We present new images (ground-based optical and mid-infrared [MIR] from the Spitzer Space Telescope) and spectra (from Spitzer) of the archetypal starburst galaxy M82. The Spitzer data show that the MIR emission extends at least 6 kpc along the minor axis of the galaxy. We use the optical and infrared data to demonstrate that the extended emission is dominated by emission from dust. The colors of the MIR emission and the spectra indicate that there is a strong component of aromatic feature emission (the MIR features commonly attributed to polycyclic aromatic hydrocarbons). The dust continuum and aromatic feature emission are both strong in the well-known superwind region of this galaxy; clearly, the carrier of the aromatic features can survive in close proximity to the wind, far from the plane of the galaxy. We also see significant emission by dust well outside the superwind region, providing the clearest picture to date of the dust distribution in the halo of this galaxy.

Muraki et al.

We present three transits of GJ 1214b, observed as part of the Apache Point Observatory Survey of Transit Lightcurves of Exoplanets (APOSTLE). We used APOSTLE r-band lightcurves in conjunction with previously gathered data of GJ 1214b to re-derive system parameters. By using parameters such as transit duration and ingress/egress length we are able to reduce the degeneracies between parameters in the fitted transit model, which is a preferred condition for Markov Chain Monte Carlo techniques typically used to quantify uncertainties in measured parameters. The joint analysis of this multi-wavelength dataset confirms earlier estimates of system parameters including planetary orbital period, the planet-to-star radius ratio and stellar density. Estimating the absolute mass and radius of the planet directly depend on how various stellar parameters are derived. We fit the photometric spectral-energy distribution of GJ 1214 to derive stellar luminosity and estimated its absolute mass and radius from known massluminosity relations for low-mass stars. From these derived stellar properties and previously published radial velocity data we were able to refine estimates of the absolute parameters for the planet GJ 1214b. Transit times derived from our study show no evidence for strong transit timing variations. Some lightcurves we present show features that we believe are due to stellar activity. During the first night we observed a 0.8% rise in the out-of-eclipse flux of the host star lasting approximately 3 minutes. The trend has a characteristic fast-rise exponential decay shape commonly associated with stellar flares. During the second night we observed a minor brightening during the transit. Due to its symmetric shape we believe this feature might have been caused by the planet obscuring a star-spot on the stellar disk.

The Apache Point Survey of Transit Lightcurves of Exoplanets (APOSTLE) observed eleven transits of TrES-3b over two years in order to constrain system parameters and look for transit timing and depth variations. We describe an updated analysis protocol for APOSTLE data, including the reduction pipeline, transit model and Markov Chain Monte Carlo analyzer. Our estimates of the system parameters for TrES-3b are consistent with previous estimates to within the 2σ confidence level. We improved the errors (by 10-30%) on system parameters like the orbital inclination (i orb ), impact parameter (b) and stellar density (ρ ⋆ ) compared to previous measurements. The near-grazing nature of the system, and incomplete sampling of some transits, limited our ability to place reliable uncertainties on individual transit depths and hence we do not report strong evidence for variability. Our analysis of the transit timing data show no evidence for transit timing variations and our timing measurements are able to rule out Super-Earth and Gas Giant companions in low order mean motion resonance with TrES-3b.

We present the results of an observational campaign which obtained high time cadence, high precision, simultaneous optical and IR photometric observations of three M dwarf flare stars for 47 hours. The campaign was designed to characterize the behavior of energetic flare events, which routinely occur on M dwarfs, at IR wavelengths to milli-magnitude precision, and quantify to what extent such events might influence current and future efforts to detect and characterize extrasolar planets surrounding these stars. We detected and characterized four highly energetic optical flares having U -band total energies of ∼7.8 x 10 30 to ∼1.3 x 10 32 ergs, and found no corresponding response in the J, H, or Ks bandpasses at the precision of our data. For active dM3e stars, we find that a ∼1.3 x 10 32 erg U -band flare (∆U max ∼1.5 mag) will induce <8.3 (J ), <8.5 (H ), and <11.7 (Ks) milli-mags of a response. A flare of this energy or greater should occur less than once per 18 hours. For active dM4.5e stars, we find that a ∼5.1 x 10 31 erg U-band flare (∆U max ∼1.6 mag) will induce <7.8 (J ), <8.8 (H ), and <5.1 (Ks) milli-mags of a response. A flare of this energy or greater should occur less than once per 10 hours. No evidence of stellar variability not associated with discrete flare events was observed at the level of ∼3.9 milli-mags over 1 hour time-scales and at the level of ∼5.6 milli-mags over 7.5 hour time-scales. We therefore demonstrate that most M dwarf stellar activity and flares will not influence IR detection and characterization studies of M dwarf exoplanets above the level of ∼5-11 milli-mags, depending on the filter and spectral type. We speculate that the most energetic megaflares on M dwarfs, which occur at rates of once per month, are likely to be easily detected in IR observations with sensitivity of tens of milli-mags. We also discuss how recent detections of line flux enhancements during M dwarf flares could influence IR transmission spectroscopic observations of M dwarf exoplanets.