scholarly journals A photospheric and chromospheric activity analysis of the quiescent retrograde-planet host ν Octantis A

2021 ◽  
Vol 502 (2) ◽  
pp. 2793-2806
Author(s):  
D J Ramm ◽  
P Robertson ◽  
S Reffert ◽  
F Gunn ◽  
T Trifonov ◽  
...  
Keyword(s):  
Semimajor Axis ◽  
Spectroscopic Studies ◽  
Additional Line ◽  
Stellar Orbits ◽  
Qualitative And Quantitative ◽  
Spectroscopic Binary ◽  
Analysis Models ◽  
Large Survey ◽  
New Evidence ◽  
Line Depth

ABSTRACT The single-lined spectroscopic binary ν Octantis provided evidence of the first conjectured circumstellar planet demanding an orbit retrograde to the stellar orbits. The planet-like behaviour is now based on 1437 radial velocities (RVs) acquired from 2001 to 2013. ν Oct’s semimajor axis is only 2.6 au with the candidate planet orbiting $\nu ~{\rm Oct\, A}$ about mid-way between. These details seriously challenge our understanding of planet formation and our decisive modelling of orbit reconfiguration and stability scenarios. However, all non-planetary explanations are also inconsistent with numerous qualitative and quantitative tests including previous spectroscopic studies of bisectors and line-depth ratios, photometry from Hipparcos and the more recent space missions TESS and Gaia (whose increased parallax classifies $\nu ~{\rm Oct\, A}$ closer still to a subgiant, ∼K1 IV). We conducted the first large survey of $\nu ~{\rm Oct\, A}$’s chromosphere: 198 $\rm Ca\,{\small II}$ H-line and 1160 $\rm {H}\, \alpha$ indices using spectra from a previous RV campaign (2009–2013). We also acquired 135 spectra (2018–2020) primarily used for additional line-depth ratios, which are extremely sensitive to the photosphere’s temperature. We found no significant RV-correlated variability. Our line-depth ratios indicate temperature variations of only ±4 K, as achieved previously. Our atypical $\rm Ca\,{\small II}$ analysis models the indices in terms of S/N and includes covariance significantly in their errors. The $\rm {H}\, \alpha$ indices have a quasi-periodic variability that we demonstrate is due to telluric lines. Our new evidence provides further multiple arguments realistically only in favour of the planet.

The V2 syntax of Medieval Romance

2018 ◽  
pp. 17-34
Author(s):  
Sam Wolfe
Keyword(s):  
Old French ◽  
Romance Languages ◽  
Medieval Romance ◽  
Quantitative Evidence ◽  
Old Spanish ◽  
Qualitative And Quantitative ◽  
Old Occitan ◽  
Old Portuguese ◽  
New Evidence ◽  
Detailed Presentation

This chapter provides a detailed presentation of the main data and arguments which have been proposed in favour of claiming that the Medieval Romance languages were V2 systems and considers data from Old French, Old Occitan, Old Italo-Romance varieties, Old Spanish, and Old Portuguese. It provides new qualitative and quantitative evidence to show the nature of the prefield, Germanic inversion, matrix/embedded asymmetries, and the precise types of verb-first and verb-third-or-greater orders provide new evidence in favour of the V2 hypothesis. It also suggests that the diachronic emergence of a V2 grammar is entirely plausible on the basis of the available data. The main objections to the V2 account proposed in the literature are evaluated and argued to face empirical and theoretical problems.

scholarly journals Order–disorder phase transition in black hole star clusters – III. A mono-energetic cluster

2020 ◽  
Vol 493 (2) ◽  
pp. 2632-2651 ◽  
Author(s):  
Scott Tremaine
Keyword(s):  
Phase Transition ◽  
Black Hole ◽  
Maximum Entropy ◽  
Semimajor Axis ◽  
Star Clusters ◽  
Gravitational Energy ◽  
Stellar Orbits ◽  
Disorder Phase Transition ◽  
Wide Range ◽  
Temperature Equilibrium

