Nascent Stars and How to Age Them
- Anna Oliva
- Jan 15, 2024
- 2 min read
A star cluster captured by the Hubble Space Telescope via https://science.nasa.gov/mission/hubble/science/universe-uncovered/hubble-star-clusters/
As time passes and I learn more about different scientific disciplines, it has become increasingly clear that some of the most fundamental theories in biology, physics, and even chemistry have come from measuring the ages or durations of different phenomena. The measurement of time, the fourth dimension, has allowed for the development of the theory of evolution through carbon dating, the creation of rate law, and the subsequent science of chemical kinetics, discussions of the changes in our universe from its first moments to now. Indeed, the surprisingly short ages of certain cosmic phenomena relative to their distance from us have led to the theory of cosmic inflation, or that when the universe was very young (although "young" isn't the perfect term in this case, it manages to convey the point admirably) it underwent a brief period of expansion much more rapid than its current rates.
This is to say, the study of time and the time in which things happen is pretty neat and relevant. Similarly, the study of stars is a cornerstone of astronomy and our understanding of the universe. Astrophysicist Núria Miret-Roig and her team are experts in both matters and have developed a novel technique for estimating the age of stars and their adolescence.
Stars, those enormous bodies of gas floating somewhere above us, are born when differences in the densities of dust clouds lead to cloud fragments drawn together by gravitational attraction collapsing under their own weight and releasing heat. If these fragments are fortunate enough to find themselves in the presence of large amounts of particles, they become hot enough for thermonuclear fusion. When gravity surpasses heat, the cloud begins collapsing into a protostar, which now has a spinning gas disk that falls into the star or forms the surrounding solar system. The material from the disk allows the star to grow and shine enough to be seen.
Two methods of aging stars prevail in the study of star formation. The isochronous clock method uses the color and luminosity of a star to determine its age. Dynamic backtracking involves studying the movement and spread of star clusters to estimate their age.
Dr. Miret-Roig and co. have found differences between the ages given by the two methods that indicate the isochronous clocks measure the time since the star's formation while dynamic backtracking measures only then the star begins to expand past the parental cloud. Namely, the former method gives the exact age of the star since infancy whereas the latter finds how long the star has been around since adolescence. Therefore, we can now quantify how long it takes for nascent stars to develop, and can begin improving our understanding of how stars form and drift apart.
The article on this discovery:
Further reading:
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