SA experts study star formation
2010-09-07 10:13
Cape Town - Astronomers in SA are studying the stars in the Large Magellanic Cloud (LMC), a neighbouring galaxy to the Milky Way, to determine how stars are formed, and it may provide answers to their evolution and the development of planets.
"If our models are good enough, they will be able to explain our observations of stars in the LMC as well as our observations of those in the MW (Milky Way Galaxy)," Dr Chris Engelbrecht of the University of Johannesburg told News24.
"Since the LMC is so close to us, we can study far more stars in the LMC than in more distant galaxies. So, the LMC is a very attractive and convenient "laboratory" for studying how well we understand stars in general."
The LMC is an irregular galaxy, but much smaller at about a tenth of the size, or about 10 billion solar masses.
Engelbrecht said that stars in the LMC are different from those in our galaxy in that they have lower quantities of heavy metals (elements heavier than helium) which affects their life and death. This study is particularly important because our knowledge of stars has changed dramatically over the last 10 years.
Detailed deductions
"With the advent of space telescopes (like Hubble, but there are many more) and the increasingly effective use of telescopes on the Earth's surface (including the dozen or so telescopes at the national research site near Sutherland in the Northern Cape) we have seen dramatic increases in the number and the variety of direct measurements of stellar behaviour," he said.
The study of the LMC could ultimately assist astronomers in finding stars that have rocky planets similar to Earth and may even lead to finding life in the deep reaches of space.
"It is connected to the search for exoplanets, since that search depends on our knowledge of the 'parent star' to make detailed deductions about the nature of a newly-discovered planet and, as described above, this project is expected to contribute to our understanding of stellar structure," Engelbrecht said.
The research could help astronomers envisage what kind of stars should have planets, but the important "goldilocks zone" where it's neither too hot nor cold around a star would not be easy to predict because of the variables related to a particular star is unique.
The research will focus on Beta Cephei stars in the LMC to provide a clearer picture of the stars and test current scientific models of stellar behaviour.
"Our long-term plan is to study the activity of BCep (Beta Cephei) stars in the LMC in great detail, in order to investigate the discrepancy between model predictions and actually observed behaviour and (hopefully) learn new things about stellar structure and evolution.
"The work we plan to do in 2010 is expected to provide us with a clearer understanding of the individual characteristics of these 'vigorous' BCep stars so that we can initiate further studies on the detailed behaviour of a carefully selected sample of BCep stars in the LMC."
Skills shortage
Engelbrecht though, is still concerned about the skills shortage in the fields of astronomy in SA and would like to ensure that the number of astronomers is a permanent fixture in the national budget.
"My personal suggestion to remedy the situation is to add a permanent item to the national budget that will carry more permanent positions in astrophysics, associated with earmarked posts at universities and with the national institutions.
"If we can budget for a permanent air force with x number of fighter jets, a permanent navy with x number of frigates, (and I am not saying these are bad things to have), we can also budget for an astrophysics arsenal with x number of scientist," he said.
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