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134 results on '"Stansberry, John A."'

1. Thermal evolution of trans-Neptunian objects through observations of Centaurs with JWST

Author

Licandro, Javier, Pinilla-Alonso, Noemí, Holler, Bryan J., De Prá, Mário N., Melita, Mario, de Souza Feliciano, Ana Carolina, Brunetto, Rosario, Guilbert-Lepoutre, Aurélie, Hénault, Elsa, Lorenzi, Vania, Stansberry, John A., Schambeau, Charles A., Harvison, Brittany, Pendleton, Yvonne J., Cruikshank, Dale P., Müller, Thomas, McClure, Lucas, Emery, Joshua P., Peixinho, Nuno, Bannister, Michele T., and Wong, Ian

Published
2025
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2. A JWST/DiSCo-TNOs portrait of the primordial Solar System through its trans-Neptunian objects

Author

Pinilla-Alonso, Noemí, Brunetto, Rosario, De Prá, Mário N., Holler, Bryan J., Hénault, Elsa, Feliciano, Ana Carolina de Souza, Lorenzi, Vania, Pendleton, Yvonne J., Cruikshank, Dale P., Müller, Thomas G., Stansberry, John A., Emery, Joshua P., Schambeau, Charles A., Licandro, Javier, Harvison, Brittany, McClure, Lucas, Guilbert-Lepoutre, Aurélie, Peixinho, Nuno, Bannister, Michele T., and Wong, Ian

Published
2025
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3. Widespread CO2 and CO ices in the trans-Neptunian population revealed by JWST/DiSCo-TNOs

Author

De Prá, Mário N., Hénault, Elsa, Pinilla-Alonso, Noemí, Holler, Bryan J., Brunetto, Rosario, Stansberry, John A., de Souza Feliciano, Ana Carolina, Carvano, Jorge M., Harvison, Brittany, Licandro, Javier, Müller, Thomas G., Peixinho, Nuno, Lorenzi, Vania, Guilbert-Lepoutre, Aurélie, Bannister, Michele T., Pendleton, Yvonne J., Cruikshank, Dale P., Schambeau, Charles A., McClure, Lucas, and Emery, Joshua P.

Published
2025
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7. Hydrogen Gas Separation from Hydrogen/Natural Gas Mixtures by High Temperature Proton Exchange Membrane Electrochemical Hydrogen Pump

Author

Stansberry, John Michael

Subjects
Mechanical engineering, Chemical engineering, Climate change, Electrochemical Hydrogen Pump, Hydrogen, Natural Gas, Phosphoric Acid, Proton Exchange Membrane
Abstract

The proliferation of variable renewable energy resources that generate electrical power from solar and wind is a critical step in achieving a climate neutral and sustainable energy system. The successful implementation of these electrical power generators is limited due to the uncontrollable nature of their availability to produce electrical power. One method by which to shift this energy production temporally and spatially to the time and place of its demand is the production of hydrogen as a chemical energy carrier. However, this approach would require large-scale infrastructure investments to produce, store, and transport hydrogen gas. One proposed strategy for the storage and transport of hydrogen is to blend with natural gas and inject it into pre-existing natural gas infrastructure. Hydrogen gas blended into natural gas in this way can contribute to the decarbonization of the natural gas system, however it is not as valuable in terms of its economic and carbon reduction potential. This value could be recovered if the separation of high-purity hydrogen gas from a blended gas system is done in an efficient manner. Electrochemical hydrogen separation is a well-established technology for efficient hydrogen separation, which can be accomplished by electrochemical hydrogen pump (EHP) based on a proton conducting membrane (PEM). The EHP works to separate hydrogen by facilitating the electrochemical process of oxidation of hydrogen at an anode and subsequent evolution of hydrogen gas at a cathode, while other gaseous impurities are ideally unable to permeate through the membrane. The goal of this work is to investigate the potential of electrochemical separation as a highly efficient means of separating trace volumetric quantities of hydrogen gas from natural gas by using high-temperature proton exchange membrane (HT-PEM).To investigate the efficacy of this approach, a high temperature proton exchange membrane electrochemical hydrogen pump (HT-PEM EHP) based on phosphoric acid doped polybenzimidazole (PA-PBI) PEM is tested in hydrogen/methane gaseous blends while also testing the impacts of varying phosphoric acid contents in the membrane electrode assembly. Operando X-ray CT testing of the PA-PBI HT-PEM EHP is implemented to investigate the structure of the cell during pump operation under varying acid content and humidification. A two-dimensional cell model of the PBI-PA based HT-PEM EHP is developed and validated with cell testing data as well as with data from X-ray CT measurements. The emphasis of the model is on the electrochemical performance of the cell under mass transport limiting conditions and the influence of varying acid contents in the MEA.HT-PEM EHP based on a quaternary ammonium biphosphate anion ion-pair coordinated with polyphenylene (PA-QAPOH) membrane were investigated experimentally to determine their stability and performance in EHP configuration. The presence of phosphanated polypentafluorostyrene (PWN) and Nafion® ionomeric binders in the electrodes of the ion-pair EHP was found to be critical to the stability of the ion-pair EHP. Ion-pair EHP performance was characterized with respect to cell temperature and relative humidity, and the separation of high purity H2 gas from pipeline natural gas and H2 blends was demonstrated. The suitability of alternative sulfonic acid ionomers in the ion-pair HT-PEM EHP was measured and compared to state of the art HT-PEM EHP based on sol-gel PBI-PA membrane for low concentration hydrogen gas concentration blends in methane and in natural gas.

Published
2024

8. Proton Exchange Membrane (PEM) Water Electrolysis: Cell-Level Considerations for Gigawatt-Scale Deployment.

Author

Wang, Cliffton Ray, Stansberry, John M., Mukundan, Rangachary, Chang, Hung-Ming Joseph, Kulkarni, Devashish, Park, Andrew M., Plymill, Austin B., Firas, Nausir Mahmoud, Liu, Christopher Pantayatiwong, Lang, Jack T., Lee, Jason Keonhag, Tolouei, Nadia E., Morimoto, Yu, Wang, CH, Zhu, Gaohua, Brouwer, Jack, Atanassov, Plamen, Capuano, Christopher B., Mittelsteadt, Cortney, and Peng, Xiong

Abstract

Hydrogen produced with no greenhouse gas emissions is termed "green hydrogen" and will be essential to reaching decarbonization targets set forth by nearly every country as per the Paris Agreement. Proton exchange membrane water electrolyzers (PEMWEs) are expected to contribute substantially to the green hydrogen market. However, PEMWE market penetration is insignificant, accounting for less than a gigawatt of global capacity. Achieving substantive decarbonization via green hydrogen will require PEMWEs to reach capacities of hundreds of gigawatts by 2030. This paper serves as an overarching roadmap for cell-level improvements necessary for gigawatt-scale PEMWE deployment, with insights from three well-established hydrogen technology companies included. Analyses will be presented for economies of scale, renewable energy prices, government policies, accelerated stress tests, and component-specific improvements. [ABSTRACT FROM AUTHOR]

Published
2025
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9. Widespread CO2 and CO ices in the trans-Neptunian population revealed by JWST/DiSCo-TNOs.

Author

De Prá, Mário N., Hénault, Elsa, Pinilla-Alonso, Noemí, Holler, Bryan J., Brunetto, Rosario, Stansberry, John A., de Souza Feliciano, Ana Carolina, Carvano, Jorge M., Harvison, Brittany, Licandro, Javier, Müller, Thomas G., Peixinho, Nuno, Lorenzi, Vania, Guilbert-Lepoutre, Aurélie, Bannister, Michele T., Pendleton, Yvonne J., Cruikshank, Dale P., Schambeau, Charles A., McClure, Lucas, and Emery, Joshua P.

Published
2025
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14. The distribution of H2O, CH3OH, and hydrocarbon-ices on Pluto: Analysis of New Horizons spectral images

Author

Cook, Jason C., Dalle Ore, Cristina M., Protopapa, Silvia, Binzel, Richard P., Cruikshank, Dale P., Earle, Alissa, Grundy, William M., Ennico, Kimberly, Howett, Carly, Jennings, Donald E., Lunsford, Allen W., Olkin, Catherine B., Parker, Alex H., Philippe, Sylvain, Reuter, Dennis, Schmitt, Bernard, Singer, Kelsi, Stansberry, John A., Stern, S. Alan, Verbiscer, Anne, Weaver, Harold A., Young, Leslie A., Hanley, Jennifer, Alketbi, Fatima, Thompson, Garrett L., Pearce, Logan A., Lindberg, Gerrick E., and Tegler, Stephen C.

