232 research outputs found
An Eccentric Eclipsing Binary: CGAur
In this study, we present CG Aur's photometric observations obtained in the
observing seasons 2011 and 2012, the first available multi-colour light curves.
Their shape indicates that the system is an Algol binary. The light curve
analyses reveal that CG Aur is a detached binary system with an effective
temperature difference between the components, approximately 1000 K. The first
estimate of the absolute dimensions of the components indicated that the system
locates on the main sequence in the HR diagram. The primary component is
slightly evolved from the ZAMS.Comment: 18 pages, 6 figures, 3 table
Brightness variations in totally-eclipsing binary GSC4589-2999
We present multi-colour CCD photometry of GSC4589-2999 obtained in 2008 and
2009. The observations indicate that the system is an active Algol binary.
Based on the new data, the mean brightness of the system is decreasing through
the years 2007-2009. The light curves obtained in 2008-2009 are modelled using
the Wilson-Devinney code. We also discussed the light and colour variations of
the system at different orbital phases. Evidence suggests that these brightness
and colour variations are due to the rotation of unevenly distributed starspots
on two components of the system.Comment: 17 pages, 3 figures, 3 table
BD+36 3317: An algol type eclipsing binary in Delta Lyrae cluster
In this paper, we present standard Johnson UBV photometry of the eclipsing
binary BD+36 3317 which is known as a member of Delta Lyrae (Stephenson 1)
cluster. We determined colors and brightness of the system, calculated E(B - V)
color excess. We discovered that the system shows total eclipse in secondary
minimum. Using this advantage, we found that the primary component of the
system has B9 - A0 spectral type. Although there is no published orbital
solution, we tried to estimate the physical properties of the system from
simultaneous analysis of UBV light curves with 2003 version of Wilson-Devinney
code. Then we considered photometric solution results together with
evolutionary models and estimated the masses of the components as M1 = 2.5 Msun
and M2 = 1.6 Msun. Those estimations gave the distance of the system as 353 pc.
Considering the uncertainties in distance estimation, resulting distance is in
agreement with the distance of Delta Lyrae cluster.Comment: 18 pages, 4 figures, 5 table
The statistical analyses of flares detected in B band photometry of UV Ceti type stars
In this study, we present the unpublished flare data collected from 222
flares detected in the B band observations of five stars and the results
derived by statistical analysis and modeling of these data. Six basic
properties have been found with a statistical analysis method applied to all
models and analyses for the flares detected in the B band observation of UV
Ceti type stars. We have also compared the U and B bands with the analysis
results. This comparison allowed us to evaluate the methods used in the
analyses. The analyses provided the following results. (1) The flares were
separated into two types, fast and slow flares. (2) The mean values of the
equivalent durations of the slow and the fast flares differ by a factor of 16.2
\pm 3.7. (3) Regardless of the total flare duration, the maximum flare energy
can reach a different Plateau level for each star. (4) The Plateau values of EV
Lac and EQ Peg are higher than the others. (5) The minimum values of the total
flare duration increase toward the later spectral types. This value is called
the Half-Life value in models. (6) Both the maximum flare rise times and the
total flare duration obtained from the observed flares decrease toward the
later spectral types.Comment: 17 pages, 10 figures, 8 table
Measurement of the B0-anti-B0-Oscillation Frequency with Inclusive Dilepton Events
The - oscillation frequency has been measured with a sample of
23 million \B\bar B pairs collected with the BABAR detector at the PEP-II
asymmetric B Factory at SLAC. In this sample, we select events in which both B
mesons decay semileptonically and use the charge of the leptons to identify the
flavor of each B meson. A simultaneous fit to the decay time difference
distributions for opposite- and same-sign dilepton events gives ps.Comment: 7 pages, 1 figure, submitted to Physical Review Letter
Body appreciation around the world: Measurement invariance of the Body Appreciation Scale-2 (BAS-2) across 65 nations, 40 languages, gender identities, and age.
