Orbital Solutions and Absolute Elements of the Eclipsing Binary MY Cygni

Differential UBV photoelectric photometry for the eclipsing binary MY Cyg is presented. The Wilson-Devinney program is used to simultaneously solve the three light curves together with previously published radial velocities. A comparison is made with the previous solution found with the Russell-Merrill method. We examine the long-term apsidal motion of this well-detached, slightly eccentric system. We determine absolute dimensions, discuss metallicity/Am-star issues, and estimate the evolutionary status of the stars

Classifying the unknown: discovering novel gravitational-wave detector glitches using similarity learning

The observation of gravitational waves from compact binary coalescences by LIGO and Virgo has begun a new era in astronomy. A critical challenge in making detections is determining whether loud transient features in the data are caused by gravitational waves or by instrumental or environmental sources. The citizen-science project \emph{Gravity Spy} has been demonstrated as an efficient infrastructure for classifying known types of noise transients (glitches) through a combination of data analysis performed by both citizen volunteers and machine learning. We present the next iteration of this project, using similarity indices to empower citizen scientists to create large data sets of unknown transients, which can then be used to facilitate supervised machine-learning characterization. This new evolution aims to alleviate a persistent challenge that plagues both citizen-science and instrumental detector work: the ability to build large samples of relatively rare events. Using two families of transient noise that appeared unexpectedly during LIGO's second observing run (O2), we demonstrate the impact that the similarity indices could have had on finding these new glitch types in the Gravity Spy program

KIC 4247791: A SB4 system with two eclipsing binaries (2EBs)

KIC 4247791 is an eclipsing binary observed by the Kepler satellite mission. We wish to determine the nature of its components and in particular the origin of a shallow dip in its Kepler light curve that previous investigations have been unable to explain in a unique way. We analyze newly obtained high-resolution spectra of the star using synthetic spectra based on atmosphere models, derive the radial velocities of the stellar components from cross-correlation with a synthetic template, and calculate the orbital solution. We use the JKTEBOP program to model the Kepler light curve of KIC 4247791. We find KIC 4247791 to be a SB4 star. The radial velocity variations of its four components can be explained by two separate eclipsing binaries. In contradiction to previous photometric findings, we show that the observed composite spectrum as well as the derived masses of all four of its components correspond to spectral type F. The observed small dip in the light curve is not caused by a transit-like phenomenon but by the eclipses of the second binary system. We find evidence that KIC 4247791 might belong to the very rare hierarchical SB4 systems with two eclipsing binaries.Comment: 6 pages, 8 figures, 2 table

Lack of Transit Timing Variations of OGLE-TR-111b: A re-analysis with six new epochs

We present six new transits of the exoplanet OGLE-TR-111b observed with the Magellan Telescopes in Chile between April 2008 and March 2009. We combine these new transits with five previously published transit epochs for this planet between 2005 and 2006 to extend the analysis of transit timing variations reported for this system. We derive a new planetary radius value of 1.019 +/- 0.026 R_J, which is intermediate to the previously reported radii of 1.067 +/- 0.054 R_J (Winn et al. 2007) and 0.922 +/- 0.057 R_J (Diaz et al. 2008). We also examine the transit timing variation and duration change claims of Diaz et al. (2008). Our analysis of all eleven transit epochs does not reveal any points with deviations larger than 2 sigma, and most points are well within 1 sigma. Although the transit duration nominally decreases over the four year span of the data, systematic errors in the photometry can account for this result. Therefore, there is no compelling evidence for either a timing or a duration variation in this system. Numerical integrations place an upper limit of about 1 M_E on the mass of a potential second planet in a 2:1 mean-motion resonance with OGLE-TR-111b.Comment: 28 pages, 7 tables, 6 figures. Accepted by Ap

Identification of long-duration noise transients in LIGO and Virgo

The LIGO and Virgo detectors are sensitive to a variety of noise sources, such as instrumental artifacts and environmental disturbances. The Stochastic Transient Analysis Multi-detector Pipeline (STAMP) has been developed to search for long-duration (t$\gtrsim$1s) gravitational-wave (GW) signals. This pipeline can also be used to identify environmental noise transients. Here we present an algorithm to determine when long-duration noise sources couple into the interferometers, as well as identify what these noise sources are. We analyze the cross-power between a GW strain channel and an environmental sensor, using pattern recognition tools to identify statistically significant structure in cross-power time-frequency maps. We identify interferometer noise from airplanes, helicopters, thunderstorms and other sources. Examples from LIGO's sixth science run, S6, and Virgo's third scientific run, VSR3, are presented.Comment: 10 pages, 7 figures, Gravitational-wave Physics & Astronomy Worksho

Seismic topographic scattering in the context of GW detector site selection

In this paper, we present a calculation of seismic scattering from irregular surface topography in the Born approximation. Based on US-wide topographic data, we investigate topographic scattering at specific sites to demonstrate its impact on Newtonian-noise estimation and subtraction for future gravitational-wave detectors. We find that topographic scattering at a comparatively flat site in Oregon would not pose any problems, whereas scattering at a second site in Montana leads to significant broadening of wave amplitudes in wavenumber space that would make Newtonian-noise subtraction very challenging. Therefore, it is shown that topographic scattering should be included as criterion in the site-selection process of future low-frequency gravitational-wave detectors.Comment: 16 pages, 7 figure