Published
2019
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15. Composition of Pluto’s small satellites: Analysis of New Horizons spectral images

Author

Cook, Jason C., Ore, Cristina M. Dalle, Protopapa, Silvia, Binzel, Richard P., Cartwright, Richard, Cruikshank, Dale P., Earle, Alissa, Grundy, William M., Ennico, Kimberly, Howett, Carly, Jennings, Donald E., Lunsford, Allen W., Olkin, Catherine B., Parker, Alex H., Philippe, Sylvain, Reuter, Dennis, Schmitt, Bernard, Stansberry, John A., Alan Stern, S., Verbiscer, Anne, Weaver, Harold A., and Young, Leslie A.

Published
2018
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17. Physical Characterization of TNOs with the James Webb Space Telescope

Author

Parker, Alex, Pinilla-Alonso, Noemi, Santos-Sanz, Pablo, Stansberry, John, Alvarez-Candal, Alvaro, Bannister, Michele, Benecchi, Susan, Cook, Jason, Fraser, Wesley, Grundy, Will, Guilbert, Aurelie, Merline, Bill, Moullet, Arielle, Mueller, Michael, Olkin, Cathy, and Ragozzine, Darin

Published
2016

23. The James Webb Space Telescope Mission

Author

Gardner, Jonathan P., Mather, John C., Abbott, Randy, Abell, James S., Abernathy, Mark, Abney, Faith E., Abraham, John G., Abraham, Roberto, Abul-Huda, Yasin M., Acton, Scott, Adams, Cynthia K., Adams, Evan, Adler, David S., Adriaensen, Maarten, Aguilar, Jonathan Albert, Ahmed, Mansoor, Ahmed, Nasif S., Ahmed, Tanjira, Albat, Rüdeger, Albert, Loïc, Alberts, Stacey, Aldridge, David, Allen, Mary Marsha, Allen, Shaune S., Altenburg, Martin, Altunc, Serhat, Alvarez, Jose Lorenzo, Álvarez-Márquez, Javier, de Oliveira, Catarina Alves, Ambrose, Leslie L., Anandakrishnan, Satya M., Andersen, Gregory C., Anderson, Harry James, Anderson, Jay, Anderson, Kristen, Anderson, Sara M., Aprea, Julio, Archer, Benita J., Arenberg, Jonathan W., Argyriou, Ioannis, Arribas, Santiago, Artigau, Étienne, Arvai, Amanda Rose, Atcheson, Paul, Atkinson, Charles B., Averbukh, Jesse, Aymergen, Cagatay, Bacinski, John J., Baggett, Wayne E., Bagnasco, Giorgio, Baker, Lynn L., Balzano, Vicki Ann, Banks, Kimberly A., Baran, David A., Barker, Elizabeth A., Barrett, Larry K., Barringer, Bruce O., Barto, Allison, Bast, William, Baudoz, Pierre, Baum, Stefi, Beatty, Thomas G., Beaulieu, Mathilde, Bechtold, Kathryn, Beck, Tracy, Beddard, Megan M., Beichman, Charles, Bellagama, Larry, Bely, Pierre, Berger, Timothy W., Bergeron, Louis E., Darveau-Bernier, Antoine, Bertch, Maria D., Beskow, Charlotte, Betz, Laura E., Biagetti, Carl P., Birkmann, Stephan, Bjorklund, Kurt F., Blackwood, James D., Blazek, Ronald Paul, Blossfeld, Stephen, Bluth, Marcel, Boccaletti, Anthony, Boegner Jr., Martin E., Bohlin, Ralph C., Boia, John Joseph, Böker, Torsten, Bonaventura, N., Bond, Nicholas A., Bosley, Kari Ann, Boucarut, Rene A., Bouchet, Patrice, Bouwman, Jeroen, Bower, Gary, Bowers, Ariel S., Bowers, Charles W., Boyce, Leslye A., Boyer, Christine T., Boyer, Martha L., Boyer, Michael, Boyer, Robert, Bradley, Larry D., Brady, Gregory R., Brandl, Bernhard R., Brannen, Judith L., Breda, David, Bremmer, Harold G., Brennan, David, Bresnahan, Pamela A., Bright, Stacey N., Broiles, Brian J., Bromenschenkel, Asa, Brooks, Brian H., Brooks, Keira J., Brown, Bob, Brown, Bruce, Brown, Thomas M., Bruce, Barry W., Bryson, Jonathan G., Bujanda, Edwin D., Bullock, Blake M., Bunker, A. J., Bureo, Rafael, Burt, Irving J., Bush, James Aaron, Bushouse, Howard A., Bussman, Marie C., Cabaud, Olivier, Cale, Steven, Calhoon, Charles D., Calvani, Humberto, Canipe, Alicia M., Caputo, Francis M., Cara, Mihai, Carey, Larkin, Case, Michael Eli, Cesari, Thaddeus, Cetorelli, Lee D., Chance, Don R., Chandler, Lynn, Chaney, Dave, Chapman, George N., Charlot, S., Chayer, Pierre, Cheezum, Jeffrey I., Chen, Bin, Chen, Christine H., Cherinka, Brian, Chichester, Sarah C., Chilton, Zachary S., Chittiraibalan, Dharini, Clampin, Mark, Clark, Charles R., Clark, Kerry W., Clark, Stephanie M., Claybrooks, Edward E., Cleveland, Keith A., Cohen, Andrew L., Cohen, Lester M., Colón, Knicole D., Coleman, Benee L., Colina, Luis, Comber, Brian J., Comeau, Thomas M., Comer, Thomas, Reis, Alain Conde, Connolly, Dennis C., Conroy, Kyle E., Contos, Adam R., Contreras, James, Cook, Neil J., Cooper, James L., Cooper, Rachel Aviva, Correia, Michael F., Correnti, Matteo, Cossou, Christophe, Costanza, Brian F., Coulais, Alain, Cox, Colin R., Coyle, Ray T., Cracraft, Misty M., Noriega-Crespo, Alberto, Crew, Keith A., Curtis, Gary J., Cusveller, Bianca, Maciel, Cleyciane Da Costa, Dailey, Christopher T., Daugeron, Frédéric, Davidson, Greg S., Davies, James E., Davis, Katherine Anne, Davis, Michael S., Day, Ratna, de Chambure, Daniel, de Jong, Pauline, De Marchi, Guido, Dean, Bruce H., Decker, John E., Delisa, Amy S., Dell, Lawrence C., Dellagatta, Gail, Dembinska, Franciszka, Demosthenes, Sandor, Dencheva, Nadezhda M., Deneu, Philippe, DePriest, William W., Deschenes, Jeremy, Dethienne, Nathalie, Detre, Örs Hunor, Diaz, Rosa Izela, Dicken, Daniel, DiFelice, Audrey S., Dillman, Matthew, Disharoon, Maureen O., van Dishoeck, Ewine F., Dixon, William V., Doggett, Jesse B., Dominguez, Keisha L., Donaldson, Thomas S., Doria-Warner, Cristina M., Santos, Tony Dos, Doty, Heather, Douglas Jr., Robert E., Doyon, René, Dressler, Alan, Driggers, Jennifer, Driggers, Phillip A., Dunn, Jamie L., DuPrie, Kimberly C., Dupuis, Jean, Durning, John, Dutta, Sanghamitra B., Earl, Nicholas M., Eccleston, Paul, Ecobichon, Pascal, Egami, Eiichi, Ehrenwinkler, Ralf, Eisenhamer, Jonathan D., Eisenhower, Michael, Eisenstein, Daniel J., Hamel, Zaky El, Elie, Michelle L., Elliott, James, Elliott, Kyle Wesley, Engesser, Michael, Espinoza, Néstor, Etienne, Odessa, Etxaluze, Mireya, Evans, Leah, Fabreguettes, Luce, Falcolini, Massimo, Falini, Patrick R., Fatig, Curtis, Feeney, Matthew, Feinberg, Lee D., Fels, Raymond, Ferdous, Nazma, Ferguson, Henry C., Ferrarese, Laura, Ferreira, Marie-Héléne, Ferruit, Pierre, Ferry, Malcolm, Filippazzo, Joseph Charles, Firre, Daniel, Fix, Mees, Flagey, Nicolas, Flanagan, Kathryn A., Fleming, Scott W., Florian, Michael, Flynn, James R., Foiadelli, Luca, Fontaine, Mark R., Fontanella, Erin Marie, Forshay, Peter Randolph, Fortner, Elizabeth A., Fox, Ori D., Framarini, Alexandro P., Francisco, John I., Franck, Randy, Franx, Marijn, Franz, David E., Friedman, Scott D., Friend, Katheryn E., Frost, James R., Fu, Henry, Fullerton, Alexander W., Gaillard, Lionel, Galkin, Sergey, Gallagher, Ben, Galyer, Anthony D., Marín, Macarena García, Gardner, Lisa E., Garland, Dennis, Garrett, Bruce Albert, Gasman, Danny, Gáspár, András, Gastaud, René, Gaudreau, Daniel, Gauthier, Peter