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We present the first resolved map of plane-of-sky magnetic field strength for a quiescent molecular cloud. GRSMC 45.60+0.30 subtends 40 x 10 pc at a distance of 1.88 kpc, masses 16,000 M_sun, and exhibits no star formation. Near-infrared background starlight polarizations were obtained for the Galactic Plane Infrared Polarization Survey using the 1.8 m Perkins telescope and the Mimir instrument. The cloud area of 0.78 deg2 contains 2684 significant starlight polarizations for Two Micron All Sky Survey matched stars brighter than 12.5 mag in the H band. Polarizations are generally aligned with the cloud's major axis, showing an average position angle dispersion of 15 \pm 2{\deg} and polarization of 1.8 \pm 0.6%. The polarizations were combined with Galactic Ring Survey 13CO spectroscopy and the Chandrasekhar-Fermi method to estimate plane-of-sky magnetic field strengths, with an angular resolution of 100 arcsec. The average plane-of-sky magnetic field strength across the cloud is 5.40 \pm 0.04 {\mu}G. The magnetic field strength map exhibits seven enhancements or "magnetic cores." These cores show an average magnetic field strength of 8.3 \pm 0.9 {\mu}G, radius of 1.2 \pm 0.2 pc, intercore spacing of 5.7 \pm 0.9 pc, and exclusively subcritical mass-to-flux ratios, implying their magnetic fields continue to suppress star formation. The magnetic field strength shows a power-law dependence on gas volume density, with slope 0.75 \pm 0.02 for n_{H_2} >=10 cm-3. This power-law index is identical to those in studies at higher densities, but disagrees with predictions for the densities probed here., Comment: 11 pages, 15 figures, published in ApJ (2012, 755, 130)

We report the discovery of a previously unknown massive Galactic star cluster at l=29.22, b=-0.20. Identified visually in mid-IR images from the Spitzer GLIMPSE survey, the cluster contains at least 8 late-type supergiants, based on followup near-IR spectroscopy, and an additional 3-6 candidate supergiant embers having IR photometry consistent with a similar distance and reddening. The cluster lies at a local minimum in the 13-CO column density and 8 micron emission. We interpret this feature as a hole carved by the energetic winds of the evolving massive stars. The 13-CO hole seen in molecular maps at V_LSR ~95 km/s corresponds to near/far kinematic distances of 6.1/8.7+/-1 kpc. We calculate a mean spectrophotometric distance of 7.0^+3.7_-2.4 kpc, broadly consistent with the kinematic distances inferred. This location places it near the northern end of the Galactic bar. For the mean extinction of A_V=12.6+/-0.5 mag (A_K=1.5+/-0.1 mag), the color-magnitude diagram of probable cluster members is well fit by isochrones in the age range 18-24 Myr. The estimated cluster mass is ~20,000 Msun. With the most massive original cluster stars likely deceased, no strong radio emission is detected in this vicinity. As such, this RSG cluster is representative of adolescent massive Galactic clusters that lie hidden behind many magnitudes of dust obscuration. This cluster joins two similar red supergiant clusters as residents of the volatile region where the end of our Galaxy's bar joins the base of the Scutum-Crux piral arm, suggesting a recent episode of widespread massive star formation there., Comment: 26 pages; Accepted for publication in The Astronomical Journal 2009 March 13; Submitted 2008 November 6. Reports a concurrent discovery of the star cluster investigated by Clark et al. in arXiv:0903.1754

Science opportunities and recommendations concerning optical/infrared polarimetry for the upcoming decade in the fields of stars and stellar evolution. Community-based White Paper to Astro2010 in response to the call for such papers., Comment: White Paper to the Stars and Stellar Evolution (SSE) Science Frontiers Panel of the Astro2010 Decadal Survey

Science opportunities and recommendations concerning optical/infrared polarimetry for the upcoming decade in the field of Galactic science. Community-based White Paper to Astro2010 in response to the call for such papers., Comment: White Paper to the Galactic Neighborhood (GAN) Science Frontiers Panel of the Astro2010 Decadal Survey