The atmosphere of HAT-P-1 b

A couple of recent HST transmission spectroscopy papers on HAT-P-1b.

Hubble Space Telescope hot Jupiter Transmission Spectral Survey: detection of water in HAT-P-1b from Wide Field Camera 3 near-infrared spatial scan observations
http://arxiv.org/abs/1308.2106v1

HST hot Jupiter Transmission Spectral Survey: A detection of Na and strong optical absorption in HAT-P-1b
http://arxiv.org/abs/1310.0083