Timothy, Geers, Vincent, Geithner, Paul H., Gennaro, Mario, Gerber, John, Gereau, John C., Giampaoli, Robert, Giardino, Giovanna, Gibbons, Paul C., Gilbert, Karolina, Gilman, Larry, Girard, Julien H., Giuliano, Mark E., Gkountis, Konstantinos, Glasse, Alistair, Glassmire, Kirk Zachary, Glauser, Adrian Michael, Glazer, Stuart D., Goldberg, Joshua, Golimowski, David A., Gonzaga, Shireen P., Gordon, Karl D., Gordon, Shawn J., Goudfrooij, Paul, Gough, Michael J., Graham, Adrian J., Grau, Christopher M., Green, Joel David, Greene, Gretchen R., Greene, Thomas P., Greenfield, Perry E., Greenhouse, Matthew A., Greve, Thomas R., Greville, Edgar M., Grimaldi, Stefano, Groe, Frank E., Groebner, Andrew, Grumm, David M., Grundy, Timothy, Güdel, Manuel, Guillard, Pierre, Guldalian, John, Gunn, Christopher A., Gurule, Anthony, Gutman, Irvin Meyer, Guy, Paul D., Guyot, Benjamin, Hack, Warren J., Haderlein, Peter, Hagan, James B., Hagedorn, Andria, Hainline, Kevin, Haley, Craig, Hami, Maryam, Hamilton, Forrest Clifford, Hammann, Jeffrey, Hammel, Heidi B., Hanley, Christopher J., Hansen, Carl August, Hardy, Bruce, Harnisch, Bernd, Harr, Michael Hunter, Harris, Pamela, Hart, Jessica Ann, Hartig, George F., Hasan, Hashima, Hashim, Kathleen Marie, Hashimoto, Ryan, Haskins, Sujee J., Hawkins, Robert Edward, Hayden, Brian, Hayden, William L., Healy, Mike, Hecht, Karen, Heeg, Vince J., Hejal, Reem, Helm, Kristopher A., Hengemihle, Nicholas J., Henning, Thomas, Henry, Alaina, Henry, Ronald L., Henshaw, Katherine, Hernandez, Scarlin, Herrington, Donald C., Heske, Astrid, Hesman, Brigette Emily, Hickey, David L., Hilbert, Bryan N., Hines, Dean C., Hinz, Michael R., Hirsch, Michael, Hitcho, Robert S., Hodapp, Klaus, Hodge, Philip E., Hoffman, Melissa, Holfeltz, Sherie T., Holler, Bryan Jason, Hoppa, Jennifer Rose, Horner, Scott, Howard, Joseph M., Howard, Richard J., Huber, Jean M., Hunkeler, Joseph S., Hunter, Alexander, Hunter, David Gavin, Hurd, Spencer W., Hurst, Brendan J., Hutchings, John B., Hylan, Jason E., Ignat, Luminita Ilinca, Illingworth, Garth, Irish, Sandra M., Isaacs III, John C., Jackson Jr., Wallace C., Jaffe, Daniel T., Jahic, Jasmin, Jahromi, Amir, Jakobsen, Peter, James, Bryan, James, John C., James, LeAndrea Rae, Jamieson, William Brian, Jandra, Raymond D., Jayawardhana, Ray, Jedrzejewski, Robert, Jeffers, Basil S., Jensen, Peter, Joanne, Egges, Johns, Alan T., Johnson, Carl A., Johnson, Eric L., Johnson, Patricia, Johnson, Phillip Stephen, Johnson, Thomas K., Johnson, Timothy W., Johnstone, Doug, Jollet, Delphine, Jones, Danny P., Jones, Gregory S., Jones, Olivia C., Jones, Ronald A., Jones, Vicki, Jordan, Ian J., Jordan, Margaret E., Jue, Reginald, Jurkowski, Mark H., Justis, Grant, Justtanont, Kay, Kaleida, Catherine C., Kalirai, Jason S., Kalmanson, Phillip Cabrales, Kaltenegger, Lisa, Kammerer, Jens, Kan, Samuel K., Kanarek, Graham Childs, Kao, Shaw-Hong, Karakla, Diane M., Karl, Hermann, Kassin, Susan A., Kauffman, David D., Kavanagh, Patrick, Kelley, Leigh L., Kelly, Douglas M., Kendrew, Sarah, Kennedy, Herbert V., Kenny, Deborah A., Keski-Kuha, Ritva A., Keyes, Charles D., Khan, Ali, Kidwell, Richard C., Kimble, Randy A., King, James S., King, Richard C., Kinzel, Wayne M., Kirk, Jeffrey R., Kirkpatrick, Marc E., Klaassen, Pamela, Klingemann, Lana, Klintworth, Paul U., Knapp, Bryan Adam, Knight, Scott, Knollenberg, Perry J., Knutsen, Daniel Mark, Koehler, Robert, Koekemoer, Anton M., Kofler, Earl T., Kontson, Vicki L., Kovacs, Aiden Rose, Kozhurina-Platais, Vera, Krause, Oliver, Kriss, Gerard A., Krist, John, Kristoffersen, Monica R., Krogel, Claudia, Krueger, Anthony P., Kulp, Bernard A., Kumari, Nimisha, Kwan, Sandy W., Kyprianou, Mark, Labador, Aurora Gadiano, Labiano, Álvaro, Lafrenière, David, Lagage, Pierre-Olivier, Laidler, Victoria G., Laine, Benoit, Laird, Simon, Lajoie, Charles-Philippe, Lallo, Matthew D., Lam, May Yen, LaMassa, Stephanie Marie, Lambros, Scott D., Lampenfield, Richard Joseph, Lander, Matthew Ed, Langston, James Hutton, Larson, Kirsten, Larson, Melora, LaVerghetta, Robert Joseph, Law, David R., Lawrence, Jon F., Lee, David W., Lee, Janice, Lee, Yat-Ning Paul, Leisenring, Jarron, Leveille, Michael Dunlap, Levenson, Nancy A., Levi, Joshua S., Levine, Marie B., Lewis, Dan, Lewis, Jake, Lewis, Nikole, Libralato, Mattia, Lidon, Norbert, Liebrecht, Paula Louisa, Lightsey, Paul, Lilly, Simon, Lim, Frederick C., Lim, Pey Lian, Ling, Sai-Kwong, Link, Lisa J., Link, Miranda Nicole, Lipinski, Jamie L., Liu, XiaoLi, Lo, Amy S., Lobmeyer, Lynette, Logue, Ryan M., Long, Chris A., Long, Douglas R., Long, Ilana D., Long, Knox S., López-Caniego, Marcos, Lotz, Jennifer M., Love-Pruitt, Jennifer M., Lubskiy, Michael, Luers, Edward B., Luetgens, Robert A., Luevano, Annetta J., Lui, Sarah Marie G. Flores, Lund III, James M., Lundquist, Ray A., Lunine, Jonathan, Lützgendorf, Nora, Lynch, Richard J., MacDonald, Alex J., MacDonald, Kenneth, Macias, Matthew J., Macklis, Keith I., Maghami, Peiman, Maharaja, Rishabh Y., Maiolino, Roberto, Makrygiannis, Konstantinos G., Malla, Sunita Giri, Malumuth, Eliot M., Manjavacas, Elena, Marini, Andrea, Marrione, Amanda, Marston, Anthony, Martel, André R, Martin, Didier, Martin, Peter G., Martinez, Kristin L., Maschmann, Marc, Masci, Gregory L., Masetti, Margaret E., Maszkiewicz, Michael, Matthews, Gary, Matuskey, Jacob E., McBrayer, Glen A., McCarthy, Donald W., McCaughrean, Mark J., McClare, Leslie A., McClare, Michael D., McCloskey, John C., McClurg, Taylore D., McCoy, Martin, McElwain, Michael W., McGregor, Roy D., McGuffey, Douglas B., McKay, Andrew G., McKenzie, William K., McLean, Brian, McMaster, Matthew, McNeil, Warren, De Meester, Wim, Mehalick, Kimberly L., Meixner, Margaret, Meléndez, Marcio, Menzel, Michael P., Menzel, Michael T., Merz, Matthew, Mesterharm, David D., Meyer, Michael R., Meyett, Michele L., Meza, Luis E., Midwinter, Calvin, Milam, Stefanie N., Miller, Jay Todd, Miller, William C., Miskey, Cherie L., Misselt, Karl, Mitchell, Eileen P., Mohan, Martin, Montoya, Emily E., Moran, Michael J., Morishita, Takahiro, Moro-Martín, Amaya, Morrison, Debra L., Morrison, Jane, Morse, Ernie C., Moschos, Michael, Moseley, S. H., Mosier, Gary E., Mosner, Peter, Mountain, Matt, Muckenthaler, Jason S., Mueller, Donald G., Mueller, Migo, Muhiem, Daniella, Mühlmann, Prisca, Mullally, Susan Elizabeth, Mullen, Stephanie M., Munger, Alan J, Murphy, Jess, Murray, Katherine T., Muzerolle, James C., Mycroft, Matthew, Myers, Andrew, Myers, Carey R., Myers, Fred Richard R., Myers, Richard, Myrick, Kaila, Nagle IV, Adrian F., Nayak, Omnarayani, Naylor, Bret, Neff, Susan G., Nelan, Edmund