domingo, 12 de julio de 2020

Exoplaneta menor que la Tierra | Actualidad | Investigación y Ciencia

Exoplaneta menor que la Tierra | Actualidad | Investigación y Ciencia





¿Un supermarte alrededor de Próxima Centauri?

Es posible que se haya encontrado otro planeta en los datos de nuevas observaciones de la estrella más cercana a nosotros. Su masa estaría entre la de Marte y la de la Tierra.

El universo en rayos X | Investigación y Ciencia | Investigación y Ciencia

El universo en rayos X | Investigación y Ciencia | Investigación y Ciencia





El universo en rayos X

Tras dos décadas en el espacio, el observatorio de rayos X Chandra sigue revelando nuevos secretos del cosmos.

Descubierto el agujero negro más cercano a la Tierra | Actualidad | Investigación y Ciencia

Descubierto el agujero negro más cercano a la Tierra | Actualidad | Investigación y Ciencia





Descubierto el agujero negro más cercano a la Tierra

El objeto, que no emite radiación, podría ser «la punta del iceberg» de una toda una población similar de agujeros negros, según los investigadores.

La constante de Hubble y el magnetismo primordial | Actualidad | Investigación y Ciencia

La constante de Hubble y el magnetismo primordial | Actualidad | Investigación y Ciencia





Se empieza a descubrir el universo magnético oculto

Los astrónomos están descubriendo que buena parte del cosmos está impregnada de campos magnéticos. Si esos campos proceden de la gran explosión, podrían ser la solución de un gran misterio cosmológico.

Luz comprimida y ondas gravitacionales | Actualidad | Investigación y Ciencia

Luz comprimida y ondas gravitacionales | Actualidad | Investigación y Ciencia





Se ha demostrado que las fluctuaciones cuánticas afectan a los objetos macroscópicos

Se ha informado de un método que mejora más allá de su límite intrínseco la precisión de las mediciones que hacen los detectores de ondas gravitatorias, y se ha mostrado que las fluctuaciones cuánticas pueden alterar la posición de objetos macroscópicos.

AGN en galaxias enanas | Actualidad | Investigación y Ciencia

AGN en galaxias enanas | Actualidad | Investigación y Ciencia





Grandes agujeros negros en pequeñas galaxias

Se ha visto que galaxias «enanas», pequeñas, de poco brillo pues, ocultan agujeros negros que expelen gas desde sus inmediaciones.

Nucleosíntesis de elementos pesados | Actualidad | Investigación y Ciencia

Nucleosíntesis de elementos pesados | Actualidad | Investigación y Ciencia





Se confirma que las colisiones de estrellas de neutrones crean elementos pesados

En la radiación del suceso de ondas gravitatorias GW170817 se ha detectado la presencia de estroncio. Es una confirmación de que es en sucesos así donde deben de formarse alrededor de la mitad de los elementos más pesados que el hierro. El origen de esos núcleos atómicos estuvo poco claro para los investigadores durante decenios.

Pares pesados de estrellas de neutrones | Actualidad | Investigación y Ciencia

Pares pesados de estrellas de neutrones | Actualidad | Investigación y Ciencia





Hace falta un «cambio radical» tras la última colisión de estrellas de neutrones

Una fusión entre estrellas de neutrones observada recientemente desafía las expectativas de los astrónomos. Les lleva a poner en duda ideas que parecían muy asentadas sobre las estrellas de neutrones y las supernovas que las crean. «Tenemos que volver a pensarlo todo desde el principio».

El interior de las estrellas de neutrones | Actualidad | Investigación y Ciencia

El interior de las estrellas de neutrones | Actualidad | Investigación y Ciencia





Viene la edad de oro de la física de las estrellas de neutrones

Estos residuos estelares están entre los objetos más enigmáticos del universo. Ahora se está empezando a descubrir sus secretos.

Ondas gravitacionales y agujeros de gusano | Investigación y Ciencia | Investigación y Ciencia

Ondas gravitacionales y agujeros de gusano | Investigación y Ciencia | Investigación y Ciencia





Ecos desde el horizonte

La astronomía de ondas gravitacionales podrá responder pronto a una pregunta fundamental: ¿son los agujeros negros el tipo de objetos que predice la relatividad general?

