There are other stars in this neighbourhood. Other stars call this area home. What is the neighbourhood's history? The birth of all those stars, what triggered it?
A team of astronomy experts say they have pieced together the history and identified the cause of a series of exploding stars.
A series of stars exploded in our neighbourhood. The Local Bubble was created by creating a huge bubble of gas. The Sun is in the middle of the void. The Sun's neighbours formed on the edge of the bubble after the supernova explosions.
The findings are presented in a new study. The Local Bubble is what drives the star formation near the Sun. Catherine Zucker is an astronomer and data visualization expert.
The Local Bubble that we see today was formed by about 15 supernovae over millions of years.
>
Catherine Zucker is the lead author.
Clouds of hydrogen gas called Giant Clouds (GMC) form stars. Enough gas has to be gathered in one spot for a star to form. This happens when the density of the gas changes. If enough time passes and the conditions are right, enough gas clumps together to cause fusion, and a star is born.
When supernovae explode, stars can also form. A lot of energy is released by a nova explosion, and it travels outward in a shockwave. The density of the clouds is increased by the force of the shockwave. That can lead to new stars.
The stars formed on the edge of the Local Bubble, which is also the edge of supernova shockwaves. The density of the Interstellar Medium is lower inside the Local Bubble than it is outside. The edge of the ISM bubble was formed by the series of supernovae explosions.
This is an incredible detective story, driven by both data and theory.
>
The study co-author is a professor.
Over time, the edge of the bubble has fragmented and collapsed into clouds. Its edge is no longer smooth. There are seven star-forming regions on the bubble's surface, according to the team. The prominent parts of the complex are called Orion A and Orion B. The paper says that every well-known cloud within 200 pc of the Sun lies on the surface of the Local Bubble. The exception might be the Perseus Molecular Cloud.
The star formation was not all at once. In their paper, the authors state that it happened in four different eras: 10 Myr ago, 6 Myr ago, 4 Myr ago, and the present age. They don't know the exact number of supernovae that exploded to create the bubble, but they settled on 15 as the most likely number. Zucker, who is now a NASA Hubble Fellow, said that about 15 supernovae have gone off over millions of years to form the Local Bubble.
The Local Bubble and sequential star formation are shown in this figure. The coloured paths show the cluster tracebacks. The tracebacks were shown as empty circles to guide the eye, since the modelling is sensitive to the dynamics of the gas before it becomes stars. After the cluster birth, the tracebacks are shown with filled circles and end in a large dot, which shows the cluster's current position. The evolution of the Local Bubble is a model that we put in for time snapshots. The sun entered the Local Bubble around 5 Myr ago, and the solar orbit is shown in yellow dots. Zucker et al 2022.
Zucker said that he could explain how all nearby star formation began for the first time.
Zucker is a data visualization specialist. Zucker and her colleagues created an interactive tool to explore the Local Bubble.
Zucker and her colleagues created an interactive tool. Zucker et al 2022.
Some of the stars on the edge of the Local Bubble might be seen by Universe Today readers. The most massive star in the Sco-Cen is the red supergiant Antares. One of the largest stars visible with the naked eye is Antares, the 15th brightest star in the sky.
Zucker and her colleagues created a video explaining their work.
The Local Bubble is a void in the middle of the universe that is linked to nearby star-forming regions.
The Local Bubble is a slowly growing object, like a car after you take your foot off the gas. Zucker said it was coasting along at about 4 miles per second. It has lost most of its oomph and has slowed down.
This work was heavily influenced by the data from the Gaia spacecraft. The position and velocity of one billion stars was used to create a 3D model of our universe.
The team traced back the motions of stars to see the formation of the bubble. The clear implication of theobserved geometry and motions is that all the star-forming regions within 200 pc of the Sun formed.
They explain in their paper that gas has been swept up by the Local Bubble.
All Rights Reserved © 2024
