Evidence for an FU Orionis-like Outburst from a Classical T Tauri Star

We present pre- and post-outburst observations of the new FU Orionis-like young stellar object PTF 10qpf (also known as LkHα 188-G4 and HBC 722). Prior to this outburst, LkHα 188-G4 was classified as a classical T Tauri star (CTTS) on the basis of its optical emission-line spectrum superposed on a K8-type photosphere and its photometric variability. The mid-infrared spectral index of LkHα 188-G4 indicates a Class II-type object. LkHα 188-G4 exhibited a steady rise by ~1 mag over ~11 months starting in August 2009, before a subsequent more abrupt rise of >3 mag on a timescale of ~2 months. Observations taken during the eruption exhibit the defining characteristics of FU Orionis variables: (1) an increase in brightness by ≳ 4 mag, (2) a bright optical/near-infrared reflection nebula appeared, (3) optical spectra are consistent with a G supergiant and dominated by absorption lines, the only exception being Hα which is characterized by a P Cygni profile, (4) near-infrared spectra resemble those of late K-M giants/supergiants with enhanced absorption seen in the molecular bands of CO and H_(2)O, and (5) outflow signatures in H and He are seen in the form of blueshifted absorption profiles. LkHα 188-G4 is the first member of the FU Orionis-like class with a well-sampled optical to mid-infrared spectral energy distribution in the pre-outburst phase. The association of the PTF 10qpf outburst with the previously identified CTTS LkHα 188-G4 (HBC 722) provides strong evidence that FU Orionis-like eruptions represent periods of enhanced disk accretion and outflow, likely triggered by instabilities in the disk. The early identification of PTF 10qpf as an FU Orionis-like variable will enable detailed photometric and spectroscopic observations during its post-outburst evolution for comparison with other known outbursting objects

Evidence for an FU Orionis-like Outburst from a Classical T Tauri Star

We present pre- and post-outburst observations of the new FU Orionis-like young stellar object PTF 10qpf (also known as LkHa 188-G4 and HBC 722). Prior to this outburst, LkHa 188-G4 was classified as a classical T Tauri star on the basis of its optical emission-line spectrum superposed on a K8-type photosphere, and its photometric variability. The mid-infrared spectral index of LkHa 188-G4 indicates a Class II-type object. LkHa 188-G4 exhibited a steady rise by ~1 mag over ~11 months starting in Aug. 2009, before a subsequent more abrupt rise of > 3 mag on a time scale of ~2 months. Observations taken during the eruption exhibit the defining characteristics of FU Orionis variables: (i) an increase in brightness by > 4 mag, (ii) a bright optical/near-infrared reflection nebula appeared, (iii) optical spectra are consistent with a G supergiant and dominated by absorption lines, the only exception being Halpha which is characterized by a P Cygni profile, (iv) near-infrared spectra resemble those of late K--M giants/supergiants with enhanced absorption seen in the molecular bands of CO and H_2O, and (v) outflow signatures in H and He are seen in the form of blueshifted absorption profiles. LkHa 188-G4 is the first member of the FU Orionis-like class with a well-sampled optical to mid-infrared spectral energy distribution in the pre-outburst phase. The association of the PTF 10qpf outburst with the previously identified classical T Tauri star LkHa 188-G4 (HBC 722) provides strong evidence that FU Orionis-like eruptions represent periods of enhanced disk accretion and outflow, likely triggered by instabilities in the disk. The early identification of PTF 10qpf as an FU Orionis-like variable will enable detailed photometric and spectroscopic observations during its post-outburst evolution for comparison with other known outbursting objects.Comment: 14 pages, 11 figures, ApJ accepte

