The Cosmic Talk #3

Hey nerd! Welcome back to The Cosmic Talk. In this edition, we will be covering some recent studies that dive deep into some epic spacey topics, and discuss one of the biggest achievements mankind has ever made.

On October 7th, 2019, a paper touching on the properties of Super Spiral Galaxies was released, and as it turns out, they spin so fast that they shouldn’t be able to exist. Similar to a traditional spiral galaxy, like our own Milky Way, or our neighbor Andromeda, a Super Spiral Galaxy, was discovered in 2016. What makes it so “super”, is the galaxies colossal size, having almost 10x more mass and producing way more light than that of a normal spiral galaxy. So far, we’ve discovered only 100 of these galaxies. Unlike other galaxies that have a rotation curve, which defines the speed of stars orbiting around the center of the galaxy, theirs tend to be much faster than they should, to a point that they shouldn’t be able to exist. The stars double, almost triple their speed, orbiting roughly around 220 km/s. So what makes it possible for the galaxies to stay intact? All of these galaxies have a tremendous amount of dark matter inside of them. Dark matter allows these stars to spin really fast without falling apart, holding these galaxies together. This further proves the mysterious dark matter’s existence.

For each Super Spiral Galaxy, their galactic halos (an extended, roughly spherical component of a galaxy which extends past the main, visible component) are extremely large. Their size is equivalent to a typical dark matter halo in an actual galactic structure. This helps suggest that these galaxies are formed by having several galaxies combine together, and the dark matter begins to form a bubble around them.

This spectacular galactic formation could be the future of our own Milky Way 10 billion years from now, based on what we know now about galaxy evolution. But, the most important thing we’ve discovered to come out of our studies of Super Spiral Galaxies is the proof of dark matter. Super Spiral Galaxies tend to have less star formation within them, which is suggested to be caused by the extreme amounts of dark matter and the gravitational power they have, and the fact of the speed and motion of the gas, being too fast for stars to form. Whether or not we ever know the truth about these mysterious galaxies, they’re still an amazing discovery nonetheless. 

On October 9th, another paper was published, discussing information about Magnetars, extremely powerful neutron stars with a powerful magnetic field, and most importantly, their origins. To give an example of how powerful a Magnetar truly is, if one was placed 100 km from earth, every life process in your body would immediately stop working, and you would cease to exist.

What makes a Magnetar so different from a neutron star is how fast they normally spin. Magnetars typically spin up to one time per second, if not sometimes faster. These extreme speeds is what gives the Magnetar it’s powerful magnetic field. They also tend to produce more gamma rays and x-rays (powerful radiation) than a neutron star. 

Magnetars don’t have a very long life span. Normally, they live for around 10,000 years before becoming a regular neutron star. This helps to explain why there are so few living in the universe, only 30 million in our galaxy, which is not a lot compared to the grand scheme of things. 

For a long time, we’ve questioned the origin of these mysterious stars. Computers were never powerful enough to test the ideas we had of how the stars came to be, but now the technology has advanced enough, we finally have a better idea of where they come from. It is hypothesized that these stars are the outcome of a collision between two very massive stars, that of which forms one gigantic star. This star is a very unusual, very magnetically powerful star known as a Blue Straggler. Most Blue Stragglers are most commonly found in globular clusters, a spherical cluster of stars that orbits a galactic core. There they live out their life, drawing close to the globular cluster’s center, and with time, they die and go supernova, then becoming a Magnetar. 

These happenings are quite rare, so it’s unlikely we’ll ever catch one in our lifetime to have a better idea of what the truth is, but such a theory is still something to geek out over, and makes for something interesting to learn more about.

For our last topic, we’ve had a suggestion made by a reader to cover something quite extraordinary, the Voyager Mission, and the success that Voyager 2 made quite recently in the beginning of this month. Voyager 2 has left our solar system and reached interstellar space, making it the second ever spacecraft to do so, the first being it’s sibling Voyager 1 making the same achievement in 2012. 

Voyager 2 was launched in 1977 and performed the first flybys ever of Uranus and Neptune, taking a different path than that of its sibling when they diverged while passing Saturn. 

Voyager 2 was also the first spacecraft to ever sample plasmas. The data collected by both of the probes were very similar, such as the density of the particles; though, Voyager 2 did notice a few different things that had scientists questioning the sun’s movement through our galaxy.

The sun creates a breeze of electrically charged particles because of its magnetic field. This is known as a Solar Wind. The winds can travel in all directions, taking its magnetism with it as it enters the interstellar medium. These two things don’t mix, and instead form a bubble called a Heliosphere that extends 11 billion miles outward from the sun, protecting us from outside radiation. The outermost edge of this bubble is called the Heliopause, which is the boundary between us and interstellar space. The Heliopause has what you could call a “leaky border”, letting the two winds mix at the boundary between the bubble and the interstellar medium. When the Voyager 2 passed through, it saw a ton of low energy particles, 100 million of them, that had passed through the Heliopause, and the Voyager 1 noticed a good amount of interstellar particles floating about the Heliosphere as well. The Heliosphere’s shape is also still a mystery. We predict that it is spherical, due to the pressure exerted by the interstellar medium, but there certainly could be other possibilities.

Interstellar space was a lot stranger than we thought, proving some of our previous predictions wrong. As it turns out, particles exert 10x more pressure in interstellar space than previously thought. Voyager 2’s instruments to measure temperature, because Voyager 1 was broken, were able to detect that it is also much hotter than what we expected, at about 54,000 degrees Fahrenheit. 

These discoveries and achievements are certainly exciting in the world of astronomy, introducing new ideas of the universe, furthering our understanding, and proving the abilities of humankind. Super Spiral Galaxies, Magnetars, and Voyager 2, all things that us nerds can definitely be excited about, leaving us to wonder what will be next. This has been The Cosmic Talk, until next time!