The Body Appreciation Scale-2 (BAS-2) is a widely used measure of a core facet of the positive body image construct. However, extant research concerning measurement invariance of the BAS-2 across a large number of nations remains limited. Here, we utilised the Body Image in Nature (BINS) dataset - with data collected between 2020 and 2022 - to assess measurement invariance of the BAS-2 across 65 nations, 40 languages, gender identities, and age groups. Multi-group confirmatory factor analysis indicated that full scalar invariance was upheld across all nations, languages, gender identities, and age groups, suggesting that the unidimensional BAS-2 model has widespread applicability. There were large differences across nations and languages in latent body appreciation, while differences across gender identities and age groups were negligible-to-small. Additionally, greater body appreciation was significantly associated with higher life satisfaction, being single (versus being married or in a committed relationship), and greater rurality (versus urbanicity). Across a subset of nations where nation-level data were available, greater body appreciation was also significantly associated with greater cultural distance from the United States and greater relative income inequality. These findings suggest that the BAS-2 likely captures a near-universal conceptualisation of the body appreciation construct, which should facilitate further cross-cultural research. [Abstract copyright: Copyright © 2023 The Authors. Published by Elsevier Ltd.. All rights reserved.
Search for gravitational waves from Scorpius X-1 in the second Advanced LIGO observing run with an improved hidden Markov model
We present results from a semicoherent search for continuous gravitational waves from the low-mass x-ray binary Scorpius X-1, using a hidden Markov model (HMM) to track spin wandering. This search improves on previous HMM-based searches of LIGO data by using an improved frequency domain matched filter, the J-statistic, and by analyzing data from Advanced LIGO's second observing run. In the frequency range searched, from 60 to 650 Hz, we find no evidence of gravitational radiation. At 194.6 Hz, the most sensitive search frequency, we report an upper limit on gravitational wave strain (at 95% confidence) of h095%=3.47×10-25 when marginalizing over source inclination angle. This is the most sensitive search for Scorpius X-1, to date, that is specifically designed to be robust in the presence of spin wandering. © 2019 American Physical Society
Search for Gravitational Waves Associated with Gamma-Ray Bursts Detected by Fermi and Swift during the LIGO-Virgo Run O3b
We search for gravitational-wave signals associated with gamma-ray bursts (GRBs) detected by the Fermi and Swift satellites during the second half of the third observing run of Advanced LIGO and Advanced Virgo (2019 November 1 15:00 UTC-2020 March 27 17:00 UTC). We conduct two independent searches: A generic gravitational-wave transients search to analyze 86 GRBs and an analysis to target binary mergers with at least one neutron star as short GRB progenitors for 17 events. We find no significant evidence for gravitational-wave signals associated with any of these GRBs. A weighted binomial test of the combined results finds no evidence for subthreshold gravitational-wave signals associated with this GRB ensemble either. We use several source types and signal morphologies during the searches, resulting in lower bounds on the estimated distance to each GRB. Finally, we constrain the population of low-luminosity short GRBs using results from the first to the third observing runs of Advanced LIGO and Advanced Virgo. The resulting population is in accordance with the local binary neutron star merger rate. © 2022. The Author(s). Published by the American Astronomical Society
Open data from the third observing run of LIGO, Virgo, KAGRA, and GEO
The global network of gravitational-wave observatories now includes five detectors, namely LIGO Hanford, LIGO Livingston, Virgo, KAGRA, and GEO 600. These detectors collected data during their third observing run, O3, composed of three phases: O3a starting in 2019 April and lasting six months, O3b starting in 2019 November and lasting five months, and O3GK starting in 2020 April and lasting two weeks. In this paper we describe these data and various other science products that can be freely accessed through the Gravitational Wave Open Science Center at https://gwosc.org. The main data set, consisting of the gravitational-wave strain time series that contains the astrophysical signals, is released together with supporting data useful for their analysis and documentation, tutorials, as well as analysis software packages
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