Johanna Vos1, Beth Biller1, Katelyn Allers2, Mariangela Bonavita1, Esther Buenzli3, Wolfgang Brandner3, Derek Homeier4,5, Thomas Henning3, Taisiya Kopytova3, Michael Liu6, E Manjavacas3,7, J Schlieder3,8 1University of Edinburgh, 2Bucknell University, 3MPIA Heidelberg, 4Universität Heidelberg, 5Université de Lyon, 6IfA Hawaii, 7IAC, 8NASA Ames Photometric Monitoring is a Key Probe of Weather Phenomena on Exoplanets Condensate Clouds in Exoplanet Atmospheres • The L/T transition is characterised by a J-band brightening as well as a dramatic blueward shift in the NIR color- magnitude diagram. • Directly imaged planets occupy the same temperature regime as L/T transition brown dwarfs, and were expected to exhibit similar atmospheric properties. • However most young exoplanets appear much redder in the near- IR than their brown dwarf counterparts at similar Teff,as shown in Fig. 1. Young, Isolated Brown Dwarfs: • Allow higher photometric precision than directly imaged planets • Young objects are likely to have higher variability amplitudes (Metchev et al. 2015). • By studying young objects we push further into the planetary mass regime. Condensate Clouds + Rapid Rotation Photometric Variability Photometric variability has been detected across the full L-T spectral range, with considerably higher variability amplitudes observed at the L/T transition. Directly imaged planets occupy the same temperature regime as L and T type brown dwarfs and are likely to exhibit similar variability. Main Objectives: • To discover the first weather patterns on planetary-mass objects. • To characterise these weather patterns via multi-wavelength follow-up monitoring. • Formation of condensate clouds in the atmosphere • Condensate clouds sink or break up. L Dwarfs @ 2100 K T Dwarfs @ 1200 K L0 L2 L4 L6 L8 T0 T2 T4 Spectral Type 0 1 2 3 4 5 Targets Fig. 2: Spectral type of objects observed. Fig. 1: Color-magnitude diagram of M, L, T brown dwarfs with directly imaged exoplanets plotted in colour (Liu et al., 2013). References Biller, B. A., Vos, J., Bonavita, M., et al. 2015, ApJ, 813, L23 Buenzli E. et al., 2012, Ap. J. L., 760, L31 Liu M. C. et al., 2013, Ap. J. L., 777, L20 Radigan J., 2014, Ap. J., 797, 120 Metchev, S. A., Heinze, A., Apai, D., et al. 2015, ApJ, 799, 154 Results and Future Prospects • High-amplitude variability detection (Figure 3) for the free-ﬂoating planet PSO J318.5-22 (Biller, Vos et al. 2015). • Multi-wavelength follow-up: • determine the rotational period • characterise vertical and horizontal cloud structures (Buenzli et al., 2012). • 4 tentative lower-amplitude variability detections (<5%), e.g. Figure 4. Fig. 4: Detrended light curve for a tentative variability detection shown in red. Sample reference star lightcurve shown in blue. Fig. 3: High amplitude variability detection for PSO J318.5-22. Reference star light curve shown in blue. (Biller et al. 2015) email: jvos@roe.ac.uk The First Search for Exoplanet Weather 0.96 0.98 1.00 1.02 1.04 JS 0 1 2 3 4 Elapsed Time (hr) 0.975 1.000 1.025 0.90 0.95 1.00 1.05 1.10 PSO J318.5-22 JS 0 1 2 3 4 5 Elapsed Time (hr) 0.95 1.00 1.05 • Constrain the fraction which show variability on rotational timescales. • Probe the eﬀects of surface gravity on cloud structure via comparison with previous brown dwarf variability surveys such as Radigan et al. (2014). We are conducting the first statistically significant search for weather patterns on free-floating young planetary mass objects using the SoFI instrument at the New Technology 3.5m Telescope. Future Goals: