Search Results - "Leonard, Douglas C"

Constraining the Type Ia Supernova Progenitor: The Search for Hydrogen in Nebular Spectra by Leonard, Douglas C

“…Despite intense scrutiny, the progenitor system(s) that gives rise to Type Ia supernovae remains unknown. The favored theory invokes a carbon-oxygen white…”
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The First Systematic Study of Type Ibc Supernova Multi-band Light Curves by Drout, Maria R, Soderberg, Alicia M, Gal-Yam, Avishay, Cenko, S. Bradley, Fox, Derek B, Leonard, Douglas C, Sand, David J, Moon, Dae-Sik, Arcavi, Iair, Green, Yoav

“…We present detailed optical photometry for 25 Type Ibc supernovae (SNe Ibc) within d 150 Mpc obtained with the robotic Palomar 60 inch telescope in 2004-2007…”
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EARLY EMISSION FROM THE TYPE IIn SUPERNOVA 1998S AT HIGH RESOLUTION by Shivvers, Isaac, Groh, Jose H., Mauerhan, Jon C., Fox, Ori D., Leonard, Douglas C., Filippenko, Alexei V.

“…ABSTRACT The well-studied Type IIn supernova (SN IIn) 1998S is often dubbed the prototypical SN IIn, and it provides a unique opportunity to study its…”
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Supernova 2017eaw: Molecule and Dust Formation from Infrared Observations by Tinyanont, Samaporn, Kasliwal, Mansi M, Krafton, Kelsie, Lau, Ryan, Rho, Jeonghee, Leonard, Douglas C, De, Kishalay, Jencson, Jacob, Mawet, Dimitri, Millar-Blanchaer, Maxwell, Nilsson, Ricky, Yan, Lin, Gehrz, Robert D, Helou, George, Van Dyk, Schuyler D, Serabyn, Eugene, Fox, Ori D, Clayton, Geoffrey

“…We present infrared (IR) photometry and spectroscopy of the Type II-P SN 2017eaw and its progenitor in the nearby galaxy NGC 6946. Progenitor observations in…”
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Multi-epoch spectropolarimetry of SN 2009ip: direct evidence for aspherical circumstellar material by Mauerhan, Jon, Williams, G. Grant, Smith, Nathan, Smith, Paul S., Filippenko, Alexei V., Hoffman, Jennifer L., Milne, Peter, Leonard, Douglas C., Clubb, Kelsey I., Fox, Ori D., Kelly, Patrick L.

“…We present spectropolarimetry of SN 2009ip throughout the evolution of its 2012 explosion. During the 2012a phase, when the spectrum exhibits broad P-Cygni…”
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Unusually Fast-Evolving Supernova by Poznanski, Dovi, Chornock, Ryan, Nugent, Peter E, Bloom, Joshua S, Filippenko, Alexei V, Ganeshalingam, Mohan, Leonard, Douglas C, Li, Weidong, Thomas, Rollin C

“…Analyses of supernovae (SNe) have revealed two main types of progenitors: exploding white dwarfs and collapsing massive stars. Here we describe SN 2002bj,…”
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ASYMMETRIES IN SN 2014J NEAR MAXIMUM LIGHT REVEALED THROUGH SPECTROPOLARIMETRY by Porter, Amber L., Leising, Mark D., Williams, G. Grant, Milne, Peter, Smith, Paul, Smith, Nathan, Bilinski, Christopher, Hoffman, Jennifer L., Huk, Leah, Leonard, Douglas C.

“…ABSTRACT We present spectropolarimetric observations of the nearby Type Ia supernova SN 2014J in M82 over six epochs: +0, +7, +23, +51, +77, +109, and +111…”
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Improved Standardization of Type II-P Supernovae: Application to an Expanded Sample by Poznanski, Dovi, Butler, Nathaniel, Filippenko, Alexei V, Ganeshalingam, Mohan, Li, Weidong, Bloom, Joshua S, Chornock, Ryan, Foley, Ryan J, Nugent, Peter E, Silverman, Jeffrey M, Cenko, S. Bradley, Gates, Elinor L, Leonard, Douglas C, Miller, Adam A, Modjaz, Maryam, Serduke, Frank J. D, Smith, Nathan, Swift, Brandon J, Wong, Diane S

“…In the epoch of precise and accurate cosmology, cross-confirmation using a variety of cosmographic methods is paramount to circumvent systematic uncertainties…”
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Spectropolarimetry of SN 2011dh in M51: geometric insights on a Type IIb supernova progenitor and explosion by Mauerhan, Jon C., Williams, G. Grant, Leonard, Douglas C., Smith, Paul S., Filippenko, Alexei V., Smith, Nathan, Hoffman, Jennifer L., Huk, Leah, Clubb, Kelsey I., Silverman, Jeffrey M., Cenko, S. Bradley, Milne, Peter, Gal-Yam, Avishay, Ben-Ami, Sagi

“…We present seven epochs of spectropolarimetry of the Type IIb supernova (SN IIb) 2011dh in M51, spanning 86 d of its evolution. The first epoch was obtained…”
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The Standardizability of Type Ia Supernovae in the Near-Infrared: Evidence for a Peak-Luminosity Versus Decline-Rate Relation in the Near-Infrared by Kattner, ShiAnne, Leonard, Douglas C., Burns, Christopher R., Phillips, M. M., Folatelli, Gastón, Morrell, Nidia, Stritzinger, Maximilian D., Hamuy, Mario, Freedman, Wendy L., Persson, Sven E., Roth, Miguel, Suntzeff, Nicholas B.

