dwarfs in an outer field of NGC 6397, which was observed by HST for 126 orbits in 2005. The...
Davis, D. Saul, Richer, Harvey B., Anderson, Jay, Brewer, J. H., Hurley, J., Kalirai, Jasonjot S., ...
Using Hubble Space Telescope observations of the globular cluster NGC 6397, we constrain the cluster's binary fraction. The observations consist of two fields: the primary science field, a single...
Deep advanced camera for surveys imaging in the globular cluster NGC 6397: reduction methods (2008)
Anderson, Jay, King, Ivan R., Richer, Harvey B., Fahlman, Gregory G., Hansen, Brad M. S., Hurley, Jarrod, ...
We describe here the reduction methods that we developed to study the faintest red dwarfs and white dwarfs in an outer field of NGC 6397, which was observed by HST for 126 orbits in 2005. The...
Fiducial Stellar Population Sequences for the u'g'r'i'z' System (2007)
Clem, James L., VandenBerg, Don A., Stetson, Peter B.
We describe an extensive observational project that has obtained high-quality and homogeneous photometry for a number of different Galactic star clusters (including M 92, M 13, M 3, M 71, and NGC...
Dominion Astrophysical Observatory (2007)
Francisco G. Valdes, Luis E. Campusano, Juan D. Vel'asquez, Peter B. Stetson
Departamento de Ciencias de la Computaci'on
Shaun M. Hughes, Barry F. Madore (2007)
And Jeremy California, Shaun M. Hughes, Barry F. Madore, Jeremy R. Mould, Laura Ferrarese, C. Ford, ...
The Distance Scale (HO) Key Project for Space Telescope ( aims employ the period-luminosity relation to measure galaxy distances out as far as the Virgo cluster. The vital steps in this program are...
Future Development of the DAOPHOT Crowded-Field Photometry Package (2007)
Peter B. Stetson, Lindsey E. Davis, Dennis R. Crabtree
The DAOPHOT package has been widely used by the astronomical community for obtaining stellar photometry in crowded fields. The first section of this paper discusses the port of DAOPHOT to the IRAF...
NGC 2419, M92, and the Age Gradient in the Galactic Halo (2007)
William Harris, Roger A. Bell, Don A. Vandenberg, Michael Bolte, Peter B. Stetson, James E. Hesser, ...
The WFPC2 camera on HST has been used to obtain photometry of the low-metallicity ([Fe/H] = \Gamma2:14), outer-halo globular cluster NGC 2419. Our color-magnitude diagram in (V; V \Gamma I) reaches V...
Discovery Of Cepheid Variables In The Virgo Cluster Galaxy Ngc 4571 (2007)
Michael Pierce, Douglas L. Welch, Robert D. Mcclure, Peter B. Stetson
We present the results of a survey for Cepheid variables in the Virgo Cluster spiral NGC 4571 using the High-Resolution Camera (HRCam) on the Canada-France-Hawaii Telescope. Our 13 epochs, taken over...
Probing the Faintest Stars in a Globular Star Cluster (2007)
Richer, Harvey B., Anderson, Jay, Brewer, James, Davis, Saul, Fahlman, Gregory G., Hansen, Brad M. S., ...
NGC 6397 is the second closest globular star cluster to the Sun. Using 5 days of time on the Hubble Space Telescope, we have constructed the deepest ever color-magnitude diagram for this cluster. We...
The Space Motion of the Globular Cluster NGC 6397 (2007)
Kalirai, Jasonjot S., Anderson, Jay, Richer, Harvey B., King, Ivan R., Brewer, James P., Carraro, Giovanni, ...
As a by-product of high-precision, ultra-deep stellar photometry in the Galactic globular cluster NGC 6397 with the Hubble Space Telescope, we are able to measure a large population of background...
The space motion of the globular cluster NGC 6397 (2007)
Kalirai, Jasonjot S., Anderson, Jay, Richer, Harvey B., King, Ivan R., Brewer, James P., Carraro, Giovanni, ...
As a by-product of high-precision, ultradeep stellar photometry in the Galactic globular cluster NGC 6397 with the Hubble Space Telescope, we are able to measure a large population of background...
The space motion of the globular cluster NGC 6397 (2007)
Kalirai, Jasonjot S., Anderson, Jay, Richer, Harvey B., King, Ivan R., Brewer, James P., Carraro, Giovanni, ...
As a by-product of high-precision, ultradeep stellar photometry in the Galactic globular cluster NGC 6397 with the Hubble Space Telescope, we are able to measure a large population of background...
The space motion of the globular cluster NGC 6397 (2007)
Kalirai, Jasonjot S., Anderson, Jay, Richer, Harvey B., King, Ivan R., Brewer, James P., Carraro, Giovanni, ...
As a by-product of high-precision, ultradeep stellar photometry in the Galactic globular cluster NGC 6397 with the Hubble Space Telescope, we are able to measure a large population of background...
The white dwarf cooling sequence of NGC 6397 (2007)
Hansen, Brad M. S., Anderson, Jay, Brewer, James, Dotter, Aaron, Fahlman, Greg G., Hurley, Jarrod, ...
We present the results of a deep Hubble Space Telescope (HST) exposure of the nearby globular cluster NGC 6397, focussing attention on the cluster's white dwarf cooling sequence. This sequence is...
The space motion of the globular cluster NGC 6397 (2007)
Kalirai, Jasonjot S., Anderson, Jay, Richer, Harvey B., King, Ivan R., Brewer, James P., Carraro, Giovanni, ...