P., Nella, John, Nguyen, Duy Tuong, Nguyen, Michael N., Nickson, Bryony, Nidhiry, John Joseph, Niedner, Malcolm B., Nieto-Santisteban, Maria, Nikolov, Nikolay K., Nishisaka, Mary Ann, Nota, Antonella, O'Mara, Robyn C., Oboryshko, Michael, O'Brien, Marcus B., Ochs, William R., Offenberg, Joel D., Ogle, Patrick Michael, Ohl, Raymond G., Olmsted, Joseph Hamden, Osborne, Shannon Barbara, O'Shaughnessy, Brian Patrick, Östlin, Göran, O'Sullivan, Brian, Otor, O. Justin, Ottens, Richard, Ouellette, Nathalie N. -Q., Outlaw, Daria J., Owens, Beverly A., Pacifici, Camilla, Page, James Christophe, Paranilam, James G., Park, Sang, Parrish, Keith A., Paschal, Laura, Patapis, Polychronis, Patel, Jignasha, Patrick, Keith, Pattishall Jr., Robert A., Paul, Douglas William, Paul, Shirley J., Pauly, Tyler Andrew, Pavlovsky, Cheryl M., Peña-Guerrero, Maria, Pedder, Andrew H., Peek, Matthew Weldon, Pelham, Patricia A., Penanen, Konstantin, Perriello, Beth A., Perrin, Marshall D., Perrine, Richard F., Perrygo, Chuck, Peslier, Muriel, Petach, Michael, Peterson, Karla A., Pfarr, Tom, Pierson, James M., Pietraszkiewicz, Martin, Pilchen, Guy, Pipher, Judy L., Pirzkal, Norbert, Pitman, Joseph T., Player, Danielle M., Plesha, Rachel, Plitzke, Anja, Pohner, John A., Poletis, Karyn Konstantin, Pollizzi, Joseph A., Polster, Ethan, Pontius, James T., Pontoppidan, Klaus, Porges, Susana C., Potter, Gregg D., Prescott, Stephen, Proffitt, Charles R., Pueyo, Laurent, Neira, Irma Aracely Quispe, Radich, Armando, Rager, Reiko T., Rameau, Julien, Ramey, Deborah D., Alarcon, Rafael Ramos, Rampini, Riccardo, Rapp, Robert, Rashford, Robert A., Rauscher, Bernard J., Ravindranath, Swara, Rawle, Timothy, Rawlings, Tynika N., Ray, Tom, Regan, Michael W., Rehm, Brian, Rehm, Kenneth D., Reid, Neill, Reis, Carl A., Renk, Florian, Reoch, Tom B., Ressler, Michael, Rest, Armin W., Reynolds, Paul J., Richon, Joel G., Richon, Karen V., Ridgaway, Michael, Riedel, Adric Richard, Rieke, George H., Rieke, Marcia, Rifelli, Richard E., Rigby, Jane R., Riggs, Catherine S., Ringel, Nancy J., Ritchie, Christine E., Rix, Hans-Walter, Robberto, Massimo, Robinson, Michael S., Robinson, Orion, Rock, Frank W., Rodriguez, David R., del Pino, Bruno Rodríguez, Roellig, Thomas, Rohrbach, Scott O., Roman, Anthony J., Romelfanger, Frederick J., Romo Jr., Felipe P., Rosales, Jose J., Rose, Perry, Roteliuk, Anthony F., Roth, Marc N., Rothwell, Braden Quinn, Rouzaud, Sylvain, Rowe, Jason, Rowlands, Neil, Roy, Arpita, Royer, Pierre, Rui, Chunlei, Rumler, Peter, Rumpl, William, Russ, Melissa L., Ryan, Michael B., Ryan, Richard M., Saad, Karl, Sabata, Modhumita, Sabatino, Rick, Sabbi, Elena, Sabelhaus, Phillip A., Sabia, Stephen, Sahu, Kailash C., Saif, Babak N., Salvignol, Jean-Christophe, Samara-Ratna, Piyal, Samuelson, Bridget S., Sanders, Felicia A., Sappington, Bradley, Sargent, B. A., Sauer, Arne, Savadkin, Bruce J., Sawicki, Marcin, Schappell, Tina M., Scheffer, Caroline, Scheithauer, Silvia, Scherer, Ron, Schiff, Conrad, Schlawin, Everett, Schmeitzky, Olivier, Schmitz, Tyler S., Schmude, Donald J., Schneider, Analyn, Schreiber, Jürgen, Schroeven-Deceuninck, Hilde, Schultz, John J., Schwab, Ryan, Schwartz, Curtis H., Scoccimarro, Dario, Scott, John F., Scott, Michelle B., Seaton, Bonita L., Seely, Bruce S., Seery, Bernard, Seidleck, Mark, Sembach, Kenneth, Shanahan, Clare Elizabeth, Shaughnessy, Bryan, Shaw, Richard A., Shay, Christopher Michael, Sheehan, Even, Sheth, Kartik, Shih, Hsin-Yi, Shivaei, Irene, Siegel, Noah, Sienkiewicz, Matthew G., Simmons, Debra D., Simon, Bernard P., Sirianni, Marco, Sivaramakrishnan, Anand, Slade, Jeffrey E., Sloan, G. C., Slocum, Christine E., Slowinski, Steven E., Smith, Corbett T., Smith, Eric P., Smith, Erin C., Smith, Koby, Smith, Robert, Smith, Stephanie J., Smolik, John L., Soderblom, David R., Sohn, Sangmo Tony, Sokol, Jeff, Sonneborn, George, Sontag, Christopher D., Sooy, Peter R., Soummer, Remi, Southwood, Dana M., Spain, Kay, Sparmo, Joseph, Speer, David T., Spencer, Richard, Sprofera, Joseph D., Stallcup, Scott S., Stanley, Marcia K., Stansberry, John A., Stark, Christopher C., Starr, Carl W., Stassi, Diane Y., Steck, Jane A., Steeley, Christine D., Stephens, Matthew A., Stephenson, Ralph J., Stewart, Alphonso C., Stiavelli, Massimo, Stockman Jr., Hervey, Strada, Paolo, Straughn, Amber N., Streetman, Scott, Strickland, David Kendal, Strobele, Jingping F., Stuhlinger, Martin, Stys, Jeffrey Edward, Such, Miguel, Sukhatme, Kalyani, Sullivan, Joseph F., Sullivan, Pamela C., Sumner, Sandra M., Sun, Fengwu, Sunnquist, Benjamin Dale, Swade, Daryl Allen, Swam, Michael S., Swenton, Diane F., Swoish, Robby A., Litten, Oi In Tam, Tamas, Laszlo, Tao, Andrew, Taylor, David K., Taylor, Joanna M., Plate, Maurice te, Van Tea, Mason, Teague, Kelly K., Telfer, Randal C., Temim, Tea, Texter, Scott C., Thatte, Deepashri G., Thompson, Christopher Lee, Thompson, Linda M., Thomson, Shaun R., Thronson, Harley, Tierney, C. M., Tikkanen, Tuomo, Tinnin, Lee, Tippet, William Thomas, Todd, Connor William, Tran, Hien D., Trauger, John, Trejo, Edwin Gregorio, Truong, Justin Hoang Vinh, Tsukamoto, Christine L., Tufail, Yasir, Tumlinson, Jason, Tustain, Samuel, Tyra, Harrison, Ubeda, Leonardo, Underwood, Kelli, Uzzo, Michael A., Vaclavik, Steven, Valenduc, Frida, Valenti, Jeff A., Van Campen, Julie, van de Wetering, Inge, Van Der Marel, Roeland P., van Haarlem, Remy, Vandenbussche, Bart, Vanterpool, Dona D., Vernoy, Michael R., Costas, Maria Begoña Vila, Volk, Kevin, Voorzaat, Piet, Voyton, Mark F., Vydra, Ekaterina, Waddy, Darryl J., Waelkens, Christoffel, Wahlgren, Glenn Michael, Walker Jr., Frederick E., Wander, Michel, Warfield, Christine K., Warner, Gerald, Wasiak, Francis C., Wasiak, Matthew F., Wehner, James, Weiler, Kevin R., Weilert, Mark, Weiss, Stanley B., Wells, Martyn, Welty, Alan D., Wheate, Lauren, Wheeler, Thomas P., White, Christy L., Whitehouse, Paul, Whiteleather, Jennifer Margaret, Whitman, William Russell, Williams, Christina C., Willmer, Christopher N. A., Willott, Chris J., Willoughby, Scott P., Wilson, Andrew, Wilson, Debra, Wilson, Donna V., Windhorst, Rogier, Wislowski, Emily Christine, Wolfe, David J., Wolfe, Michael A., Wolff, Schuyler, Wondel, Amancio, Woo, Cindy, Woods, Robert T., Worden, Elaine, Workman, William, Wright, Gillian S., Wu, Carl, Wu, Chi-Rai, Wun, Dakin D., Wymer, Kristen B., Yadetie, Thomas, Yan, Isabelle C., Yang, Keith C., Yates, Kayla L., Yeager, Christopher R., Yerger, Ethan John, Young, Erick T., Young, Gary, Yu, Gene, Yu, Susan, Zak, Dean S., Zeidler, Peter, Zepp, Robert, Zhou, Julia, Zincke, Christian A., Zonak, Stephanie, and Zondag, Elisabeth

