Radionuclides from Windscale discharges II: Their dispersion in Scottish and Norwegian coastal circulation

Measurement of the concentrations of 134Cs, 137Cs, 90Sr, 238Pu, and 239, 240Pu in Scottish and Norwegian coastal waters in 1976 and 1978 provides information on dispersal pathways, transport times, and dilution in these waters of radioactive waste discharged to the Irish Sea from the Windscale nuclear fuel reprocessing plant in Cumbria, U. K...

Radionuclides from Windscale discharges I: Nonequilibrium tracer experiments in high-latitude oceanography

The releases of soluble radionuclides from the nuclear fuel reprocessing plant at Windscale represent for some artificial radionuclides a major addition to the inventories due to nuclear test fallout on the northern hemisphere…

A mass balance for 137Cs and 90Sr in the North Atlantic Ocean

The total inventory of 137Cs(3272 kCi) and 90Sr(2257 kCi) in the North Atlantic Ocean in 1972, as well as the subinventories in the 0 to 1000 m, 1000 to 2000 m, 2000 m to bottom layers, continental shelf waters and bottom sediments, have been estimated. We have been careful to provide reliable estimates of uncertainty for each of these values. We have also estimated the inputs of 137Cs to the Atlantic Ocean as direct fallout (2065 kCi), or as ocean current transport (240 kCi) since the start of large scale nuclear testing...

Molecular astronomy of cool stars and sub-stellar objects

The optical and infrared spectra of a wide variety of `cool' astronomical objects including the Sun, sunspots, K-, M- and S-type stars, carbon stars, brown dwarfs and extrasolar planets are reviewed. The review provides the necessary astronomical background for chemical physicists to understand and appreciate the unique molecular environments found in astronomy. The calculation of molecular opacities needed to simulate the observed spectral energy distributions is discussed

The K2-ESPRINT Project VI: K2-105 b, a Hot-Neptune around a Metal-rich G-dwarf

We report on the confirmation that the candidate transits observed for the star EPIC 211525389 are due to a short-period Neptune-sized planet. The host star, located in K2 campaign field 5, is a metal-rich ([Fe/H] = 0.26$\pm$0.05) G-dwarf (T_eff = 5430$\pm$70 K and log g = 4.48$\pm$0.09), based on observations with the High Dispersion Spectrograph (HDS) on the Subaru 8.2m telescope. High-spatial resolution AO imaging with HiCIAO on the Subaru telescope excludes faint companions near the host star, and the false positive probability of this target is found to be <$10^{-6}$ using the open source vespa code. A joint analysis of transit light curves from K2 and additional ground-based multi-color transit photometry with MuSCAT on the Okayama 1.88m telescope gives the orbital period of P = 8.266902$\pm$0.000070 days and consistent transit depths of $R_p/R_\star \sim 0.035$ or $(R_p/R_\star)^2 \sim 0.0012$. The transit depth corresponds to a planetary radius of $R_p = 3.59_{-0.39}^{+0.44} R_{\oplus}$, indicating that EPIC 211525389 b is a short-period Neptune-sized planet. Radial velocities of the host star, obtained with the Subaru HDS, lead to a 3\sigma\ upper limit of 90 $M_{\oplus} (0.00027 M_{\odot})$ on the mass of EPIC 211525389 b, confirming its planetary nature. We expect this planet, newly named K2-105 b, to be the subject of future studies to characterize its mass, atmosphere, spin-orbit (mis)alignment, as well as investigate the possibility of additional planets in the system.Comment: 11 pages, 9 figures, 4 tables, PASJ accepte

