How Do Supernova Remnants Form and Affect the Universe?
When a really large old star runs out of fuel, the fabric that's left collapses inwards. The temperature at the centre of the star increases by millions of degrees and finally, it explodes in a supernova. The light from a supernova can be up to around twenty times brighter than the light from the original stars. Supernova remnant is nothing but just an outcome of the explosion of the star in a supernova. The supernova remnant is also abbreviated as SNR by many cosmologists.
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The study of supernova itself is an interesting concept that will lead us to understand how the stars were created and the many structures such as supernova remnants that lead us to the information of the nuclear explosion in the stars. In this article, we will discuss supernovas and the supernova remnant along with this Tycho supernova, vela supernova and Vela supernova remnant in detail.
Tycho Supernova:
Tycho supernova is also known as the death of the star. In the year 1572, a danish renowned astronomer Tycho Brahe (Who is the very first astronomer to detect a comet) was among those that had noticed a replacement bright object within the constellation Cassiopeia. Adding fuel to the intellectual fire that Copernicus initiated, Tycho Brahe demonstrated this new star was way far beyond the Moon, which it had been possible for the universe beyond the Sun and planets to change or transit.
Astrophysicists now know that Tycho Brahe’s new star wasn't new in the least. Rather it signalled and opened the door for the most interesting aspect known as the death of a star in a supernova, an explosion so bright that it can outshine the light radiation from an entire galaxy. This particular supernova was quite a different one, which occurs when a white dwarf star pulls material from or merges with a close-by companion star until a violent explosion is triggered. The white dwarf star is obliterated, sending its debris hurtling into space in all directions.
In its 20 years of operation, NASA’s Chandra X-ray Observatory has successfully captured unparalleled X-ray images of the many supernova remnants.
NASA’s Chandra reveals an intriguing pattern of bright clumps and fainter areas in the Tycho supernova remnant. What caused this thicket of knots within the aftermath of this enormous explosion? Was the huge explosion itself the reason behind this clumpiness, or was it something that happened afterwards?
The latest images captured the Tycho supernova from NASA’s Chandra is providing us clues. To emphasize the clumps in the image and the three-dimensional nature of the Tycho supernova, astrophysicists selected two narrow ranges of X-ray energies to isolate material (silicon, coloured red) moving away from Earth, and moving towards us (also silicon, coloured blue). The other colours (wavelengths) within the image (yellow, green, blue-green, orange and purple) show a broad range of various energies and elements and a mix of directions of motion. In this new composite image, Chandra’s X-ray data are combined with an optical image of the celebs within the same field of view from the Digitized Sky Survey.
Vela Supernova:
We know that the Moon is the biggest celestial object in the night sky that’s visible to the naked eye. But there are many objects that are too faint to see even though they are much larger than the moon. An ideal example is a nebula in the constellation Vela, its size is about 16 times the width of the Moon i.e., almost the size of your fist held at arm’s length. And it’s getting larger all the time.
The Vela Supernova Remnant is 800 about light-years away. It was born almost 11,000 years ago as observed from the Earth, when a supergiant star exploded releasing tremendous light energy, blasting its outer layers into space in all directions. As those layers run into the surrounding clouds of gas and dust, they glow and appear to be a bunch of huge light radiations striking. If we look across the entire electromagnetic spectrum, starting from the radio waves to X-rays, the nebula appears more or less like a mound of billowing clouds.
When the star inflated and exploded into space, the outer layers were expelled at up to a certain per cent of the speed of light. So over time, the nebula has inflated to a diameter of around more than a hundred light-years. And an interesting fact is that it’s still expanding at the rate of more than two million miles per hour.
The rate of inflation of the nebula is one way in which astrophysicists determine when the star exploded. Another is the star’s outermost core, known as a neutron star. It spins rapidly in such a way that it will be emitting pulses of energy with each turn. Determining how quickly it’s slowing down gives a rough estimate of when the neutron star was formed, it will inform us when the actually massive star died or the exact time of the star's death.
The Vela Supernova Remnant is in the region of Vela, the sails, which hugs the southern horizon at nightfall. The nebula is sufficiently large but faint, thus it is difficult to detect with the naked eye and we need a good telescope to observe it.
The Vela supernova remnant (SNR) is found to be one of the closest supernovae to the earth. The Geminga pulsar is even more closer (and also resulted from a supernova) and in the year 1998 another supernova remnant was discovered which was also found to be one of the closest ones to the earth, RX J0852.0-4622, according to which our point of view appears to be contained in the southeastern part of the Vela remnant. One estimate and determine its distance and it is found to be only around 200 parsecs away (which makes around 650 ly), even more closely than the Vela remnant, and, surprisingly, it appears to have exploded much more recently, around the last thousand years, because it is still radiating gamma radiation from the decay of titanium-44. This remnant was not observed earlier because, in most wavelengths, it is lost because of the presence of the Vela remnant.
Fun Facts:
Our universe tells us so many things. Somewhere in the cosmos or space, a star might be reaching the end of its life. Or maybe it is a massive star, collapsing under the effect of its own gravity. Or maybe it’s a dense cinder of a star, greedily gathering matter from a companion star until it can not handle its own mass and the reason for the death of the star goes on.