El interior de las estrellas de neutrones | Investigación y Ciencia | Investigación y Ciencia

El interior de las estrellas de neutrones | Investigación y Ciencia | Investigación y Ciencia





El interior de las estrellas de neutrones

En el seno de estos astros, las fuerzas nucleares y la gravedad operan en los límites de la física conocida. Varias observaciones recientes han abierto un nuevo camino para descifrar sus enigmas.

Una nueva propuesta para detectar ondas gravitatorias | Investigación y Ciencia | Investigación y Ciencia

Una nueva propuesta para detectar ondas gravitatorias | Investigación y Ciencia | Investigación y Ciencia





Detector de sobremesa

Un pequeño detector de ondas gravitacionales podría estudiar la materia oscura.

De los agujeros negros a la gravedad cuántica | Investigación y Ciencia | Investigación y Ciencia

De los agujeros negros a la gravedad cuántica | Investigación y Ciencia | Investigación y Ciencia





Descifrar la gravedad (presentación)

Una nueva técnica para medir la expansión del universo | Actualidad | Investigación y Ciencia

Una nueva técnica para medir la expansión del universo | Actualidad | Investigación y Ciencia





Una nueva técnica para medir la expansión del universo

El método, basado en el estudio de la radiación gamma emitida por galaxias distantes, aporta una pieza más a uno de los mayores rompecabezas de la cosmología actual: ¿cuánto vale exactamente la constante de Hubble?

Aceleración de la expansión cósmica | Actualidad | Investigación y Ciencia

Aceleración de la expansión cósmica | Actualidad | Investigación y Ciencia





¿Que no hay energía oscura? ¿Cómo que no?, dicen los cosmólogos

Un estudio ha puesto en entredicho la misteriosa fuerza antigravitacional conocida como energía oscura. Pero los cosmólogos han contraatacado.

¿Y si viviéramos en un universo asimétrico? | Actualidad | Investigación y Ciencia

¿Y si viviéramos en un universo asimétrico? | Actualidad | Investigación y Ciencia





¿Y si viviéramos en un universo asimétrico?

Un estudio sobre cúmulos de galaxias pone en duda uno de los postulados fundamentales de la cosmología moderna. No todos los expertos se muestran convencidos.

El mayor telescopio óptico de la Tierra | Investigación y Ciencia | Investigación y Ciencia

El mayor telescopio óptico de la Tierra | Investigación y Ciencia | Investigación y Ciencia





El mayor ojo del planeta

El Telescopio Extremadamente Grande observará el cosmos con un detalle sin precedentes, desde el sistema solar hasta las primeras estrellas del universo.

El universo como obra de arte | Investigación y Ciencia | Investigación y Ciencia

El universo como obra de arte | Investigación y Ciencia | Investigación y Ciencia





La armonía en las leyes de la naturaleza

El premio nóbel Frank Wilczek reflexiona en esta entrevista sobre la estética de las leyes naturales y sobre las principales incógnitas a las que se enfrenta la física fundamental en el siglo XXI.

Resuelto el problema de la galaxia sin materia oscura | Investigación y Ciencia | Investigación y Ciencia

Resuelto el problema de la galaxia sin materia oscura | Investigación y Ciencia | Investigación y Ciencia





¿Una galaxia sin materia oscura?

En 2018, un trabajo afirmó haber descubierto una galaxia carente de la sustancia invisible que permea el cosmos. Dos estudios recientes rebaten dicho resultado.

Las leyes físicas y la naturaleza de la realidad | Investigación y Ciencia | Investigación y Ciencia

Las leyes físicas y la naturaleza de la realidad | Investigación y Ciencia | Investigación y Ciencia





A las puertas de la realidad

¿Puede la física acercarnos a una comprensión verdaderamente fundamental del mundo?

En busca de agujeros blancos | Investigación y Ciencia | Investigación y Ciencia

En busca de agujeros blancos | Investigación y Ciencia | Investigación y Ciencia





En busca de agujeros blancos

Los agujeros blancos, hipotéticos astros que expulsarían materia sin absorberla jamás, podrían ser el destino último de los agujeros negros. Su detección abriría una ventana a la gravedad cuántica.

¿Puede haber agua en Plutón? | Investigación y Ciencia | Investigación y Ciencia

¿Puede haber agua en Plutón? | Investigación y Ciencia | Investigación y Ciencia





Colisiones en Plutón

Las simulaciones de un antiguo impacto refuerzan la idea de que el planeta enano posee un océano subterráneo.