Supplement: Going the Distance: Mapping Host Galaxies of LIGO and Virgo Sources in Three Dimensions Using Local Cosmography and Targeted Follow-up

This is a supplement to the Letter of Singer et al. (https://arxiv.org/abs/1603.07333), in which we demonstrated a rapid algorithm for obtaining joint 3D estimates of sky location and luminosity distance from observations of binary neutron star mergers with Advanced LIGO and Virgo. We argued that combining the reconstructed volumes with positions and redshifts of possible host galaxies can provide large-aperture but small field of view instruments with a manageable list of targets to search for optical or infrared emission. In this Supplement, we document the new HEALPix-based file format for 3D localizations of gravitational-wave transients. We include Python sample code to show the reader how to perform simple manipulations of the 3D sky maps and extract ranked lists of likely host galaxies. Finally, we include mathematical details of the rapid volume reconstruction algorithm.Comment: For associated data release, see http://asd.gsfc.nasa.gov/Leo.Singer/going-the-distanc

A randomised trial of robotic and open prostatectomy in men with localised prostate cancer

Background: Prostate cancer is the most common male cancer in the Western world however there is ongoing debate about the optimal treatment strategy for localised disease. While surgery remains the most commonly received treatment for localised disease in Australia more recently a robotic approach has emerged as an alternative to open and laparoscopic surgery. However, high level data is not yet available to support this as a superior approach or to guide treatment decision making between the alternatives. This paper presents the design of a randomised trial of Robotic and Open Prostatectomy for men newly diagnosed with localised prostate cancer that seeks to answer this question.Methods/design: 200 men per treatment arm (400 men in total) are being recruited after diagnosis and before treatment through a major public hospital outpatient clinic and randomised to 1) Robotic Prostatectomy or 2) Open Prostatectomy. All robotic prostatectomies are being performed by one surgeon and all open prostatectomies are being performed by one other surgeon. Outcomes are being measured pre-operatively and at 6 weeks and 3, 6, 12 and 24 months post-surgery. Oncological outcomes are being related to positive surgical margins, biochemical recurrence +/- the need for further treatment. Non-oncological outcome measures include: pain, physical and mental functioning, fatigue, summary (preference-based utility scores) and domain-specific QoL (urinary incontinence, bowel function and erectile function), cancer specific distress, psychological distress, decision-related distress and time to return to usual activities. Cost modelling of each approach, as well as full economic appraisal, is also being undertaken.Discussion: The study will provide recommendations about the relative benefits of Robotic and Open Prostatectomy to support informed patient decision making about treatment for localised prostate cancer; and to assist in treatment services planning for this patient group.Trial registration: ACTRN12611000661976

Maintaining Structural Stability of Poly(lactic acid): Effects of Multifunctional Epoxy based Reactive Oligomers

In order to reduce the effects of hydrolytic degradation and to maintain sufficient viscosity during processing of biomass based poly(l-lactic acid) (PLLA), various epoxy functional reactive oligomers have been characterized and incorporated into the degraded fragments as chain extenders. The molecular weight of PLLA increased with the increase in functionality of the reactive oligomers. No further increase in molecular weight was observed for oligomers with functionality of greater than five. Under our experimental conditions, no gelation was found even when the highest functionality reactive oligomers were used. This is attributed to the preferential reaction of the carboxylic acid versus the negligible reactivity of the hydroxyl groups, present at the two ends of the degraded PLLA chains, with the epoxy groups. The study provides a clear understanding of the degradation and chain extension reaction of poly(lactic acid) (PLA) with epoxy functional reactive oligomers. It is also shown that a higher functionality and concentration of the reactive oligomers is needed, to bring about a sufficient increase in the molecular weight and hence the hydrolytic stability in circumstances when PLA chains suffer significant degradation during processing

Observations of the GRB afterglow ATLAS17aeu and its possible association with GW170104

We report the discovery and multi-wavelength data analysis of the peculiar optical transient, ATLAS17aeu. This transient was identified in the skymap of the LIGO gravitational wave event GW170104 by our ATLAS and Pan-STARRS coverage. ATLAS17aeu was discovered 23.1hrs after GW170104 and rapidly faded over the next 3 nights, with a spectrum revealing a blue featureless continuum. The transient was also detected as a fading x-ray source by Swift and in the radio at 6 and 15 GHz. A gamma ray burst GRB170105A was detected by 3 satellites 19.04hrs after GW170104 and 4.10hrs before our first optical detection. We analyse the multi-wavelength fluxes in the context of the known GRB population and discuss the observed sky rates of GRBs and their afterglows. We find it statistically likely that ATLAS17aeu is an afterglow associated with GRB170105A, with a chance coincidence ruled out at the 99\% confidence or 2.6$\sigma$. A long, soft GRB within a redshift range of $1 \lesssim z \lesssim 2.9$ would be consistent with all the observed multi-wavelength data. The Poisson probability of a chance occurrence of GW170104 and ATLAS17aeu is $p=0.04$. This is the probability of a chance coincidence in 2D sky location and in time. These observations indicate that ATLAS17aeu is plausibly a normal GRB afterglow at significantly higher redshift than the distance constraint for GW170104 and therefore a chance coincidence. However if a redshift of the faint host were to place it within the GW170104 distance range, then physical association with GW170104 should be considered.Comment: 16 pages, 6 figures, accepted to Ap