A Spectroscopic and Photometric Survey of Stars in the Field of L1457: A New Distance Determination

We present a spectroscopic and photometric survey of a sample of field stars in the region of the molecular cloud L1457. High-quality coud? feed spectra, together with five-band photometry in the Sloan Digital Sky Survey system and near-infrared archival data from the Two Micron All Sky Survey, are used to derive color excesses and distances for the stars. Based on these data, a new distance estimate of 360 ? 30 pc is derived for the cloud, supporting recent results by K. L. Luhman. The data further indicate that the north-south velocity gradient seen in the millimeter-wave CO data is mirrored in a distance gradient, with the northern part of the cloud being closer to us. A second, less opaque, layer of extinction is detected at ~80 pc. This distance is consistent with the earlier distance estimates to the cloud, based on Na I absorption. We identify this layer with the wall of the hot Local Bubble. Hence, the dense cloud is not, as previously thought, associated with the Local Bubble.