Stochastic particle acceleration in solar flares

It is proposed that particles during the second phase of solar flares are accelerated by stochastic resonant scattering off hydromagnetic waves and first order Fermi acceleration in shock waves generated in the impulsive phase of the flare. Solutions allow arbitrary power law momentum dependences of the momentum diffusion coefficient as well as the momentum diffusion coefficient as well as the momentum loss time. The acceleration time scale to a characteristic energy approximately 100 keV for protons can be as short as 5s. The resulting electron spectra show a characteristic double power law with a transition around 200 keV and are correlated to the proton spectra evaluated under equal boundary conditions, indicating that electrons and protons are accelerated by the same mechanism. The correlation between the different spectral indices in the electron double power law and between electron and proton spectra are governed by the ratio of first to second order acceleration and therefore allow a determination of the Alfven Mach number of the shock wave

A study of solid-propellant vaporization and diffusion processes Final technical report

Vaporization rate and diffusion coefficient determined for organic additives to polyurethane solid propellants - dioctyl adipate and ferrocen

TASS Mark IV Photometric Survey of the Northern Sky

The Amateur Sky Survey (TASS) is a loose confederation of amateur and professional astronomers. We describe the design and construction of our Mark IV systems, a set of wide-field telescopes with CCD cameras which take simultaneous images in the $V$ and $I_C$ passbands. We explain our observational procedures and the pipeline which processes and reduces the images into lists of stellar positions and magnitudes. We have compiled a large database of measurements for stars in the northern celestial hemisphere with $V$-band magnitudes in the range 7 < V < 13. This paper describes data taken over the four-year period starting November, 2001. One of our results is a catalog of repeated measurements on the Johnson-Cousins system for over 4.3 million stars.Comment: Accepted for publication in December, 2006, issue of PASP. 44 pages including 20 figures. Patches catalog available at http://spiff.rit.edu/tass/patches

Reducing Stress and Preventing Anxiety in African American Adolescents: A Culturally-Grounded Approach

Evidenced-based and culturally adapted stress-reduction interventions for urban African American adolescents who are at risk for anxiety and other problems related to stress are needed. This study presents intervention components and preliminary outcome findings of a culturally adapted stress-reduction intervention for urban African American adolescents. Preliminary findings support the efficacy of the intervention to reduce anxiety and enhance general cognitive competencies, such as coping strategies, self-efficacy, and positive thinking, among participants, in comparison to controls. Clinical implications of the stress-reduction intervention for the prevention of psychopathology, particularly among African American adolescents, are discussed

Spatial evolution of 26-day recurrent galactic cosmic ray decreases: Correlated Ulysses COSPIN/KET and SOHO COSTEP observations

In December 1995 the Ulysses spacecraft was at a radial distance of 3 AU from the Sun and 60{degree} northern heliographic latitude. To that time the Solar and Heliospheric Observatory (SOHO) started its mission. On board of both spacecraft particle sensors are measuring electrons, protons and helium nuclei in the MeV to GeV energy range. In early 1996 the counting rates of several hundred MeV galactic cosmic rays at Ulysses and at SOHO (Earth orbit) were modulated by recurrent cosmic ray decreases (RCRDs). The RCRDs at SOHO were found to be associated with a corotating interaction region (CIRs). A Lomb (spectral) analysis was performed on the galactic cosmic ray flux from February 1996 to June 1996. Surprisingly, the most probable frequency is {approximately} 28 days and not 26 or 27 days, corresponding to one solar rotation. The amplitude of the RCRDs is {approximately} 2.3% on both spacecraft. The variation in the solar wind speed shows the same periodicities and is anticorrelated to the variation in the cosmic ray flux. In contrast to the RCRDs the amplitude found in the solar wind speed is four times larger at WIND (120 km/s) than at Ulysses (32 km/s). The solar wind proton density and magnetic field strength yielded no significant periodicities, neither at Ulysses nor at WIND. Comparing the RCRDs with coronal hole structures observed in the FE XIV line, they found that a single coronal hole close to the heliographic equation can account for the RCRDs observed simultaneously at Ulysses and SOHO. The coronal hole boundaries changed towards lower Carrington longitudes and vanished slowly. The changes of the boundaries during the investigated period could explain a 28 day periodicity

