D
Douglas L. Welch
Researcher at McMaster University
Publications - 188
Citations - 10675
Douglas L. Welch is an academic researcher from McMaster University. The author has contributed to research in topics: Cepheid variable & Stars. The author has an hindex of 54, co-authored 188 publications receiving 10192 citations. Previous affiliations of Douglas L. Welch include McMaster-Carr & National Science Foundation.
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Journal ArticleDOI
The MACHO Project: Microlensing Results from 5.7 Years of Large Magellanic Cloud Observations
Charles Alcock,Charles Alcock,R. A. Allsman,David R. Alves,Tim Axelrod,Andrew C. Becker,David P. Bennett,David P. Bennett,Kem H Cook,Kem H Cook,N. Dalal,N. Dalal,Andrew J. Drake,Andrew J. Drake,Kenneth C. Freeman,Marla Geha,Kim Griest,Kim Griest,Matthew J. Lehner,S. L. Marshall,S. L. Marshall,Dante Minniti,C. A. Nelson,C. A. Nelson,Bruce A. Peterson,P. Popowski,M. R. Pratt,Peter J. Quinn,Christopher W. Stubbs,Christopher W. Stubbs,Christopher W. Stubbs,William J. Sutherland,A. B. Tomaney,T. Vandehei,T. Vandehei,Douglas L. Welch +35 more
TL;DR: In this paper, an analysis of 5.7 yr of photometry on 11.9 million stars in the Large Magellanic Cloud (LMC) reveals 13-17 microlensing events, which is significantly more than the 2-4 events expected from lensing by known stellar populations.
Journal ArticleDOI
The MACHO Project Large Magellanic Cloud Microlensing Results from the First Two Years and the Nature of the Galactic Dark Halo
Charles Alcock,Charles Alcock,R. A. Allsman,David R. Alves,David R. Alves,Tim Axelrod,Andrew C. Becker,Andrew C. Becker,David P. Bennett,Kem H Cook,Kem H Cook,Kenneth C. Freeman,Kim Griest,Kim Griest,J. A. Guern,J. A. Guern,Matthew J. Lehner,Matthew J. Lehner,S. L. Marshall,S. L. Marshall,Bruce A. Peterson,M. R. Pratt,M. R. Pratt,M. R. Pratt,Peter J. Quinn,A. W. Rodgers,Christopher W. Stubbs,Christopher W. Stubbs,William J. Sutherland,Douglas L. Welch +29 more
TL;DR: In this paper, the authors estimate the total microlensing optical depth toward the LMC from events with 2 < < 200 days to be τ2002=2.9×10−7 based upon their eight event sample.
Journal ArticleDOI
A Critical Review of Selected Techniques for Measuring Extragalactic Distances
George H. Jacoby,David Branch,Robin Ciardullo,Roger L. Davies,William E. Harris,Michael J. Pierce,Christopher J. Pritchet,John L. Tonry,Douglas L. Welch +8 more
TL;DR: In this article, the authors review seven of the most reliable indicators used for deriving distances to galaxies as far way as 100 Mpc: globular-cluster luminosity functions (GCLF), novae, Type Ia supernovae (SN Ia), H I-line-width relations, planetary-nebula luminosity function (PNLF), surface-brightness fluctuations (SBF), and fundamental plane relationship for elliptical galaxies (Dn - sigma).
Journal ArticleDOI
BVRI Light Curves for 29 Type Ia Supernovae
Mario Hamuy,M. M. Phillips,N. B. Suntzeff,R. A. Schommer,José Maza,R. Antezana,M. Wischnjewsky,G. Valladares,Cesar Muena,L. E. Gonzalez,R. Aviles,L. Wells,Robert Connon Smith,M. Navarrete,Ricardo Covarrubias,Gerard M. Williger,Alistair R. Walker,Andrew C. Layden,J. H. Elias,Jack A. Baldwin,M. Hernandez,H. Tirado,P. Ugarte,Richard Elston,N. Saavedra,F. Barrientos,Edgardo Costa,P. Lira,Maria Teresa Ruiz,Claudio Anguita,X. Gomez,P. Ortiz,Massimo DellaValle,J Danziger,Jesper Storm,Yong-Cheol Kim,Charles D. Bailyn,Eric P. Rubenstein,Douglas L. Tucker,S. Cersosimo,Rene A. Mendez,L. Siciliano,W. H. Sherry,Brian Chaboyer,R. A. Koopmann,Doug Geisler,A. Sarajedini,Arjun Dey,Neil De Grasse Tyson,R. M. Rich,R. Gal,Robert Lamontagne,Nelson Caldwell,Puragra Guhathakurta,Andrew C. Phillips,Paula Szkody,Charles F. Prosser,L. C. Ho,R. McMahan,G. Baggley,K. P. Cheng,R. Havlen,K. Wakamatsu,K. Janes,M. Malkan,F. K. Baganoff,Patrick Seitzer,Michael M. Shara,C. R. Sturch,James E. Hesser,Patrick Hartigan,J Hughes,Douglas L. Welch,T. B. Williams,Henry C. Ferguson,Paul Francis,L. French,Michael Bolte,Joshua Roth,S. C. Odewahn,Steve B. Howell,Wojtek Krzeminski +81 more
TL;DR: In this article, M.M.H. and M.J.C. acknowledge support provided for this work by the National Science Foundation through grant number======GF-1002-96 from the Association of Universities for Research in Astronomy, Inc., under NSF Cooperative Agreement No. AST-8947990 and from Fundacion Andes under======Project C-12984.
Journal ArticleDOI
Robust variable star detection techniques suitable for automated searches: new results for NGC 1866
TL;DR: In this article, sensitive techniques for identifying variable stars in multiepoch photometry lists made in two or more bandpasses or pairwise in a single bandpass were described.