“…ABSTRACT We analyze the standardizability of Type Ia supernovae (SNe Ia) in the near-infrared (NIR) by investigating the correlation between observed peak NIR…”
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The Dual-Axis Circumstellar Environment of the Type IIn Supernova 1997eg by Hoffman, Jennifer L, Leonard, Douglas C, Chornock, Ryan, Filippenko, Alexei V, Barth, Aaron J, Matheson, Thomas

“…We present multi-epoch spectral and spectropolarimetric observations of the Type IIn supernova (SN) 1997eg that indicate the presence of a flattened disklike…”
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A non-spherical core in the explosion of supernova SN 2004dj by Leonard, Douglas C, Filippenko, Alexei V, Ganeshalingam, Mohan, Serduke, Franklin J. D, Li, Weidong, Swift, Brandon J, Gal-Yam, Avishay, Foley, Ryan J, Fox, Derek B, Park, Sung, Hoffman, Jennifer L, Wong, Diane S

“…An important and perhaps critical clue to the mechanism driving the explosion of massive stars as supernovae is provided by the accumulating evidence for…”
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Optical Photometry and Spectroscopy of the SN 1998bw–like Type Ic Supernova 2002ap by Foley, Ryan J., Papenkova, Marina S., Swift, Brandon J., Filippenko, Alexei V., Li, Weidong, Mazzali, Paolo A., Chornock, Ryan, Leonard, Douglas C., Van Dyk, Schuyler D.

“…We present optical photometric and spectral data of the peculiar Type Ic supernova SN 2002ap. Photometric coverage includesUBVRIbands from 2002 January 30, the…”
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Evidence for Asphericity in the Type IIn Supernova SN 1998S by Leonard, Douglas C, Filippenko, Alexei V, Barth, Aaron J, Matheson, Thomas

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Toward a Cosmological Hubble Diagram for Type II-P Supernovae by Nugent, Peter, Sullivan, Mark, Ellis, Richard, Gal-Yam, Avishay, Leonard, Douglas C, Howell, D. Andrew, Astier, Pierre, Carlberg, Raymond G, Conley, Alex, Fabbro, Sebastien, Fouchez, Dominique, Neill, James D, Pain, Reynald, Perrett, Kathy, Pritchet, Chris J, Regnault, Nicolas

“…We present the first high-redshift Hubble diagram for Type II-P supernovae (SNe II-P) based on five events at redshift up to z 6 0.3. This diagram was…”
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The Cepheid Distance to NGC 1637: A Direct Test of the Expanding Photosphere Method Distance to SN 1999em by Leonard, Douglas C, Kanbur, Shashi M, Ngeow, Choong C, Tanvir, Nial R

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The Distance to SN 1999em in NGC 1637 from the Expanding Photosphere Method by Leonard, Douglas C., Filippenko, Alexei V., Gates, Elinor L., Li, Weidong, Eastman, Ronald G., Barth, Aaron J., Bus, Schelte J., Chornock, Ryan, Coil, Alison L., Frink, Sabine, Grady, Carol A., Harris, Alan W., Malkan, Matthew A., Matheson, Thomas, Quirrenbach, Andreas, Treffers, Richard R.

“…We present 30 optical spectra and 49 photometric epochs sampling the first 517 days after discovery of supernova (SN) 1999em and derive its distance through…”
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Optical and Ultraviolet Spectroscopy of SN 1995N: Evidence for Strong Circumstellar Interaction by Fransson, Claes, Chevalier, Roger A, Filippenko, Alexei V, Leibundgut, Bruno, Barth, Aaron J, Fesen, Robert A, Kirshner, Robert P, Leonard, Douglas C, Li, Weidong, Lundqvist, Peter, Sollerman, Jesper, Van Dyk, Schuyler D

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Direct Analysis of Spectra of Type Ib Supernovae by Branch, David, Benetti, S, Kasen, Daniel, Baron, E, Jeffery, David J, Hatano, Kazuhito, Stathakis, R. A, Filippenko, Alexei V, Matheson, Thomas, Pastorello, A, Altavilla, G, Cappellaro, E, Rizzi, L, Turatto, M, Li, Weidong, Leonard, Douglas C, Shields, Joseph C

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Spectropolarimetry of the Type II Supernovae 1997ds, 1998A, and 1999gi by Leonard, Douglas C., Filippenko, Alexei V.

“…We present single‐epoch spectropolarimetry of the Type II supernovae (SNe II) 1997ds, 1998A, and 1999gi. SN 1997ds and SN 1998A were both observed during the…”
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