Open AccessA search for starlight reflected from υ And's innermost planet
Author(s) -
Collier Cameron Andrew,
Horne Keith,
Penny Alan,
Leigh Christopher
Publication year - 2002
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1046/j.1365-8711.2002.05084.x
Subject(s) - starlight , physics , geometric albedo , planet , astrophysics , albedo (alchemy) , radius , astronomy , atmosphere (unit) , orbital inclination , doppler effect , stars , photometry (optics) , binary number , meteorology , art , computer security , arithmetic , mathematics , performance art , computer science , art history
In data from three clear nights of échelle spectroscopy in 2000 October/November, and using improved Doppler tomographic signal‐analysis techniques, we have carried out a deep search for starlight reflected from the innermost of υ (upsilon) And's three planets. We place upper limits on the planet's radius R p as functions of its projected orbital velocity K p ≈139 sin i km s −1 for various assumptions about the wavelength‐dependent geometric albedo spectrum p ( λ ) of its atmosphere. For a grey albedo p we find , with 0.1 per cent false‐alarm probability (4 σ ). For a Sudarsky, Burrows & Pinto Class V model atmosphere, the mean albedo in our 380–676 nm bandpass is 〈p〉∼0.42 , requiring R p <1.51R J , whereas an (isolated) Class IV model with 〈p〉∼0.19 requires R p <2.23R J . The star's v rot sin i∼10 km s −1 and estimated rotation period P rot ∼10 d suggest a high orbital inclination i∼70°–80° . We also develop methods for assessing the false‐alarm probabilities of faint candidate detections, and for extracting information about the albedo spectrum and other planetary parameters from faint reflected‐light signals.