#AstroMiniBR: Explore the galactic quarter of the Milky Way

Every week, TecMundo and #AstroMiniBR brings together five relevant and entertaining astronomical curiosities produced by the world’s collaborators. profile on twitter to spread the knowledge of this science, which is the oldest!

#1: Space junk in Brazil

On March 16 of this year, a couple found a very strange and completely unusual object on the land of their rural property: a large piece of bent metal about four meters long. It was located in the city of São Mateus do Sul in the state of Paraná and immediately created a mystery about its origin.

The piece was then forwarded to experts at the Brazilian Space Agency (AEB), who published their analysis results yesterday (06/02): the structure is most likely debris from SpaceX’s billionaire Falcon 9 rocket. elon musk. The object has been in orbit since 2015, when Falcon 9 launched into space and ran out of fuel to return to Earth’s surface. Since then, some of its wreckage has morphed into lower and lower orbits until it re-entered the atmosphere.

Experts from the AEB, as well as from the BRAMON (Brazilian Meteor Observation Network), believe that the object is part of the rocket engine nozzle, is made of a metallic alloy of titanium and niobium, and is therefore resistant to very high temperatures.

#2: Galactic Quarter of the Milky Way

Considering astronomical scales in our distance measurements, few things make you feel lonely. This is because even individual objects millions, billions, or even trillions of kilometers away, such as stars, planets, and galaxies, are close to something on larger scales.

For example, the closest star to the Sun is about 4.2 light-years away. While this value becomes much more impressive if we consider even larger scales such as intergalactic dimensions and distances, it is still small compared to some other distances.

with our galaxy, Milky Way, same happens. Solitary, if observed individually, has a large number of neighbor friends located in the same gravitational influence zone in the Universe, called the Local Group. The Local Group consists of 54 galaxies that include the famous Andromeda galaxies and the Small and Large Magellanic Clouds. All of these combined galaxies are about 10 million light-years across and are part of an even larger structure called the Virgo Supercluster!

#3: A double couple

At first glance, Beta Cygni is a single bright star visible to the naked eye in the constellation Cygnus. About 420 light-years from the Solar System, a more detailed view through the eyepiece of a small telescope is sufficient and will show what it’s hiding: another nearby star, making it a nice binary pair (at least in hypothesis, since they could also be an optical pair, so just they are close from the visual perspective of the observer).

For this reason, Beta Cygni is also known as Albireo AB to signify the existence of the two stars that make it up. The above image highlights the color difference of both stars and arranges them together with the visible spectrum associated with that starlight.

From these spectra it is possible to deduce that Albireo A has the typical features of a giant K-type star that is cooler than the Sun. Albireo B has the spectrum of a main sequence star much hotter than the Sun!

#4: Why is sunset usually reddish?

We’ve all seen the sun set or rise on the horizon at least once in our lives. As we know, these beautiful shows are accompanied by typical lights in red and orange tones in the sky.

But do you know why this is?

This answer comes from the physical phenomenon known as Rayleigh scattering, and here’s why: At the beginning and end of the day, the Sun is very low in the sky, very close to the horizon, which means that the light it emits travels. in a much thicker atmosphere until it reaches our eyes.

Because blue light is more strongly scattered by the atmosphere, it tends to scatter and deviate several times before reaching us. This means that there are relatively more shades of yellow, orange and red for us to see!

#5: A meteor mosaic!

Meteorites entering Earth’s atmosphere, giving rise to popular shooting stars, are not uncommon events. Quite the contrary: the Earth is bombarded every day by hundreds of tons of interplanetary debris and space rocks circulating in our Solar System.

The image above presents a beautiful mosaic of a series of photos recorded by NASA of a meteor shower that occurred between April and May 2013. Known as Eta Aquarids, this rain is caused by space debris left by the transit of Halley’s comet. !