Search

We conducted a survey of nearby binary systems composed of main sequence stars of spectral types F and G in order to improve our understanding of the hierarchical nature of multiple star systems. Using Robo-AO, the first robotic adaptive optics instrument, we collected high angular resolution images with deep and well-defined detection limits in the SDSS $i'$ band. A total of 695 components belonging to 595 systems were observed. We prioritized observations of faint secondary components with separations over $10''$ to quantify the still poorly constrained frequency of their sub-systems. Of the 214 secondaries observed, 39 contain such subsystems; 19 of those were discovered with Robo-AO. The selection-corrected frequency of secondary sub-systems with periods from $10^{3.5}$ to $10^5$ days is 0.12$\pm$0.03, the same as the frequency of such companions to the primary. Half of the secondary pairs belong to quadruple systems where the primary is also a close pair, showing that the presence of sub-systems in both components of the outer binary is correlated. The relatively large abundance of 2+2 quadruple systems is a new finding, and will require more exploration of the formation mechanism of multiple star systems. We also targeted close binaries with periods less than 100~yr, searching for their distant tertiary components, and discovered 17 certain and 2 potential new triples. In a sub-sample of 241 close binaries, 71 have additional outer companions. The overall frequency of tertiary components is not enhanced, compared to all (non-binary) targets, but in the range of outer periods from $10^6$ to $10^{7.5}$ days (separations on the order of 500~AU), the frequency of tertiary components is 0.16$\pm$0.03, exceeding by almost a factor of two the frequency of similar systems among all targets (0.09).

Robo-AO is the first automated laser adaptive optics instrument. In just its second year of scientific operations, it has completed the largest adaptive optics surveys to date, each comprising thousands of targets. Robo-AO uses a fully automated queue scheduling system that selects targets based on criteria entered on a per observing program or per target basis, and includes the ability to coordinate with US Strategic Command automatically to avoid lasing space assets. This enables Robo-AO to select among thousands of targets at a time, and achieve an average observation rate of approximately 20 targets per hour., Comment: 13 pages, 4 figures

The Fermi Gamma-ray Burst Monitor (GBM) triggers on-board in response to∼40 short gamma-ray bursts (SGRBs) per year; however, their large localization regions have made the search for optical counterparts a challenging endeavour. We have developed and executed an extensive program with the wide field of view of the Zwicky Transient Facility (ZTF) camera, mounted on the Palomar 48 inch Oschin telescope (P48), to perform target-of-opportunity (ToO) observations on 10Fermi-GBM SGRBsduring 2018 and 2020-2021. Bridging the large sky areas with small field of view optical telescopesin order to track the evolution of potential candidates, we look for the elusive SGRB afterglows andkilonovae (KNe) associated with these high-energy events. No counterpart has yet been found, eventhough more than 10 ground based telescopes, part of the Global Relay of Observatories WatchingTransients Happen (GROWTH) network, have taken part in these efforts. The candidate selectionprocedure and the follow-up strategy have shown that ZTF is an efficient instrument for searchingfor poorly localized SGRBs, retrieving a reasonable number of candidates to follow-up and showingpromising capabilities as the community approaches the multi-messenger era. Based on the medianlimiting magnitude of ZTF, our searches would have been able to retrieve a GW170817-like event upto∼200 Mpc and SGRB afterglows to z = 0.16 or 0.4, depending on the assumed underlying energymodel. Future ToOs will expand the horizon to z = 0.2 and 0.7 respectively.

Robo-AO is the first astronomical laser guide star adaptive optics (AO) system designed to operate completely independent of human supervision. A single computer commands the AO system, the laser guide star, visible and near-infrared science cameras (which double as tip-tip sensors), the telescope, and other instrument functions. Autonomous startup and shutdown sequences as well as concatenated visible observations were demonstrated in late 2011. The fully robotic software is currently operating during a month long demonstration of Robo-AO at the Palomar Observatory 60-inch telescope.

This paper reports on two studies conducted at Washburn University (Kansas) to evaluate the ability of preservice fine arts teachers to transmit knowledge of subject to students through the demonstration of teaching competencies. Answers were sought to the following questions: (1) what were the perceptions relative to student teachers' knowledge of subject; and (2) to what extent were teaching competencies demonstrated. The sample in the first study consisted of student teachers (N=22) prepared to teach music, and their cooperating teachers (N=24); the second study included student teachers (N=12) prepared to teach art, along with their cooperating teachers (N=13). Cooperating teachers provided ratings data with respect to the abilities demonstrated by student teachers; preservice teachers provided data using the same evaluative instrument designed for assessing their own competencies and knowledge of the subject fields. Thirty-one tables display findings of subject area knowledge and competencies assessments, and frequency of response to numerical positions of rating scale by cooperating teachers and students in art and music from 1985-1990. The paper concludes with a technical discussion of results and copies of evaluative instruments. (LL)

This study investigated the ability of preservice secondary school history and social studies teachers to transmit knowledge of the subject to students through methodologies designed to translate theory into practice. Participants in the study were 23 student teachers certified to teach history and social studies by Washburn University (Kansas) from spring 1985 through spring 1990 and their respective cooperating teachers. Cooperating teachers completed a rating scale and provided data regarding teaching abilities demonstrated by student teachers. Student teachers also provided data by using the same evaluative instrument for assessing their own abilities in history and social studies. The other areas of the evaluation included the student teachers' ability to transmit subject matter to students and to translate theory into practice. Results suggest that cooperating teachers tended to rate student teachers higher than the preservice teachers rated themselves. Five appendices, comprising about 80 percent of this document are: (1) history and social studies tables, the mean and standard deviation; (2) tables ranking mean values derived from the evaluation of student teachers in history; (3) tables ranking mean values derived from the evaluation of student teachers in social studies; (4) tables presenting frequency of response to numerical position on rating scale; and (5) the evaluative instruments. (LL)