Related papers: The white dwarf cooling sequence in the old open c…

We use 10 orbits of Advanced Camera for Surveys observations to reach the end of the white dwarf cooling sequence in the solar-metallicity open cluster NGC 2158. Our photometry and completeness tests show that the end falls at magnitude…

In the old, populous, and metal-rich open cluster NGC 6791 we have used deep HST/ACS images to track the white dwarf cooling sequence down to m_F606W~28.5. The white dwarf luminosity function shows a well defined peak at m_F606W~27.4, and a…

We report on the white dwarf cooling sequence of the old globular cluster NGC 6752, which is chemically complex and hosts a blue horizontal branch. This is one of the last globular cluster white dwarf (WD) cooling sequences accessible to…

We have used deep HST WFPC2 observations of two fields in NGC 2420 to produce a cluster CMD down to V = 27. After imposing morphological selection criteria we find eight candidate white dwarfs in NGC 2420. Our completeness estimates…

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 theoretical, on the determination of the cluster…

We present the results of a deep Hubble Space Telescope (HST) exposure of the nearby globular cluster NGC6397, focussing attention on the cluster's white dwarf cooling sequence. This sequence is shown to extend over 5 magnitudes in depth,…

We present deep photometric observations of the open cluster NGC 2477 using HST/WFPC2. By identifying seven cluster white dwarf candidates, we present an analysis of the white dwarf age of this cluster, using both the traditional method of…

A deep imaging survey covering the entire $23\arcmin$ diameter of the old open cluster M67 to $V = 25$ has been carried out using the mosaic imager (UHCam) on the Canada-France-Hawaii Telescope. The cluster color-magnitude diagram (CMD) can…

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 observed and sizeable WD populations were…

We present new white dwarf cooling models which incorporate an accurate outer boundary condition based on new opacity and detailed radiative transfer calculations. We find that helium atmosphere dwarfs cool considerably faster than has…

We present deep CCD photometry of the very rich, intermediate aged (similar to the Hyades) open star cluster NGC 2099 (M37). The V, B-V color-magnitude diagram (CMD) for the cluster shows an extremely well populated and very tightly…

The white dwarf luminosity function of a stellar cluster will have a sharp truncation at a luminosity which is determined by the time since formation of the first white dwarfs in that cluster. Calculation of the dependence of this limiting…

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 sharply for I >25.5, consistent with the…

NGC 6791 is a well studied open cluster1 that it is so close to us that can be imaged down to very faint luminosities. The main sequence turn-off age (~8 Gyr) and the age derived from the termination of the white dwarf cooling sequence (~6…

We present our final study of the white dwarf cooling sequence (WD CS) in the globular cluster NGC 6752. The investigation is the main goal of a dedicated Hubble Space Telescope large Program, for which all the observations are now…

We have employed precise V and I photometry of NGC 188 at WIYN to explore the cluster luminosity function (LF) and study the cluster white dwarfs (WDs). Our photometry is offset by V = 0.052 (fainter) from Sandage (1962) and Eggen & Sandage…

I explore the current ability of both white dwarf cooling theory and main sequence stellar evolution theory to accurately determine stellar population ages by comparing ages derived using both techniques for open clusters ranging from 0.1…

We present new observations of the white dwarf sequence of the old open cluster NGC 6791. The brighter peak previously observed in the white dwarf luminosity function (WDLF) is now better delineated, and the second, fainter peak that we…

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 cluster. Adopting a distance modulus of…

We use 14 orbits of ACS observations to reach the end of the white-dwarf cooling sequence in the globular cluster M4. Our photometry and completeness tests show that the end is located at magnitude m_F606W = 28.5+/-0.1, which implies an age…