As a by-product of high-precision, ultradeep stellar photometry in the Galactic globular cluster NGC 6397 with the Hubble Space Telescope, we are able to measure a large population of background...
The white dwarf cooling sequence of NGC 6397 (2007)
Hansen, Brad M. S., Anderson, Jay, Brewer, James, Dotter, Aaron, Fahlman, Greg G., Hurley, Jarrod, ...
We present the results of a deep Hubble Space Telescope (HST) exposure of the nearby globular cluster NGC 6397, focussing attention on the cluster's white dwarf cooling sequence. This sequence is...
Studying old populations with RR Lyrae Variables in the Local Group (2006)
C. Gallart, D. MartÃnez Delgado, Peter B. Stetson
Studying old populations with RR Lyrae Variables in the Local Group
The Chemical Abundances of the Stellar Populations in the Leo I and Leo II dSph Galaxies (2006)
Bosler, Tammy L., Smecker-Hane, Tammy A., Stetson, Peter B.
We have obtained spectra of 102 red giant branch (RGB) stars in the Leo I dwarf spheroidal galaxy (dSph) and 74 RGB stars in the Leo II dSph using LRIS on the Keck I 10-meter Telescope. We report on...
The Discovery of Cepheids and a Distance to NGC 5128 (2006)
Ferrarese, Laura, Mould, Jeremy R., Stetson, Peter B., Tonry, John L., Blakeslee, John P., Ajhar, Edward A.
We discuss a new distance to NGC 5128 (Centaurus A) based on Cepheid variables observed with the Hubble Space Telescope. Twelve F555W (V) and six F814W (I) epochs of cosmic-ray-split Wide Field...
Probing the faintest stars in a globular star cluster (2006)
Richer, Harvey B., Anderson, Jay, Brewer, James, Davis, Saul, Fahlman, Gregory G., Hansen, Brad M. S., ...
NGC 6397 is the second closest globular star cluster to the Sun. Using 5 days of time on the Hubble Space Telescope, we have constructed an ultradeep color-magnitude diagram for this cluster. We see...
Probing the faintest stars in a globular star cluster (2006)
Richer, Harvey B., Anderson, Jay, Brewer, James, Davis, Saul, Fahlman, Gregory G., Hansen, Brad M. S., ...
NGC 6397 is the second closest globular star cluster to the Sun. Using 5 days of time on the Hubble Space Telescope, we have constructed an ultradeep color-magnitude diagram for this cluster. We see...
Chemical Compositions of Red Giant Stars in Old Large Magellanic Cloud Globular Clusters (2005)
Johnson, Jennifer A., Ivans, Inese I., Stetson, Peter B.
We have observed ten red giant stars in four old Large Magellanic Cloud globular clusters with the high-resolution spectrograph MIKE on the Magellan Landon Clay 6.5-m telescope. The stars in our...
C and N Abundances in Stars At the Base of the Red Giant Branch in M15 (2005)
Cohen, Judith G., Briley, Michael M., Stetson, Peter B.
We present an analysis of a large sample of moderate resolution Keck LRIS spectra of subgiants and stars at the base of the RGB in M15, most within the range 16.5 < V < 19.5 (1.2 < M_V < 4.2), with...
Homogeneous Photometry IV: On the Standard Sequence in the Globular Cluster NGC2419 (2005)
A new analysis of CCD-based BVRI broad-band photometry for the globular cluster NGC2419 is presented, based on 340 CCD images either donated by colleagues or retrieved from public archives. The...
Riess, Adam G., Li, Weidong, Stetson, Peter B., Filippenko, Alexei V., Jha, Saurabh, Kirshner, Robert P., ...
We report observations of two nearby Type Ia supernovae (SNe Ia) for which observations of Cepheid variables in the host galaxies have been obtained with the Hubble Space Telescope: SN 1994ae in NGC...
Limits on Hubble Constant from the Distance of M100 (2004)
Mould, Jeremy, Huchra, John P., Bresolin, Fabio, Ferrarese, Laura, Ford, Holland C., Freedman, Wendy L., ...
We examine the consequences of a 17 Mpc M100 distance, questioning its consistency with supernova and other distances.
A Star Catalog for the Open Cluster NGC188 (2004)
Stetson, Peter B., McClure, Robert D., VandenBerg, Don A.
We present new BVRI broad-band photometry for the old open cluster NGC188 based upon analysis of 299 CCD images either obtained by us, donated by colleagues, or retrieved from public archives. We...
Searching for variability in the globular cluster messier 4 (2004)
Brewer, James, Fahlman, Greg G., Ferdman, Robert D., Gibson, Bradley Kenneth, Hansen, Brad M. S., Huber, Mark E., ...
Time-series data taken with the Hubble Space Telescope of a field six core radii (~5') from the center of the globular cluster Messier 4, and covering a period of about 10 weeks in early 2001, have...
Hubble Space Telescope observations of the white dwarf cooling sequence of M4 (2004)
Hansen, Brad M., Richer, Harvey B., Fahlman, Greg G., Stetson, Peter B., Brewer, James, Currie, Thayne, ...
We investigate in detail the white dwarf cooling sequence of the globular cluster Messier 4. In particular, we study the influence of various systematic uncertainties, both observational and...
Kalirai, Jasonjot J., Richer, Harvey B., Hansen, Brad M., Stetson, Peter B., Shara, Michael M., Saviane, Ivo, ...
