An Improbable Solution to the Underluminosity of 2M1207B: A Hot Protoplanet Collision Afterglow

摘要: We introduce an alternative hypothesis to explain the very low luminosity of cool (L-type) companion ~25 MJup, ~8 Myr old brown dwarf 2M1207A. Recently, Mohanty et al. found that effective temperature estimates for 2M1207B (1600 ± 100 K) are grossly inconsistent with its lying on same isochrone as primary, being a factor ~10 underluminous at all bands between I (0.8 μm) and L' (3.6 μm). this discrepancy by suggesting is 8 MJup object surrounded edge-on disk comprised large dust grains producing 2.5 mag achromatic extinction. offer explanation: apparent flux reflects actual source luminosity. Given temperature, we infer small radius (~49,000 km), range plausible densities, estimate mass < MJup. suggest hot protoplanet collision afterglow show radiative timescale such 1% age system. If our correct, surface gravity should be order magnitude lower than predicted