ABSTRACT Supermassive black holes at the centres of galaxies are often surrounded by dense star clusters. For a wide range of cluster properties and orbital radii the resonant relaxation times in these clusters are much shorter than the Hubble time. Since resonant relaxation conserves semimajor axes, these clusters should be in the maximum-entropy state consistent with the given semimajor axis distribution. We determine these maximum-entropy equilibria in a simplified model in which all of the stars have the same semimajor axes. We find that the cluster exhibits a phase transition from a disordered, spherical, high-temperature equilibrium to an ordered low-temperature equilibrium in which the stellar orbits have a preferred orientation or line of apsides. Here ‘temperature’ is a measure of the non-Keplerian or self-gravitational energy of the cluster; in the spherical state, temperature is a function of the rms eccentricity of the stars. We explore a simple two-parameter model of black hole star clusters – the two parameters are semimajor axis and black hole mass – and find that clusters are susceptible to the lopsided phase transition over a range of ∼102 in semimajor axis, mostly for black hole masses $\lesssim 10^{7.5}\, \mathrm{M}_{\odot }$.

scholarly journals Mk III Interferometer: Milliarcsecond “Visual” Orbits of Spectroscopic Binaries

1994 ◽  
Vol 158 ◽  
pp. 410-412
Author(s):  
C.A. Hummel ◽  
J.T. Armstrong
Keyword(s):  
Uncertainty Analysis ◽  
Semimajor Axis ◽  
Spectroscopic Binaries ◽  
Optical Interferometer ◽  
Analysis Techniques ◽  
Spectroscopic Binary ◽  
The Mean

The spectroscopic binary observing program of the Mark III Optical Interferometer has produced four published orbits and 22 preliminary orbits. The mean (formal) precision is 0.3% for measurements of sin i and 0.7% for measurements of the semimajor axis a. We list the stars for which we have obtained orbits or preliminary orbits and describe our data and uncertainty analysis techniques.

scholarly journals Preferences and Uses of a Remote Lab from the Students’ Viewpoint

2016 ◽  
Vol 12 (03) ◽  
pp. 53 ◽  
Author(s):  
Federico Lerro ◽  
Susana Marchisio
Keyword(s):  
Quantitative Data ◽  
Virtual Classroom ◽  
Learning Resource ◽  
Qualitative And Quantitative ◽  
Electronic Engineering ◽  
Remote Laboratories ◽  
Remote Lab ◽  
Second Year ◽  
New Evidence ◽  
Comprehensive Study

This paper aims to present new evidence and findings that enhance and enrich the knowledge of the preferences and uses of the remote laboratories from the students´ viewpoint. Specifically, the study aims to recognize the students’ preferences in selecting the remote lab as a learning resource, beyond the uses promoted by the professorship. Likewise, we seek to know the reasons given by students that support those preferences. The research was conducted at Facultad de Ciencias Exactas, Ingeniería y Agrimensura (FCEIA), Universidad Nacional de Rosario (UNR), Argentina, by using the “FCEIA-UNR Electronics Physics Remote Lab” and involving almost 300 students in the second year of Electronic Engineering. The lab is integrated into the Learning Management System (LMS) e-ducativa, Facebook and Twitter, allowing the students to log in without additional authentication, both from the virtual classroom or from those social networks. We collected empirical evidence from both, users' opinions and productions, and also, from registers of the remote lab itself, involving more than 4000 successful tests completed on the lab´s database. We achieved both qualitative and quantitative data that allow us to get a comprehensive study from the students’ perspective.

scholarly journals NGTS J214358.5−380102 – NGTS discovery of the most eccentric known eclipsing M-dwarf binary system

2020 ◽  
Vol 494 (3) ◽  
pp. 3950-3961 ◽  
Author(s):  
Jack S Acton ◽  
Michael R Goad ◽  
Liam Raynard ◽  
Sarah L Casewell ◽  
James A G Jackman ◽  
...  
Keyword(s):  
Binary Systems ◽  
Spectral Energy Distribution ◽  
Semimajor Axis ◽  
Spectral Energy ◽  
Orbital Eccentricity ◽  
Distribution Fitting ◽  
Stellar Orbits ◽  
Interesting Insight ◽  
Stellar Masses ◽  
M Dwarf

ABSTRACT We present the discovery of NGTS J214358.5–380102, an eccentric M-dwarf binary discovered by the Next-Generation Transit Survey (NGTS). The system period of 7.618 d is greater than many known eclipsing M-dwarf binary systems. Its orbital eccentricity of $0.323^{+0.0014}_{-0.0037}$ is large relative to the period and semimajor axis of the binary. Global modelling of photometry and radial velocities indicates stellar masses of MA = $0.426 ^{+0.0056}_{-0.0049}$ M⊙, MB = $0.455 ^{+0.0058}_{-0.0052}$ M⊙ and stellar radii RA = $0.461 ^{+0.038}_{-0.025}$ R⊙, RB = $0.411 ^{+0.027}_{-0.039}$ R⊙, respectively. Comparisons with stellar models for low-mass stars show that one star is consistent with model predictions whereas the other is substantially oversized. Spectral analysis of the system suggests a primary of spectral type M3V, consistent with both modelled masses and radii, and with spectral energy distribution fitting of NGTS photometry. As the most eccentric eclipsing M-dwarf binary known, NGTS J214358.5–380102 provides an interesting insight into the strength of tidal effects in the circularization of stellar orbits.