Not available.
Richer, Harvey B., Brewer, James, Fahlman, Greg G., Kalirai, Jasonjot J., Stetson, Peter B., Hansen, Brad M., ...
We respond to the recent paper by De Marchi et al. on the white dwarf cooling age of M4. The authors question the data analysis and interpretation that led to our conclusions in Hansen et al. in...
Hubble Space Telescope observations of the main sequence of M4 (2004)
Richer, Harvey B., Fahlman, Greg T., Brewer, James, Davis, Stuart, Kalirai, Jasonjot J., Stetson, Peter B., ...
We present new results from a photometric study of the main-sequence stars in M4 (NGC 6121=C1620-264), the closest globular cluster to the Sun. Multifield, multiepoch observations at approximately 1,...
Searching for variability in the globular cluster messier 4 (2004)
Ferdman, Robert D., Richer, Harvey B., Brewer, James, Fahlman, Greg G., Gibson, Brad K., Hansen, Brad M., ...
Time-series data taken with the Hubble Space Telescope of a field six core radii (~5') from the center of the globular cluster Messier 4, and covering a period of about 10 weeks in early 2001, have...
Hubble Space Telescope observations of the main sequence of M4 (2004)
Richer, Harvey B., Fahlman, Greg G., Brewer, James, Davis, Stuart, Kalirai, Jasonjot S., Stetson, Peter B., ...
We present new results from a photometric study of the main-sequence stars in M4 (NGC 6121=C1620-264), the closest globular cluster to the Sun. Multifield, multiepoch observations at approximately 1,...
Hubble Space Telescope observations of the white dwarf cooling sequence of M4 (2004)
Hansen, Brad M., Richer, Harvey B., Fahlman, Greg G., Stetson, Peter B., Brewer, James, Currie, Thayne, ...
We investigate in detail the white dwarf cooling sequence of the globular cluster Messier 4. In particular, we study the influence of various systematic uncertainties, both observational and...
Kalirai, Jasonjot S., Richer, Harvey B., Hansen, Brad M., Stetson, Peter B., Shara, Michael M., Saviane, Ivo, ...
Not available.
Richer, Harvey B., Brewer, James, Fahlman, Greg G., Kalirai, Jasonjot S., Stetson, Peter B., Hansen, Brad M., ...
We respond to the recent paper by De Marchi et al. on the white dwarf cooling age of M4. The authors question the data analysis and interpretation that led to our conclusions in Hansen et al. in...
Searching for variability in the globular cluster messier 4 (2004)
Ferdman, Robert D., Richer, Harvey B., Brewer, James, Fahlman, Greg G., Gibson, Brad K., Hansen, Brad M., ...
Time-series data taken with the Hubble Space Telescope of a field six core radii (~5') from the center of the globular cluster Messier 4, and covering a period of about 10 weeks in early 2001, have...
Hubble Space Telescope observations of the main sequence of M4 (2004)
Richer, Harvey B., Fahlman, Greg T., Brewer, James, Davis, Stuart, Kalirai, Jasonjot J., Stetson, Peter B., ...
We present new results from a photometric study of the main-sequence stars in M4 (NGC 6121=C1620-264), the closest globular cluster to the Sun. Multifield, multiepoch observations at approximately 1,...
Hubble Space Telescope observations of the white dwarf cooling sequence of M4 (2004)
Hansen, Brad M., Richer, Harvey B., Fahlman, Greg G., Stetson, Peter B., Brewer, James, Currie, Thayne, ...
We investigate in detail the white dwarf cooling sequence of the globular cluster Messier 4. In particular, we study the influence of various systematic uncertainties, both observational and...
Kalirai, Jasonjot J., Richer, Harvey B., Hansen, Brad M., Stetson, Peter B., Shara, Michael M., Saviane, Ivo, ...
Not available.
Richer, Harvey B., Brewer, James, Fahlman, Greg G., Kalirai, Jasonjot J., Stetson, Peter B., Hansen, Brad M., ...
We respond to the recent paper by De Marchi et al. on the white dwarf cooling age of M4. The authors question the data analysis and interpretation that led to our conclusions in Hansen et al. in...
Searching for variability in the globular cluster messier 4 (2004)
Ferdman, Robert D., Richer, Harvey B., Brewer, James, Fahlman, Greg G., Gibson, Brad K., Hansen, Brad M., ...
Time-series data taken with the Hubble Space Telescope of a field six core radii (~5') from the center of the globular cluster Messier 4, and covering a period of about 10 weeks in early 2001, have...
Hubble Space Telescope observations of the white dwarf cooling sequence of M4 (2004)
Hansen, Brad M., Richer, Harvey B., Fahlman, Greg G., Stetson, Peter B., Brewer, James, Currie, Thayne, ...
We investigate in detail the white dwarf cooling sequence of the globular cluster Messier 4. In particular, we study the influence of various systematic uncertainties, both observational and...
Kalirai, Jasonjot J., Richer, Harvey B., Hansen, Brad M., Stetson, Peter B., Shara, Michael M., Saviane, Ivo, ...
Not available.
Richer, Harvey B., Brewer, James, Fahlman, Greg G., Kalirai, Jasonjot J., Stetson, Peter B., Hansen, Brad M., ...
We respond to the recent paper by De Marchi et al. on the white dwarf cooling age of M4. The authors question the data analysis and interpretation that led to our conclusions in Hansen et al. in...