Subjects
FOS: Physical sciences, Astrophysics - Instrumentation and Methods for Astrophysics, Instrumentation and Methods for Astrophysics (astro-ph.IM)
Abstract

Twenty-six years ago a small committee report, building on earlier studies, expounded a compelling and poetic vision for the future of astronomy, calling for an infrared-optimized space telescope with an aperture of at least $4m$. With the support of their governments in the US, Europe, and Canada, 20,000 people realized that vision as the $6.5m$ James Webb Space Telescope. A generation of astronomers will celebrate their accomplishments for the life of the mission, potentially as long as 20 years, and beyond. This report and the scientific discoveries that follow are extended thank-you notes to the 20,000 team members. The telescope is working perfectly, with much better image quality than expected. In this and accompanying papers, we give a brief history, describe the observatory, outline its objectives and current observing program, and discuss the inventions and people who made it possible. We cite detailed reports on the design and the measured performance on orbit., Comment: Accepted by PASP for the special issue on The James Webb Space Telescope Overview, 29 pages, 4 figures

Published
2023
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24. Observations of Transiting Exoplanets with the James Webb Space Telescope ( JWST )

Author

Beichman, Charles, Benneke, Bjoern, Knutson, Heather, Smith, Roger, Lagage, Pierre-Olivier, Dressing, Courtney, Latham, David, Lunine, Jonathan, Birkmann, Stephan, Ferruit, Pierre, Giardino, Giovanna, Kempton, Eliza, Carey, Sean, Krick, Jessica, Deroo, Pieter D., Mandell, Avi, Ressler, Michael E., Shporer, Avi, Swain, Mark, Vasisht, Gautam, Ricker, George, Bouwman, Jeroen, Crossfield, Ian, Greene, Tom, Howell, Steve, Christiansen, Jessie, Ciardi, David, Clampin, Mark, Greenhouse, Matt, Sozzetti, Alessandro, Goudfrooij, Paul, Hines, Dean, Keyes, Tony, Lee, Janice, McCullough, Peter, Robberto, Massimo, Stansberry, John, Valenti, Jeff, Rieke, Marcia, Rieke, George, Fortney, Jonathan, Bean, Jacob, Kreidberg, Laura, Ehrenreich, David, Deming, Drake, Albert, Loïc, Doyon, René, and Sing, David

Published
2014
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25. DYNAMIC ANALYSIS OF A PROTON EXCHANGE MEMBRANE ELECTROLYZER INTEGRATED WITH A NATURAL GAS COMBINED CYCLE POWER PLANT FOR POWER-TO-GAS APPLICATIONS

Author

Stansberry, John

Subjects
Energy, Sustainability, Engineering, Electrolyzer, Energy Storage, Hydrogen, Power-to-gas, Solar, Wind
Abstract

Proton exchange membrane electrolyzers (PEMEZ) are an attractive technology choice as the principal piece of equipment in power-to-gas (P2G), however their usage within the context of P2G has not yet been thoroughly investigated, and no pilot plants for power-to-gas with PEMEZ have as yet been realized in the United States. In this study, a PEM electrolyzer was modified to have dynamic dispatch capabilities, then subsequently operated and studied in detail as a part of the UC Irvine P2G demonstration. The system operated at sustained part load conditions and load followed variable renewable energy resources. Furthermore, the impact on emissions due to the addition of hydrogen to the high pressure natural gas fuel feed to the University of California Irvine (UCI) Central Plant’s combustion turbine is analyzed.Solar PV load following was found to have minimal impact on system efficiency in producing hydrogen from electrolysis, however wind load following did result in sustained low load conditions that did impact system efficiency significantly. Reduced efficiency due to sustained low part load conditions could be circumvented by cycling PEMEZ off completely and starting up as the load signal reached the minimum effective point again. The effective compression of hydrogen electrochemically in the PEMEZ was demonstrated to nearly match the efficiency of ideal isothermal compression using a semi-empirical model developed from sustained part load operation testing of the PEMEZ.Addition of hydrogen to the natural gas fired combustion turbine showed very little likelihood of impact on emissions of criteria pollutants (CO, NOx). A slightly significant correlation between reduction in natural gas usage, and by extension emissions of CO2, was noted.

Published
2018

26. First Sample of H$\alpha$+[O III] $\lambda$5007 Line Emitters at $z > 6$ Through JWST/NIRCam Slitless Spectroscopy: Physical Properties and Line Luminosity Functions

Author

Sun, Fengwu, Egami, Eiichi, Pirzkal, Nor, Rieke, Marcia, Baum, Stefi, Boyer, Martha, Boyett, Kristan, Bunker, Andrew J., Cameron, Alex J., Curti, Mirko, Eisenstein, Daniel J., Gennaro, Mario, Greene, Thomas P., Jaffe, Daniel, Kelly, Doug, Koekemoer, Anton M., Kumari, Nimisha, Maiolino, Roberto, Maseda, Michael, Perna, Michele, Rest, Armin, Robertson, Brant E., Schlawin, Everett, Smit, Renske, Stansberry, John, Sunnquist, Ben, Tacchella, Sandro, Williams, Christina C., and Willmer, Christopher N. A.

Subjects
Astrophysics - Astrophysics of Galaxies
Abstract

We present a sample of four emission-line galaxies at $z=6.11-6.35$ that were serendipitously discovered using the commissioning data for the JWST/NIRCam wide-field slitless spectroscopy (WFSS) mode. One of them (at $z=6.11$) has been reported previously while the others are new discoveries. These sources are selected by the secure detections of both [O III] $\lambda$5007 and H$\alpha$ lines with other fainter lines tentatively detected in some cases (e.g., [O II] $\lambda$3727, [O III] $\lambda$4959). In the [O III]/H$\beta$ - [N II]/H$\alpha$ Baldwin-Phillips-Terlevich diagram, these galaxies occupy the same parameter space as that of $z\sim2$ star-forming galaxies, indicating that they have been enriched rapidly to sub-solar metallicities ($\sim$0.4 $Z_{\odot}$), similar to galaxies with comparable stellar masses at much lower redshifts. The detection of strong H$\alpha$ lines suggests a higher ionizing photon production efficiency within galaxies in the early Universe. We find brightening of the [O III] $\lambda$5007 line luminosity function (LF) from $z=3$ to 6, and weak or no redshift evolution of the H$\alpha$ line LF from $z=2$ to 6. Both LFs are under-predicted at $z\sim6$ by a factor of $\sim$10 in certain cosmological simulations. This further indicates a global Ly$\alpha$ photon escape fraction of 7-10% at $z\sim6$, slightly lower than previous estimates through the comparison of the UV-derived star-formation rate density and Ly$\alpha$ luminosity density. Our sample recovers $66^{+128}_{-44}$% of $z=6.0-6.6$ galaxies in the survey volume with stellar masses greater than $5\times10^8$ $M_{\odot}$, suggesting the ubiquity of strong H$\alpha$ and [O III] line emitters in the Epoch of Reionization, which will be further uncovered in the era of JWST., Comment: 26 pages, 11 figures, accepted for publication in ApJ on May 11, 2023

Published
2022

27. An Energetic Eruption With Associated SO 1.707 Micron Emissions at Io's Kanehekili Fluctus and a Brightening Event at Loki Patera Observed by JWST.

