A 5 μm image of β Pictoris b at A sub-Jupiter projected separation: Evidence for a misalignment between the planet and the inner, warped disk

Abstract

We present and analyze a new M′ detection of the young exoplanet β Pictoris b from 2008 VLT/NaCo data at a separation of ≈4 AU and a high signal-to-noise rereduction of L′ data taken in 2009 December. Based on our orbital analysis, the planet's orbit is viewed almost perfectly edge-on (i ∼ 89deg) and has a Saturn-like semimajor axis of 9.50AU+3.93 AU- 1.7 AU. Intriguingly, the planet's orbit is aligned with the major axis of the outer disk (Ω ∼ 31deg) but is probably misaligned with the warp/inclined disk at 80 AU, often cited as a signpost for the planet's existence. Our results motivate new studies to clarify how β Pic b sculpts debris disk structures and whether a second planet is required to explain the warp/inclined disk. © 2011. The American Astronomical Society. All rights reserved.