On Oct 24, 2007, at 7:45 AM, Brian Thomas wrote:
> On Wednesday 24 October 2007, Frederic V. Hessman wrote:
>
>> IVOAT:stellarobjects "stellar objects"
>
> OK, I'm not a theorist, but isn't that already handled by
> IVOAT:star (??).
> Do we want to start getting in the business of aliased terms (beyond
> what already exist in the IAU Thesaurus)?
I would have thought that an ontologist would dote on splitting such hairs - well, not hairs precisely for objects in the range of 10^30 kg, but you get the idea :-)
A star is like a planet in that we all want it to have a detailed definition, even if we disagree on those details. For most of us, however, a star's energy budget includes nuclear reactions. By such a definition, compact post-nuclear residue such as white dwarfs and neutron "stars" may be stellar objects, but are not stars. Stellar objects in the 1 Msun range begin life as stars. (I would think coalescing nebulae are not yet stellar objects.) Objects in the 10^-3 Msun range aren't stellar at all, but rather planets (whatever the heck that means). Brown dwarfs would likely be considered stellar objects, but not stars. Black holes are neither. (A stellar object, like a quasi-stellar object, probably has to emit EM radiation.) One would think stellar objects are subclassed from compact objects, and stars are subclassed from stellar objects.
Or maybe Rick meant something entirely different. His fundamental point was that for his purposes such a distinction might make sense. For yours, perhaps not.
If we don't want to recognize aliases, perhaps we should have no interest in the IAU Thesaurus.