Astronomers Uncover Briefest Supernova-Powered Gamma-Ray Burst

Gamma-ray bursts (GRBs) are among the brightest and most energetic events in the Universe, but scientists are still figuring out exactly what causes these fleeting events [1]. Astronomers divide GRBs into two broad categories based on their duration. Short GRBs blaze into life in less than two seconds and are thought to be caused by the merging of binary neutron stars [2]. Those that last longer are classified as long GRBs, and have been associated with supernova explosions caused by the implosions of massive stars [3]. However, the recent discovery of the shortest-ever GRB produced during a supernova shows that GRBs don’t fit neatly into the boxes astronomers have created for them.

This discovery represents the shortest gamma-ray emission caused by a supernova during the collapse of a massive star,” commented Tomás Ahumada, who led this research and is a PhD candidate at the University of Maryland and astronomer at NASA’s Goddard Space Flight Center. “It lasted for only 0.6 second, and it sits on the brink between a successful and a failed gamma-ray burst.

The team believes that this and some other supernova-related GRBs are appearing short because the jets of gamma rays that emerge from the collapsing star’s poles aren’t strong enough to completely escape the star — almost failing to produce a GRB — and that other collapsing stars have such weak jets that they don’t produce GRBs at all.

This discovery could also help explain an astronomical mystery. Long GRBs are associated with a specific type of supernova (called Type Ic-BL). However, astronomers observe many more of these supernovae than long GRBs. This discovery of the shortest GRB associated with a supernova suggests that some of these supernova-caused GRBs are masquerading as short GRBs thought to be created by neutron-star mergers, and are therefore not getting counted as the supernova kind.

Our discovery suggests that, since we observe many more of these supernovae than long gamma-ray bursts, most collapsing stars fail to produce a GRB jet that breaks through the outer envelope of the collapsing star,” explained Ahumada. “We think this event was effectively a fizzle, one that was close to not happening at all.” 

The team was able to determine that this GRB — identified as GRB 200826A — originated from a supernova explosion thanks to the imaging capabilities of the Gemini Multi-Object Spectrograph on Gemini North in Hawai‘i. The researchers used Gemini North to obtain images of the GRB’s host galaxy 28, 45, and 80 days after the GRB was first detected on 26 August 2020 by a network of observatories that included NASA’s Fermi Gamma-ray Space Telescope. Gemini’s observations allowed the team to spot the tell-tale rise in energy that signifies a supernova, despite the blast’s location in a galaxy 6.6 billion light-years away.

This was a complicated endeavor as we needed to separate the light of an already faint galaxy from the light of a supernova,” said Ahumada. “Gemini is the only ground-based telescope that can do follow-up observations like this with a flexible-enough schedule to let us squeeze in our observations.” 

This result shows that classifying GRBs based solely on their duration may not be the best approach, and that additional observations are needed to determine a GRB’s cause.

We were originally hunting for merging neutron stars, which are thought to produce short gamma-ray bursts,” added Ahumada. “Once we discovered GRB 200826A, however, we realized that this burst was more likely to be caused by a collapsing star’s supernova, which was a surprise!”

“The Gemini observatories continue to shed new light on the nature of these incredible explosions occurring across the distant Universe,” said Martin Still, Gemini Program Officer at NSF“Dedicated instrumentation arriving for use over the next decade will maintain Gemini’s leadership in the follow-up of these awe-inspiring cosmic events.”

Notes

[1] Gamma-ray bursts occur extremely rarely, but when they do occur they release a spectacular amount of energy. In just a few seconds, a typical GRB will release more energy than the Sun will over its 10-billion-year lifetime.

[2] Neutron stars are some of the smallest, densest, and strangest astronomical objects in the Universe. Formed by the collapse of massive stars, they compress the mass of 1.4 Suns into a ball only 10 kilometers across. The material of neutron stars is as dense as the nucleus of an atom, and a single teaspoon of neutron-star material would weigh as much as Mount Everest on Earth. As well as their incredible density, neutron stars are also intensely hot and possess magnetic fields millions of times stronger than Earth’s.

[3] A star that has collapsed under its own gravity at the end of its life is also known as a collapsar. At the end of their lives, stars run out of the hydrogen that sustains nuclear reactions in their cores. Without the stabilizing pressure of these reactions, stars cannot fight gravity, and they collapse into an exotic stellar remnant. The mass of a star determines its fate: stars smaller than 1.4 times the mass of the Sun shrink to white dwarfs, larger stars collapse into neutron stars, and the largest stars collapse entirely, forming black holes.