scholarly journals Fresh Evidence and Factual Innocence in the Criminal Division of the Court of Appeal

2017 ◽  
Vol 81 (4) ◽  
pp. 303-327 ◽  
Author(s):  
Stephanie Roberts
Keyword(s):  
Empirical Research ◽  
Wrongful Convictions ◽  
Jury Verdict ◽  
Qualitative And Quantitative ◽  
Factual Error ◽  
The Law ◽  
New Evidence ◽  
Court Of Appeal ◽  
Broad Consensus

One of the main criticisms of the Criminal Division of the Court of Appeal has been that it is deficient at identifying and correcting the wrongful convictions of the factually innocent. These criticisms stem from the court’s perceived difficulties in relation to appeals based on factual error. The main ground of appeal for errors of fact is fresh evidence, and these appeals are particularly problematic because they require the court to trespass on the role of the jury somewhat in assessing new evidence on appeal against the evidence at trial in order to determine whether the conviction is unsafe. The broad consensus is that the court’s difficulties are caused by three main issues: its deference to the jury verdict; its reverence for the principle of finality; and a lack of resources to deal with huge numbers appealing. There is less agreement in identifying the source of the problems because it is not clear whether they derive from legislative powers or the interpretation of those powers by the judiciary. This article uses both qualitative and quantitative empirical research in order to try to determine what the court’s approach is in fresh evidence appeals and, if there are problems, whether it is the law or the interpretation of the law by the judiciary which is to blame. It also proposes reforms designed to make it easier for the court to rectify miscarriages of justice.

Systematic effects in observed parallaxes

1978 ◽  
Vol 48 ◽  
pp. 31-35
Author(s):  
R. B. Hanson
Keyword(s):  
Error Estimates ◽  
Zero Point ◽  
Absolute Zero ◽  
Apparent Magnitude ◽  
Coherent System ◽  
Preliminary Results ◽  
General Catalogue ◽  
Systematic Effects ◽  
New Evidence ◽  
Right Ascension

Several outstanding problems affecting the existing parallaxes should be resolved to form a coherent system for the new General Catalogue proposed by van Altena, as well as to improve luminosity calibrations and other parallax applications. Lutz has reviewed several of these problems, such as: (A) systematic differences between observatories, (B) external error estimates, (C) the absolute zero point, and (D) systematic observational effects (in right ascension, declination, apparent magnitude, etc.). Here we explore the use of cluster and spectroscopic parallaxes, and the distributions of observed parallaxes, to bring new evidence to bear on these classic problems. Several preliminary results have been obtained.

Expression of laminin and beta-1 integrin in embryonic, neonatal, and adult rat heart

1991 ◽  
Vol 49 ◽  
pp. 182-183
Author(s):  
R.L. Price ◽  
T.K. Borg ◽  
L. Terracio ◽  
M. Nakagawa
Keyword(s):  
Temporal Expression ◽  
Qualitative And Quantitative ◽  
Adult Rat ◽  
Cytoplasmic Face ◽  
Extracellular Matrix Components ◽  
Basement Membrane Component ◽  
Beta 1 Integrin ◽  
Quantitative Changes ◽  
Cytoskeletal Elements ◽  
External Face

Little is known about the temporal expression of extracellular matrix components (ECM) and its receptors during development of the heart. Recent reports have shown that ECM components undergo both qualitative and quantitative changes during development, and it is believed that ECM components are important in the regulation of cell migration and cell:cell and cell:ECM recognition and adhesion.Integrins are transmembrane glycoproteins which bind several ECM components on their external face and cytoskeletal elements on the cytoplasmic face. Laminin is a basement membrane component which has been recognized as an important site for cell adhesion. Both the integrins and laminin are expressed early in development and continue to be expressed in the adult heart. With their documented roles in cell recognition, and cell:cell and cell:ECM migration and adhesion these proteins appear to be important components in development of the heart, and their temporal expression may play a pivotal role in morphogenesis and myofibrillogenesis of the heart.

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