Deep L' and M-band Imaging for Planets Around Vega and epsilon Eridani

Abstract

We have obtained deep Adaptive Optics (AO) images of Vega and epsilon Eri to search for planetary-mass companions. We observed at the MMT in the L' (3.8 micron) and M (4.8 micron) bands using Clio, a recently commissioned imager optimized for these wavelengths. Observing at these long wavelengths represents a departure from the H band (1.65 microns) more commonly used for AO imaging searches for extrasolar planets. The long wavelengths offer better predicted planet/star flux ratios and cleaner (higher Strehl) AO images, at the cost of lower diffraction limited resolution and higher sky background. We have not detected any planets or planet candidates around Vega or epsilon Eri. We report the sensitivities obtained around both stars, which correspond to upper limits on any planetary companions which may exist. The sensitivities of our L' and M band observations are comparable to those of the best H-regime observations of these stars. For epsilon Eri our M band observations deliver considerably better sensitivity to close-in planets than any previously published results, and we show that the M band is by far the best wavelength choice for attempts at ground-based AO imaging of the known planet epsilon Eri b. The Clio camera itself with MMTAO may be capable of detecting epsilon Eri b at its 2010 apastron, given a multi-night observing campaign. Clio appears to be the only currently existing AO imager that has a realistic possibility of detecting epsilon Eri b.

45 pages, 15 figures, accepted to ApJ

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Cited by in corpus (11)

• Spitzer/IRAC Limits to Planetary Companions of Fomalhaut and epsilon Eridani
• The Northern Arc of $\epsilon$ Eridani's Debris Ring as Seen by ALMA
• Vega's hot dust from icy planetesimals scattered inward by an outward-migrating planetary system
• High-contrast Imaging with Spitzer: Deep Observations of Vega, Fomalhaut, and epsilon Eridani
• The Lyot Project Direct Imaging Survey of Substellar Companions: Statistical Analysis and Information from Nondetections
• Dust Populations in the Iconic Vega Planetary System Resolved by ALMA
• Clearing residual planetesimals by sweeping secular resonances in transitional disks: a lone-planet scenario for the wide gaps in debris disks around Vega and Fomalhaut
• A decade of radial-velocity monitoring of Vega and new limits on the presence of planets
• Searching for Planets Orbiting Vega with the James Webb Space Telescope
• Planet Search with the Keck/NIRC2 Vortex Coronagraph in Ms-band for Vega
• Radial velocity analysis of stars with debris discs