More information

This research was presented in the paper Discovery and Confirmation of the Shortest Gamma Ray Burst from a Collapsar in the journal Nature Astronomy.

The team is composed of Tomás Ahumada (Department of Astronomy, University of Maryland; Astrophysics Science Division, NASA Goddard Space Flight Center; and Center for Research and Exploration in Space Science and Technology, NASA Goddard Space Flight Center), Leo P. Singer (Astrophysics Science Division, NASA Goddard Space Flight Center; Joint Space-Science Institute, University of Maryland), Shreya Anand (Division of Physics, Mathematics and Astronomy, California Institute of Technology), Michael W. Coughlin (School of Physics and Astronomy, University of Minnesota), Mansi M. Kasliwal (Division of Physics, Mathematics, and Astronomy, California Institute of Technology), Geoffrey Ryan (Department of Astronomy, University of Maryland; Astrophysics Science Division, NASA Goddard Space Flight Center), Igor Andreoni (Division of Physics, Mathematics, and Astronomy, California Institute of Technology), S. Bradley Cenko (Astrophysics Science Division, NASA Goddard Space Flight Center; Joint Space-Science Institute, University of Maryland), Christoffer Fremling (Division of Physics, Mathematics, and Astronomy, California Institute of Technology), Harsh Kumar (Indian Institute of Technology Bombay; LSSTC Data Science Fellow), Peter T. H. Pang (Nikhef, Department of Physics, Utrecht University), Eric Burns (Louisiana State University), Virginia Cunningham (Department of Astronomy, University of Maryland; Astrophysics Science Division, NASA Goddard Space Flight Center), Simone Dichiara (Department of Astronomy, University of Maryland; Astrophysics Science Division, NASA Goddard Space Flight Center), Tim Dietrich (Institut für Physik und Astronomie, Universität Potsdam; Max Planck Institute for Gravitational Physics, Albert Einstein Institute), Dmitry S. Svinkin (Ioffe Institute, Polytekhnicheskaya), Mouza Almualla (American University of Sharjah), Alberto J. Castro-Tirado (Instituto de Astrofísica de Andalucía; Departamento de Ingeniería de Sistemas y Automática, Escuela de Ingenieros Industriales), Kishalay De (Division of Physics, Mathematics, and Astronomy, California Institute of Technology), Rachel Dunwoody (School of Physics, University College Dublin), Pradip Gatkine (Division of Physics, Mathematics, and Astronomy, California Institute of Technology), Erica Hammerstein (Department of Astronomy, University of Maryland), Shabnam Iyyani (Inter-University Centre for Astronomy and Astrophysics), Joseph Mangan (School of Physics, University College Dublin), Dan Perley (Astrophysics Research Institute, Liverpool John Moores University), Sonalika Purkayastha (National Centre for Radio Astrophysics, Tata Institute of Fundamental Research), Eric Bellm (DIRAC Institute, Department of Physics and Astronomy, University of Washington), Varun Bhalerao (Indian Institute of Technology Bombay), Bryce Bolin (Division of Physics, Mathematics, and Astronomy, California Institute of Technology), Mattia Bulla (Nordita, KTH Royal Institute of Technology and Stockholm University), Christopher Cannella (Duke University, Electrical and Computer Engineering), Poonam Chandra (National Centre for Radio Astrophysics and Swarna Jayanti Fellow, Department of Science & Technology), Dmitry A. Duev (Division of Physics, Mathematics, and Astronomy, California Institute of Technology), Dmitry Frederiks (Ioffe Institute, Polytekhnicheskaya), Avishay Gal-Yam (Department of Particle Physics and Astrophysics, Hebrew University), Matthew Graham (Division of Physics, Mathematics, and Astronomy, California Institute of Technology), Anna Y. Q. Ho (Miller Institute for Basic Research in Science, University of California; Department of Astronomy, University of California – Berkeley), Kevin Hurley (Space Sciences Laboratory, University of California – Berkeley), Viraj Karambelkar (Division of Physics, Mathematics, and Astronomy, California Institute of Technology), Erik C. Kool (The Oskar Klein Centre, Department of Astronomy), S. R. Kulkarni (Division of Physics, Mathematics, and Astronomy, California Institute of Technology), Ashish Mahabal (Division of Physics, Mathematics, and Astronomy, California Institute of Technology), Frank Masci (IPAC, California Institute of Technology), Sheila McBreen (School of Physics, University College Dublin), Shashi B. Pandey (Aryabhatta Research Institute of Observational Sciences), Simeon Reusch (Deutsches Elektronen Synchrotron DESY; Institut für Physik, Humboldt-Universität zu Berlin), Anna Ridnaia (Ioffe Institute, Polytekhnicheskaya), Philippe Rosnet (Université Clermont Auvergne, CNRS; IN2P3, Laboratoire de Physique de Clermont), Benjamin Rusholme (IPAC, California Institute of Technology), Ana Sagués Carracedo (The Oskar Klein Centre, Department of Physics), Roger Smith (Caltech Optical Observatories, California Institute of Technology), Maayane Soumagnac (Department of Particle Physics and Astrophysics, Weizmann Institute of Science, Lawrence Berkeley National Laboratory), Robert Stein (Deutsches Elektronen Synchrotron DESY; and Institut für Physik, Humboldt-Universität zu Berlin), Eleonora Troja (Department of Astronomy, University of Maryland; Astrophysics Science Division, NASA Goddard Space Flight Center), Anastasia Tsvetkova (Ioffe Institute, Polytekhnicheskaya), Richard Walters (Caltech Optical Observatories, California Institute of Technology), and Azamat F. Valeev (Special Astrophysical Observatory, Russian Academy of Sciences).

