Stars, the Storytellers

By Johina Maria

Photo by Denis Degioanni on Unsplash

​On a clear starry night, when you are gazing up at the multitude of stars that adorn the velveteen sky, do you realize that you are staring at a snapshot of the Universe from a distant past?

The stars that are cozying up in the comfort of the night sky, might not even exist now.
 
Light from the sun takes about 8 minutes and 20 seconds to reach the earth.  When you are looking at the sun, the sunspots, the eruptions, and the wild mechanics of the solar wind are about 8 minutes and 20 seconds old. So, what you see up in the sky is the past. 

Suppose there is another planet 10,000,000 light years from us teeming with intelligent life; when they look at us through a hypothetical telescope, they are not going to see the clutter of buildings or the glitter of traffic lights. They are going to see a Tyrannosaurus shuffling though dense coniferous jungles, pterodactyls flying across scrublands, and riparian forests and oceans teeming with ichthyosaurs, plesiosaurs, mosasaurs, and sea turtles. It would be like using a time machine.
 
Stars, inscribed with the memories of light, are the museum of our universe’s past telling a plethora of stories - some of which we have deciphered while some remain mysteries. Hidden behind the veils of time, they narrate the stories of their birth and death.  

​​The birthplace of stars are dust clouds called nebulae, which are pockets of dust and gas that have collapsed under their own weight. Out of these shriveled and shrinking masses of gas is born a baby star, known as the protostar. The interstellar dust keeps it safe and makes it hard to detect this little one.  
 
The baby star gains momentum and spins faster, and with increasing pressure, the temperature rises. Thus begins the next stage of its life as nuclear fusion begins at the core – this is the longest stage called the main sequence. Hydrogen is converted to helium, which releases a huge amount of energy, keeping the star burning hot and bright; the baby star is now in its youth.

​Our very own sun is a unique main sequence star, spreading joy, sunshine, and supporting life. 

A rapidly spinning neutron star (the ultra-dense core of the exploded star) is embedded in the center of the Crab Nebula, which is itself the remnant of a supernova. Credit:   NASA, ESA, J. Hester, A. Loll (ASU)

A corona mass ejection erupts from our sun. Photo by NASA on Unsplash

Towards the end of a star’s lifetime, hydrogen runs out, the pace of nuclear fusion slows, and the star cools down without the large amounts of energy keeping it bright. How long it lives depends entirely on how massive the star. For stars about the size of our sun, as hydrogen supply runs low, helium shrinks to the core, and they become red giants. When all the hydrogen is used up, the star contracts to its core and begins to fade into a white dwarf. 
 
Massive stars will go on using helium when they run out of hydrogen, the temperatures rising until ultimately they explode as supernovas. With this spectacular explosion, stellar material scatters into space, leaving behind a dense body called the neutron star. And just like any life, stars are born and then they die.

This image combines data from four space telescopes to create a multi-wavelength view of all that remains of RCW 86, the oldest documented example of a supernova, first witnessed in 185 AD. Image Credit: X-ray: NASA/CXC/SAO & ESA; Infared: NASA/JPL-Caltech/B. Williams (NCSU)

​But the story doesn’t end there as the remnants of these stars - carbon, nitrogen, and other heavier elements, which are thrown out into space – become the building blocks of life. We are forged from these elements manufactured in stars. We are truly made up of star stuff! 

We point our telescopes to the sky, capture starlight at all wavelengths and colors and wonder about their stories. If they are covered up by clouds of interstellar dust, we peer into them with infrared radiation, all to know who they are, what they are made up of, and the tale of how they came to be.
 
We study the stars’ light, and by how bright they are, we know how far away they are and how old they are. Our star-manufactured-selves stare out at the night sky and ponder about these beings and try to infer their unique stories. 
  
Although stars are always twinkling, some stars change their brightness over time. Their outer surface can expand with pressure, causing an increase in brightness, and then shrink like a deflated balloon, decreasing in brightness, not to be seen until they shine once again. 

Like humans, some stars traverse the universe along with their companions. They share their orbits with a companion star, sometimes even sharing material with the other. Low-mass stars that pipe in materials from their higher-mass companions are infamously dubbed as vampire stars. We also have zombie stars (the remnants of a supernova explosion) return to life by feeding on higher mass stars, thus transforming into vampire stars themselves. From our backyard, some stars appear thick as thieves, neighbours on a distant shore, all because they fall along our line of sight. In reality, they are millions of light years apart destined never to meet along the same cosmic coast.

This illustration shows a newly discovered dwarf nova system, in which a white dwarf star is pulling material off a brown dwarf companion. Credits: NASA and L. Hustak (STScI)

Scientists study age-old globular star clusters hoping to find a glimpse of how the universe came to be – yet another story to be told. In the thousand lights that flicker above and under our planet, each traveling star lives a profound life that is strangely chaotic, poignant and as complex as our own. The sky is full of stories, most of which we will never know. ​

Photo by Ken Cheung on Unsplash

Johina Maria

An Astrophysicist from God's own country, Kerala, Johina has a voracious appetite for books, poetry and music. She is forever minting away words at her blog 'Love by the Moon', where you can find her poetry and random ramblings about life. Settled in Dubai, she is working at AUS, Sharjah as a research assistant in Stellar Astrophysics. She is also working as a teacher bringing STEAM into classrooms where she hopes to highlight the integration of Art and Astronomy in STEM education.