Hubble Space Telescope observations of the main sequence of M4 (2004)
Richer, Harvey B., Fahlman, Greg T., Brewer, James, Davis, Stuart, Kalirai, Jasonjot J., Stetson, Peter B., ...
We present new results from a photometric study of the main-sequence stars in M4 (NGC 6121=C1620-264), the closest globular cluster to the Sun. Multifield, multiepoch observations at approximately 1,...
Searching for variability in the globular cluster messier 4 (2004)
Ferdman, Robert D., Richer, Harvey B., Brewer, James, Fahlman, Greg G., Gibson, Brad K., Hansen, Brad M., ...
Time-series data taken with the Hubble Space Telescope of a field six core radii (~5') from the center of the globular cluster Messier 4, and covering a period of about 10 weeks in early 2001, have...
Hubble Space Telescope observations of the white dwarf cooling sequence of M4 (2004)
Hansen, Brad M., Richer, Harvey B., Fahlman, Greg G., Stetson, Peter B., Brewer, James, Currie, Thayne, ...
We investigate in detail the white dwarf cooling sequence of the globular cluster Messier 4. In particular, we study the influence of various systematic uncertainties, both observational and...
Kalirai, Jasonjot S., Richer, Harvey B., Hansen, Brad M., Stetson, Peter B., Shara, Michael M., Saviane, Ivo, ...
Not available.
Richer, Harvey B., Brewer, James, Fahlman, Greg G., Kalirai, Jasonjot S., Stetson, Peter B., Hansen, Brad M., ...
We respond to the recent paper by De Marchi et al. on the white dwarf cooling age of M4. The authors question the data analysis and interpretation that led to our conclusions in Hansen et al. in...
Hubble Space Telescope observations of the main sequence of M4 (2004)
Richer, Harvey B., Fahlman, Greg G., Brewer, James, Davis, Stuart, Kalirai, Jasonjot S., Stetson, Peter B., ...
We present new results from a photometric study of the main-sequence stars in M4 (NGC 6121=C1620-264), the closest globular cluster to the Sun. Multifield, multiepoch observations at approximately 1,...
The Chemical Inhomogeneity of Faint M13 Stars: C and N Abundances (2003)
Briley, Michael M., Cohen, Judith G., Stetson, Peter B.
Building upon earlier observations which demonstrate substantial star-to-star differences in the carbon abundances of M13 subgiants, we present new Keck LRIS spectra reaching more that 1.5 mag below...
HST Snaphot Study of Variable Stars in Globular Clusters: Inner Region of NGC 6441 (2003)
Pritzl, Barton J., Smith, Horace A., Stetson, Peter B., Catelan, Marcio, Sweigart, Allen V., Layden, Andrew C., ...
[Abridged] We present the results of a Hubble Space Telescope snapshot program to survey the inner region of the globular cluster NGC 6441 for its variable stars. A total of 57 variable stars was...
Searching for Variability in the Globular Cluster Messier 4 (2003)
Ferdman, Robert D., Richer, Harvey B., Brewer, James, Fahlman, Greg G., Gibson, Brad K., Hansen, Brad M. S., ...
Time-series data taken with the Hubble Space Telescope of a field six core radii (~5') from the center of the globular cluster Messier 4, and covering a period of about 10 weeks in early 2001, have...
Kalirai, Jasonjot S., Richer, Harvey B., Hansen, Brad M., Stetson, Peter B., Shara, Michael M., Saviane, Ivo, ...
We establish an extragalactic, zero-motion frame of reference within the deepest optical image of a globular star cluster, an HST 123-orbit exposure of M4 (GO 8679, cycle 9). The line of sight beyond...
Carbon Abundances of Faint Stars in M13 - Evidence for Two Abundance Altering Mechanisms (2002)
Briley, Michael M., Cohen, Judith G., Stetson, Peter B.
We present an analysis of CH band strengths in Keck LRIS spectra of a sample of 81 stars in M13 within 2 magnitudes of the main-sequence turnoff. The subgiants clearly exhibit a substantial (a factor...
The Lower Main Sequence and Mass Function of the Globular Cluster Messier 4 (2002)
Richer, Harvey B., Brewer, James, Fahlman, Gregory G., Gibson, Brad K., Hansen, Brad M., Ibata, Rodrigo, ...
The deepest optical image ever in a globular star cluster, a Hubble Space Telescope (HST) 123 orbit exposure in a single field of Messier 4, was obtained in 2 filters (F606W, F814W) over a 10 week...
The White Dwarf Cooling Sequence of the Globular Cluster Messier 4 (2002)
Hansen, Brad M. S., Brewer, James, Fahlman, Greg G., Gibson, Brad K., Ibata, Rodrigo, Limongi, Marco, ...
We present the white dwarf sequence of the globular cluster M4, based on a 123 orbit Hubble Space Telescope exposure, with limiting magnitude V = 30, I = 28. The white dwarf luminosity function rises...
The white dwarf cooling sequence of the globular cluster Messier 4 (2002)
Hansen, Brad M., Brewer, James, Fahlman, Greg G., Gibson, Bradley K., Ibata, Rodrigo A., Limongi, Marco, ...
We present the white dwarf sequence of the globular cluster M4, based on a 123 orbit Hubble Space Telescope exposure, with a limiting magnitude of V~30 and I~28. The white dwarf luminosity function...
