L-dwarf variability: Magnetic star spots or non-uniform clouds?
| dc.creator | Gelino, Christopher R. | |
| dc.creator | Marley, Mark S. | |
| dc.creator | Holtzman, Jon A. | |
| dc.creator | Ackerman, Andrew S. | |
| dc.creator | Lodders, Katharina | |
| dc.date | 2001-06-04 | |
| dc.date.accessioned | 2026-07-07T01:58:47Z | |
| dc.date.available | 2026-07-07T01:58:47Z | |
| dc.description | The recent discovery of photometric variations in L dwarfs has opened a discussion on the cause of the variations. We argue against the existence of magnetic spots in these atmospheres and favor the idea that non-uniform condensate coverage (i.e. clouds) is responsible for the variations. The magnetic Reynolds number (Rm) in the atmosphere of L dwarfs, which describes how well the gas couples with the magnetic field, is too small (<<1) to support the formation of magnetic spots. In constrast silicate and iron clouds form in the photospheres of L dwarfs. Inhomogeneities in such cloud decks can plausibly produce the observed photometric variations. Further evidence in support of clouds is the tendency for variable L dwarfs to be bluer in J-Ks than the average L dwarf of a given spectral type. This color effect is expected if clear holes appear in an otherwise uniform cloud layer. | |
| dc.description | submitted to ApJL, 13 pages, 2 figures | |
| dc.identifier | https://arxiv.org/abs/astro-ph/0106062 | |
| dc.identifier | http://arxiv.org/abs/astro-ph/0106062 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/2857 | |
| dc.subject | Astrophysics | |
| dc.title | L-dwarf variability: Magnetic star spots or non-uniform clouds? | |
| dc.type | text |