Orion revisited. II. The foreground population to Orion A

Following the recent discovery of a large population of young stars in front of the Orion Nebula, we carried out an observational campaign with the DECam wide-field camera covering ~10~deg^2 centered on NGC 1980 to confirm, probe the extent of, and characterize this foreground population of pre-main-sequence stars. We confirm the presence of a large foreground population towards the Orion A cloud. This population contains several distinct subgroups, including NGC1980 and NGC1981, and stretches across several degrees in front of the Orion A cloud. By comparing the location of their sequence in various color-magnitude diagrams with other clusters, we found a distance and an age of 380pc and 5~10Myr, in good agreement with previous estimates. Our final sample includes 2123 candidate members and is complete from below the hydrogen-burning limit to about 0.3Msun, where the data start to be limited by saturation. Extrapolating the mass function to the high masses, we estimate a total number of ~2600 members in the surveyed region. We confirm the presence of a rich, contiguous, and essentially coeval population of about 2600 foreground stars in front of the Orion A cloud, loosely clustered around NGC1980, NGC1981, and a new group in the foreground of the OMC-2/3. For the area of the cloud surveyed, this result implies that there are more young stars in the foreground population than young stars inside the cloud. Assuming a normal initial mass function, we estimate that between one to a few supernovae must have exploded in the foreground population in the past few million years, close to the surface of Orion A, which might be responsible, together with stellar winds, for the structure and star formation activity in these clouds. This long-overlooked foreground stellar population is of great significance, calling for a revision of the star formation history in this region of the Galaxy.Comment: Accepted for publication in A&

Automated supervised classification of variable stars I. Methodology

The fast classification of new variable stars is an important step in making them available for further research. Selection of science targets from large databases is much more efficient if they have been classified first. Defining the classes in terms of physical parameters is also important to get an unbiased statistical view on the variability mechanisms and the borders of instability strips. Our goal is twofold: provide an overview of the stellar variability classes that are presently known, in terms of some relevant stellar parameters; use the class descriptions obtained as the basis for an automated `supervised classification' of large databases. Such automated classification will compare and assign new objects to a set of pre-defined variability training classes. For every variability class, a literature search was performed to find as many well-known member stars as possible, or a considerable subset if too many were present. Next, we searched on-line and private databases for their light curves in the visible band and performed period analysis and harmonic fitting. The derived light curve parameters are used to describe the classes and define the training classifiers. We compared the performance of different classifiers in terms of percentage of correct identification, of confusion among classes and of computation time. We describe how well the classes can be separated using the proposed set of parameters and how future improvements can be made, based on new large databases such as the light curves to be assembled by the CoRoT and Kepler space missions.Comment: This paper has been accepted for publication in Astronomy and Astrophysics (reference AA/2007/7638) Number of pages: 27 Number of figures: 1

Fiduciary Society Unleashed: The Road Ahead for the Financial Sector

Informational asymmetries, misaligned incentives, and artificially elongated chains of intermediation have created a disconnect between the financial sector and the “real economy” that is detrimental to the public interest. Courts and regulators are increasingly intervening to break the cycle. We argue that fiduciary law offers a conceptual framework both for understanding and responding to this trend, and that the financial sector, rather than waiting for this trend to develop and reacting to new rules in a piecemeal way, should be proactive and try to shape the way in which this trend develops. We describe some elements of what such an approach might look like, and consider how regulators and political institutions can encourage financial institutions to adopt this approach, and in so doing support a broader transition to a more sustainable economy

The Public Fiduciary: Emerging Themes in Canadian Fiduciary Law for Pension Trustees

As society increasingly faces governance challenges at all levels, there is a growing recognition of the need to take a longer term and more systemic view of fiduciary obligations. We begin this article with a summary discussion of how fiduciary duties have developed and been applied in the pension fund context. We then review the efforts of the Supreme Court of Canada to develop a broader conceptual framework for fiduciary duties and consider steps that might be taken to address and mitigate liability in respect of these duties in the context of pension fund administration. We conclude by considering the trajectory of the law and how it appears to be positioning fiduciaries with public responsibilities and, in doing so, could alter legal and governance precepts

The Public Fiduciary: Emerging Themes in Canadian Fiduciary Law for Pension Trustees

As society increasingly faces governance challenges at all levels, there is a growing recognition of the need to take a longer term and more systemic view of fiduciary obligations. We begin this article with a summary discussion of how fiduciary duties have developed and been applied in the pension fund context. We then review the efforts of the Supreme Court of Canada to develop a broader conceptual framework for fiduciary duties and consider steps that might be taken to address and mitigate liability in respect of these duties in the context of pension fund administration. We conclude by considering the trajectory of the law and how it appears to be positioning fiduciaries with public responsibilities and, in doing so, could alter legal and governance precepts

Reconnecting the Financial Sector to the Real Economy: A Plan for Action

Informational asymmetries, misaligned incentives, and artificially elongated chains of intermediation have created a disconnect between the financial sector and the real economy that is detrimental to the public interest. Courts and regulators are increasingly intervening to break the cycle. Fiduciary law offers a conceptual framework both for understanding and responding to this trend. This article argues that the financial sector, rather than waiting for this trend to develop and reacting to new rules in a piecemeal way, should be proactive and shape the way in which the trend develops

Reconnecting the Financial Sector to the Real Economy: A Plan for Action

Informational asymmetries, misaligned incentives, and artificially elongated chains of intermediation have created a disconnect between the financial sector and the real economy that is detrimental to the public interest. Courts and regulators are increasingly intervening to break the cycle. Fiduciary law offers a conceptual framework both for understanding and responding to this trend. This article argues that the financial sector, rather than waiting for this trend to develop and reacting to new rules in a piecemeal way, should be proactive and shape the way in which the trend develops

The Public Fiduciary: Emerging Themes in Canadian Fiduciary Law for Pension Trustees

As society increasingly faces governance challenges at all levels, there is a growing recognition of the need to take a longer term and more systemic view of fiduciary obligations. We begin this article with a summary discussion of how fiduciary duties have developed and been applied in the pension fund context. We then review the efforts of the Supreme Court of Canada to develop a broader conceptual framework for fiduciary duties and consider steps that might be taken to address and mitigate liability in respect of these duties in the context of pension fund administration. We conclude by considering the trajectory of the law and how it appears to be positioning fiduciaries with public responsibilities and, in doing so, could alter legal and governance precepts

In Search Of Things Past And Future: Judicial Activism And Corporate Purpose

Corporate purpose does not lend itself to any clear or constant definition. Rather, courts’ understanding of corporate purpose adapts over time to reflect evolving social norms and expectations as to the proper role of the corporation in society. We use the oppression remedy under Canadian corporate law to explore how Canadian courts have and will continue to play a key role in shifting legal and market understandings of corporate purpose towards a more long-termist, stakeholder-focused perspective. We begin by exploring the rationale for moving the law in this direction, outlining some of the causes and effects of short-term horizons on corporate and investment manager decision making, and how ideology and overly conservative legal advice contribute to this dynamic. We then outline an emerging role for judicial activism in breaking the log jam and helping us to re-focus on the real strength of capitalism—its flexibility to evolve and respond to a society’s expressed needs