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The enigmatic highly peculiar binary system HD 66051
HD 66051 (V414 Pup) is an eclipsing and spectroscopic double-lined binary, hosting two chemically peculiar stars: a highly peculiar B star as pri-mary and an Am star as secondary. It also shows out-of-eclipse variability that is due to chemical spots. Using a set of high-resolution spectropolarimetric observations, a weak magnetic field on the primary was found. The investigation of the new high-resolution UVES spectrum of HD 66051 allowed us to decide on the chemical peculiarity type of both components with more reliability. © 2020 Astronomical Institute, Slovak Academy of Sciences
Revenue divergence and competitive balance in a divisional sports league
The North American model of resource allocation in professional sports leagues is adapted for English (association) football. The theoretical relationship between revenue and competitive balance is shown to be robust with respect to changes in teams’ objectives and labour market conditions. Empirical revenue functions are reported for 1926-1999. These indicate a shift in the composition of demand favouring big-city teams and an increase in the sensitivity of revenue to performance. An analysis of match results in the FA Cup competition suggests an increase in competitive imbalance between teams at different levels of the league’s divisional hierarchy, as the theory suggests
Identifying Very Metal-Rich Stars with Low-Resolution Spectra: Finding Planet-Search Targets
We present empirical calibrations that estimate stellar metallicity,
effective temperature and surface gravity as a function of Lick/IDS indices.
These calibrations have been derived from a training set of 261 stars for which
(1) high-precision measurements of [Fe/H], T_eff and log g have been made using
spectral-synthesis analysis of HIRES spectra, and (2) Lick indices have also
been measured. Our [Fe/H] calibration, which has precision 0.07 dex, has
identified a number of bright (V < 9) metal-rich stars which are now being
screened for hot Jupiter-type planets. Using the Yonsei-Yale stellar models, we
show that the calibrations provide distance estimates accurate to 20% for
nearby stars.
This paper outlines the second tier of the screening of planet-search targets
by the N2K Consortium, a project designed to identify the stars most likely to
harbor extrasolar planets. Discoveries by the N2K Consortium include the
transiting hot Saturn HD 149026 b (Sato et al. 2005, astro-ph/0507009) and HD
88133 b (Fischer et al. 2005). See Ammons et al. (2005, In Press) for a
description of the first tier of N2K metallicity screening, calibrations using
broadband photometry.Comment: Accepted for publication in the Astrophysical Journa
Applicability of frozen-viscosity models of unsteady wall shear stress
The validity of assumed frozen-viscosity conditions underpinning an important class of theoretical models of unsteady wall shear
stress in transient flows in pipes and channels is assessed using detailed computational fluid dynamics (CFD) simulations. The need for
approximate one-dimensional ð1DÞfx; tg models of the wall stress is unavoidable in analyses of transient flows in extensive pipe networks
because it would be economically impracticable to use higher order methods of analysis. However, the bases of the various models have never
been established rigorously. It is shown herein that a commonly used approach developed by the first authors is flawed in the case of smoothwall
flows although it is more plausible for rough-wall flows. The assessment process is undertaken for a particular, but important, unsteady
flow case, namely, a uniform acceleration from an initially steady turbulent flow. First, detailed predictions from a validated CFD method are
used to derive baseline solutions with which predictions based on approximate models can be compared. Then, alternative solutions are
obtained using various prescribed frozen-viscosity distributions. Differences between these solutions and the baseline solutions are used
to determine which frozen-viscosity distributions are the most promising starting points for developing 1Dfx; tg models of unsteady components
of wall shear stress. It is shown that no frozen-viscosity distribution performs well for large times after the commencement of an
acceleration. However, even the simplest approximation (laminar) performs well for short durations—which is when the greatest amplitudes
of the unsteady components occu
ROTSE All Sky Surveys for Variable Stars I: Test Fields
The ROTSE-I experiment has generated CCD photometry for the entire Northern
sky in two epochs nightly since March 1998. These sky patrol data are a
powerful resource for studies of astrophysical transients. As a demonstration
project, we present first results of a search for periodic variable stars
derived from ROTSE-I observations. Variable identification, period
determination, and type classification are conducted via automatic algorithms.
In a set of nine ROTSE-I sky patrol fields covering about 2000 square degrees
we identify 1781 periodic variable stars with mean magnitudes between m_v=10.0
and m_v=15.5. About 90% of these objects are newly identified as variable.
Examples of many familiar types are presented. All classifications for this
study have been manually confirmed. The selection criteria for this analysis
have been conservatively defined, and are known to be biased against some
variable classes. This preliminary study includes only 5.6% of the total
ROTSE-I sky coverage, suggesting that the full ROTSE-I variable catalog will
include more than 32,000 periodic variable stars.Comment: Accepted for publication in AJ 4/00. LaTeX manuscript. (28 pages, 11
postscript figures and 1 gif
Modelling the Galactic Bar Using Red Clump Giants
The color-magnitude diagrams of stars obtained for 12
fields across the Galactic bulge with the OGLE project reveal a well-defined
population of bulge red clump giants. We find that the distributions of the
apparent magnitudes of the red clump stars are systematically fainter when
moving towards lower galactic fields. The most plausible explanation of
this distinct trend is that the Galactic bulge is a bar, whose nearest end lies
at positive galactic longitude. We model this Galactic bar by fitting for all
fields the observed luminosity functions in the red clump region of the
color-magnitude diagram. We find that almost regardless of the analytical
function used to describe the 3-D stars distribution of the Galactic bar, the
resulting models have the major axis inclined to the line of sight by
, with axis ratios corresponding to . This
puts a strong constraint on the possible range of the Galactic bar models.
Gravitational microlensing can provide us with additional constrains on the
structure of the Galactic bar.Comment: submitted to the New Astronomy, 27 pages, 11 figures; also available
at ftp://www.astro.princeton.edu/stanek/Barmodel and through WWW at
http://www.astro.princeton.edu/~library/prep.htm
Staring into the abyss? The state of UK rugby's Super League
Rugby League's Super League was formed in 1995, due to unprecedented turmoil experienced in rugby league in Australia and a desire to run a season parallel to the Australian game during the British summer. The predicted outcomes of the Super League included greater uncertainty of outcome, increased attendances, and higher revenues for clubs, ultimately leading to the transformation of rugby league from a northern minority sport into a national/international sport. However, twenty years on, it appears that the Super League is running short of the objectives that it set itself. This paper analyses the financial health of Super League clubs alongside trends in attendance and participation. In summary, all three indicators of performance are poor in relation to the objectives set. These factors point to a bleak future for the sport and rugby league needs to produce a sustainable business model to keep both the clubs and the sport alive
Observation of a large parity nonconserving analyzing power in Xe
A large parity nonconserving longitudinal analyzing power was discovered in polarized-neutron transmission through Xe. An analyzing power of 4.3±0.2% was observed in a p-wave resonance at En=3.2 eV. The measurement was performed with a liquid Xe target of natural isotopic abundance that was placed in the polarized epithermal neutron beam, flight path 2, at the Manuel Lujan Neutron Science Center. This apparatus was constructed by the TRIPLE Collaboration, and has been used for studies of parity symmetry in compound nuclear resonances. Part of the motivation of the experiment was to discover a nucleus appropriate for a sensitive test of time-reversal invariance in polarized-neutron transmission. The large analyzing power of the observed resonance may make it possible to design a test of time reversal invariance using a polarized-Xe target
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