NSF’s NOIRLab (National Optical-Infrared Astronomy Research Laboratory), the US center for ground-based optical-infrared astronomy, operates the international Gemini Observatory (a facility of NSFNRC–CanadaANID–ChileMCTIC–BrazilMINCyT–Argentina, and KASI–Republic of Korea), Kitt Peak National Observatory (KPNO), Cerro Tololo Inter-American Observatory (CTIO), the Community Science and Data Center (CSDC), and Vera C. Rubin Observatory (operated in cooperation with the Department of Energy’s SLAC National Accelerator Laboratory). It is managed by the Association of Universities for Research in Astronomy (AURA) under a cooperative agreement with NSF and is headquartered in Tucson, Arizona. The astronomical community is honored to have the opportunity to conduct astronomical research on Iolkam Du’ag (Kitt Peak) in Arizona, on Maunakea in Hawai‘i, and on Cerro Tololo and Cerro Pachón in Chile. We recognize and acknowledge the very significant cultural role and reverence that these sites have to the Tohono O’odham Nation, to the Native Hawaiian community, and to the local communities in Chile, respectively.

Links

Contacts

Tomás Ahumada
University of Maryland and NASA Goddard Space Flight Center
Email: [email protected]

Amanda Kocz
Press and Internal Communications Officer
NSF’s NOIRLab
Cell: +1 626 524 5884
Email: [email protected]

 

Joven astrónomo chileno descubre supernova que produjo intrigante señal de rayos gamas

Se trata de una inesperada y breve emisión de rayos gamma

Un equipo internacional de más de 50 investigadores liderados por el astrónomo chileno Matías Ahumada, descubrió la emisión de rayos gamma más breve causada por la explosión de una estrella masiva usando el telescopio Gemini, un programa de NOIRLab de NSF y AURA. Se trata de una señal de apenas 0,6 segundos de duración que fue identificada como la implosión de una estrella masiva en una galaxia distante. Si bien las emisiones de rayos gamma generadas por supernovas suelen tener más del doble de duración, esta particular emisión sugiere que las explosiones breves de rayos gamma son en realidad eventos de mayor duración, aunque disfrazados.

La explosion de rayos gamma (GRB por sus siglas en inglés) se encuentran entre los eventos más energéticos y brillantes del Universo, y los científicos están investigando qué causa estos eventos fugaces [1]. Los astrónomos dividen las emisiones de rayos gamma en dos amplias categorías basadas en su duración. Los GRB cortos cobran vida en menos de dos segundos y se cree que son causados por la fusión de estrellas de neutrones binarios [2]. Aquellos que duran más se clasifican como GRB largos y se han asociado con explosiones de supernovas causadas por las implosiones de estrellas masivas [3]. Sin embargo, el reciente descubrimiento del GRB más corto jamás producido durante una supernova muestra que los GRB no encajan perfectamente en las clasificaciones que los astrónomos han creado para ellos.