Author

de Pater, Imke, Lellouch, Emmanuel, Strobel, Darrell F., de Kleer, Katherine, Fouchet, Thierry, Wong, Michael H., Holler, Bryan J., Stansberry, John, Fry, Patrick M., Brown, Michael E., Bockelée‐Morvan, Dominique, Trumbo, Samantha K., Fletcher, L. N., Hedman, Matthew M., Molter, Edward M., Showalter, Mark, Tiscareno, Matthew S., Cazaux, Stéphanie, Hueso, Ricardo, and Luszcz‐Cook, Statia

Subjects
VOLCANIC eruptions, SPACE telescopes, VOLCANOES, EXCITED states, HIGH temperatures, LOW temperatures, CORONAL mass ejections
Abstract

We observed Io with the James Webb Space Telescope (JWST) while the satellite was in eclipse, and detected thermal emission from several volcanoes. The data were taken as part of our JWST‐ERS program #1373 on 15 November 2022. Kanehekili Fluctus was exceptionally bright, and Loki Patera had most likely entered a new brightening phase. Spectra were taken with NIRSpec/IFU at a resolving power R ≈ 2,700 between 1.65 and 5.3 µm. The spectra were matched by a combination of blackbody curves that showed that the highest temperature, ∼1,200 K, for Kanehekili Fluctus originated from an area ∼0.25 km2 in size, and for Loki Patera this high temperature was confined to an area of ∼0.06 km2. Lower temperatures, down to 300 K, cover areas of ∼2,000 km2 for Kanehekili Fluctus, and ∼5,000 km2 for Loki Patera. We further detected the a1Δ ⇒ X3Σ− 1.707 µm rovibronic forbidden SO emission band complex over the southern hemisphere, which peaked at the location of Kanehekili Fluctus. This is the first time this emission has been seen above an active volcano, and suggests that the origin of such emissions is ejection of SO molecules directly from the vent in an excited state, after having been equilibrated at temperatures of ∼1,500 K below the surface, as was previously hypothesized. Plain Language Summary: We observed Io with JWST in November 2022 while the satellite was in Jupiter's shadow, and glowing volcanoes show up without being (partially) obscured by reflected sunlight. We detected the volcanoes Loki Patera and Kanehekili Fluctus; the latter was exceptionally bright, and Loki Patera had likely entered a new brightening phase. Both volcanoes show erupting lavas at temperatures of at least 1,200 K, originating at a vent of ∼0.25 km2 in size for Kanehekili Fluctus and <0.1 km2 for Loki Patera. In addition to lava, Kanehekili Fluctus spews out gases, and we detected, for the first time, SO emission at 1.707 μm right over the volcano. This is the first time this emission has been seen above an active volcano, and suggests that such emissions are produced by SO molecules immediately upon leaving the vent. Key Points: James Webb Space Telescope observations detected an energetic eruption at Kanehekili Fluctus, and a new brightening event at Loki PateraThe erupting lavas have a temperature of at least 1,200 K over an area of ∼0.25 km2 or lessWe detected, for the first time, a clear association of the 1.707 micron forbidden SO emissions with an active volcano [ABSTRACT FROM AUTHOR]

Published
2023
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28. The Geophysical Environment of (486958) Arrokoth—A Small Kuiper Belt Object Explored by New Horizons

Author

Keane, James T., Porter, Simon B., Beyer, Ross A., Umurhan, Orkan M., McKinnon, William B., Moore, Jeffrey M., Spencer, John R., Stern, S. Alan, Bierson, Carver J., Binzel, Richard P., Hamilton, Douglas P., Lisse, Carey M., Mao, Xiaochen, Protopapa, Silvia, Schenk, Paul M., Showalter, Mark R., Stansberry, John A., White, Oliver L., Verbiscer, Anne J., Parker, Joel W., Olkin, Catherine B., Weaver, Harold A., and Singer, Kelsi N.

Abstract

NASA's New Horizons mission performed the first flyby of a small Kuiper Belt Object (KBO), (486958) Arrokoth on 1 January 2019. The fast flyby revealed a fascinating, flattened, contact binary replete with a variety of unexpected geologic terrains. However, the irregular shape and constraints imposed by the fast flyby makes it a challenge to understand these features. Here we use the latest New Horizons shape models of Arrokoth to investigate its geophysical environment, including its surface slopes, gravity field, and moments of inertia—which are critical context for understanding Arrokoth's formation, evolution, and peculiar geology. We find that Arrokoth's surface features have a complicated relationship to its geophysical environment. For example, bright material tends to be concentrated in geopotential lows (like the neck), consistent with mass wasting—however, this trend is not consistently observed across Arrokoth. Mass wasting may naturally explain some aspects of Arrokoth's geology, but the actual dynamics of material transport may be complicated owing to Arrokoth's unique shape, spin-rate, and inferred density. While New Horizons's fast and distant flyby precluded directly measuring Arrokoth's mass, we used techniques previously pioneered for comets and asteroids to infer its density. We find that Arrokoth has a low bulk density of ρ = 235 kg/m3 (1σ range: 155–600 kg/m3). This density is low compared to previously explored small bodies, but is comparable to comets, select binary KBOs, and the ring-moons of Saturn. This low density may be a critical data-point for understanding the formation of planetesimals at the dawn of the Solar System.

Published
2022

32. Absolute Calibration and Characterization of the Multiband Imaging Photometer for Spitzer . II. 70 μm Imaging

Author

Gordon, Karl D., Engelbracht, Charles W., Fadda, Dario, Stansberry, John, Wachter, Stefanie, Frayer, Dave T., Rieke, George, Noriega‐Crespo, Alberto, Latter, William B., Young, Erick, Neugebauer, Gerry, Balog, Zoltan, Beeman, Jeffrey W., Dole, Hervé, Egami, Eiichi, Haller, Eugene E., Hines, Dean, Kelly, Doug, Marleau, Francine, Misselt, Karl, Morrison, Jane, Pérez‐González, Pablo, Rho, Jeonghee, and Wheaton, Wm. A.

Published
2007
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34. Reduction Algorithms for the Multiband Imaging Photometer for Spitzer

Author

Gordon, Karl D., Rieke, George H., Engelbracht, Charles W., Muzerolle, James, Stansberry, John A., Misselt, Karl A., Morrison, Jane E., Cadien, James, Young, Erick T., Dole, Hervé, Kelly, Douglas M., Alonso‐Herrero, Almudena, Egami, Eiichi, Su, Kate Y. L., Papovich, Casey, Smith, Paul S., Hines, Dean C., Rieke, Marcia J., Blaylock, Myra, Pérez‐González, Pablo G., Le Floc’h, Emeric, Hinz, Joannah L., Latter, William B., Hesselroth, Ted, Frayer, David T., Noriega‐Crespo, Alberto, Masci, Frank J., Padgett, Deborah L., Smylie, Matthew P., and Haegel, Nancy M.

Published
2005
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35. Performance of NIRCam on JWST in Flight.

Author

Rieke, Marcia J., Kelly, Douglas M., Misselt, Karl, Stansberry, John, Boyer, Martha, Beatty, Thomas, Egami, Eiichi, Florian, Michael, Greene, Thomas P., Hainline, Kevin, Leisenring, Jarron, Roellig, Thomas, Schlawin, Everett, Sun, Fengwu, Tinnin, Lee, Williams, Christina C., Willmer, Christopher N. A., Wilson, Debra, Clark, Charles R., and Rohrbach, Scott

Subjects
SPACE telescopes, INFRARED cameras, CAMERAS, ASTRONOMERS
Abstract

The Near Infrared Camera for the James Webb Space Telescope (JWST) is delivering the imagery that astronomers have hoped for ever since JWST was proposed back in the 1990s. In the Commissioning Period that extended from right after launch to early 2022 July, NIRCam has been subjected to a number of performance tests and operational checks. The camera is exceeding prelaunch expectations in virtually all areas, with very few surprises discovered in flight. NIRCam also delivered the imagery needed by the Wavefront Sensing Team for use in aligning the telescope mirror segments. [ABSTRACT FROM AUTHOR]

Published
2023
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36. JWST NIRCam Defocused Imaging: Photometric Stability Performance and How It Can Sense Mirror Tilts.

