Big News On Dwarf Stars Rejigs Stellar Clocks

Stars like our Sun get old and become Red Giants. Then they get older and eventually Shed Their Skins (outer layers) leaving behind a remnant which we call a White Dwarf.


White dwarf stars are some of the oldest stellar objects in the universe. They are incredibly useful to astronomers as their predictable lifecycle allows them to be used as cosmic clocks to estimate the age of groups of neighboring stars to a high degree of accuracy

In this article “Fading White Dwarfs Confirm the Age of the Universe” you can see what that means. That article is from 15 yeas ago and in it you will find this: ” The rate of white dwarf cooling is well understood “

I remembered that from my youth when I was more interested in cosmology. Cosmologists like standard candles and standard clocks. They make determining the age and size / distance of stars, galaxies and the universe possible.

This is how that works: When I was 12 I used what I knew of the the expansion of the universe and the Red Shift (the farther away a galaxy is the faster it is receding from us) to calculate the edge of the visible universe to around 12.5 Billion Light Years. At / after that point the stars are receding from us at the speed of light so we’d never see anything – a simplistic idea but that’s where the limit worked out to be. It was a fun exercise from before I had any access to a calculator. (PC’s didn’t show up for nearly 20 years.) And it you believe in the Big Bang that would also correlate with the approximate age of the universe.

But the nature of science is to push back the boundaries of our knowledge and understanding – to make the universe of our knowledge larger. And it’s not uncommon for the gains to show us where we were wrong or our understanding was incomplete. Which is a good thing.

So when I was reading “Thousands of stars turning into crystals” at Science Daily I got a smile when I read “This could make them potentially billions of years older than previously thought”. Cool (that’s a pun also)

What does that mean for the research in the article from 15 years ago?
Does it change the calculations that Richer used to determine an age of the universe?

I’ll confess that I’m not all that sure if it does or not because Richer’s team was looking for a thermal cutoff point in white dwarf populations – the older the stars the cooler the stars so when you run out of them you have found the coldest stars.

From that temperature you can reverse the clock and determine age because “the rate of white dwarf cooling is well understood ” as was believed back then. But if that rate isn’t what they thought it was back then, if the stars they could find are actually billions of years older than they had thought 15 years ago then it’s likely that this calculation will have be redone. And the best guesstimate of the age of the universe will have to be adjusted . . . again. (Steady State was so much simpler – there was no ‘beginning’ πŸ™‚

Meanwhile another part of my brain is trying to figure out if there’s any SF material in mining White Dwarf cores for dense crystalline Oxygen . . . or Carbon. Maybe the Oxy cores are clad in Diamond or some other exotic variant of Carbon. And that there may be 15,000 of these within 300 light years from here . . . makes it feel like the Big Empty is kinda crowded. Which makes for more potential SF fodder.

About xamble

Most things I do involve computers. Nowadays that sounds stupid to hear because everyone uses computers. Except I was saying that before the IBM PC came on the scene. (hint: my first programs were entered on punch cards in an IBM-29) Now I mostly use them. Mostly to provide a community service in my small town. Because I could when it was asked and still can. And I'm a wannabe writer. Various books in various states of incompleteness. A few short stories. Might do more of that.
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1 Response to Big News On Dwarf Stars Rejigs Stellar Clocks

  1. Pingback: How Your Measuring Tool Was Made Makes A Difference In Cosmology | xamble rambles

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