“Este descubrimiento representa la emisión de rayos gamma más corta causada por una supernova durante el colapso de una estrella masiva”, comentó Tomás Ahumada, quien dirigió esta investigación y es candidato a doctor en la Universidad de Maryland y astrónomo en el Centro de Vuelo Espacial Goddard de la NASA. “Duró sólo 0,6 segundos, y se encuentra al borde entre una explosión de rayos gamma exitosa y una fallida”.

El equipo cree que éste y algunos otros GRB relacionados con supernovas están pareciendo cortos porque los chorros de rayos gamma que emergen de los polos de la estrella en colapso no son lo suficientemente fuertes como para escapar por completo de la estrella, produciendo  GRB fallidos, y además de haber otras estrellas que colapsan emitiendo chorros tan débiles que no producen GRB en absoluto.

Este descubrimiento también podría ayudar a explicar un misterio astronómico. Los GRB largos están asociados con un tipo específico de supernova (llamado Tipo Ic-BL). Sin embargo, los astrónomos observan muchas más de estas supernovas que GRB largas. Este descubrimiento del GRB más corto asociado con una supernova sugiere que algunos de estos GRB causados ​​por supernovas se disfrazan como GRB cortos que se cree que fueron creados por fusiones de estrellas de neutrones y, por lo tanto, no se cuentan como del tipo de supernova.

“Nuestro descubrimiento sugiere que, dado que observamos muchas más de estas supernovas que estallidos largos de rayos gamma, la mayoría de las estrellas que colapsan no producen GRB capaces de atravesar la envoltura exterior de la estrella que colapsa”, explicó Ahumada. “Creemos que este evento fue efectivamente un fracaso, uno que estuvo cerca de no suceder en absoluto”.

El equipo pudo determinar que este GRB, identificado como GRB 200826A, se originó a partir de una explosión de supernova gracias a las capacidades de imagen del espectrógrafo de objetos múltiples de Gemini Norte en Hawai‘i. Los investigadores utilizaron el telescopio Gemini Norte para obtener imágenes de la galaxia anfitriona del GRB 28, 45 y 80 días después de que el GRB fuera detectado por primera vez el 26 de agosto de 2020 por una red de observatorios que incluía el telescopio espacial de rayos gamma Fermi de la NASA. Las observaciones de Gemini permitieron al equipo detectar el aumento revelador de energía que significa una supernova, a pesar de la ubicación de la explosión en una galaxia a 6.600 mil millones de años luz de distancia.

“Este fue un esfuerzo complicado ya que necesitábamos separar la luz de una galaxia ya débil de la luz de una supernova”, dijo Ahumada. “Gemini es el único telescopio terrestre que puede realizar observaciones de seguimiento como esta con un horario lo suficientemente flexible como para permitirnos exprimir nuestras observaciones”.

Este resultado muestra que clasificar las GRB basándose únicamente en su duración no es lo más correcto y que se necesitan observaciones adicionales para determinar la causa de una GRB.

“Originalmente estábamos buscando estrellas de neutrones fusionadas, que se cree que producen estallidos cortos de rayos gamma”, agregó Ahumada. “Cuando descubrimos GRB 200826A, nos dimos cuenta de que era más probable que este estallido fuera causado por la supernova de una estrella en colapso, ¡lo cual fue una sorpresa!”

“Los telescopios Gemini continúan arrojando nueva luz sobre la naturaleza de estas increíbles explosiones que ocurren en el Universo distante”, señaló Martin Still, Jefe del Programa Gemini de la Fundación Nacional de Ciencias de Estados Unidos. “La instrumentación especializada que llegará durante la próxima década mantendrá el liderazgo de Gemini en el seguimiento de estos impresionantes eventos cósmicos”.

Notas

[1] Los estallidos de rayos gamma ocurren muy raramente, pero cuando ocurren liberan una cantidad espectacular de energía. En sólo unos segundos, un GRB típico liberará más energía que el Sol durante sus 10 mil millones de años de vida.

