Hello warstek friends, I hope you are given health. As we know that outer space is indeed a lot of interesting cosmic events to be studied. One of the cosmic events that occur is a star explosion. This star explosion is indeed one of the ways in which a star dies.
Star explosions are divided into several types depending on the specifications of the star itself. So what is it?
Nova
It should also be noted that Nova is different from a supernova. The point is that Nova is a star that is burning brightly again after previously being dead for years.
There is also a theory where a nova is a stellar explosion that occurs due to the interaction of two double star systems. In astronomy, there are many types of stars, one of which is a double star . Namely two stars that interact with each other because of the gravity of the two stars. However, these two stars do not collide and do not move away from each other. Usually, white dwarfs tend to be double stars
A white dwarf is the core of a star that is very small and quite hot compared to ordinary stars. White Dwarfs are also atoms of a dead star where they have used up all the existing fuel.
If one of the binary stars is a dwarf, the other begins to expand into a red giant. This is a phase of evolution towards the end of a star’s life before entering the white dwarf phase. At that time the white dwarf was able to pull material from the red giant star with its gravity. Now the material sucked by the white dwarf will become Hydrogen. If it reaches the hot white dwarf, then it will ignite and detonate a fairly large nuclear. The explosion is what we call Nova.
Supernova
Surely you are familiar with Supernova. A supernova is a stellar explosion that is bigger or more violent than a nova. Well, a supernova itself occurs when a large star runs out of fuel, a collapse that ends in an explosion. The explosion that occurred was so spectacular that it was called a supernova. This explosive event lasted for several weeks and was a rare occurrence. Simply put, a supernova is the process of the death of a massive star.
he name “supernova” itself is thought to have been coined by Walter Baade and Fritz Zwicky in a lecture at Caltech during 1931. It was used as a “super-Novae” in a journal paper published by Knut Lundmark in 1933, and in a 1934 paper by Baade and Zwicky.
Supernovae usually occur on average once every 50 years in a galaxy the size of the Milky Way. You could say a star can explode every moment or so in the universe. This includes not too far from Earth.
Supernova Types
Basically supernova explosions are basically divided into 2 types. But it can still be subdivided into several types depending on the mass of the star , as defined by Fritz Zwicky, namely:
- Type I supernova
This type of supernova occurs when a star steals matter from a nearby star until a nuclear reaction ignites. There is also a theory that this partner star could provide the white dwarf with enough mass for the white dwarf’s core to reach a critical density of 1.4 times the mass of the Sun. Thus, this results in the uncontrolled burning of carbon and oxygen, which triggers the star to explode.
Type I supernovae are subdivided based on their spectrum. One of them is type Ia which shows strong ionized silicon absorption lines. There is also a type I Supernova which is not so strong, so it is classified as type Ib and Ic. Type Ib exhibits a strong neutral helium line while Type Ic has none at all. The light curves are all similar, although type Ia is generally brighter at peak luminosity, but the light curve is not important for this classification of type I supernovae.
- Type II supernova
In this type, the star runs out of nuclear fuel and thereafter collapses under its own gravity. Usually this star is 5 – 10 times the size of the Sun. For this type of supernova, it is possible to form a black hole.
- Type III, IV, and V . supernovas
In addition to the 2 types of supernova, there are other types, you know. It is known that this was defined by Fritz Zwicky. It is very rare for this type of supernova which certainly does not meet the criteria of a type I or type II supernova. The only member of the Type III supernova is SN 1961i which is located at NGC 4303 as a prototype which is further classified as a Type II Supernova. Class IV is known to have the only member as well as prototype status, namely SN 1961f located at NGC 3003.
Type V class refers to SN 1961V located NGC 1058. Initially classified by Fritz Zwicky as a “Type V” supernova. However, it has been argued that SN 1961V was not a genuine supernova, but a super-explosion from a glowing blue variable star similar to Carinae.
Hypernova
Hypernova itself is basically a supernova. But the difference between the two is that the Hypernova has an explosion whose luminosity is 100 times higher than that of a supernova. Sometimes Hypernova is often called a super luminous supernova or superluminous supernova (SLSN) or Collapsar . Hypernova itself can occur from the collapse of a massive star population of 3 or the merger of 2 stars with a binary system.
Although it is not certain which process is appropriate. But what has been confirmed, is only the formation of black holes and the release of large amounts of energy in the form of gamma rays. Gamma rays are a very powerful form of light. These rays have about 10000 – 10 million more energy than the visible light.
