Every week, the TecMundo and #AstroMiniBR bring together five relevant and fun astronomical curiosities produced by the collaborators of the profile on twitter to spread the knowledge of this science that is the oldest of all!
#1: This is the furthest place on the planet from anything
O ponto mais inacessível da Terra!
Conhecido como Ponto Nemo, está localizado no meio do Oceano Pacífico e é o local mais distante de qualquer continente no planeta.
— Nícolas Oliveira (@nicooliveira_) June 29, 2022
Want to get away from everything and everyone on your next vacation? You couldn’t make a better choice of a place than Point Nemo!
Located in the middle of the Pacific Ocean and officially called the Point of Inaccessibility of the Pacific, the region is popularly known as Point Nemo in homage to the famous underwater sailor in Jules Verne’s novel Twenty Thousand Leagues Under the Sea. Its location is at coordinates 48°52.6’S 123°23.6’W and it is at an average distance of approximately 2,800 kilometers from any portion of land on the planet! The closest landmasses to the region are one of the Pitcairn Islands to the north, one of the Easter Islands to the northeast, and an island off the coast of Antarctica to the south.
The location is so isolated and people are so far away from it that the closest humans to Point Nemo aren’t even on Earth: astronauts aboard the International Space Station are about 408 kilometers from the Earth’s surface at any given time, and when they orbit over the region, become the closest humans there.
Also, due to the fact that there is practically no human, animal or plant life on the site, some Russian and European space agencies often use Point Nemo as a space graveyard for their satellite and rocket fragments.
#2: The portrait of a family night!
Saturno não coube na imagem (com lente 14mm na DSLR full frame), mas a Lua e todos os outros planetas do Sistema Solar posaram direitinho pra esse retrato de família. #AstroMiniBR pic.twitter.com/DgzWwJOEGy
— Projeto Céu Profundo (@CeuProfundo) June 27, 2022
The beautiful record above was made by the team of Projeto Céu Profundo, a collaborative initiative for dissemination and scientific education focused on Astronomy and citizen science projects. It shows all the planets in the Solar System, with the exception of Saturn: Mercury, Venus, Mars, Jupiter, Uranus and Neptune. The Earth, of course, is represented by the surface.
All the planets in the photo are practically aligned and this is not a coincidence. This is because all the planets orbit the Sun in an almost equal plane, called the ecliptic plane. When viewed from within this plane, as is the case for our observation, for example, all the planets appear confined to a single band.
It is a coincidence, however, when several of the brightest planets appear in almost the same direction and that was precisely the coincidence captured in the photograph above: the six planets and the Moon are highlighted along with a myriad of stars!
The photograph was taken on the 25th in the city of São José dos Campos.
#3: What is the end of life for the biggest stars in the Universe like?
Como as maiores estrelas morrem? É isso que essa equipe da Universidade do Arizona tenta resolver, observando VY Canis Majoris. O modelo clássico diz que elas explodem como supernovas, mas os novos dados mostram que isso não necessariamente acontece! #AstroMiniBR pic.twitter.com/Np7zswsful
— Thiago S Gonçalves (@thiagosgbr) June 28, 2022
All stars die when their nuclear fuel runs out, but the events that occur at the end of a star’s life are directly linked to its mass.
Medium-sized stars, roughly up to about 1.4 times the mass of our Sun, die beautifully but not as dramatically as larger stars. In the case of these stars, like our Sun, as their hydrogen is used up, they swell to become red giants, fusing helium in their cores, before shedding their outer layers and often forming what we call planetary nebula. The star’s core remains a “white dwarf” that cools over billions and billions of years.
Very massive stars use up their hydrogen fuel quickly, but are hot enough to fuse heavier elements like helium and carbon. Once there is no more fuel, the star collapses and the outer layers explode as a “supernova”. What is left after a supernova explosion is a neutron star, which is the collapsed core of the star or, if the star is massive enough, a black hole.
This is the classic scenario of stellar evolution, however, recent studies indicate other possibilities for the end of life of these titans where the stellar mass ejection occurs in a different way to a “traditional” supernova.
#4: A stellar jam
Os braços de galáxias espirais são como a Avenida Brasil às 18h.
As estrelas orbitam a sua galáxia hospedeira sem estar presos aos braços, e podem os atravessar. Os braços são como regiões com um grande engarramento de estrelas e gás. #AstroMinibr pic.twitter.com/RdMdEBiGVX
— Ana Carolina Posses (@astroposses) June 28, 2022
The spiral arm structure of spiral galaxies can be explained by the concept of density waves, in which the spiral pattern of the arms rotates at a certain angular frequency (standard speed), while the stars in the galactic disk are orbiting at a different speed depending on its distance from the center of the galaxy.
In this way, the arms of a spiral galaxy, made up of areas of higher density, are similar to a traffic jam on a highway: cars pass through the congestion, the density of cars increases in the middle of it, while the total flow of traffic cars, that is, the traffic itself, moves more slowly.
#5: How big is the Andromeda Galaxy in the sky?
A galáxia de Andrômeda ocupa uma área tão grande do céu (3º = 6 Luas Cheias) que mal dá pra ter noção do que o Hubble, com um campo de visão de 3 minutos de arco (1/10 da Lua Cheia) está observando. Os retângulos são alguns campos observados pelo Hubble na M31. #AstroMiniBR https://t.co/7oQjM7vvBk pic.twitter.com/zt7OwpeJHU
— Astronomia Dois ponto Zero (@AstronomiaDois) June 30, 2022
The huge and beautiful spiral galaxy Andromeda (also known as M31) is just 2.5 million light-years away from us and is another spiral galaxy closest to the Milky Way.
Andromeda is visible to the unaided eye as a small, faint, diffuse speck, but because its surface brightness is so low, casual observers cannot appreciate the galaxy’s impressive expanse in planet Earth’s sky. For comparison, Andromeda is about 6 times bigger than the Full Moon in the night sky!