[2] Las estrellas de neutrones son algunos de los objetos astronómicos más pequeños, densos y extraños del Universo. Formados por el colapso de estrellas masivas, comprimen la masa de 1,4 soles en una bola de solo 10 kilómetros de diámetro. El material de las estrellas de neutrones es tan denso como el núcleo de un átomo, y una sola cucharadita de material de estrella de neutrones pesaría tanto como el Monte Everest en la Tierra. Además de su increíble densidad, las estrellas de neutrones también son intensamente calientes y poseen campos magnéticos millones de veces más fuertes que los de la Tierra.

[3] Una estrella que colapsó por su propia gravedad al final de su vida también se conoce como collapsar. Al final de sus vidas, las estrellas se quedan sin el hidrógeno que sustenta las reacciones nucleares en sus núcleos.Sin la presión estabilizadora de estas reacciones, las estrellas no pueden luchar contra la gravedad y colapsan en un exótico remanente estelar. La masa de una estrella determina su destino: las estrellas menores a 1,4 veces la masa del Sol se reducen a enanas blancas, las estrellas más grandes colapsan en estrellas de neutrones y las estrellas gigantes colapsan por completo, formando agujeros negros.

Más Información

Esta investigación fue presentada en el artículo científico titulado Discovery and Confirmation of the Shortest Gamma Ray Burst from a Collapsar que será publicado en la revista Nature Astronomy.

El equipo estaba compuesto por Tomás Ahumada (Department of Astronomy, University of Maryland; Astrophysics Science Division, NASA Goddard Space Flight Center; and Center for Research and Exploration in Space Science and Technology, NASA Goddard Space Flight Center), Leo P. Singer (Astrophysics Science Division, NASA Goddard Space Flight Center; Joint Space-Science Institute, University of Maryland), Shreya Anand (Division of Physics, Mathematics and Astronomy, California Institute of Technology), Michael W. Coughlin (School of Physics and Astronomy, University of Minnesota), Mansi M. Kasliwal (Division of Physics, Mathematics, and Astronomy, California Institute of Technology), Geoffrey Ryan (Department of Astronomy, University of Maryland; Astrophysics Science Division, NASA Goddard Space Flight Center), Igor Andreoni (Division of Physics, Mathematics, and Astronomy, California Institute of Technology), S. Bradley Cenko (Astrophysics Science Division, NASA Goddard Space Flight Center; Joint Space-Science Institute, University of Maryland), Christoffer Fremling (Division of Physics, Mathematics, and Astronomy, California Institute of Technology), Harsh Kumar (Indian Institute of Technology Bombay; LSSTC Data Science Fellow), Peter T. H. Pang (Nikhef, Department of Physics, Utrecht University), Eric Burns (Louisiana State University), Virginia Cunningham (Department of Astronomy, University of Maryland; Astrophysics Science Division, NASA Goddard Space Flight Center), Simone Dichiara (Department of Astronomy, University of Maryland; Astrophysics Science Division, NASA Goddard Space Flight Center), Tim Dietrich (Institut für Physik und Astronomie, Universität Potsdam; Max Planck Institute for Gravitational Physics, Albert Einstein Institute), Dmitry S. Svinkin (Ioffe Institute, Polytekhnicheskaya), Mouza Almualla (American University of Sharjah), Alberto J. Castro-Tirado (Instituto de Astrofísica de Andalucía; Departamento de Ingeniería de Sistemas y Automática, Escuela de Ingenieros Industriales), Kishalay De (Division of Physics, Mathematics, and Astronomy, California Institute of Technology), Rachel Dunwoody (School of Physics, University College Dublin), Pradip Gatkine (Division of Physics, Mathematics, and Astronomy, California Institute of Technology), Erica Hammerstein (Department of Astronomy, University of Maryland), Shabnam Iyyani (Inter-University Centre for Astronomy and Astrophysics), Joseph Mangan (School of Physics, University College Dublin), Dan Perley (Astrophysics Research Institute, Liverpool John Moores University), Sonalika Purkayastha (National Centre for Radio Astrophysics, Tata Institute of Fundamental Research), Eric Bellm (DIRAC Institute, Department of Physics and Astronomy, University of Washington), Varun Bhalerao (Indian Institute of Technology Bombay), Bryce Bolin (Division of Physics, Mathematics, and Astronomy, California Institute of Technology), Mattia Bulla (Nordita, KTH Royal Institute of Technology and Stockholm University), Christopher Cannella (Duke University, Electrical and Computer Engineering), Poonam Chandra (National Centre for Radio Astrophysics and Swarna Jayanti Fellow, Department of Science & Technology), Dmitry A. Duev (Division of Physics, Mathematics, and Astronomy, California Institute of Technology), Dmitry Frederiks (Ioffe Institute, Polytekhnicheskaya), Avishay Gal-Yam (Department of Particle Physics and Astrophysics, Hebrew University), Matthew Graham (Division of Physics, Mathematics, and Astronomy, California Institute of Technology), Anna Y. Q. Ho (Miller Institute for Basic Research in Science, University of California; Department of Astronomy, University of California – Berkeley), Kevin Hurley (Space Sciences Laboratory, University of California – Berkeley), Viraj Karambelkar (Division of Physics, Mathematics, and Astronomy, California Institute of Technology), Erik C. Kool (The Oskar Klein Centre, Department of Astronomy), S. R. Kulkarni (Division of Physics, Mathematics, and Astronomy, California Institute of Technology), Ashish Mahabal (Division of Physics, Mathematics, and Astronomy, California Institute of Technology), Frank Masci (IPAC, California Institute of Technology), Sheila McBreen (School of Physics, University College Dublin), Shashi B. Pandey (Aryabhatta Research Institute of Observational Sciences), Simeon Reusch (Deutsches Elektronen Synchrotron DESY; Institut für Physik, Humboldt-Universität zu Berlin), Anna Ridnaia (Ioffe Institute, Polytekhnicheskaya), Philippe Rosnet (Université Clermont Auvergne, CNRS; IN2P3, Laboratoire de Physique de Clermont), Benjamin Rusholme (IPAC, California Institute of Technology), Ana Sagués Carracedo (The Oskar Klein Centre, Department of Physics), Roger Smith (Caltech Optical Observatories, California Institute of Technology), Maayane Soumagnac (Department of Particle Physics and Astrophysics, Weizmann Institute of Science, Lawrence Berkeley National Laboratory), Robert Stein (Deutsches Elektronen Synchrotron DESY; and Institut für Physik, Humboldt-Universität zu Berlin), Eleonora Troja (Department of Astronomy, University of Maryland; Astrophysics Science Division, NASA Goddard Space Flight Center), Anastasia Tsvetkova (Ioffe Institute, Polytekhnicheskaya), Richard Walters (Caltech Optical Observatories, California Institute of Technology), and Azamat F. Valeev (Special Astrophysical Observatory, Russian Academy of Sciences).