Keen observer of crafts, Jyotsna Bhatt imbibed the traditional and the modern | Lifestyle News,The Indian Express

Keen observer of crafts, Jyotsna Bhatt imbibed the traditional and the modern | Lifestyle News,The Indian Express

ceramic artist, jyotsna bhatt, jyotsna bhatt dead, indianexpress,

Keen observer of crafts, Jyotsna Bhatt imbibed the traditional and the modern

JULY 12, 2020 4:05:24 AM
Known to be one of India's prominent ceramic artists, Baroda-based Bhatt breathed her last on July 11, two days after she suffered a stroke. She was 80.

Renowned ceramic artist Jyotsna Bhatt passes away | Lifestyle News,The Indian Express

Renowned ceramic artist Jyotsna Bhatt passes away | Lifestyle News,The Indian Express

ceramic artist, jyotsna bhatt, jyotsna bhatt dead, indianexpress,

Renowned ceramic artist Jyotsna Bhatt passes away

JULY 11, 2020 9:50:34 PM
Known to be one of India's best-known ceramic artists, Baroda-based Bhatt breathed her last on July 11, two days after she suffered a stroke.

Explained: The Kuaizhou-11 rocket, and China’s commercial space industry | Explained News,The Indian Express

Explained: The Kuaizhou-11 rocket, and China’s commercial space industry | Explained News,The Indian Express

Kuaizhou-11 rocket, China, China rocket launch, China Kuaizhou-11 rocket, China rocket, Indian Express

Explained: The Kuaizhou-11 rocket, and China’s commercial space industry

JULY 12, 2020 12:48:08 PM
Kuaizhou, meaning "fast ship" in Chinese, was operated by the commercial launch firm Expace, and was originally scheduled for 2018 after being developed three years earlier.

sábado, 11 de julio de 2020

Abell 2384: Bending the Bridge Between Two Galaxy Clusters | NASA

Abell 2384: Bending the Bridge Between Two Galaxy Clusters | NASA



Abell 2384: Bending 

the Bridge Between 

Two Galaxy Clusters

Abell 2384
Several hundred million years ago, two galaxy clusters collided and then passed through each other. This mighty event released a flood of hot gas from each galaxy cluster that formed an unusual bridge between the two objects. This bridge is now being pummeled by particles driven away from a supermassive black hole.
Galaxy clusters are the largest objects in the universe held together by gravity. They contain hundreds or thousands of galaxies, vast amounts of multi-million-degree gas that glow in X-rays, and enormous reservoirs of unseen dark matter.
The system known as Abell 2384 shows the giant structures that can result when two galaxy clusters collide. A superheated gas bridge in Abell 2384 is shown in this composite image of X-rays from NASA's Chandra X-ray Observatory and ESA's XMM-Newton (blue), as well as the Giant Metrewave Radio Telescope in India (red). This new multi-wavelength view reveals the effects of a jet shooting away from a supermassive black hole in the center of a galaxy in one of the clusters. The jet is so powerful that it is bending the shape of the gas bridge, which extends for over 3 million light years and has the mass of about 6 trillion Suns.
Last Updated: May 11, 2020
Editor: Yvette Smith

