Optical Photometric Observations of GEO Debris

We report on a continuing program of optical photometric measurements of faint orbital debris at geosynchronous Earth orbit (GEO). These observations can be compared with laboratory studies of actual spacecraft materials in an effort to determine what the faint debris at GEO may be. We have optical observations from Cerro Tololo Inter-American Observatory (CTIO) in Chile of two samples of debris: 1. GEO objects discovered in a survey with the University of Michigan's 0.6-m aperture Curtis-Schmidt telescope MODEST (for Michigan Orbital DEbris Survey Telescope), and then followed up in real-time with the CTIO/SMARTS 0.9-m for orbits and photometry. Our goal is to determine 6 parameter orbits and measure colors for all objects fainter than R = 15 t11 magnitude that are discovered in the MODEST survey. 2. A smaller sample of high area to mass ratio (AMR) objects discovered independently, and acquired using predictions from orbits derived from independent tracking data collected days prior to the observations. Our optical observations in standard astronomical BVRI filters are done with either telescope, and with the telescope tracking the debris object at the object's angular rate. Observations in different filters are obtained sequentially. We have obtained 71 calibrated sequences of R-B-V-I-R magnitudes. A total of 66 of these sequences have 3 or more good measurements in all filters (not contaminated by star streaks or in Earth's shadow). Most of these sequences show brightness variations, but a small subset has observed brightness variations consistent with that expected from observational errors alone. The majority of these stable objects are redder than a solar color in both B-R and R-I. There is no dependence on color with brightness. For a smaller sample of objects we have observed with synchronized CCD cameras on the two telescopes. The CTIO 0.9-m observes in B, and MODEST in R. The CCD cameras are electronically linked together so that the start time and duration of observations are the same to better than 50 milliseconds. Thus, the B-R color is a true measure of the surface of the debris piece facing the telescopes for that observation. Any change in color reflects a real change in the debris surface. We will compare our observations with models and laboratory measurements of selected surfaces

Evolution of Spin Direction of Accreting Magnetic Protostars and Spin-Orbit Misalignment in Exoplanetary Systems

Recent observations have shown that in many exoplanetary systems the spin axis of the parent star is misaligned with the planet's orbital axis. These have been used to argue against the scenario that short-period planets migrated to their present-day locations due to tidal interactions with their natal discs. However, this interpretation is based on the assumption that the spins of young stars are parallel to the rotation axes of protostellar discs around them. We show that the interaction between a magnetic star and its circumstellar disc can (but not always) have the effect of pushing the stellar spin axis away from the disc angular momentum axis toward the perpendicular state and even the retrograde state. Planets formed in the disc may therefore have their orbital axes misaligned with the stellar spin axis, even before any additional planet-planet scatterings or Kozai interactions take place. In general, magnetosphere--disc interactions lead to a broad distribution of the spin--orbit angles, with some systems aligned and other systems misaligned.Comment: 10 pages, 5 figures. Comments/clarifications and a new figure (Fig.3) are added. To be published in MNRA

Agricultural Irrigated Land and Irrigation Water Use in Utah

Utah is considered the second driest state in the United States. As a result, much of the agriculture and horticulture in Utah depends upon irrigation. Irrigation is an important feature of agriculture in Utah. The distribution of irrigated and water use varies across the state, based on water availability, topography, and soils. In recent years, sprinkler irrigation has overtaken surface methods as the dominant irrigation method, based on irrigated area, in Utah. About 75% to 80% of water withdrawals in Utah are for irrigation, with about 68% of that water being consumptive use. Alfalfa, other hay crops, and pasture are grown on about 80% of irrigated agricultural lands in Utah

Bell Ford Bridge Reconstruction Project

The Bell Ford Bridge was originally constructed in 1869 until it collapsed in the 20th century. The remains were salvaged and stored for 20 years until it was to be rebuilt in Hamilton County, IN. This is the only remaining Combination Post Truss in existence and was rebuilt using 95% of the original iron and 10% of the original timber

Accurate Irrigation Water Flow Measurement in Pipes

Flow measurement is an important component of water management. There are many methods that can be used to measure water flow, and different methods and technologies are used for pipe flow as compared to open channel (canal) flow. In this fact sheet, we cover only pipe flow, and for that, only technologies that are most common in conventional irrigation practice. We also address some basic principles of flow measurement along with some pros and cons for different measurement technologies

Chandra unveils a binary Active Galactic Nucleus in Mrk463

We analyse Chandra, XMM-Newton and HST data of the double-nucleus Ultraluminous Infrared Galaxy (ULIRG), Mrk463. The Chandra detection of two luminous ($\mathrm{L}_\mathrm{2-10 keV}=1.5\times10^{43}$ and $3.8\times10^{42}$ erg cm$^{-2}$ s$^{-1}$), unresolved nuclei in Mrk~463 indicates that this galaxy hosts a binary AGN, with a projected separation of $\simeq3.8$ kpc ($3.83\pm0.01$ arcsec). While the East nucleus was already known to be a Seyfert 2 (and this is further confirmed by our Chandra detection of a neutral iron line), this is the first unambiguous evidence in favour of the AGN nature of the West nucleus. Mrk463 is therefore the clearest case so far for a binary AGN, after NGC6240.Comment: 7 pages, 7 figures, accepted for publication in MNRA