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Research draft

brown dwarf

vr.tr.brown-dwarf · PHY.SPC

Let an agent describe brown dwarfs by designation, spectral type, mass, temperature and detection, with sourced data.

Thing Registry Physical world and living systems

Research draft, second pass

A second pass drafted this model: the structure a model of this thing needs, and what is known about it in the world. The line under this one says how the second half was obtained - researched against sources, or recalled without web access, in which case nothing here was read anywhere and every claim is a lead to verify. Unreviewed either way.

written by Claude from model knowledge without web access - no source was read, every claim is a lead to verify

Researched by: Claude

Purpose and description

Let an agent describe brown dwarfs by designation, spectral type, mass, temperature and detection, with sourced data.

A substellar object more massive than a planet (roughly 13-80 Jupiter masses) but not massive enough to sustain hydrogen fusion; brown dwarfs glow faintly in infrared and are classed as L, T and Y types.

What it is for: A class of objects bridging stars and planets.

It can be classify by spectral type; estimate mass and age; detect in infrared surveys; study atmospheres.

Distinguishing features

No sustained hydrogen fusion

Deuterium burning in heavier ones

Cool atmospheres with clouds

Fade over time

What it looks like

Dim, reddish to magenta objects visible mainly in infrared.

Physical character

mass: about 13-80 Jupiter masses

surface temperature: about 250-3000 K - Y to L types

How it is recognised

Spectral types L, T, Y

Designations from surveys such as WISE

Planetary-mass objects are lighter

Related models

is a kind of - category

substellar object

is contrasted with - neighbours

red dwarf and planet

is detected by - method

infrared surveys

is studied by - field

astronomy

In practice

Families and kinds

L-type brown dwarfs

T-type brown dwarfs

Y-type brown dwarfs

binary brown dwarfs

Identifiers

survey designation WISE or 2MASS names catalogues

Standards and regulation

IAU nomenclature

Failure modes and hazards

Confusing with planets or red dwarfs

Uncertain mass estimates stated as exact

Also called

T-type brown dwarfY-type brown dwarf

Where this came from

wikidata · CC0 1.0

Drafted structure

Bundle to layer to finding to question, as the second pass will find it: 4 bundles · 8 layers · 8 findings · 16 questions.

Identity Which brown dwarf.

Designations identify.

Designation

Name.

Designation

Designation.

  1. What is its designation? provenance
  2. In which survey was it found? provenance

Type

Spectral class.

Type

Spectral type.

  1. What is its spectral type? definition
  2. How was it classified? provenance
Properties Measurements.

Properties need sources.

Mass

Estimate.

Mass

Mass.

  1. What is its estimated mass, and how uncertain? measurement
  2. How was it estimated? provenance

Temperature

Atmosphere.

Temperature

Temperature.

  1. What is its temperature? measurement
  2. What molecules appear in its spectrum? measurement
Boundaries Star or planet.

Boundaries are debated.

Upper limit

Stars.

Upper

Stellar boundary.

  1. Is it below the hydrogen fusion limit? boundary
  2. How certain is that? boundary

Lower limit

Planets.

Lower

Planetary boundary.

  1. Is it above the deuterium limit or classed by formation? boundary
  2. Which definition is used? definition
Observing Detection.

Brown dwarfs are faint.

Instruments

Infrared telescopes.

Instruments

Instruments.

  1. Which telescopes observed it? provenance
  2. In which bands? definition

Nearby

Distance.

Nearby

Distance.

  1. How far away is it? measurement
  2. Is it among the nearest known? provenance

What the second pass must settle

  • Should spectral types be separate entries?
  • How should survey catalogues be linked?
  • How should the mass boundaries be recorded?