In Planet Formation, It's Location, Location, Location | NASA

In Planet Formation, It's Location, Location, Location | NASA



In Planet Formation, 

It's Location, Location, Location

Astronomers using NASA's Hubble Space Telescope are finding that planets have a tough time forming in the rough-and-tumble central region of the massive, crowded star cluster Westerlund 2. Located 20,000 light-years away, Westerlund 2 is a unique laboratory to study stellar evolutionary processes because it's relatively nearby, quite young, and contains a large stellar population.
The brilliant tapestry of young stars flaring to life resembles a glittering fireworks display in this Hubble Space Telescope im
The brilliant tapestry of young stars flaring to life resembles a glittering fireworks display in this Hubble Space Telescope image. The sparkling centerpiece of this fireworks show is a giant cluster of thousands of stars called Westerlund 2. The cluster resides in a raucous stellar breeding ground known as Gum 29, located 20,000 light-years away from Earth in the constellation Carina. Hubble's Wide Field Camera 3 pierced through the dusty veil shrouding the stellar nursery in near-infrared light, giving astronomers a clear view of the nebula and the dense concentration of stars in the central cluster. The cluster measures between six light-years and 13 light-years across.
Credits: NASA, ESA, the Hubble Heritage Team (STScI/AURA), A. Nota (ESA/STScI) and the Westerlund 2 Science Team
A three-year Hubble study of stars in Westerlund 2 revealed that the precursors to planet-forming disks encircling stars near the cluster's center are mysteriously devoid of large, dense clouds of dust that in a few million years could become planets.
However, the observations show that stars on the cluster's periphery do have the immense planet-forming dust clouds embedded in their disks. Researchers think our solar system followed this recipe when it formed 4.6 billion years ago.
So why do some stars in Westerlund 2 have a difficult time forming planets while others do not? It seems that planet formation depends on location, location, location. The most massive and brightest stars in the cluster congregate in the core, which is verified by observations of other star-forming regions. The cluster's center contains at least 30 extremely massive stars, some weighing up to 80 times the mass of the Sun. Their blistering ultraviolet radiation and hurricane-like stellar winds of charged particles blowtorch disks around neighboring lower-mass stars, dispersing the giant dust clouds.
"Basically, if you have monster stars, their energy is going to alter the properties of the disks around nearby, less massive stars," explained Elena Sabbi, of the Space Telescope Science Institute in Baltimore and lead researcher of the Hubble study. "You may still have a disk, but the stars change the composition of the dust in the disks, so it's harder to create stable structures that will eventually lead to planets. We think the dust either evaporates away in 1 million years, or it changes in composition and size so dramatically that planets don't have the building blocks to form."
The Hubble observations represent the first time that astronomers analyzed an extremely dense star cluster to study which environments are favorable to planet formation. Scientists, however, are still debating whether bulky stars are born in the center or whether they migrate there. Westerlund 2 already has massive stars in its core, even though it is a comparatively young, 2-million-year-old system.
Using Hubble's Wide Field Camera 3, the researchers found that of the nearly 5,000 stars in Westerlund 2 with masses between 0.1 to 5 times the Sun's mass, 1,500 of them show fluctuations in their light as the stars accrete material from their disks. Orbiting material clumped within the disk would temporarily block some of the starlight, causing brightness fluctuations.
However, Hubble detected the signature of such orbiting material only around stars outside the cluster's packed central region. The telescope witnessed large drops in brightness for as much as 10 to 20 days around 5% of the stars before they returned to normal brightness. They did not detect these dips in brightness in stars residing within four light-years of the center. These fluctuations could be caused by large clumps of dust passing in front of the star. The clumps would be in a disk tilted nearly edge-on to the view from Earth. "We think they are planetesimals or structures in formation," Sabbi explained. "These could be the seeds that eventually lead to planets in more evolved systems. These are the systems we don't see close to very massive stars. We see them only in systems outside the center."
Thanks to Hubble, astronomers can now see how stars are accreting in environments that are like the early universe, where clusters were dominated by monster stars. So far, the best known nearby stellar environment that contains massive stars is the starbirth region in the Orion Nebula. However, Westerlund 2 is a richer target because of its larger stellar population.
"Hubble's observations of Westerlund 2 give us a much better sense of how stars of different masses change over time, and how powerful winds and radiation from very massive stars affect nearby lower-mass stars and their disks," Sabbi said. "We see, for example, that lower-mass stars, like our Sun, that are near extremely massive stars in the cluster still have disks and still can accrete material as they grow. But the structure of their disks (and thus their planet-forming capability) seems to be very different from that of disks around stars forming in a calmer environment farther away from the cluster core. This information is important for building models of planet formation and stellar evolution."
This cluster will be an excellent laboratory for follow-up observations with NASA's upcoming James Webb Space Telescope, an infrared observatory. Hubble has helped astronomers identify the stars that have possible planetary structures. With Webb, researchers can study which disks around stars are not accreting material and which disks still have material that could build up into planets. This information on 1,500 stars will allow astronomers to map a path on how star systems grow and evolve. Webb also can study the chemistry of the disks in different evolutionary phases and watch how they change, and help astronomers determine what influence environment plays in their evolution.
NASA's Nancy Grace Roman Space Telescope, another planned infrared observatory, will be able to perform Sabbi's study on a much larger area.​ Westerlund 2 is just a small slice of an immense star-formation region. These vast regions contain clusters of stars with different ages and different densities. Astronomers could use Roman Space Telescope observations to start to build up statistics on how a star's characteristics, like its mass or outflows, affect its own evolution or the nature of stars that form nearby. The observations could also provide more information on how planets form in tough environments.
Sabbi's team's results appeared in The Astrophysical Journal.
The Hubble Space Telescope is a project of international cooperation between NASA and ESA (European Space Agency). NASA's Goddard Space Flight Center in Greenbelt, Maryland, manages the telescope. The Space Telescope Science Institute (STScI) in Baltimore conducts Hubble science operations. STScI is operated for NASA by the Association of Universities for Research in Astronomy in Washington, D.C.

