Milky Way

Qual é a idade da Via Láctea? Space

Qual é a idade da Via Láctea?

Nossa galáxia natal contém até 400 bilhões de estrelas, e para cruzá-la seriam necessários 200.000 anos, mesmo à velocidade da luz. Um objeto tão grande (que é bastante médio em comparação cósmica) não surge da noite para o dia. Na verdade, a Via Láctea nasceu relativamente cedo - numa época em que o universo ainda era bastante jovem. Mas quando exatamente, e como você mede isso? Muito simplesmente, se você quer saber a idade de uma floresta, você determina a idade de suas árvores. As estrelas da Via Láctea não têm anéis anuais, mas com o aumento da idade…
The great barrier is real – for cosmic rays Astrophysics

The great barrier is real – for cosmic rays

The great barrier surrounding the core of the Milky Way is encountered in 2287 by the starship NCC-1701-A under the command of Captain James T. Kirk. Supposedly, it is impenetrable, and any ship that nevertheless dares to cross it will be destroyed. Kirk and his squad from the USS Enterprise prove the legend to be false. In fact, there is a kind of barrier around the galactic center - and this barrier is not an impenetrable wall. But, as astronomers have now discovered, it is an obstacle to cosmic rays. (mais…)
Even the core of the Milky Way gives birth to stars Astrophysics

Even the core of the Milky Way gives birth to stars

Since Star Trek V we know that the core of the Milky Way is a very special area. There is no galactic barrier there, but there is a gigantic black hole (Sagittarius A*) with the fields it produces and a lot of stars in a small space. With average distances of less than one light year the night sky of a planet must be very bright there. New stars are formed from clusters of gas and dust clouds. The process is disturbed when magnetic fields waft through it or passing stars deform the cloud with their gravitational pull. In…
Milky Way’s Family Tree Astrophysics

Milky Way’s Family Tree

From small to large: this is one of the possible ways in which structures are created in the universe. Galaxies like our Milky Way are formed when several small predecessor objects join together. But what exactly did the Milky Way form from? An international team of astrophysicists led by Dr. Diederik Kruijssen from the Center for Astronomy at the University of Heidelberg has succeeded in reconstructing the merging history of our home galaxy and creating its family tree. To this end, the researchers analyzed the properties of globular star clusters orbiting the Milky Way. Globular clusters are dense groups…
Milky Way vs. Andromeda: the collision has already begun Astrophysics

Milky Way vs. Andromeda: the collision has already begun

It’s inevitable that the Milky Way and the Andromeda Galaxy will one day collide and merge, even though right now there’s still 2.5 million light-years between them. Thus, the light that we see from Andromeda today was emitted from there 2.5 million years ago. The two most massive members of the Local Group are approaching each other at 120 kilometers per second. In three to four billion years (so while our Sun is still alive), up to 1.3 billion stars of the two galaxies will encounter each other. After another maybe three billion years, the merger will produce a…
How, not that long ago, the center of the Milky Way exploded Astrophysics

How, not that long ago, the center of the Milky Way exploded

Right now, despite its 4.2 million solar masses, Sagittarius A*, the gigantic black hole at the center of the Milky Way, appears to be a harmless, sleeping giant. But that wasn’t always the case. If one of our ancestors, Australopithecus, had been able to observe the skies over Africa 3.5 million years ago (thus, long after the extinction of the dinosaurs) just as intensively as we can, he might have been able to witness a gigantic, approximately 300,000-year-long explosion in the center of the Milky Way, which created conical bursts of radiation extending through both poles of the galaxy…
How our Milky Way was born Astrophysics

How our Milky Way was born

13 billion years ago, the universe looked quite different. Stars formed in rapid sequence and joined to form dwarf galaxies that grew bigger through collisions with each other, in order to finally become the massive galaxies we see today. Our Milky Way was formed through a similar process. Spanish researchers at the Instituto de Astrofísica de Canarias (IAC) have now succeeded in retracing the development of our home galaxy using data from the Gaia satellite. To do this, the astronomers compared the position, brightness, and distance of a million stars within a 6,500 light-year sphere. In this way, they…
How heavy is the Milky Way? Space

How heavy is the Milky Way?

How much does our home galaxy, the Milky Way, weigh? It’s not a very easy task to determine the true dimensions of an object when you live inside that object. Imagine trying to measure the size of your house while sitting at the kitchen table. On top of that, a large part of its mass is not even visible, because it’s dark matter. Scientists estimate there are about 100 to 300 billion stars in the Milky Way. That gives a visible mass of approximately 900 billion Suns at a diameter of 170,000 to 200,000 light-years. But the visible mass…