The Deuterium-Burning Mass Limit for Brown Dwarfs and Giant Planets
| Autor: | John A. Milsom, Adam Burrows, David S. Spiegel |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2010 |
| Předmět: |
Physics
Earth and Planetary Astrophysics (astro-ph.EP) Range (particle radiation) Abundance (chemistry) Metallicity Brown dwarf chemistry.chemical_element FOS: Physical sciences Astronomy and Astrophysics Astrophysics Deuterium chemistry Astrophysics - Solar and Stellar Astrophysics Space and Planetary Science Planet Limit (mathematics) Helium Solar and Stellar Astrophysics (astro-ph.SR) Astrophysics - Earth and Planetary Astrophysics |
| Popis: | There is no universally acknowledged criterion to distinguish brown dwarfs from planets. Numerous studies have used or suggested a definition based on an object's mass, taking the ~13-Jupiter mass (M_J) limit for the ignition of deuterium. Here, we investigate various deuterium-burning masses for a range of models. We find that, while 13 M_J is generally a reasonable rule of thumb, the deuterium fusion mass depends on the helium abundance, the initial deuterium abundance, the metallicity of the model, and on what fraction of an object's initial deuterium abundance must combust in order for the object to qualify as having burned deuterium. Even though, for most proto-brown dwarf conditions, 50% of the initial deuterium will burn if the object's mass is ~(13.0 +/- 0.8)M_J, the full range of possibilities is significantly broader. For models ranging from zero-metallicity to more than three times solar metallicity, the deuterium burning mass ranges from ~11.0 M_J (for 3-times solar metallicity, 10% of initial deuterium burned) to ~16.3 M_J (for zero metallicity, 90% of initial deuterium burned). "Models" section expanded, references added, accepted by ApJ |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|