Claire Andreoli
NASA's Goddard Space Flight Center, Greenbelt, Md.
301-286-1940
claire.andreoli@nasa.gov
Donna Weaver / Ray Villard
Space Telescope Science Institute, Baltimore
410-338-4493 / 410-338-4514
dweaver@stsci.edu / villard@stsci.edu
Elena Sabbi
Space Telescope Science Institute, Baltimore
sabbi@stsci.edu
Last Updated: May 29, 2020
Editor: Lynn Jenner

Lithium Comes From Exploding Stars | NASA

Lithium Comes From Exploding Stars | NASA



Lithium Comes From 

Exploding Stars

The element lithium has all kinds of uses on Earth: in lithium-ion batteries, in heat-resistant glass and ceramics, and in certain medications that psychiatrists prescribe. Now, a new NASA-funded study suggests that most of the lithium in our solar system — and even in the galaxy — came from bright stellar explosions called classical novae. 
Illustration of Hero Starrfield
Artist’s interpretation of the explosion of a recurrent nova, RS Ophiuci. This is a binary star in the constellation of Ophiuchus and is approximately 5,000 light-years away. It explodes roughly every 20 years when the gas flowing from the large star that falls onto the white dwarf reaches temperatures exceeding 10 million degrees.
Credits: Illustration by David A. Hardy
A classical nova happens when a white dwarf (a stellar remnant about the diameter of Earth, but the mass of the Sun) is orbited by a larger star. Gas falls from the larger star onto the white dwarf and when enough gas has accumulated on the white dwarf, an explosion, or nova, occurs. There are about 50 of these explosions per year in our galaxy, and the brightest ones are observed by astronomers worldwide.
Researchers led by Sumner Starrfield of Arizona State University, funded by a NASA theory grant, used a mixture of computer predictions and observational data to determine the amount of lithium produced in a nova explosion. The computer models estimated how gas is ejected in a nova and what its chemical composition should be. 
To develop these models, researchers referenced observations of classical novae from many different telescopes. Their previous work used ground-based telescopes, space telescopes including NASA’s Hubble and Spitzer, and the 747 airborne observatory SOFIA.
While the big bang created a small amount of lithium in the initial formation of the universe, the majority of lithium gets manufactured in the nuclear reactions that power the nova explosions. This study suggests that the nova explosions would then distribute that lithium throughout the galaxy, and deliver most of the lithium we use today in electronics and medicine. 
This new insight about lithium represents one piece of the puzzle that many astronomers are working on: Which kinds of stellar processes produce which elements.
The team also determined that a fraction of these classical novae will evolve until they explode as kind of supernova called type Ia. These exploding stars become brighter than a galaxy and can be discovered at very large distances in the universe. 
Type Ia supernovae have been used to study the evolution of the universe and were the supernovae used in the mid-1990s to discover dark energy, which is causing the expansion of the universe to speed up. These explosions also produce much of the iron in the galaxy and solar system, an important constituent of our red blood cells, which carry oxygen throughout the body.
“This is ongoing research in both theory and observations,” says Starrfield. “While we continue to work on theories, we’re looking forward to when we can use NASA’s James Webb Space Telescope and the newly named Nancy Grace Roman Space Telescope to observe novae and learn more about the origins of our universe.”  

Media Contact
Elizabeth Landau

NASA Headquarters, Washington, DC
Media Contact
Karin Valentine
Arizona State University
Last Updated: June 1, 2020
Editor: Tricia Talbert