PTF10nvg: An Outbursting Class I Protostar in the Pelican/North American Nebula

During a synoptic survey of the North American Nebula region, the Palomar Transient Factory (PTF) detected an optical outburst (dubbed PTF10nvg) associated with the previously unstudied flat or rising spectrum infrared source IRAS 20496+4354. The PTF R-band light curve reveals that PTF10nvg brightened by more than 5 mag during the current outburst, rising to a peak magnitude of R~13.5 in 2010 Sep. Follow-up observations indicate PTF10nvg has undergone a similar ~5 mag brightening in the K band, and possesses a rich emission-line spectrum, including numerous lines commonly assumed to trace mass accretion and outflows. Many of these lines are blueshifted by ~175 km/s from the North American Nebula's rest velocity, suggesting that PTF10nvg is driving an outflow. Optical spectra of PTF10nvg show several TiO/VO bandheads fully in emission, indicating the presence of an unusual amount of dense (> 10^10 cm^-3), warm (1500-4000 K) circumstellar material. Near-infrared spectra of PTF10nvg appear quite similar to a spectrum of McNeil's Nebula/V1647 Ori, a young star which has undergone several brightenings in recent decades, and 06297+1021W, a Class I protostar with a similarly rich near--infrared emission line spectrum. While further monitoring is required to fully understand this event, we conclude that the brightening of PTF10nvg is indicative of enhanced accretion and outflow in this Class-I-type protostellar object, similar to the behavior of V1647 Ori in 2004-2005.Comment: Accepted to the Astronomical Journal; 21 pages, 11 figures, 6 tables in emulateapj format; v2 fixes typo in abstract; v3 updates status to accepted, adjusts affiliations, adds acknowledgmen

Three New Eclipsing White-dwarf - M-dwarf Binaries Discovered in a Search for Transiting Planets Around M-dwarfs

We present three new eclipsing white-dwarf / M-dwarf binary systems discovered during a search for transiting planets around M-dwarfs. Unlike most known eclipsing systems of this type, the optical and infrared emission is dominated by the M-dwarf components, and the systems have optical colors and discovery light curves consistent with being Jupiter-radius transiting planets around early M-dwarfs. We detail the PTF/M-dwarf transiting planet survey, part of the Palomar Transient Factory (PTF). We present a Graphics Processing Unit (GPU)-based box-least-squares search for transits that runs approximately 8X faster than similar algorithms implemented on general purpose systems. For the discovered systems, we decompose low-resolution spectra of the systems into white-dwarf and M-dwarf components, and use radial velocity measurements and cooling models to estimate masses and radii for the white dwarfs. The systems are compact, with periods between 0.35 and 0.45 days and semimajor axes of approximately 2 solar radii (0.01 AU). We use the Robo-AO laser guide star adaptive optics system to tentatively identify one of the objects as a triple system. We also use high-cadence photometry to put an upper limit on the white dwarf radius of 0.025 solar radii (95% confidence) in one of the systems. We estimate that 0.08% (90% confidence) of M-dwarfs are in these short-period, post-common-envelope white-dwarf / M-dwarf binaries where the optical light is dominated by the M-dwarf. Similar eclipsing binary systems can have arbitrarily small eclipse depths in red bands and generate plausible small-planet-transit light curves. As such, these systems are a source of false positives for M-dwarf transiting planet searches. We present several ways to rapidly distinguish these binaries from transiting planet systems.Comment: 14 pages, 14 figures, submitted to Ap

Magnitude in innovation change: adaptation and reinvention in Enterprise Architecture implementation

This paper revisits the concept of innovation changes during the implementation process. Prior literature has mostly focused on innovation changes during the adaptation process and organizational-level effects of those changes. However, such a theoretical lens leaves out an important dimension in the magnitude of changes: the potential community-level effects of changes. Large-scale, radical adaptation can be conceptualized as reinvention events that alter the nature of the innovation and create ripple-effects in the community. Thus, innovation changes include two possible processes: adaptation and reinvention. Through an in-depth case study of Enterprise Architecture implementation in an U.S. State government, this study illustrates how reinvention of innovation concepts can push the boundary of change, creating a new way of implementation in a community. The findings suggest the need to adjust our conventional methodological approach and theoretical lens in studying innovation changes and to investigate not only organizational-level effects from adaptation but also community-level effects

Alternative Designs in Widespread Innovation Adoption: Empirical Evidence from Enterprise Architecture Implementation in US State Governments

