We summarize five years of continuous monitoring of accretion-powered pulsars with the Burst and Transient Source Experiment (BATSE) on the Compton Gamma Ray Observatory. Our 20-70 keV observations have determined or refined the orbital parameters of 13 binaries, discovered 5 new transient accreting pulsars, measured the pulsed flux history during outbursts of 12 transients (GRO J1744-28, 4U 0115+634, GRO J1750-27, GS 0834-430, 2S 1417-624, GRO J1948+32, EXO 2030+375, GRO J1008-57, A 0535+26, GRO J2058+42, 4U 1145-619 and A 1118-616), and also measured the accretion torque history of during outbursts of 6 of those transients whose orbital parameters were also known. We have also continuously measured the pulsed flux and spin frequency for eight persistently accreting pulsars (Her X-1, Cen X-3, Vela X-1, OAO 1657-415, GX 301-2, 4U 1626-67, 4U 1538-52, and GX 1+4). Because of their continuity and uniformity over a long baseline, BATSE observations have provided new insights into the long-term behavior of accreting magnetic stars. We have found that all accreting pulsars show stochastic variations in their spin frequencies and luminosities, including those displaying secular spin-up or spin-down on long time scales, blurring the conventional distinction between disk-fed and wind-fed binaries. Pulsed flux and accretion torque are strongly correlated in outbursts of transient accreting pulsars, but uncorrelated, or even anticorrelated, in persistent sources.Comment: LaTeX, psfig, 90 pages, 42 figures. To appear in Dec. 1997 ApJS, Vol 113, #

No abstract

[1] The atmosphere's response to the total solar eclipse of 4 December 2002 is studied using a prototype high-altitude global numerical weather prediction model (NOGAPS-ALPHA). Local reductions in solar ultraviolet (UV) radiation during the eclipse are estimated using astronomical calculations of umbral and penumbral surface trajectories and observed solar limb darkening at $200-300 nm. In NOGAPS-ALPHA these UV eclipse shadows yield stratospheric radiative cooling rate footprints peaking near 27 K day À1 , a value 2-3 times larger than assumed in previous modeling. Difference fields between NOGAPS-ALPHA runs with and without this eclipse forcing reveal vertically deep middle atmospheric responses, with three-dimensional horizontal structures very similar to the large-scale ''bow-wave'' response first proposed by Chimonas (1970). Such structure appears clearly only at later times when total eclipses have abated and gravity waves generated in the stratosphere have had time to propagate vertically. Bow-wave amplitudes and direct thermal cooling responses are both small (]1 K for temperature and ]2-3 m s À1 for horizontal winds), contradicting some rocketsonde measurements that suggest much larger responses near 50-60 km altitude. We also find clear evidence of a bow-wave-like response in the model's surface pressure fields, with an amplitude $0.1-0.5 hPa, while surface air temperatures in NOGAPS-ALPHA show $4 K cooling over Africa during the eclipse. Both findings are consistent with surface atmospheric data acquired during previous eclipse passages.

No abstract