NOT ALONE? - Our galaxy contains 100 billion planets: Study - INDIA

 

URL copied to clipboard

	Contrary to previous belief, the latest research by astronomers suggests star systems with planets are actually the norm across the cosmos. WASHINGTON: Our galaxy contains at least 100 billion planets - approximately one for every star - and many of them could harbour life, a new study claims. Contrary to previous belief, the latest research by astronomers suggests star systems with planets are actually the norm across the cosmos. Astronomers at the California Institute of Technology made their estimate while analysing planets orbiting a star called Kepler-32 - planets that are representative of the vast majority of planets in our galaxy, NASA said. "There are at least 100 billion planets in the galaxy, just our galaxy," said John Johnson, assistant professor of planetary astronomy at Caltech and co-author of the study. "That's mind-boggling," said Johnson in a statement. "It's a staggering number, if you think about it. Basically, there's one of these planets per star," added Jonathan Swift, lead author of the study. One of the fundamental questions regarding the origin of planets is how many of them there are. Like the Caltech group, other teams of astronomers have estimated that there is roughly one planet per star, but this is the first time researchers have made such an estimate by studying M-dwarf systems, the most numerous population of planets known. The planetary system in question, which was detected by NASA's Kepler space telescope, contains five planets. Two of the planets orbiting Kepler-32 had previously been discovered by other astronomers. The Caltech team confirmed the remaining three, then analysed the five-planet system and compared it to other systems found by Kepler. M-dwarf systems like Kepler-32's are quite different from our own solar system. For one, M dwarfs are cooler and much smaller than the Sun. Kepler-32, for example, has half the mass of the sun and half its radius. The radii of its five planets range from 0.8 to 2.7 times that of Earth, and those planets orbit extremely close to their star. The whole Kepler-32 system fits within just over a tenth of an astronomical unit (the average distance between Earth and the Sun) - a distance that is about a third of the radius of Mercury's orbit around the Sun. The fact that M-dwarf systems vastly outnumber other kinds of systems carries a profound implication, according to Johnson, which is that our solar system is extremely rare.

 

 

 

 

UNIVERSE II - IMAGEN DE UNA GALAXIA

La imagen más detallada de una galaxia

Impresión artística del cuásar 3C 279. | ESO

Un equipo internacional de astrónomos ha observado el corazón de un cuásar distante con una precisión dos millones de veces mayor que la del ojo humano. Se trata de una imagen sin precedentes de una galaxia, la más detallada lograda hasta ahora, que es posible gracias a la conexión de tres telescopios en distintos lugares de la tierra.

Los astrónomos conectaron el telescopio 'APEX' (Atacama Pathfinder Experiment) ubicado en Chile con el conjunto 'Submiliter Array' (Hawái, EE.UU) y el 'Submiliter Telescope' (Arizona, EE.UU). Han obtenido una imagen precisa del cuásar 3C 279, que contiene un agujero negro supermasivo con una masa de alrededor de mil millones de veces la del Sol.

Estas observaciones son un paso crucial para la obtención de imágenes de la sombra de agujeros negros supermasivos tanto del centro de nuestra galaxia, la Vía Láctea, como de otras galaxias. La sombra — una región oscura vista en contraste con un fondo más brillante — está causada porque la luz se dobla a causa del agujero negro, y sería la primera evidencia observacional directa de la existencia de un horizonte de sucesos en un agujero negro, la frontera a partir de la cual ni siquiera la luz puede escapar.

Los telescopios se conectaron con la técnica conocida como interferometría de base ancha (VLBI, por sus siglas en inglés), la cual ha posibilitado la precisión de las observaciones. Esto permite que múltiples telescopios actúen como uno solo, tan grande como la distancia que los separa.

En el futuro se prevé conectar aún más telescopios con el objetivo de crear el Telescopio de Horizonte de Sucesos, que es el que permitiría obtener las imágenes de los agujeros negros supermasivos de las galaxias.

La imagen de esta cuásar posee una nitidez nunca antes conseguida. La técnica de conexión ha permitido distinguir detalles con una resolución dos millones de veces mayor que la que obtendría el ojo humano.

'APEX' es el mayor telescopio utilizado en el proyecto y es el resultado de la colaboración entre el Instituto Max Planck de Radioastronomía, el Observatorio Espacial de Onsala y el Observatorio Austral Europeo (ESO, por sus siglas en inglés). Este, ubicado en Chile a 5.000 metros de altitud en los Andes chilenos, participa por primera vez en una observación VLBI y supone la culminación de tres años de trabajo para la ubicación del telescopio.

El telescopio 'APEX' es importante también por otros motivos. Comparte ubicación y numerosos aspectos relacionados con su tecnología con el nuevo conjunto de telescopios 'ALMA' (Atacama Large Millimeter/submillimeter Array), aún en construcción y que contará con 54 antenas de 12 metros de diámetro. Se está estudiando la posible conexión de 'ALMA' a la red, lo que aportaría una sensibilidad 10 veces mayor que las de las pruebas iniciales. Este sería el paso definitivo para que la sombra del agujero negro de la Vía Lactea sea accesible en futuras observaciones.

SCIENCE - BRAZIL / USA

Sun will survive the collision of the milky way

 

with Andromeda

 

Hubble data with simulation shows how shock will affect our cosmic neighborhood

Simulation shows how appears the night sky on Earth early in the merger of the milky way with Andromeda Galaxy, 4 billion years from now Nasa

RIO – Nasa Astronomers used the Hubble space telescope data to simulate a more extreme events that our cosmic neighbourhood will pass, the shock of the milky way with Andromeda Galaxy (M31), expected to happen in a 4 billion years. According to the models, the Solar System and Earth must survive the crash, but probably will be cast to a new region of space.

-Our findings are statistically consistent with a front collision between Andromeda and our Milky Way – Roeland van der Marel said, of the Space Telescope Science Institute (STScI), which manages the Hubble.

The simulation was possible after detailed data analysis on space telescope Andromeda movement. The Galaxy today is approximately 2.5 million light years away, but progresses rapidly toward the milky way due to mutual gravitational attraction. The oyster model still you will need other 2 billion years for the two galaxies will unite completely, leaving behind their formats spirals and becoming a huge elliptical galaxy.

-After almost a century of speculation about the future fate of the Andromeda Galaxy and the milky way, finally we have a clear scenario of how events will unfold over the next few billion years – told Tony Sohn, also of Sangmo STScI.

Although the galaxies into shock, the stars within them are so widely separated from the others that they should not impinge on the meeting. Despite this, they are thrown into new orbits around the new Galactic core and simulations indicate that our Solar system is likely to be released for further away from it than it is currently. To make things even more complicated, however, the Triangulum Galaxy (M33), Andromeda, dwarf companion will join the collision and probably merge to Andromeda-Milky Way Galaxy pair. There is still a small chance of M33 with the milky way collide before Andromeda.

Leia mais sobre esse assunto em http://oglobo.globo.com/ciencia/sol-sobrevivera-colisao-da-via-lactea-com-andromeda-5093625#ixzz1wdNjLVdl