No place like home in crowded core of Omega Centauri – Astronomy Now

No place like home in crowded core of Omega Centauri – Astronomy Now

The star-packed core of Omega Centauri, one of the biggest globular clusters in the Milky Way and a well-recognized targer for newbie astronomers. This beautiful view was captured by the Hubble Space Telescope. Image: NASA, ESA, and the Hubble SM4 ERO Team

Omega Centauri, the biggest globular star cluster in the Milky Way and a favorite goal for newbie astronomers in southern latitudes, is full of some 10 million stars. One can solely think about the glory of the evening sky an alien would possibly take pleasure in from a planet orbiting a star in the cluster’s core. But primarily based on a brand new research, aliens – and steady photo voltaic programs – are unlikely to be discovered.

Writing in The Astrophysical Journal, Stephen Kane, a planetary astrophysicist on the University of California-Riverside, and Sarah Deveny, a graduate pupil at San Francisco State University, conclude stars are packed so intently collectively in the core of Omega Centauri that disruptive gravitational interactions would happen each million years or so.

That virtually definitely would forestall the formation of photo voltaic programs with planets in steady orbits over the timescales vital for all times to evolve.

For comparability, the closest star to Earth’s Sun is in the Alpha Centauri system some four.2 mild years – 40 trillion kilometres (25 trillion miles) – away. In the core of Omega Centauri, the typical distance between stars is simply zero.16 mild years, or 1.5 trillion kilometres (940 billion miles).

Omega Centauri, as seen by the European Southern Observatory’s VLT Survey Telescope. Image: ESO/INAF-VST/OmegaCAM. Acknowledgement: A. Grado, L. Limatola/INAF-Capodimonte Observatory

“The rate at which stars gravitationally interact with each other would be too high to harbour stable habitable planets,” Deveny stated. “Looking at clusters with similar or higher encounter rates to Omega Centauri’s could lead to the same conclusion. So, studying globular clusters with lower encounter rates might lead to a higher probability of finding stable habitable planets.”

The conclusions have been primarily based on an evaluation of 350,000 stars in Omega Centauri’s core with the correct temperature and age, primarily based on their color, to host life-bearing exoplanets. Because most of the celebrities in the core are purple dwarfs, their liveable zones, the place liquid water may exist, can be a lot nearer to their dad or mum stars than the liveable area Earth enjoys orbiting the Sun.

“The core of Omega Centauri could potentially be populated with a plethora of compact planetary systems that harbour habitable-zone planets close to a host star,” Kane stated. “An example of such a system is TRAPPIST-1, a miniature version of our own solar system that is 40 light years away and is currently viewed as one of the most promising places to look for alien life.”

But the numbers don’t seem to work out for stars in the cores of giant globular clusters. When astronomers and amateurs prepare their telescopes on Omega Centauri, it’s unlikely anybody is trying again.

Source link