The Amateur Sky Survey Mark III Project

The Amateur Sky Survey (TASS) is a loose confederation of amateur and professional astronomers. We describe the design and construction of our Mark III system, a set of wide-field drift-scan CCD cameras which monitor the celestial equator down to thirteenth magnitude in several passbands. We explain the methods by which images are gathered, processed, and reduced into lists of stellar positions and magnitudes. Over the period October, 1996, to November, 1998, we compiled a large database of photometric measurements. One of our results is the "tenxcat" catalog, which contains measurements on the standard Johnson-Cousins system for 367,241 stars; it contains links to the light curves of these stars as well.Comment: 20 pages, including 4 figures; additional JPEG files for Figures 1, 2. Submitted to PAS

A Measurement of the Flux of Cosmic Ray Iron at 5 x 10^13 eV

We present results from the initial flight of our Balloon Air CHerenkov (BACH) payload. BACH detects air Cherenkov radiation from cosmic ray nuclei as coincident flashes in two optical modules. The flight (dubbed PDQ BACH) took place on April 22, 1998 from Ft. Sumner, New Mexico. During an exposure of 2.75 hours, with a typical threshold energy for iron nuclei of 2.2$\times10^{13}$ eV, we observed several events cleanly identifiable as iron group nuclei. Analysis of the data yields a new flux measurement that is fully consistent with that reported by other investigations.Comment: 16 pages, 7 Figures, accepted for publication in Astroparticle Physic

Refined stellar, orbital and planetary parameters of the eccentric HAT-P-2 planetary system

We present refined parameters for the extrasolar planetary system HAT-P-2 (also known as HD 147506), based on new radial velocity and photometric data. HAT-P-2b is a transiting extrasolar planet that exhibits an eccentric orbit. We present a detailed analysis of the planetary and stellar parameters, yielding consistent results for the mass and radius of the star, better constraints on the orbital eccentricity, and refined planetary parameters. The improved parameters for the host star are M_star = 1.36 +/- 0.04 M_sun and R_star = 1.64 +/- 0.08 R_sun, while the planet has a mass of M_p = 9.09 +/- 0.24 M_Jup and radius of R_p = 1.16 +/- 0.08 R_Jup. The refined transit epoch and period for the planet are E = 2,454,387.49375 +/- 0.00074 (BJD) and P = 5.6334729 +/- 0.0000061 (days), and the orbital eccentricity and argument of periastron are e = 0.5171 +/- 0.0033 and omega = 185.22 +/- 0.95 degrees. These orbital elements allow us to predict the timings of secondary eclipses with a reasonable accuracy of ~15 minutes. We also discuss the effects of this significant eccentricity including the characterization of the asymmetry in the transit light curve. Simple formulae are presented for the above, and these, in turn, can be used to constrain the orbital eccentricity using purely photometric data. These will be particularly useful for very high precision, space-borne observations of transiting planets.Comment: Revised version, accepted for publication in MNRAS, 11 pages, 6 figure

Isolation Effects on the Moon: High Topographic Slope Observations from the LRO and LOLA Instruments

The extremely low temperatures in the Moon's polar permanent shadow regions (PSR) has long been considered a unique factor necessary for entrapping volatile Hydrogen (H). However, recent discoveries indicate some H concentrations lie outside PSR, suggesting other geophysical factors may also influence H distributions. In this study we consider insolation and its resulting thermal effects as a loss/redistribution process influencing the Moon's near-surface < 1m volatile H budget. To isolate regional (5deg latitude band) insolation effects we correlate two data sets collected from the ongoing, 1.5 year long mapping mission of the Lunar Reconnaissance Orbiter (LRO). Epithermal neutron mapping data from the Lunar Exploration Neutron Detector (LEND) is registered and analyzed in the context of slope derivations from Lunar topography maps produced by the Lunar Observing Laser Altimeter (LOLA). Lunar epithermal neutrons are inferred to be direct geochemical evidence for near-surface H due to the correlated suppression of surface leakage fluxes of epithermal neutrons with increased H concentration. Regional suppressions of neutrons seen in LEND maps are considered localized evidence of H concentration increase in the upper 1 m of the Lunar surface. To quantify spatially localized insolation effects, LEND data are averaged from sparsely distributed pixels, classed as a function of the LOLA slope derivations