The lower main sequence and mass function of the globular cluster Messier 4 (2002)
Richer, Harvey B., Brewer, James, Fahlman, Gregory G., Gibson, Brad K., Hansen, Brad M., Ibata, Rodrigo A., ...
The deepest optical image ever in a globular star cluster, a Hubble Space Telescope (HST) 123 orbit exposure in a single field of Messier 4, was obtained in 2 filters (F606W, F814W) over a 10 week...
The white dwarf cooling sequence of the globular cluster Messier 4 (2002)
Hansen, Brad M., Brewer, James, Fahlman, Greg G., Gibson, Bradley K., Ibata, Rodrigo A., Limongi, Marco, ...
We present the white dwarf sequence of the globular cluster M4, based on a 123 orbit Hubble Space Telescope exposure, with a limiting magnitude of V~30 and I~28. The white dwarf luminosity function...
The lower main sequence and mass function of the globular cluster Messier 4 (2002)
Richer, Harvey B., Brewer, James, Fahlman, Gregory G., Gibson, Brad K., Hansen, Brad M., Ibata, Rodrigo A., ...
The deepest optical image ever in a globular star cluster, a Hubble Space Telescope (HST) 123 orbit exposure in a single field of Messier 4, was obtained in 2 filters (F606W, F814W) over a 10 week...
The white dwarf cooling sequence of the globular cluster Messier 4 (2002)
Hansen, Brad M., Brewer, James, Fahlman, Greg G., Gibson, Bradley K., Ibata, Rodrigo A., Limongi, Marco, ...
We present the white dwarf sequence of the globular cluster M4, based on a 123 orbit Hubble Space Telescope exposure, with a limiting magnitude of V~30 and I~28. The white dwarf luminosity function...
The lower main sequence and mass function of the globular cluster Messier 4 (2002)
Richer, Harvey B., Brewer, James, Fahlman, Gregory G., Gibson, Brad K., Hansen, Brad M., Ibata, Rodrigo A., ...
The deepest optical image ever in a globular star cluster, a Hubble Space Telescope (HST) 123 orbit exposure in a single field of Messier 4, was obtained in 2 filters (F606W, F814W) over a 10 week...
The white dwarf cooling sequence of the globular cluster Messier 4 (2002)
Hansen, Brad M., Brewer, James, Fahlman, Greg G., Gibson, Bradley K., Ibata, Rodrigo A., Limongi, Marco, ...
We present the white dwarf sequence of the globular cluster M4, based on a 123 orbit Hubble Space Telescope exposure, with a limiting magnitude of V~30 and I~28. The white dwarf luminosity function...
The lower main sequence and mass function of the globular cluster Messier 4 (2002)
Richer, Harvey B., Brewer, James, Fahlman, Gregory G., Gibson, Brad K., Hansen, Brad M., Ibata, Rodrigo A., ...
The deepest optical image ever in a globular star cluster, a Hubble Space Telescope (HST) 123 orbit exposure in a single field of Messier 4, was obtained in 2 filters (F606W, F814W) over a 10 week...
The white dwarf cooling sequence of the globular cluster Messier 4 (2002)
Hansen, Brad M., Brewer, James, Fahlman, Greg G., Gibson, Bradley K., Ibata, Rodrigo A., Limongi, Marco, ...
We present the white dwarf sequence of the globular cluster M4, based on a 123 orbit Hubble Space Telescope exposure, with a limiting magnitude of V~30 and I~28. The white dwarf luminosity function...
The lower main sequence and mass function of the globular cluster Messier 4 (2002)
Richer, Harvey B., Brewer, James, Fahlman, Gregory G., Gibson, Brad K., Hansen, Brad M., Ibata, Rodrigo A., ...
The deepest optical image ever in a globular star cluster, a Hubble Space Telescope (HST) 123 orbit exposure in a single field of Messier 4, was obtained in 2 filters (F606W, F814W) over a 10 week...
C and N Abundances in Stars At the Base of the Red Giant Branch in M5 (2001)
Cohen, Judith G., Briley, Michael M., Stetson, Peter B.
We present an analysis of a large sample of moderate resolution Keck LRIS spectra of subgiant (V \sim 17.2) and fainter stars in the Galactic globular cluster M5 (NGC 5904) with the goal of deriving...
The Distance to Supernova 1998aq in NGC3982 (2001)
Stetson, Peter B., Gibson, Brad K.
The distance to NGC3982, host galaxy to the Type Ia supernova SN1998aq, is derived using 32 Cepheids discovered in archival multi-epoch Hubble Space Telescope observations. Employing recent Large...
The Star Formation History of the Large Magellanic Cloud (2001)
Smecker-Hane, Tammy A., Cole, Andrew A., Gallagher III, John S., Stetson, Peter B.
Using WFPC2 aboard the Hubble Space Telescope, we have created deep color-magnitude diagrams in the V and I passbands for approximately 100,000 stars in a field at the center of the LMC bar and...
Supernova 1991T and the value of the hubble constant (2001)
Gibson, Brad K., Stetson, Peter B.
Based on multiepoch Hubble Space Telescope observations, we present the discovery of 16 high-quality Cepheid candidates in NGC 4527. Corrected for metallicity effects in the Cepheid period-luminosity...
Final results from the Hubble Space Telescope key project to measure the Hubble Constant (2001)
Freedman, Wendy L., Madore, Barry F., Gibson, Brad K., Ferrarese, Laura, Kelson, Daniel D., Sakai, Shoko, ...
