Extrasolar Auroras spotted

[Cray]

Around a brown dwarf no less, and a million times brighter than Earth's.
http://www.bbc.com/news/science-environment-33711161

[stevebowers]

"We already known from observations of brown dwarves that they have clouds in the atmosphere. Now we know they also show auroras, it is yet more reason to consider brown dwarves as scaled-up versions of planets rather than scaled-down version of stars."

Interesting. Are the planets around a brown dwarf more like moons?

Note the use of 'dwarves' in this article; I'm pretty sure it should be 'dwarfs' (this is one of my pet peeves).

[Cray]

"We already known from observations of brown dwarves that they have clouds in the atmosphere. Now we know they also show auroras, it is yet more reason to consider brown dwarves as scaled-up versions of planets rather than scaled-down version of stars."

Interesting. Are the planets around a brown dwarf more like moons?

I suspect they're similar to the planets of very dim red dwarves, at least at the upper end like these M8.5V brown dwarves.

[iancampbell]

"We already known from observations of brown dwarves that they have clouds in the atmosphere. Now we know they also show auroras, it is yet more reason to consider brown dwarves as scaled-up versions of planets rather than scaled-down version of stars."

Interesting. Are the planets around a brown dwarf more like moons?

Note the use of 'dwarves' in this article; I'm pretty sure it should be 'dwarfs' (this is one of my pet peeves).

Yup. You can blame Tolkein, I think. IIRC, "dwarves" was meant to apply to members of the ancient race of Middle-Earth who had a separate creation from the other free races. Not to small adult humans or, as in this case, small stars.

Unfortunately, that sort of fine distinction tends to get lost.

Regarding the issue of planets vs. moons - of course that's a matter of definition; Pluto didn't change because a few hundred humans decided to call it something different. Maybe the answer to that question depends on whether the brown dwarf is in orbit around a star?

[four]

Note the use of 'dwarves' in this article; I'm pretty sure it should be 'dwarfs' (this is one of my pet peeves).

http://www.oxforddictionaries.com/defini...lish/dwarf

https://en.wiktionary.org/wiki/dwarf

http://www.collinsdictionary.com/diction...olicy=true

Wiktionary, the Oxford dictionary, and the Collins dictionary all agree that either plural is acceptable for all uses of the term.

I think it's fair to say that both "dwarfs" and "dwarves" are fully correct plurals, for any sense of the word "dwarf".

[stevebowers]

I disagree, but there you go. As an editorial decision, there won't be any brown dwarves in OA if I spot 'em.

On the other hand, the use of dwarves as the plural for mythical short people has plenty of precedence, and plenty of clades might fall into this category. Like elves, it is a name I'd rather avoid if we could as it is a bit derivative.

[Cray]

I disagree, but there you go. As an editorial decision, there won't be any brown dwarves in OA if I spot 'em.

Should compromise on a neutral, phonetically correct term like "dorf"?

[CptnMus]

I've always thought (probably incorrectly) that 'Dwarves' was more appropriate (or looks more appropriate) when pluralizing (google search: how do i stop these dwarves breaking all my crockery?) and 'Dwarfs' when when using as a diminutive (Andre the giant clearly dwarfs Arnold Schwarzenegger).

[stevebowers]

Tolkien said he used the form 'dwarves' as an analogy to 'elves', assuming that the correct plural 'dwarfs' would have changed over time in a world where the word 'dwarf' was commonplace. As an etymologist he knew that words change and become irregular the more they are used, while rarely used worlds stay regular.

However I notice that the form 'dwarves' was already in use before Tolkien, albeit very rarely and apparently always in reference to mythical people, not stars or other small objects. So he was using an older, rare form as a deliberate archaism.

Nowadays astronomers tend to use 'dwarfs', but not consistently; science reporters are less reliable. You won't find a single reference to brown, yellow, orange or white dwarves on the Wiki astronomy pages, for example; this is probably due to some pedant with an idée fixe, no doubt.