Planets of binary stars as possible homes for alien life
Simulation of binary star. Credit: From Jørgensen, Kuruwita et al.

Half of the sun-size stars are not straight. The planetary systems around single stars may be different from the planetary systems aroundbinary stars. This shows new targets in the search for extraterrestrial life forms.

Since the only known planet with life is the Earth, planetary systems around stars of similar size are obvious targets for Astronomers trying to locate extraterrestrial life. There are nearly every second stars in that category. According to a new result from research at the University of Copenhagen, planetary systems are formed in a different way than single stars.

The result is exciting since the search for extraterrestrial life will be equipped with several new, extremely powerful instruments within the coming years. Understanding how planets are formed around different types of stars is important. The project leader says that the results may point to places which would be particularly interesting to investigate for the existence of life.

The results of the project are published in the journal Nature.

The planetary system is shaped by bursts.

A young star about 1,000 lightyears from Earth has been observed by the ALMA telescopes. There is a disk of gas and dust surrounding the star system. Researchers can only get a snapshot of the evolution of the star system from the observations. The team has complemented the observations with computer simulations.

The observations allow us to zoom in on the stars and study how dust and gas move towards the disk. The simulations will tell us which physics are at play, and how the stars have evolved up till the snapshot we observe, and their future evolution.

The movement of gas and dust does not always follow a straight line. The movement becomes very strong at certain points in time for relatively short periods of time. The star becomes ten to one hundred times brighter when it returns to its normal state.

Planets of binary stars as possible homes for alien life
ALMA's world at night. Credit: ESO/B. Tafreshi (twanight.org)

The dual star can explain the pattern. When the two stars encircle each other, their joint gravity will affect the surrounding gas and dust disk in a way which causes huge amounts of material to fall towards the star.

The heating will be caused by the falling material. The heat will make the star brighter.

The gas and dust disk will be torn apart by these bursts. The structure of the later planetary system may be influenced by the bursts.

Building blocks are carried by comets for life.

The observed stellar system is too young for planets to have formed. The team wants to investigate the formation of planetary systems by obtaining more observational time at ALMA.

Not only planets but also comets will be in focus.

Comets are likely to play a key role in creating possibilities for life to evolve. There is a high content of ice in comets. It can be assumed that the organic molecule are preserved in comets when a planet is barren, and that later comet impacts will introduce the molecule to the planet's surface.

Understanding the role of the bursts is important.

Video simulation of binary star. The binary star system, NGC 1333-IRAS2A, is surrounded by a disc consisting of gas and dust. Notably, the movement of gas and dust does not follow a continuous pattern. For relatively shorts periods of ten to one hundred years every thousand years the movement becomes very strong. The binary star becomes ten to one hundred times brighter, until it returns to its regular state. Credit: Jørgensen, Kuruwita et al.

The heating caused by the bursts will cause the dust grains to evaporate. The chemical composition of the material from which planets are formed may be altered by this.

The research scope includes chemistry.

The wavelengths covered by ALMA allow us to see a lot of complex organic Molecules, so Molecules with 9-12 atoms and containing carbon. Molecules like this can be used to build blocks for more complex Molecules which are key to life as we know it. For example, the fund in comets has been for the amino acids.

Powerful tools are part of the search for life in space.

ALMA has 66 telescopes and is not a single instrument. This allows for a much better resolution than could have been obtained with a single telescope.

The search for extraterrestrial life will soon be joined by the James Webb Space Telescope. The SKA and the ELT are both planned to begin observing at the end of the decade. The ELT will be the biggest optical telescope in the world and will be able to observe the atmospheric conditions of planets outside the Solar System. The SKA will consist of thousands of telescopes in South Africa and Australia and will have longer wavelength than ALMA.

The SKA will allow for direct observing of large organic molecules. The James Webb Space Telescope can be used to observe the molecule in ice. ALMA is well suited for observing gas-forming molecules. Combining the different sources will provide a lot of exciting results.

More information: Jes Jørgensen, Binarity of a protostar affects the evolution of the disk and planets, Nature (2022). DOI: 10.1038/s41586-022-04659-4. www.nature.com/articles/s41586-022-04659-4 Journal information: Nature Citation: Planets of binary stars as possible homes for alien life (2022, May 23) retrieved 23 May 2022 from https://phys.org/news/2022-05-planets-binary-stars-homes-alien.html This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.