We present here the final results of the Hubble Space Telescope (HST) Key Project to measure the Hubble constant. We summarize our method, the results, and the uncertainties, tabulate our revised...
Macri, Lucas M., Calzetti, Daniela, Freedman, Wendy L., Gibson, Brad K., Graham, John A., Huchra, John P., ...
We present the results of near-infrared observations of extragalactic Cepheids made with the Near-Infrared Camera and Multi-Object Spectrometer on board the Hubble Space Telescope (HST). The...
Supernova 1991T and the value of the hubble constant (2001)
Gibson, Brad K., Stetson, Peter B.
Based on multiepoch Hubble Space Telescope observations, we present the discovery of 16 high-quality Cepheid candidates in NGC 4527. Corrected for metallicity effects in the Cepheid period-luminosity...
Final results from the Hubble Space Telescope key project to measure the Hubble Constant (2001)
Freedman, Wendy L., Madore, Barry F., Gibson, Brad K., Ferrarese, Laura, Kelson, Daniel D., Sakai, Shoko, ...
We present here the final results of the Hubble Space Telescope (HST) Key Project to measure the Hubble constant. We summarize our method, the results, and the uncertainties, tabulate our revised...
Macri, Lucas M., Calzetti, Daniela, Freedman, Wendy L., Gibson, Brad K., Graham, John A., Huchra, John P., ...
We present the results of near-infrared observations of extragalactic Cepheids made with the Near-Infrared Camera and Multi-Object Spectrometer on board the Hubble Space Telescope (HST). The...
Supernova 1991T and the value of the hubble constant (2001)
Gibson, Brad K., Stetson, Peter B.
Based on multiepoch Hubble Space Telescope observations, we present the discovery of 16 high-quality Cepheid candidates in NGC 4527. Corrected for metallicity effects in the Cepheid period-luminosity...
Final results from the Hubble Space Telescope key project to measure the Hubble Constant (2001)
Freedman, Wendy L., Madore, Barry F., Gibson, Brad K., Ferrarese, Laura, Kelson, Daniel D., Sakai, Shoko, ...
We present here the final results of the Hubble Space Telescope (HST) Key Project to measure the Hubble constant. We summarize our method, the results, and the uncertainties, tabulate our revised...
Macri, Lucas M., Calzetti, Daniela, Freedman, Wendy L., Gibson, Brad K., Graham, John A., Huchra, John P., ...
We present the results of near-infrared observations of extragalactic Cepheids made with the Near-Infrared Camera and Multi-Object Spectrometer on board the Hubble Space Telescope (HST). The...
Supernova 1991T and the value of the hubble constant (2001)
Gibson, Brad K., Stetson, Peter B.
Based on multiepoch Hubble Space Telescope observations, we present the discovery of 16 high-quality Cepheid candidates in NGC 4527. Corrected for metallicity effects in the Cepheid period-luminosity...
Final results from the Hubble Space Telescope key project to measure the Hubble Constant (2001)
Freedman, Wendy L., Madore, Barry F., Gibson, Brad K., Ferrarese, Laura, Kelson, Daniel D., Sakai, Shoko, ...
We present here the final results of the Hubble Space Telescope (HST) Key Project to measure the Hubble constant. We summarize our method, the results, and the uncertainties, tabulate our revised...
Macri, Lucas M., Calzetti, Daniela, Freedman, Wendy L., Gibson, Brad K., Graham, John A., Huchra, John P., ...
We present the results of near-infrared observations of extragalactic Cepheids made with the Near-Infrared Camera and Multi-Object Spectrometer on board the Hubble Space Telescope (HST). The...
Supernova 1991T and the value of the hubble constant (2001)
Gibson, Brad K., Stetson, Peter B.
Based on multiepoch Hubble Space Telescope observations, we present the discovery of 16 high-quality Cepheid candidates in NGC 4527. Corrected for metallicity effects in the Cepheid period-luminosity...
Final results from the Hubble Space Telescope key project to measure the Hubble Constant (2001)
Freedman, Wendy L., Madore, Barry F., Gibson, Brad K., Ferrarese, Laura, Kelson, Daniel D., Sakai, Shoko, ...
We present here the final results of the Hubble Space Telescope (HST) Key Project to measure the Hubble constant. We summarize our method, the results, and the uncertainties, tabulate our revised...
Macri, Lucas M., Calzetti, Daniela, Freedman, Wendy L., Gibson, Brad K., Graham, John A., Huchra, John P., ...
We present the results of near-infrared observations of extragalactic Cepheids made with the Near-Infrared Camera and Multi-Object Spectrometer on board the Hubble Space Telescope (HST). The...
A revised Cepheid distance to NGC 4258 and a test of the distance scale (2000)
Newman, Jeffrey A., Ferrarese, Laura, Stetson, Peter B., Maoz, Eyal, Zepf, Stephen E., Davis, Marc, ...
In a previous paper (Maoz et al. 1999), we reported a Hubble Space Telescope (HST) Cepheid distance to the galaxy NGC 4258 obtained using the calibrations and methods then standard for the Key...
Supernova 1991T and the Value of the Hubble Constant (2000)
Gibson, Brad K., Stetson, Peter B.
Based upon multi-epoch Hubble Space Telescope observations, we present the discovery of sixteen high-quality Cepheid candidates in NGC 4527. Corrected for metallicity effects in the Cepheid...