The dominant design theory posits that widespread innovation adoption, at least for product innovations, happens when a vendor shakeout occurs and subsequently a dominant design of the product emerges. This paper examines how the dominant design theory holds for non-product innovations: could we expect widespread adoption to occur with alternative designs? Through the widespread adoption of Enterprise Architecture in fifty US state governments, we illustrate that both premises of the dominant design theory do not apply well. Despite the widespread adoption of Enterprise Architecture, there is no sign of a shakeout in the vendor community, nor any sign of a dominant design implemented among state governments. On the contrary, alternative designs may have been more helpful to the diffusion process of Enterprise Architecture. The findings suggest research opportunities to look at organizational profiles that promote certain innovation designs, or to identify conditions and trajectories under which alternative designs are plausible

The Art of the States. IT Governance and Organizational Performance in American State Governments.

This report presents the results of a study of innovations in the organization and management of work activities. The research question addressed was whether and how administrative innovations contribute to improving the performance of organizations, such as their efficiency and effectiveness and their ability to develop and deliver innovative products and services. More specifically, the study looked at the performance effects of innovations in the governance and management of information technology (IT) in the 50 American state governments. Governments everywhere are trying to improve efficiency and effectiveness, and IT is seen as a key factor in achieving that goal. But delivering IT projects and services in state government is an activity that has to be organized and managed efficiently and effectively in order for states to achieve the desired benefits of using IT. The study focused on how states currently govern IT, how and why they made changes in the way they govern IT, and the performance outcomes they achieved from changing their IT governance arrangements. Scientifically, the study aimed to test and extend current thinking about how, why, and how much administrative innovations, in general, and IT governance arrangements, in particular, can improve organizational performance. In order to make a strong test of current ideas, the study used different measurements and data collection procedures than prior studies and examined the research questions in the public sector context. By finding that some American state governments achieved IT-related performance improvements by changing their IT governance arrangements, this study increases confidence in the idea that administrative innovations are important to organizational success. The study also significantly extends current thinking about IT governance by sho wing that governance has two dimensions — 1) organizational structure and personnel management authority and 2) decision making influence — that can each affect organizational performance, but do not necessarily go together. This means that organizations may have more choices of how to design good IT governance than is typically thought. In addition to two familiar options (centralized and decentralized), the study explored the potential of two additional governance arrangements — 1) centralization-by-standardization and 2) decentralization-by-participation. Only the first of these additional alternatives (centralization-by-standardization) was observed in the 50 American states, raising the possibility that the second option (decentralization-by-participation) is an unexploited opportunity. Although future research will be necessary before confident recommendations for action can be made, the results of this research indicate that some states are already benefiting from adopting IT governance innovations, and that other states could possibly also do so.Research Project Outcomes Repor

Design of the IT Management Arrangements in a Post-NPM Context: An Overview of the 50 US State Governments

A recurrent call for an increased use of information technology in the public administration has been made since the beginning of the “New Public Management” wave. It has been reinforced these last years through the “digital-era governance” movement, emphasizing the important role that IT may have in the effective transformation of the public institutions and in the successful delivery of citizen-centered services. However, the success of e-government is proved not to be a direct effect of the increased use of IT, but to also depend on the organizational and institutional arrangements that governments enact for the management of their IT resources. In this context, our paper proposes to offer an updated view of the way US State Governments manage, organize, and govern their IT activities. To do so, we consider the possible interactions between two dimensions: 1) the organization of IT activities and 2) the control over decisions about IT activities (also known as governance). This analysis is made for each of two categories of IT activities: 1) IT projects (such as Enterprise Architecture implementation, website development, etc.) and 2) IT services (such as the operation of networks, the daily support services, etc.). Our empirical data indeed show that neither dimension alone provides a good characterization of governmental IT management arrangements. The latter requires an in-depth understanding of how US States appear to combine a centralization and/or a decentralization design of the organization and of the control of their IT activities. The findings that we develop through this contribution have the potential to enhance the general understanding of the barriers to, and enablers of, e-government success, and to put into perspective some insights of the new public management and digital-era governance movements concerning the use of IT in the public sector