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We present a time-lapse sequence of 20 near-infrared (J and K 0 band) snapshots of the central 20 ; 20 of the Crab pulsar wind nebula, taken at subarcsecond resolution with the Hokupa'a /QUIRC adaptive optics camera on the Gemini North Telescope and sampled at intervals of 10 minutes and 24 hr. It is observed that the equatorial wisps and polar knots in the termination shock of the pulsar wind appear to fluctuate in brightness on kilosecond timescales. Maximum flux variations of AE24% AE 4% and AE14% AE 4% relative to the mean (in 1.2 ks) are measured for the wisps and knots, respectively, with the greatest statistical significance in the J band, where the nebula background is less prominent. The J and K 0 flux densities imply different near-infrared spectra for the nonthermal continuum emission from the wisps and the outermost polar knot (the

The Apache Point Galactic Evolution Experiment (APOGEE) has amassed the largest ever collection of multi-epoch, high-resolution (R ∼ 22, 500), H-band spectra for B-type emission line (Be) stars. These stars were targeted by APOGEE as telluric standard stars and subsequently identified via visual inspection as Be stars based on H i Brackett series emission or shell absorption in addition to otherwise smooth continua and occasionally non-hydrogen emission features. The 128/238 APOGEE Be stars for which emission had never previously been reported serve to increase the total number of known Be stars by ∼ 6%. Because the H-band is relatively unexplored compared to other wavelength regimes, we focus here on identification of the H-band lines and analysis of the emission peak velocity separations (∆v p ) and emission peak intensity ratios (V/R) of the usually double-peaked H i and non-hydrogen emission lines. H i Br11 emission is found to preferentially form in the circumstellar disks at an average distance of ∼2.2 stellar radii. Increasing ∆v p toward the weaker Br12-Br20 lines suggests these lines are formed interior to Br11. By contrast, the observed IR Fe ii emission lines present evidence of having significantly larger formation radii; distinctive phase lags between IR Fe ii and H i Brackett emission lines further supports that these species arise from different radii in Be disks. Several emission lines have been identified for the first time including C i 16895, a prominent feature in the spectra for almost a fifth of the sample and, as inferred from relatively large ∆v p compared to the Br11-Br20, a tracer of the inner regions of Be disks. Emission lines at 15760Å and 16781Å remain unidentified, but usually appear along with and always have similar line profile morphology to Fe ii 16878. Unlike the typical metallic lines observed for Be stars in the optical, the H-band metallic lines, such as Fe ii 16878, never exhibit any evidence of shell absorption, even when the H i lines are clearly shell-dominated. The first known example of a quasi-triple-peaked Br11 line profile is reported for HD 253659, one of several stars exhibiting intra-and/or extra-species V/R and radial velocity variation within individual spectra. Br11 profiles are presented for all discussed stars, as are full APOGEE spectra for a portion of the sample.

keV) 21,760 cm2 Energy Resolution 85 -175 eV FWHM Time Resolution 100 ns Collimator 4 arcmin FWHM Background Rate 2.2 c/s Count Rate on Crab (0.2-10 keV) 148,000 Large Area Detector (LAD) Energy Range 2-30 keV Effective Area (cm^2 @ 10 keV) 51,000 cm2 Energy Resolution 200 -300 eV FWHM Time Resolution 10 µs Collimator 1° FWHM Count Rate on Crab (2-30 keV) 156,000 Background Rate 822 c/s (5 mcrab)

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