Author

Schlawin, Everett, Beatty, Thomas, Brooks, Brian, Nikolov, Nikolay K., Greene, Thomas P., Espinoza, Néstor, Glidic, Kayli, Baka, Keith, Egami, Eiichi, Stansberry, John, Boyer, Martha, Gennaro, Mario, Leisenring, Jarron, Hilbert, Bryan, Misselt, Karl, Kelly, Doug, Canipe, Alicia, Beichman, Charles, Correnti, Matteo, and Knight, J. Scott

Abstract

We use JWST NIRCam short-wavelength photometry to capture a transit lightcurve of the exoplanet HAT-P-14 b to assess performance as part of instrument commissioning. The short-wavelength precision is 152 ppm per 27 s integration as measured over the full time series compared to a theoretical limit of 107 ppm, after corrections to spatially correlated 1/f noise. Persistence effects from charge trapping are well fit by an exponential function with short characteristic timescales, settling on the order of 5–15 minutes. The short-wavelength defocused photometry is also uniquely well suited to measure the real-time wave-front error of JWST. Analysis of the images and reconstructed wave-front maps indicates that two different hexagonal primary mirror segments exhibited "tilt events," where they changed orientation rapidly in less than ∼1.4 s. In some cases, the magnitude and timing of the flux jumps caused by tilt events can be accurately predicted with a telescope model. These tilt events can be sensed by simultaneous longer-wavelength NIRCam grism spectral images alone in the form of changes to the point-spread function, diagnosed from the full width at half maximum. They can also be sensed with the fine guidance sensor instrument from difference images. Tilt events possibly from sudden releases of stress in the backplane structure behind the mirrors were expected during the commissioning period because they were found in ground-based testing. Tilt events have shown signs of decreasing in frequency but have not disappeared completely. The detectors exhibit some minor (less than 1%) deviations from linear behavior in the first few groups of each integration, potentially impacting absolute fluxes and transit depths on bright targets, where only a handful of groups are possible. Overall, the noise is within 50% of the theoretical photon noise and read noise. This bodes well for high-precision measurements of transiting exoplanets and other time variable targets. [ABSTRACT FROM AUTHOR]

Published
2023
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37. The James Webb Space Telescope's Plan for Operations and Instrument Capabilities for Observations in the Solar System

Author

Milam, Stefanie N, Stansberry, John A, Sonneborn, George, and Thomas, Cristina

Subjects
Astronomy, Optics
Abstract

The James Webb Space Telescope (JWST) is optimized for observations in the near- and mid-infrared and will provide essential observations for targets that cannot be conducted from the ground or other missions during its lifetime. The state-of-the-art science instruments, along with the telescopeʼs moving target tracking, will enable the infrared study, with unprecedented detail, for nearly every object (Mars and beyond) in the Solar System. The goals of this special issue are to stimulate discussion and encourage participation in JWST planning among members of the planetary science community. Key science goals for various targets, observing capabilities for JWST, and highlights for the complementary nature with other missions/observatories are described in this paper.

Published
2016
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38. TNOs are Cool: A Survey of the Transneptunian Region: A Herschel Open Time Key Programme

Author

Müller, Thomas G., Lellouch, Emmanuel, Böhnhardt, Hermann, Stansberry, John, Barucci, Antonella, Crovisier, Jacques, Delsanti, Audrey, Doressoundiram, Alain, Dotto, Elisabetta, Duffard, René, Fornasier, Sonia, Groussin, Olivier, Gutiérrez, Pedro J., Hainaut, Olivier, Harris, Alan W., Hartogh, Paul, Hestroffer, Daniel, Horner, Jonathan, Jewitt, Dave, Kidger, Mark, Kiss, Csaba, Lacerda, Pedro, Lara, Luisa, Lim, Tanya, Mueller, Michael, Moreno, Raphael, Ortiz, Jose-Luis, Rengel, Miriam, Santos-Sanz, Pablo, Swinyard, Bruce, Thomas, Nicolas, Thirouin, Audrey, and Trilling, David

Published
2009
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39. Spitzer's Solar System Science Legacy: Studies of the Relics of Solar System Formation & Evolution. Part 1 - Comets, Centaurs, & Kuiper Belt Objects

Author

Lisse, Carey, Bauer, James, Cruikshank, Dale, Emery, Josh, Fernandez, Yanga, Fernandez-Valenzuela, Estela, Kelley, Michael, McKay, Adam, Reach, William, Pendleton, Yvonne, Pinilla-Alonso, Noemi, Stansberry, John, Sykes, Mark, Trilling, David, Wooden, Diane, Harker, David, Gehrz, Robert, and Woodward, Charles

Subjects
Astrophysics - Earth and Planetary Astrophysics
Abstract

In its 16 years of scientific measurements, the Spitzer Space Telescope performed a number of ground breaking and key infrared measurements of Solar System objects near and far. Targets ranged from the smallest planetesimals to the giant planets, and have helped us reform our understanding of these objects while also laying the groundwork for future infrared space-based observations like those to be undertaken by the James Webb Space Telescope in the 2020s. In this first Paper, we describe how the Spitzer Space Telescope advanced our knowledge of Solar System formation and evolution via observations of small outer Solar System planetesimals, i.e., Comets, Centaurs, and Kuiper Belt Objects (KBOs). Relics from the early formation era of our Solar System, these objects hold important information about the processes that created them. The key Spitzer observations can be grouped into 3 broad classes: characterization of new Solar System objects (comets D/ISON 2012 S1, C/2016 R2, 1I/`Oumuamua); large population surveys of known object sizes (comets, Centaurs, and KBOs); and compositional studies via spectral measurements of body surfaces and emitted materials (comets, Centaurs, and KBOs)., Comment: Published in Nature Astronomy, Volume 4, page 930. This arXiv version pre-dates the proofs corrections; the final published version is availabe at https://rdcu.be/b8fgx

Published
2020

40. Albedos and diameters of three Mars Trojan asteroids

Author

Trilling, David E., Rivkin, Andrew S., Stansberry, John A., Spahr, Timothy B., Crudo, Richard A., and Davies, John K.

Subjects
Astronomy, Mars (Planet), Astronomy, Earth sciences
Abstract

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.icarus.2007.08.002 Byline: David E. Trilling (a), Andrew S. Rivkin (b), John A. Stansberry (a), Timothy B. Spahr (c), Richard A. Crudo (a), John K. Davies (d) Keywords: Trojan asteroids; Infrared observations; Regoliths Abstract: We observed the Mars Trojan Asteroids (5261) Eureka and (101429) 1998 VF.sub.31 and the candidate Mars Trojan 2001 FR.sub.127 at 11.2 and 18.1 microns using Michelle on the Gemini North telescope. We derive diameters of 1.28, 0.78, and 0.14. The albedos for Eureka and 1998 VF.sub.31 are consistent with the taxonomic classes and compositions (S(I)/angritic and S(VII)/achondritic, respectively) and implied histories presented in a companion paper by Rivkin et al. Eureka's surface likely has a relatively high thermal inertia, implying a thin regolith that is consistent with predictions and the small size that we derive. Author Affiliation: (a) Steward Observatory, The University of Arizona, 933 N. Cherry Avenue, Tucson, AZ 85721, USA (b) Applied Physics Laboratory, Johns Hopkins University, 11100 Johns Hopkins Road, Laurel, MD 20723, USA (c) Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02139, USA (d) UK Astronomy Technology Centre, Blackford Hill, Edinburgh, EH9 3HJ, UK Article History: Received 24 April 2007; Revised 20 July 2007

Published
2007

42. Io's volcanic control of Jupiter's extended neutral clouds

Author

Mendillo, Michael, Wilson, Jody, Spencer, John, and Stansberry, John

Subjects
Jupiter (Planet) -- Research, Io (Satellite) -- Research, Astronomy, Earth sciences
Abstract

Dramatic changes in the brightness and shape of Jupiter's extended sodium nebula are found to be correlated with the infrared emission brightness of Io. Previous imaging and modeling studies have shown that varying appearances of the nebula correspond to changes in the rate and the type of loss mechanism for atmospheric escape from Io. Similarly, previous IR observational studies have assumed that enhancements in infrared emissions from Io correspond to increased levels of volcanic (lava flow) activity. In linking these processes observationally and statistically, we conclude that silicate volcanism on Io controls both the rate and the means by which sodium escapes from Io's atmosphere. During active periods, molecules containing sodium become an important transient in Io's upper atmosphere, and subsequent photochemistry and molecular-ion driven dynamics enhance the high speed sodium population, leading to the brightest nebulas observed. This is not the case during volcanically quiet times when omni-present atmospheric sputtering ejects sodium to form a modest, base-level nebula. Sodium's role as a 'trace gas' of the more abundant species of sulfur (S) and oxygen (O) is less certain during volcanic episodes. While we suggest that volcanism must also affect the escape rates of S and O, and consequently their extended neutral clouds, the different roles played by lava and plume sources for non-sodium species are far too uncertain to make definitive comparisons at this time. Keywords: Io; Jupiter, magnetosphere; Satellites, atmospheres; Volcanism

Published
2004

43. Solar System Observations with JWST

Author

Norwood, James, Hammel, Heidi, Milam, Stefanie, Stansberry, John, Lunine, Jonathan, Chanover, Nancy, Hines, Dean, Sonneborn, George, Tiscareno, Matthew, Brown, Michael, and Ferruit, Pierre

Subjects
Astronomy, Lunar And Planetary Science And Exploration
Abstract

The James Webb Space Telescope will enable a wealth of new scientific investigations in the near- and mid- infrared, with sensitivity and spatial-spectral resolution greatly surpassing its predecessors. In this paper, we focus upon Solar System science facilitated by JWST, discussing the most current information available concerning JWST instrument properties and observing techniques relevant to planetary science. We also present numerous example observing scenarios for a wide variety of Solar System targets to illustrate the potential of JWST science to the Solar System community. This paper updates and supersedes the Solar System white paper published by the JWST Project in 2010 (Lunine et al., 2010). It is based both on that paper and on a workshop held at the annual meeting of the Division for Planetary Sciences in Reno, NV in 2012.

