#AstroMiniBR: meet jellyfish galaxies!

Every week, TecMundo this #AstroMiniBR Bring together five interesting and fun astronomical curiosities produced by Twitter profile contributors to spread the knowledge of this oldest science!

#1: Ever heard of jellyfish galaxies?

Galaxy clusters are the largest gravitationally bound structures in the Universe, surpassed in size only by the vast cosmic web into which they are embedded. These systems contain hundreds to thousands of galaxies that come together due to gravitational interaction and can reach millions of light-years in size.

However, clusters of galaxies are not inviting environments for many galaxies: in addition to generating gravitational tidal forces strong enough to destroy some galaxies completely, clusters of galaxies have huge amounts of extremely hot gas that acts as a capable wind front. dust from an unfortunate galaxy moving towards you.

This phenomenon, known as drag pressure, produces jellyfish-like galaxies characterized by having “cosmic tails” produced by the interaction of galactic gas with the hot gas of the galaxy cluster. In the images above, you can see that the typically spiral-shaped galaxies have long blue filaments dotted with young stars that hang from the galactic disk and cause a jellyfish-like appearance moving in the ocean.

#2: A heavy element in the atmosphere of an exoplanet

Last Thursday (13), an international team of astronomers discovered the heaviest chemical element ever discovered suspended in the atmosphere of an exoplanet: barium.

Using data collected by the European Southern Observatory’s (ESO) Very Large Telescope (VLT), astronomers have detected chemical signals for the presence of barium in the upper atmosphere of two exoplanets, WASP-76b and WASP-121b. These planets are ultra-hot, Jupiter-like gas giants located approximately 640 and 900 light-years away, respectively, orbiting stars outside our Solar System.

These exoplanets have extremely high surface temperatures, often above 1000 °C, due to their orbits very close to their host stars. The big surprise is that the element barium, which is about two and a half times heavier than iron, quickly falls into the lower layers of the atmosphere because the planets’ gravity is so great. The discovery therefore raises intriguing new questions about how we understand planetary composition and dynamics.

#3: Estimating the amount of intelligent life in the Milky Way

The Drake equation is a mathematical expression that estimates the N number of technically advanced civilizations in the Milky Way as a function of other astronomical, biological, and psychological factors.

The equation, largely formulated by the American astrophysicist Frank Drake, was first discussed at a conference in the United States in 1961 on the search for extraterrestrial intelligence. The equation takes into account variables such as the average rate of star formation in the Galaxy, the number of planets ecologically suitable for the onset of life in such systems, the proportion of such planets where life evolves into an intelligent form. the average lifespan of these advanced civilizations. These numbers are little known and are often estimated based on different parameters, increasing the uncertainty of the estimate.

#4: Aurora australis in the southern hemisphere

Did you know there are auroras in the south? Called the aurora australis, the phenomenon is similar to the northern aurora borealis: spectacular phenomena with a variety of colors in shades of blue, red, yellow, green, and orange, creating a glowing image of natural light in the sky. curtains gently swaying in the atmosphere.

These phenomena can only be seen in the night sky and only occur in the polar regions of the planet. The activity that creates the aurora begins in the Sun from the emission of electrically charged particles (mostly free electrons and ions) that characterize what we call the solar wind. When the solar wind reaches the Earth’s periphery, it interacts with our planet’s magnetic field and “drains” these particles into the polar regions, where they interact with the light-producing molecules of the ionosphere.

#5: Cosmic dust shells

The latest image from NASA’s James Webb Space Telescope is a new perspective that reveals the striking details of binary star Wolf-Rayet 140’s structure in a new light.

The images show an unusual-looking diffraction pattern with almost concentric dust rings around the WR 140. are closest to each other and the stellar winds interact. The even spacing between the shells indicates that dust-forming events occur like clockwork.