Whatever might be the reason, this star does not actually fade quietly into the dark fabric of space and time (space-time dimension). It goes inflating, exploding its stellar guts across the universe in all dimensions, this reaction will leave us with unparalleled brightness and a tsunami of particles and elements. It becomes a supernova after the death of the star. There are many interesting facts regarding supernovae, few are as mentioned here:
1. The Oldest Observed Supernova Dates are Almost Back in Around 2000 Years:
In 185 AD, Chinese astronomers observed a bright light in the sky. Documenting their observations and the measurements in the Book of Later Han, these ancient astronomers note with the keen observation that it is sparkling like a star, and it appeared to be half the size of a bamboo mat and did not travel through the sky like a comet. Over the next eight months, this celestial visitor slowly faded and appeared to have fainted from sight. They named it a guest star.
2. Many of the Chemical Elements Were Made of Coming from Supernovae:
Everything starting from the oxygen we are inhaling and breathing to the calcium in our bones, the iron in our blood and the silicon in our computer was brewed up in the heart of a star.
3. Supernovae are Neutrino Factories:
In a short time period of 10-second, a core-collapse supernova will release a tremendous burst of more than 1058 neutrinos, many ghostly particles that can actually travel undisturbed through almost everything in the universe and in every direction. Outside of the outermost core part of a supernova, it would take around a light-year of lead to stop a neutrino. But when a star inflates and explodes, the centre of it can become so dense that even the neutrinos take a little while to escape. When the neutrinos actually made an escape, neutrinos carry away 99 per cent of the energy of the supernova.
FAQs on Supernova Remnant: Definition, Types & Significance
1. What exactly is a supernova remnant (SNR)?
A supernova remnant (SNR) is the structure resulting from the gigantic explosion of a star in a supernova. It consists of the material ejected by the explosion, expanding at thousands of kilometres per second, and the interstellar material it sweeps up and shocks along the way. Essentially, it's the aftermath and leftover cloud of a star's death.
2. What are some famous examples of supernova remnants that we can observe?
Some of the most well-known and studied supernova remnants include:
- The Crab Nebula (M1): The result of a supernova observed by Chinese astronomers in 1054 AD. It is powered by a rapidly spinning neutron star, or pulsar, at its centre.
- Cassiopeia A (Cas A): One of the brightest radio sources in the sky and a relatively young SNR in our galaxy.
- The Veil Nebula: A large, intricate remnant in the constellation Cygnus, known for its beautiful, delicate filamentary structures.
3. What are the different components that make up the remains of a supernova?
The remains of a supernova consist of two main parts:
- The Supernova Remnant (SNR): This is the expanding, glowing shell of gas and dust (ejecta) that was the star's outer layers. This material is superheated and enriched with heavy elements created during the explosion.
- The Compact Object: At the centre of the explosion, the core of the massive star collapses into an extremely dense object. This can be either a neutron star or, if the original star was massive enough, a black hole.
4. How is a supernova remnant different from a planetary nebula?
While both are shells of gas from dying stars, they originate from very different processes. A supernova remnant is formed from the violent, explosive death of a high-mass star. In contrast, a planetary nebula is formed when a low-to-medium mass star, like our Sun, gently sheds its outer layers as it runs out of fuel and becomes a white dwarf. Supernova remnants are far more energetic and expand much faster than planetary nebulae.
5. Is a supernova remnant considered a type of nebula?
Yes, a supernova remnant is a specific type of emission nebula. The term 'nebula' is a general name for any interstellar cloud of gas and dust. A supernova remnant is categorised as an emission nebula because the gas within it glows, energised by the shockwaves from the initial explosion and the radiation from the compact object left behind.
6. Why isn't a white dwarf considered a remnant of a supernova?
A white dwarf is not a remnant of a supernova because it is the end-product of a completely different stellar life path. Low-mass stars (like the Sun) are not massive enough to explode as supernovae. Instead, they run out of fuel, swell into red giants, and then peacefully shed their outer layers to form a planetary nebula, leaving behind their dense core as a white dwarf. Supernovae only happen to stars at least eight times more massive than our Sun.
7. What happens to a supernova remnant over time, and how long can it last?
A supernova remnant evolves through several phases. Initially, it expands freely. Then, it sweeps up a significant amount of interstellar gas, creating a powerful shockwave. Over tens of thousands of years, it continues to expand and cool, gradually slowing down and mixing with the surrounding interstellar medium. A supernova remnant can remain visible and distinct for about 50,000 to 100,000 years before it completely disperses and merges into the galaxy.
8. Why is it important for scientists to study supernova remnants?
Studying supernova remnants is crucial for several reasons. They are the primary source of heavy elements (like oxygen, iron, and gold) in the universe, which are essential for forming new stars, planets, and even life. The shockwaves from SNRs can also trigger the collapse of nearby gas clouds, initiating the birth of new stars. They are cosmic laboratories for understanding high-energy physics and the life cycle of stars.
