"brown dwarf stars" -> "brown dwarfs" (and some others)

[aburgasser]

since brown dwarfs and stars are physically different objects (the former don't sustain H fusion, the latter do), I would strongly recommend modifying this term to just the field standard of "brown dwarfs"

Similarly:

L dwarf stars L subdwarf stars T dwarf stars T subdwarf stars Y dwarf stars

should all have "stars" removed

[katieefrey]

Ah yea, excellent point.

For consistency and clarity, what do you think about using the format "L-type brown dwarfs" or the format "L brown dwarfs" for the child concepts of "Brown dwarfs"?

Edit: On second thought, "L brown dwarfs" would be my preferred format, since most stars in the UAT are in the format "A stars," "B stars" etc.

[aburgasser]

Hey Katie,

The (nitpicky) issue is that L dwarfs can be both stars and brown dwarfs; i.e,. they could fall under both subcategories. Is that something possible in the "web" of thesaurus terms? If not (or too messy), "L-type dwarfs" (preferred) or "L-type brown dwarfs" (acceptable) as a subcategory of "brown dwarfs" is fine.

Thanks for checking in on this!

adam

On Tue, Feb 6, 2018 at 10:13 AM, Katie Frey notifications@github.com wrote:

Ah yea, excellent point.

For consistency and clarity, what do you think about using the format "L-type brown dwarfs" or the format "L brown dwarfs" for the child concepts of "Brown dwarfs"?

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Professor of Physics Center for Astrophysics and Space Sciences University of California, San Diego

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[katieefrey]

I meant to use "L dwarfs" as an example, so would your comment also apply to the T and Y dwarfs, and the T and L subdwarfs? Can those types also be sometimes stars or sometimes brown dwarfs?

Perhaps making separate concepts, with detailed scope notes, would be a solution?: "L-type brown dwarfs" "L-type dwarf stars" etc?

I'll be thinking on this further as well.

[aburgasser]

yeah good question; I suppose hierarchically maybe something like the attached image, where the dashed lines would be second-order connections (if that is even possible):

On Tue, Feb 6, 2018 at 12:18 PM, Katie Frey notifications@github.com wrote:

I meant to use "L dwarfs" as an example, so would your comment also apply to the T and Y dwarfs, and the T and L subdwarfs? Can those types also be sometimes stars or sometimes brown dwarfs?

Perhaps making separate concepts, with detailed scope notes, would be a solution?: "L-type brown dwarfs" "L-type dwarf stars" etc?

I'll be thinking on this further as well.

— You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub https://github.com/astrothesaurus/UAT/issues/103#issuecomment-363534098, or mute the thread https://github.com/notifications/unsubscribe-auth/AFZ8PJlNcHnQ085BEZ-6Gn2QQnM5F2N5ks5tSKWQgaJpZM4RVvGm .

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Adam Burgasser, PhD

Professor of Physics Center for Astrophysics and Space Sciences University of California, San Diego

http://www.coolstarlab.org/

[katieefrey]

@aburgasser It doesn't look like the image you referenced went through. Could you send it to me in an email directly, or attached it onto a comment on this Issue thread on GitHub?

The relationships available in a Thesaurus are "narrower" "broader" and "related." The first two are parent/child pairs. The third option ("related") is vague, it indicates a link between concepts, but doesn't specify the exact relationship.

With the parent/child relationship, anything described by the child must fit wholly under the parent concept. In this case, if not all "L dwarfs" are "Brown dwarfs" the former concept cannot remain as a child of the latter.

Based on your feedback so far, this is what I'm envisioning:

Stellar astronomy > Stellar types > Brown dwarfs > L brown dwarfs Stellar astronomy > Stellar types > Brown dwarfs > L brown subdwarfs Stellar astronomy > Stellar types > Brown dwarfs > T brown dwarfs Stellar astronomy > Stellar types > Brown dwarfs > T brown subdwarfs Stellar astronomy > Stellar types > Brown dwarfs > Y brown dwarfs

Stellar astronomy > Stellar types > Late-type stars > Late-type dwarf stars > K dwarf stars Stellar astronomy > Stellar types > Late-type stars > Late-type dwarf stars > L dwarf stars Stellar astronomy > Stellar types > Late-type stars > Late-type dwarf stars > L subdwarf stars Stellar astronomy > Stellar types > Late-type stars > Late-type dwarf stars > M dwarf stars Stellar astronomy > Stellar types > Late-type stars > Late-type dwarf stars > T dwarf stars Stellar astronomy > Stellar types > Late-type stars > Late-type dwarf stars > T subdwarf stars Stellar astronomy > Stellar types > Late-type stars > Late-type dwarf stars > Y dwarf stars

Possibly, with "related" connections between "L brown dwarfs" and "L dwarf stars," between "T brown dwarfs" and "T dwarf stars," etc., if that seems appropriate.

[aburgasser]

Sorry, here's the image I was thinking, but before you sent the overarching concept map above. I guess the dashed lines might be "related"?

[kelle]

Sorry, this might be a diversion, but do we really need categories for each spectral class? I would be fine with "brown dwarfs" and "low mass stars" being the end point.

[katieefrey]

@kelle Thanks for jumping into the conversation!

It would certainly make things a lot simpler if we didn't include spectral classes. Both in terms of having less concepts, and keeping the UAT free of the ambiguity and overlap that @aburgasser has brought to my attention.

Overall it seems like usage in the ADS of the individual spectral classes for these dwarfs is lowish (200-800 hits), while "brown dwarfs" returns about 7k results, and "low mass stars" returns over 8k.

Whatever we decide, it would make the most sense that the solution for these concepts fit in with the general conversation on Stellar types.

[katieefrey]

Low mass stars added. Brown dwarf stars renamed to Brown dwarfs. A concept for general Subdwarf stars has been added.

I did not add "young" versions of the various subtypes.

Removed "stars" from T dwarfs, T subwarfs, L dwarfs, L subdwarfs, and Y dwarfs.

I'm closing this comment for now as 3.0 is being release tomorrow, but I would welcome more feedback on this in the form of a new issue, which can be aimed at a subsequent release.