Glowing dust doughnut circles white dwarf Extremely patient astroboffins have put together the first image of debris rings around a white dwarf, obtained over 12 years of Very Large Telescope observations. Researchers led by Christopher Manser of the University of Warwick’s Astronomy and Astrophysics Group used Doppler tomography* to snap the rings of SDSS1228+1040, …
Yes, I guess I did not understand the relevant sentence, namely: 'The picture features a couple of solar radii fractions for scale, "corresponding to material in circular orbits at two different distances from the star"'
I do not understand how that explains why the larger radius is outside the smaller radius.
Actually, the Doppler tomograph shows the velocities of the materials in different directions. Faster things (further away from centre) are objects in a tighter orbit. Hence the remark of an "inside out" image.
Thumbs up to the astroboffins for capturing all this detail
The RSun values are the radii of the material, not the distance at which it orbits ( which is not mentioned ).
The two circles show the orbital radius of stuff circling the white dwarf at a particular speed, compared to the radius of our sun. Further out on the speed map means higher orbital speed, hence a tighter orbit; it does take a bit of geometrical gymnastics to go from this to a "normal" view of the dust cloud.
Size (or rather, mass) of the debris particles doesn't really enter into it.
Imagine that, creating all this stuff, much of which we have little chance of ever discovering.
Especially when he gave us such poor vision.
But fair dues, He's certainly shown his dedication in universe construction.
The detail, the detail. It's all in the detail.
</snark>
"much of which we have little chance of ever discovering."
Genesis 11:
5 But the Lord came down to see the city and the tower the people were building. 6 The Lord said, “If as one people speaking the same language they have begun to do this, then nothing they plan to do will be impossible for them"
You can't be "7 times smaller", you can be 1/7 the size or 7 times larger.
Actually a term coined in the land of US marketing I believe to make something look better than it is ... In the same way that DFS, SCS, Shoddy-Goods-R-Us et al have an 'up to half price' sale where the cost price of a piece of tat is actually half price or above, never below.
I agree that it is in no sense an image of a disc. More like a horseshoe.
Too tired to think about exactly what Tom 7 means by 'but they haven't', but it is supposed to be a map of mass-velocity.
However, I do know that Tom 7 is not stupid, so pls, explain what you mean by 'but they haven't'.
I will say something else they do not: in this kind of astronomy, there is a kind of 'King's or Queen's new clothes' effect.
Many of the engineers, programmers, and mathematicians who work on these things
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Krikkit is the region formerly known as British isles, the dust clouds are cloudy weather.
Much better book than the original Hitchhiker's, where the general plot and many details were directly stolen from Venus on the Half-Shell.
I like the way Adams's japes in the later book are also applicable to Japan.
Only difference, we never got cricket! There are only seven fields in the whole country.
This is a big mistake of the English, they did not popularise the game.
So we have the Spalding-created baseball, not as interesting, I think. I hear it is based on the earlier game, rounders.
We hate the IOC for dumping softball, how many women are playing baseball?
Totally off topic but
Its entirely believable that the reason that cricket never became popular in the US is because you had a war with us Brits, and decided to throw out everything that was considered British :)
Its popular in a lot of the rest of the world
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