Stars appearing in CCD images obtained over 224 nights during the course of 69 observing runs have been calibrated to the Johnson/Kron-Cousins BVRI photometric system defined by the equatorial...
Ferrarese, Laura, Silbermann, N. A., Mould, Jeremy R., Stetson, Peter B., Saha, Abhijit, Freedman, Wendy L., ...
We explore the limits of photometric reductions of crowded stellar fields observed with the Wide Field and Planetary Camera 2 on board the Hubble Space Telescope. Two photometric procedures, based on...
Ferrarese, Laura, Ford, Holland C., Huchra, John, Kennicutt, Robert C., Mould, Jeremy R., ...
We present a compilation of Cepheid distance moduli and data for four secondary distance indicators that employ stars in the old stellar populations: the planetary nebula luminosity function (PNLF),...
Chemical Abundances in the Carina dSph Galaxy (1999)
Smecker-Hane, Tammy A., Mandushev, Georgi I., Hesser, James E., Stetson, Peter B., Da Costa, G. S., Hatzidimitriou, Despina
We report on the chemical abundances of stars in the Carina dwarf spheroidal galaxy (dSph) derived from low-resolution spectra. We have determined values of [Fe/H] for 52 stars from the reduced...
Mould, Jeremy R, Huchra, John P, Freedman, Wendy L, Kennicutt Jr, Robert C, Ferrarese, Laura, Ford, Holland C, ...
Since the launch of the Hubble Space Telescope nine years ago, Cepheid distances to 25 galaxies have been determined for the purpose of calibrating secondary distance indicators. A variety of these...
Sakai, Shoko, Mould, Jeremy R., Hughes, Shaun M. G., Huchra, John P., Macri, Lucas M., Kennicutt, Robert C., ...
This paper presents the calibration of BVRIH$ Tully-Fisher relations based on Cepheid distances to 21 galaxies within 25 Mpc, and 23 clusters within 10,000 km/s. These relations have been applied to...
Kelson, Daniel D., Illingworth, Garth D., Tonry, John L., Freedman, Wendy L., Kennicutt, Robert C., ...
Using published photometry and spectroscopy, we construct the fundamental plane and D_n-Sigma relations in Leo I, Virgo and Fornax. The published Cepheid P-L relations to spirals in these clusters...
The Luminous Type Ic SN 1992ar at z=0.145 (1999)
Clocchiatti, Alejandro, Phillips, Mark M., Suntzeff, Nicholas B., DellaValle, Massimo, Cappellaro, Enrico, Turatto, Massimo, ...
We present spectroscopic and photometric observations of SN1992ar, the more distant SN in the Calan/Tololo Survey. We compare its spectrum with those of nearby Type Ia and Ic SNe and conclude that...
Ferrarese, Laura, Mould, Jeremy R., Kennicutt, Robert C., Huchra, John, Ford, Holland C., ...
A Cepheid-based calibration is derived for four distance indicators that utilize stars in the old stellar populations: the tip of the red giant branch (TRGB), the planetary nebula luminosity function...
Gibson, Brad K., Stetson, Peter B., Freedman, Wendy L., Mould, Jeremy R., Kennicutt, Robert C., ...
Cepheid-based distances to seven Type Ia supernovae (SNe)-host galaxies have been derived using the standard HST Key Project on the Extragalactic Distance Scale pipeline. For the first time, this...
A Cepheid distance to NGC 4258 (1999)
Maoz, Eyal, Newman, Jeffrey A., Ferrarese, Laura, Stetson, Peter B., Zepf, Stephen E., Davis, Marc, ...
Distances measured using Cepheid variable stars have been essential for establishing the cosmological distance scale and the value of the Hubble constant. These stars have remained the primary...
Prosser, Charles F., Kennicutt, Robert C., Bresolin, Fabio, Saha, Abhijit, Sakai, Shoko, ...
We report on the detection of Cepheids and the first distance measurement to the spiral galaxy NGC 1326-A, a member of the Fornax cluster of galaxies. We have employed data obtained with the Wide...
Sakai, Shoko, Ferrarese, Laura, Kennicutt, Robert C., Graham, John A., Silbermann, N. A., Mould, Jeremy R., ...
The distance to NGC 3319 has been determined from Cepheid variable stars as part of the Hubble Space Telescope Key Project on the Extragalactic Distance Scale. Thirteen and four epochs of...
A Cepheid Distance to NGC 4603 in Centaurus (1999)
Newman, Jeffrey A., Zepf, Stephen E., Davis, Marc, Freedman, Wendy L., Madore, Barry F., Stetson, Peter B., ...
In an attempt to use Cepheid variables to determine the distance to the Centaurus cluster, we have obtained images of NGC 4603 with the Hubble Space Telescope on 9 epochs using WFPC2 and the F555W...
On the Photometric Consequences of Charge-Transfer Inefficiency in WFPC2 (1998)
Charge-transfer effects in photometry with Wide Field Planetary Camera 2 aboard the Hubble Space Telescope are investigated by a comparison of WFPC2 observations with groundbased photometry for the...
Gibson, Brad K., Hughes, Shaun M. G., Stetson, Peter B., Freedman, Wendy L., Kennicutt, Robert C., ...
The distance to NGC 4725 has been derived from Cepheid variables, as part of the Hubble Space Telescope Key Project on the Extragalactic Distance Scale. Thirteen F555W (V) and four F814W (I) epochs...