NOIRLab de NSF (Laboratorio Nacional de Investigación en Astronomía Óptica-Infrarroja de NSF), el centro de EE. UU. para la astronomía óptica-infrarroja en tierra, opera el Observatorio internacional Gemini (una instalación de NSFNRC–CanadaANID–ChileMCTIC–BrasilMINCyT–Argentina y KASI – República de Corea), el Observatorio Nacional de Kitt Peak (KPNO), el Observatorio Interamericano Cerro Tololo (CTIO), el Centro de Datos para la Comunidad Científica (CSDC) y el Observatorio Vera C. Rubin (operado en cooperación con el National Accelerator Laboratory (SLAC) del Departamento de Energía de Estados Unidos (DOE). Está administrado por la Asociación de Universidades para la Investigación en Astronomía (AURA) en virtud de un acuerdo de cooperación con NSF y tiene su sede en Tucson, Arizona. La comunidad astronómica tiene el honor de tener la oportunidad de realizar investigaciones astronómicas en Iolkam Du’ag (Kitt Peak) en Arizona, en Maunakea, en Hawai‘i, y en Cerro Tololo y Cerro Pachón en Chile. Reconocemos y apreciamos el importante rol cultural y la veneración que estos sitios tienen para la Nación Tohono O’odham, para la comunidad nativa de Hawai‘i y para las comunidades locales en Chile, respectivamente.

Enlaces

Contactos

Tomás Ahumada
University of Maryland and NASA Goddard Space Flight Center
Correo electrónico: [email protected]

Amanda Kocz
Press and Internal Communications Officer
NSF’s NOIRLab
Cel: +1 626 524 5884
Correo electrónico: [email protected]

Esta es una traducción del Comunicado de Prensa de NOIRLab noirlab2121.

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