Published
2014

44. First Peek with JWST/NIRCam Wide-field Slitless Spectroscopy: Serendipitous Discovery of a Strong [O iii ]/H α Emitter at z = 6.11.

Author

Sun, Fengwu, Egami, Eiichi, Pirzkal, Nor, Rieke, Marcia, Boyer, Martha, Correnti, Matteo, Gennaro, Mario, Girard, Julien, Greene, Thomas P., Kelly, Doug, Koekemoer, Anton M., Leisenring, Jarron, Misselt, Karl, Nikolov, Nikolay, Roellig, Thomas L., Stansberry, John, Williams, Christina C., and Willmer, Christopher N. A.

Published
2022
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45. Science Opportunities with the Near-IR Camera (NIRCam) on the James Webb Space Telescope (JWST)

Author

Beichman, Charles A, Rieke, Marcia, Eisenstein, Daniel, Greene, Thomas P, Krist, John, McCarthy, Don, Meyer, Michael, and Stansberry, John

Subjects
Astrophysics
Abstract

The Near-Infrared Camera (NIRCam) on the James Webb Space Telescope (JWST) offers revolutionary gains in sensitivity throughout the 1-5 micrometer region. NIRCam will enable great advances in all areas of astrophysics, from the composition of objects in our own Kuiper Belt and the physical properties of planets orbiting nearby stars to the formation of stars and the detection of the youngest galaxies in the Universe. NIRCam also plays an important role in initial alignment of JWST and the long term maintenance of its image quality. NIRCam is presently undergoing instrument Integration and Test in preparation for delivery to the JWST project. Key near-term milestones include the completion of cryogenic testing of the entire instrument; demonstration of scientific and wavefront sensing performance requirements; testing of replacement H2RG detectors arrays; and an analysis of coronagraphic performance in light of measured telescope wavefront characteristics. This paper summarizes the performance of NIRCam, the scientific and education/outreach goals of the science team, and some results of the on-going testing program.

Published
2012

46. Surface properties of large TNOs: Expanding the study to longer wavelengths with the James Webb Space Telescope

Author

Pinilla-Alonso, Noem��, Stansberry, John, and Holler, Bryan

Subjects
Earth and Planetary Astrophysics (astro-ph.EP), FOS: Physical sciences, Astrophysics - Earth and Planetary Astrophysics
Abstract

The largest trans-Neptunian objects (TNOs) represent an extremely diverse collection of primitive bodies in the outer solar system. The community typically refers to these objects as dwarf planets, though the IAU acknowledges only four TNOs officially as such: Pluto, Eris, Makemake, and Haumea. We present a list of 36 potential candidates for reclassification as dwarf planets, namely candidate dwarf planets (CDPs), which cover a wide range of sizes, geometric albedos, surface colors and probably, composition. Understanding the properties across this population, and how those properties change with size, will yield useful constraints on the environment in which these TNOs formed, as well as their dynamical evolution, and bulk interior composition. TNO surface characteristics are ideal for study with the James Webb Space Telescope (JWST), which provides imaging and spectroscopic capabilities from 0.6 to 28 $\mu$m. The four available science instruments, MIRI, NIRCam, NIRISS, and NIRSpec, and their capabilities for the study of TNOs, are presented. JWST will expand on the wavelength range observable from the ground in the near-infrared (0.6-5 $\mu$m) for compositional studies and will open a new window on TNOs in the mid-infrared (5-28 $\mu$m) for thermal characterization., Comment: Chapter to be published in the book "The Transneptunian Solar System", Dina Prialnik, Maria Antonietta Barucci, Leslie Young Eds. Elsevier 4 figures, two double panel

Published
2019

47. The Large-Grained Dust Coma of 174P/Echeclus

Author

Bauer, James M, Choi, Young-Jun, Weissman, Paul R, Stansberry, John A, Fernandez, Yanga R, Roe, Henry G, Buratti, Bonnie J, and Sung, Hyun-Il

Subjects
Astronomy
Abstract

On 2005 December 30, Y.-J. Choi and P. R. Weissman discovered that the formerly dormant Centaur 2000 EC98 was in strong outburst. Previous observations by P. Rousselot et al. spanning a 3-year period indicated a lack of coma down to the 27 mag arcsec 2 level.We present Spitzer Space Telescope MIPS observations of this newly active Centaur--now known as 174P/Echeclus (2000 EC98)--or 60558 Echeclus--taken in 2006 late February. The images show strong signal at both the 24 and 70 micron bands and reveal an extended coma about 2' in diameter. Analyses yield estimates of the coma signal contribution that are in excess of 90% of the total signal in the 24 micron band. Dust production estimates ranging from 1.7-4 x 10(exp 2) kg/s are on the order of 30 times that seen in other Centaurs. Simultaneous visible-wavelength observations were also obtained with Palomar Observatory's 200-inch telescope, the 1.8-m Vatican Advanced Technology Telescope, the Bohyunsan Optical Astronomy Observatory (BOAO) 1.8-m telescope, and Table Mountain Observatory's 0.6-m telescope, revealing a coma morphology nearly identical to the mid-IR observations. The grain size distribution derived from the data yields a log particle mass power-law with slope parameter (alpha) = -0.87 +/- 0.07, and is consistent with steady cometary-activity, such as that observed during the Stardust spacecraft's encounter at 81P/Wild 2, and not with an impact driven event, such as that caused by the Deep Impact experiment.

Published
2008

48. Interpretation of the Near-IR Spectra of the Kuiper Belt Object

Author

Eluszkiewicz, Janusz, Cady-Pereira, Karen, Brown, Michael E, and Stansberry, John A

Subjects
Lunar And Planetary Science And Exploration
Abstract

Visible and near-IR observations of the Kuiper Belt Object (136472) 2005 FY(9) have indicated the presence of unusually long (1 cm or more) optical path lengths in a layer of methane ice. Using microphysical and radiative transfer modeling, we show that even at the frigid temperatures in the outer reaches of the solar system, a slab of low porosity methane ice can indeed form by pressureless sintering of micron-sized grains, and it can qualitatively reproduce the salient features of the measured spectra. A good semiquantitative match with the near-IR spectra can be obtained with a realistic slab model, provided the spectra are scaled to a visible albedo of 0.6, at the low end of the values currently estimated from Spitzer thermal measurements. Consistent with previous modeling studies, matching spectra scaled to higher albedos requires the incorporation of strong backscattering effects. The albedo may become better constrained through an iterative application of the slab model to the analysis of the thermal measurements from Spitzer and the visible/near-IR reflectance spectra. The slab interpretation offers two falsifiable predictions (1) Absence of an opposition surge, which is commonly attributed to the fluffiness of the optical surface. This prediction is best testable with a spacecraft, as Earth-based observations at true opposition will not be possible until early next century. (2) Unlikelihood of the simultaneous occurrence of very long spectroscopic path lengths in both methane and nitrogen ice on the surface of any Kuiper Belt Object, as the more volatile nitrogen would hinder densification in methane ice.

Published
2007
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49. Pluto-Charon: Infrared Reflectance from 3.6 to 8.0 Micrometers

Author

Cruikshank, Dale P, Emery, Joshua P, Stansberry, John A, and VanCleve, Jeffrey E

Subjects
Instrumentation And Photography
Abstract

We have measured the spectral reflectance of the Pluto-Charon pair at 3.6, 4.5, 5.8, and 8.0 micrometers with the Infrared Array Camera (IRAC) (G. G. Fazzio et al. Ap.J.Supp. 154, 10-17, 2004) on the Spitzer Space Telescope (STS), at eight different longitudes that cover a full rotation of the planet. STS does not have sufficient resolution to separate the light from the planet and the satellite. The image of the Pluto-Charon pair is clearly visible at each of the four wavelengths. We will discuss the spectral reflectance in terms of models that include the known components of Pluto and Charon s surfaces, and evidence for diurnal variations.

Published
2004

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