Therefore, the current hypernova is equated with the term gamma-ray burst (GRB). GRB itself emits very strong electromagnetic radiation with a total energy much greater than a supernova. It should also be noted that the GRB was initially detected on July 2, 1967 by a US military satellite in high orbit, which at that time aimed to detect gamma radiation.
Kilonova
Ever heard of this term? Yep, a kilonova is a transient astronomical event that occurs in a compact binary system when two neutron stars or a neutron star with a black hole merge into one. A kilonova is about 1000 times brighter than a nova (but not brighter than a supernova). Neutron stars themselves are small objects measuring 20-40 km but very dense. To give that figure, 1 teaspoon of a neutron star would weigh 1 billion tons.
On August 17, 2017, a galaxy named NGC 4993, 130 light years away, baffled scientists. A unique explosion that confused them that they had never seen before. Namely the merger of two neutron stars detected by the gravitational wave observatories LIGO and Virgo. They call this “Kilonova”.
Until recently, LIGO observed gravitational waves from these colliding black holes billions of miles away. But this is the first time scientists have been able to witness electromagnetic radiation and gravitational waves during one event at a time. It should also be noted that GW170817 is the fifth detection carried out by LIGO.
There is a gravitational wave signal that lasts for up to 100 seconds starting with a frequency of 24 hertz. Covering about 3,000 cycles, which increases in amplitude and frequency to several hundred hertz. It’s packaged in the signature spiral chirp pattern.
Kilonova explosion itself identified can produce a variety of heavy elements. Examples such as gold and platinum in large enough quantities throughout the universe. It is estimated that heavy elements as much as 16,000 times the mass of Earth have formed after the Kilonova formed.
This cosmic event can provide the strongest evidence that collisions between neutron stars are the main cause of gamma-ray bursts with a fairly short duration.
Example of a Star Explosion
If previously explained the various types of star explosions in the universe. We will also explain several stellar explosions that have occurred in this universe with different explosive strengths. What are those?
- SN 2005ap, is a very high-energy and quite extreme Type II Supernova that occurred in the galaxy SDSS J130115.12+274327.5. This supernova is the brightest supernova explosion ever discovered. It is known that the supernova is 2 times brighter than SN 2006gy, and this includes Hypernova. The location of the occurrence is at a distance of 4.7 billion light years from Earth, so it is not visible to the naked eye. Its energy is equivalent to that emitted by all the stars in the Virgo supercluster of galaxies in one minute.
- GRB 080916C was a gamma-ray burst (GRB) that occurred on September 16, 2008 in the constellation Carina that was detected by NASA’s Fermi Gamma-ray Telescope. The explosion had the energy of about 5900 Type Ia supernovae exploding simultaneously. This also causes the gas jet to emit initial gamma rays to travel at a minimum speed of about 299,792,158 m/s (0.999999c). This makes this explosion the most extreme explosion ever recorded to date.
In addition to these galaxies, there are also MF83 and NGC5471B which are hypernova types, they are located in the spiral galaxy M101. There are also traces of hypernovae that were found in 2002 on M74 when one of the massive stars exploded. In addition there is also GRB 030329, which was seen in 2003 ago. This object is also known to have a spectrum that matches the characteristics of a hypernova. The GRB, which occurred at a distance of 2.6 billion light years, occurred in the constellation Leo area, which was observed by NASA’s High Energy Transient Explorer (HETE-II).
Closing
It should also be noted that Nova, Supernova, Hypernova and Kilonova are quite different from each other as described above. Maybe that’s all we have to say, thank you and hopefully it will be useful for all. Amen
Source :
- https://sciencealamonline.blogspot.com/2016/07/pengertian-nova-supernova-dan-hypernova.html
- https://www.infoastronomy.org/2017/10/mengenal-nova-supernova-hypernova-dan-kilonova.html
- https://astronesia.blogspot.com/2014/07/4-the-biggest-dan-terdahsyat-di.html
- https://www.guru Pendidikan.co.id/supernova/
- https://en.wikipedia.org/wiki/Supernova
- https://en.wikipedia.org/wiki/SN_1961I
- https://cthecosmos.com/2020/06/23/kilonov a/
- https://www. talk.co.id/septiani/beda-nova-supernova-hipernova-dan-kilonova/
Journal :