Twinkle, twinkle, any star - Sun not so special

May 21, 2008
The Sun

ANU astronomers have found there is nothing special about the Sun after conducting the most comprehensive comparison of it with other stars – adding weight to the idea that life could be common in the universe.

Scientists have long argued about whether or not the Earth has some special characteristics that led to the evolution of life. PhD researcher Jose Robles and Dr Charley Lineweaver from the Planetary Science Institute at ANU contend that this is a difficult question to answer because we don’t have information about other Earth-like planets.

“Yet the question ‘How special is the Sun?’ is easier to address because we do have observations of thousands of other Sun-like stars,” explains Dr Lineweaver.

Rather than guess what properties a star should have to enable life, the researchers decided to compare the Sun – which already hosts a life-bearing planet – to other stars.

“Our research goes further than previous work which only looked at single properties such as mass or iron content,” says Robles, who is the lead author on the research paper. “We looked at 11 properties that could plausibly be connected with life and did an analysis of these properties: The upshot is that there doesn’t seem to be anything special about the Sun. It seems to be a random star that was blindly pulled out of the bag of all stars.”

The researchers found that the Sun’s mass is the most anomalous of its properties; the Sun is more massive than 95 per cent of stars. The Sun’s orbit around the centre of the galaxy is also more circular than the orbits of 93 per cent of its peers. “But when analysing the 11 properties together, the Sun shows up as a star selected at random, rather than one selected for some life-enhancing property,” Robles says.

The research is part of the ongoing scientific understanding of our place in the universe. “Those who are searching for justification for their beliefs that terrestrial life and humanity in particular are special, will probably interpret this result as a humiliating dethronement,” says Dr Lineweaver. “Those who believe we are the scum of the universe may find our non-special status uplifting.”

The research paper A comprehensive comparison of the Sun to other stars: searching for self-selection effects, is a collaborative work between ANU, UNSW and European astronomers. It has just been accepted for publication in the Astrophysical Journal and is available online at www.mso.anu.edu.au/~josan/astrophysics.html

Source: Australian National University

Explore further: Astronomers discover likely precursors of galaxy clusters we see today

Related Stories

Researchers study fluctuations in solar radiation

Mar 18, 2015

The Sun is the Earth's principal source of energy and climate driver. Yet sometimes it sends more light to the Earth than other times. Astronomers working with Natalie Krivova at the Max Planck Institute ...

What causes the sunlight flavour in milk?

Mar 03, 2015

Most of us have tasted milk that has been left in the sun – it has a distinctive off-flavour. The reason is that milk and other dairy products turn rancid when exposed to light.

The controversy over interstellar messaging

Feb 20, 2015

Should we beam messages into deep space, announcing our presence to any extraterrestrial civilizations that might be out there? Or, should we just listen? Since the beginnings of the modern Search for Extraterrestrial ...

Ten interesting facts about asteroids

Feb 03, 2015

At first glance, looking at a bunch of space rocks doesn't sound that exciting. Like, aren't they just a bunch of rubble? What use can they be in understanding the Solar System compared to looking at planets ...

Recommended for you

Image: The tumultuous heart of the Large Magellanic Cloud

10 hours ago

A scene of jagged fiery peaks, turbulent magma-like clouds and fiercely hot bursts of bright light. Although this may be reminiscent of a raging fire or the heart of a volcano, it actually shows a cold cosmic ...

Rocky planets may orbit many double stars

Mar 30, 2015

Luke Skywalker's home in "Star Wars" is the desert planet Tatooine, with twin sunsets because it orbits two stars. So far, only uninhabitable gas-giant planets have been identified circling such binary stars, ...

Is the universe finite or infinite?

Mar 27, 2015

Two possiblities exist: either the Universe is finite and has a size, or it's infinite and goes on forever. Both possibilities have mind-bending implications.

User comments : 1

Adjust slider to filter visible comments by rank

Display comments: newest first

barakn
3 / 5 (2) May 21, 2008
That's an odd way to interpret their findings. What they may have discovered is that not all 11 of the properties they tested are important factors for life. Leaving them in makes the result seem more random than it really is.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.