Zobrazeno 1 - 10
of 107
pro vyhledávání: '"William H. Jefferys"'
Autor:
William H. Jefferys, Jonathan Anderson, D. A. van Dyk, N. Stein, R. Wagner-Kaiser, Elliot Robinson, Elizabeth J. Jeffery, T. von Hippel, David C. Stenning, Ata Sarajedini
Publikováno v:
Monthly Notices of the Royal Astronomical Society
We use Hubble Space Telescope (HST) imaging from the ACS Treasury Survey to determine fits for single population isochrones of 69 Galactic globular clusters. Using robust Bayesian analysis techniques, we simultaneously determine ages, distances, abso
Autor:
David A. van Dyk, Ted von Hippel, Steven DeGennaro, Elizabeth J. Jeffery, Nathan Stein, William H. Jefferys
Publikováno v:
Statistical Analysis and Data Mining: The ASA Data Science Journal. 6:34-52
Intricate computer models can be used to describe complex physical processes in astronomy such as the evolution of stars. Like a sampling distribution, these models typically predict observed quantities as a function of a number of unknown parameters
Autor:
William H. Jefferys, Erin M. O'Malley, Elliot Robinson, N. Stein, Ted von Hippel, David A. van Dyk, Elizabeth J. Jeffery, David C. Stenning
It takes years of effort employing the best telescopes and instruments to obtain high-quality stellar photometry, astrometry, and spectroscopy. Stellar evolution models contain the experience of lifetimes of theoretical calculations and testing. Yet
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::2ba6de8b6e5a26acb224b617d84b8f99
http://arxiv.org/abs/1605.02810
http://arxiv.org/abs/1605.02810
Autor:
Ata Sarajedini, D. A. van Dyk, T. von Hippel, David C. Stenning, R. Wagner-Kaiser, William H. Jefferys, Edward L. Robinson, N. Stein
Publikováno v:
The Astrophysical Journal
We use Cycle 21 Hubble Space Telescope (HST) observations and HST archival ACS Treasury observations of Galactic Globular Clusters to find and characterize two stellar populations in NGC 5024 (M53), NGC 5272 (M3), and NGC 6352. For these three cluste
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::5054ebd30418f6aba68adcd5cfc52184
http://hdl.handle.net/10044/1/29537
http://hdl.handle.net/10044/1/29537
Autor:
William H. Jefferys, N. Stein, Elliot Robinson, D. A. van Dyk, R. Wagner-Kaiser, David C. Stenning, Ata Sarajedini, T. von Hippel
We use Cycle 21 Hubble Space Telescope (HST) observations and HST archival ACS Treasury observations of 30 Galactic Globular Clusters to characterize two distinct stellar populations. A sophisticated Bayesian technique is employed to simultaneously s
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::d173a78521b22c2385483a40f82744c3
Autor:
Ted von Hippel, Steven DeGennaro, Elizabeth Jeffery, William H. Jefferys, Nathan Stein, David A. van Dyk
Publikováno v:
The Astrophysical Journal. 696:12-23
We have extended our Bayesian modeling of stellar clusters—which uses main-sequence stellar evolution models, a mapping between initial masses and white dwarf (WD) masses, WD cooling models, and WD atmospheres—to include binary stars, field stars
Autor:
James G. Scott, Ted von Hippel, Nathan Stein, Albert Dam, Elizabeth J. Jeffery, William H. Jefferys, Donald E Winget, Steven DeGennaro
Publikováno v:
The Astrophysical Journal. 645:1436-1447
We demonstrate a new Bayesian technique to invert color-magnitude diagrams of main sequence and white dwarf stars to reveal the underlying cluster properties of age, distance, metallicity, and line-of-sight absorption, as well as individual stellar m
Publikováno v:
International Astronomical Union Colloquium. 193:95-98
We have determined quasi-geometric distances to the Magellanic Clouds, M31 and M33. Our analysis uses a Bayesian statistical method to provide mathematically rigorous and objective solutions for individual Cepheids. We combine the individual distance
Autor:
O. G. Franz, R. J. Patterson, Barbara McArthur, T. E. Harrison, W. F. van Altena, Lawrence H. Wasserman, Arthur J. Bradley, Michael F. Skrutskie, Thomas J. Montemayor, G. Fritz Benedict, E. P. Nelan, D. Story, Peter J. Shelus, Raynor L. Duncombe, J. Rhee, William H. Jefferys, Arthur L. Whipple, P. D. Hemenway, C. L. Slesnick, Laurence W. Fredrick
Publikováno v:
The Astronomical Journal. 126:2549-2556
We present an absolute parallax and relative proper motion for the central star of the planetary nebula NGC 6853 (The Dumbell). We obtain these with astrometric data from FGS 3, a white-light interferometer on {\it HST}. Spectral classifications and
Autor:
G. W. Marcy, T. Forveille, X. Delfosse, William H. Jefferys, William Spiesman, M. Mayor, E. P. Nelan, C. Perrier, Barbara McArthur, Bertrand Goldman, R. P. Butler, G. F. Benedict
Publikováno v:
The Astrophysical Journal. 581:L115-L118
We report the first astrometrically determined mass of an extrasolar planet, a companion previously detected by Doppler spectroscopy. Radial velocities first provided an ephemeris with which to schedule a significant fraction of the {\it HST} observa