Mid-Infrared Imaging of the Bipolar Planetary Nebula M2-9 from SOFIA

We have imaged the bipolar planetary nebula M2-9 using SOFIA's FORCAST instrument in six wavelength bands between 6.6 and 37.1 $\mu m$. A bright central point source, unresolved with SOFIA's $\sim$ 4${''}$-to-5${''}$ beam, is seen at each wavelength, and the extended bipolar lobes are clearly seen at 19.7 $\mu m$ and beyond. The photometry between 10 and 25 $\mu m$ is well fit by the emission predicted from a stratified disk seen at large inclination, as has been proposed for this source by Lykou et al and by Smith and Gehrz. The principal new results in this paper relate to the distribution and properties of the dust that emits the infrared radiation. In particular, a considerable fraction of this material is spread uniformly through the lobes, although the dust density does increase at the sharp outer edge seen in higher resolution optical images of M2-9. The dust grain population in the lobes shows that small ($$ 1 $\mu m$) particles appear to be present in roughly equal amounts by mass. We suggest that collisional processing within the bipolar outflow plays an important role in establishing the particle size distribution.Comment: 40 pages, 9 figures, 2 table

Fallout nuclides in Atlantic and Pacific water columns : GEOSECS data

This report contains results of measurements of the fallout radionuclides 90Sr, 137Cs , 239,240Pu , and 241Am in large volume seawater samples collected between 1972 and 1974 in the Atlantic and Pacific as part of Geochemical Ocean Sections (GEOSECS) program. The stations for which data are reported include both the North and South Atlantic oceans and latitudes north of 20° S in the Pacific Ocean. The 90Sr and 137Cs data set has been corrected by a procedure which estimates independently the analytical blank for the laboratory which made the analysis. When the data quality and spacing permit, water column inventory estimates were made for each nuclide over depth intervals appropriate to the nuclide's distribution.Funding was provided by the United States Department of Energy under Contract DE-AC02-EV03563

A Young Planet Search in Visible and IR Light: DN Tau, V836 Tau, and V827 Tau

In searches for low-mass companions to late-type stars, correlation between radial velocity variations and line bisector slope changes indicates contamination by large starspots. Two young stars demonstrate that this test is not sufficient to rule out starspots as a cause of radial velocity variations. As part of our survey for substellar companions to T Tauri stars, we identified the ~2 Myr old planet host candidates DN Tau and V836 Tau. In both cases, visible light radial velocity modulation appears periodic and is uncorrelated with line bisector span variations, suggesting close companions of several M_Jup in these systems. However, high-resolution, infrared spectroscopy shows that starspots cause the radial velocity variations. We also report unambiguous results for V827 Tau, identified as a spotted star on the basis of both visible light and infrared spectroscopy. Our results suggest that infrared follow up observations are critical for determining the source of radial velocity modulation in young, spotted stars.Comment: Accepted for publication in the Astrophysical Journal Letter

Structural Invariance of Sunspot Umbrae Over the Solar Cycle: 1993-2004

Measurements of maximum magnetic flux, minimum intensity, and size are presented for 12 967 sunspot umbrae detected on the NASA/NSO spectromagnetograms between 1993 and 2004 to study umbral structure and strength during the solar cycle. The umbrae are selected using an automated thresholding technique. Measured umbral intensities are first corrected for a confirming observation of umbral limb-darkening. Log-normal fits to the observed size distribution confirm that the size spectrum shape does not vary with time. The intensity-magnetic flux relationship is found to be steady over the solar cycle. The dependence of umbral size on the magnetic flux and minimum intensity are also independent of cycle phase and give linear and quadratic relations, respectively. While the large sample size does show a low amplitude oscillation in the mean minimum intensity and maximum magnetic flux correlated with the solar cycle, this can be explained in terms of variations in the mean umbral size. These size variations, however, are small and do not substantiate a meaningful change in the size spectrum of the umbrae generated by the Sun. Thus, in contrast to previous reports, the observations suggest the equilibrium structure, as testified by the invariant size-magnetic field relationship, as well as the mean size (i.e. strength) of sunspot umbrae do not significantly depend on solar cycle phase.Comment: 17 pages, 6 figures. Published in Solar Physic