[ad_1]
Cosmic mystery SOLVED after 900 years: Supernova first spotted over China in 1181 identified as Pa30 – a nebula surrounding one of the hottest stars in the Milky Way
- Astronomers have solved a 900-year-old mystery about the origins of a supernova
- It was first seen over China in 1181, visible for six months and as bright as Saturn
- A weak, rapidly expanding nebula called Pa30 is now identified as the source of the explosion
- Experts say Pa30 matches the profile, location and age of the 12th century supernova
A 900-year-old cosmic mystery surrounding the origins of a supernova first spotted over China in 1181 has finally been solved.
A weak, rapidly expanding nebula called Pa30 was identified as the source of the 12th-century explosion, which Chinese and Japanese astronomers said was as bright as the planet Saturn and remained visible for six months.
Experts have said that Pa30, which surrounds Parker’s star – one of the hottest stars in the Milky Way – matches the profile, location and age of the historic supernova.
Astronomers have solved a 900-year-old mystery surrounding the origins of a supernova first spotted over China in 1181. A faint nebula called Pa30 (shown in three different images with colors showing emission of rays X) has been identified as the 12th century explosion the source
There have only been five brilliant supernovae in the Milky Way over the past millennium, including the famous Crab Nebula, but the origins of all of them except the “Chinese Guest Star” are well known.
Although 12th century astronomers recorded an approximate sky location from the 1181 sighting, no confirmed vestiges of the explosion have been identified so far.
The discovery was made by a team of international astronomers from Hong Kong, the United Kingdom, Spain, Hungary and France.
In a new research paper, they discovered that the Pa30 nebula is expanding at an extreme speed of over 1,100 km per second (at that speed, traveling from Earth to the Moon would take just five minutes).
They used this speed to derive an age of around 1,000 years, which would coincide with the events of 1181.
Professor Albert Zijlstra, of the University of Manchester, was one of the astronomers involved in the research.
He said, “Historical reports place the guest star between two Chinese constellations, Chuanshe and Huagai.
“Parker’s Star fits the position well. This means that the age and location correspond to the events of 1181. ‘
It has already been suggested that Pa30 and Parker’s Star formed as a result of the merging of two white dwarfs.
A white dwarf is what stars like the sun become at the end of their life when they have used up all their nuclear fuel.
It is believed that such white dwarf fusion events lead to a rare and relatively weak type of supernova called “Iax-type supernova”.
Professor Zijlstra said: “Only about 10% of supernovae are of this type and they are not well understood.
Professor Albert Zijlstra, University of Manchester, said all research points to Parker’s star and Pa30 as counterparts to supernova 1181 (shown on a star map)
Images of the nebula were obtained by the Kitt Peak National Observatory Telescope (shown)
“The fact that the SN1181 was weak but faded very slowly fits this type.
“This is the only such event where we can study both the remaining nebula and the merged star, and also have a description of the explosion itself.”
The fusion of residual stars, white dwarfs and neutron stars, gives rise to extreme nuclear reactions and forms heavy elements that are very rich in neutrons such as gold and platinum.
Professor Zijlstra added: “The combination of all this information such as age, location, brightness of the event and the historically recorded duration of 185 days, indicates that Parker’s Star and Pa30 are the counterparts of SN 1181.
“This is the only Iax-type supernova where detailed studies of the remaining star and nebula are possible.
“It’s nice to be able to solve both a historical mystery and an astronomical mystery. ”
The research was published in The Astrophysical Journal Letters.
SUPERNOVAE OCCUR WHEN A GIANT STAR EXPLODES
A supernova occurs when a star explodes, sending debris and particles into space.
A supernova only burns for a short time, but it can tell scientists a lot about how the universe began.
A type of supernova has shown scientists that we live in an expanding universe, which is growing at an ever increasing rate.
Scientists have also determined that supernovas play a key role in the distribution of elements in the universe.
In 1987, astronomers spotted a “titanic supernova” in a nearby galaxy blazing with the power of over 100 million suns (pictured)
There are two known types of supernova.
The first type occurs in binary star systems when one of the two stars, a white carbon-oxygen dwarf, steals matter from its companion star.
Eventually, the white dwarf accumulates too much material, causing the star to explode, resulting in a supernova.
The second type of supernova occurs at the end of a single star’s life.
As the star runs out of nuclear fuel, part of its mass drains into its core.
Eventually, the core is so heavy that it cannot support its own gravitational force, and the core collapses, causing another giant explosion.
Many of the elements found on Earth are made in the cores of stars and these elements travel to form new stars, planets, and all of the rest of the universe.
[ad_2]
Source link