Suntzeff, Nicholas B., Walker, Alistair R., Smith, Verne V., Kraft, Robert P., Klemola, Arnold, Stetson, Peter B.
We present both low and high-dispersion abundance analyses of giants drawn from the zero proper motion sample near NGC 121. For the sample of 35 stars, the mean metallicity of the SMC field near NGC...
Stetson, Peter B., Bolte, Michael, Harris, William E., Hesser, James E., Bergh, Sidney Van Den, VandenBerg, Don A., ...
We have used the WFPC2 camera on the Hubble Space Telescope to obtain photometry of the outer-halo globular clusters Palomar 3, Palomar 4, and Eridanus. These three are classic examples of the...
The Open Cluster NGC 7789: II. CCD VI Photometry (1998)
Gim, Munhwan, VandenBerg, Don. A., Stetson, Peter B., Hesser, James E., Zurek, David R.
A (V,V - I)--diagram for the intermediate-age open cluster NGC 7789 has been derived from CCD observations of more than 15,000 stars within ~ 18 arcmin of the cluster center. From the brightest...
The Open Cluster NGC 7789: I. Radial Velocities for Giant Stars (1998)
Gim, Munhwan, Hesser, James E., McClure, Robert D., Stetson, Peter B.
A total of 597 radial-velocity observations for 112 stars in the ~1.6 Gyr old open cluster NGC 7789 have been obtained since 1979 with the radial velocity spectrometer at the Dominion Astrophysical...
Ferrarese, Laura, Bresolin, Fabio, Kennicutt, Robert C., Saha, Abhijit, Stetson, Peter B., ...
We report the detection of Cepheids and a new distance to the spiral galaxy NGC 2541, based on data obtained with the Wide Field and Planetary Camera 2 on board the Hubble Space Telescope (HST). A...
HST Photometry of the Globular Cluster M4 (1998)
Ibata, Rodrigo A., Richer, Harvey B., Fahlman, Gregory G., Bolte, Michael, Bond, Howard E., Hesser, James E., ...
This paper presents a detailed description of the acquisition and processing of a large body of imaging data for three fields in the globular cluster M4 taken with the Wide Field and Planetary Camera...
Han, Mingsheng, Hoessel, John, Freedman, Wendy L., Kennicutt, Robert C., Mould, Jeremy. R., ...
The distance to NGC 7331 has been derived from Cepheid variables observed with HST/WFPC2, as part of the Extragalactic Distance Scale Key Project. Multi-epoch exposures in F555W (V) and F814W (I),...
Rawson, Daya M., Macri, Lucas M., Mould, Jeremy R., Huchra, John P., Freedman, Wendy L., Kennicutt, Robert C., ...
We report on the discovery of Cepheids in the field spiral galaxy NGC 3621, based on observations made with the Wide Field and Planetary Camera 2 on board the Hubble Space Telescope (HST). NGC 3621...
White Dwarfs in Globular Clusters: HST Observations of M4 (1997)
Richer, Harvey B., Fahlman, Gregory G., Ibata, Rodrigo A., Pryor, Carlton, Bell, Roger A., Bolte, Michael, ...
Using WFPC2 on the Hubble Space Telescope, we have isolated a sample of 258 white dwarfs (WDs) in the Galactic globular cluster M4. Fields at three radial distances from the cluster center were...
Fabry-Perot Observations of Globular Clusters III: M15 (1996)
Gebhardt, Karl, Pryor, Carlton, Williams, T. B., Hesser, James E., Stetson, Peter B.
We have used an Imaging Fabry-Perot Spectrophotometer with the Sub-arcsecond Imaging Spectrograph on the CFHT to measure velocities for 1534 stars in the globular cluster M15. Combined with previous...
Hubble Space Telescope Observations of M32: The Color-Magnitude Diagram (1996)
Grillmair, Carl J., Lauer, Tod R., Worthey, Guy, Faber, S. M., Freedman, Wendy L., Madore, Barry F., ...
We present a V-I color-magnitude diagram for a region 1'-2' from the center of M32 based on Hubble Space Telescope WFPC2 images. The broad color-luminosity distribution of red giants shows that the...
Sandquist, Eric L., Bolte, Michael, Stetson, Peter B.
We present new BVI photometry for the halo globular cluster M5, and examine the B- and I-band luminosity functions (LFs), based on over 20,000 stars. We do not see evidence in the LF of a ``subgiant...
The Relative Ages of Galactic Globular Clusters (1996)
Stetson, Peter B., VandenBerg, Don A., Bolte, Michael
We discuss the present state of knowledge and thought concerning the spread in age found among Galactic globular clusters, with some discussion of the implications for what happened during the...
Age Gradient and the Second Parameter Problem in the Galactic Halo (1996)
Richer, Harvey B., Harris, William E., Fahlman, Gregory G., Bell, Roger A., Bond, Howard E., Hesser, James E., ...
We establish a framework for determing absolute ages of Galactic globular clusters and then use these ages to investigate the age-metallicity and age-Galactocentric distance relations for the 36...
Hubble Space Telescope Observations of White Dwarfs in the Globular Cluster M4 (1995)
Richer, Harvey B., Fahlman, Gregory G., Ibata, Rodrigo A., Stetson, Peter B., Bell, Roger A., Bolte, Michael, ...
With the Wide Field Planetary Camera 2 (WFPC2) on the Hubble Space Telescope, we have discovered in M4 (NGC 6121, C 1620-264) the first extensive sequence of cooling white dwarfs seen in a globular...