A Giant Planet Undergoing Extreme-Ultraviolet Irradiation By Its Hot Massive-Star Host

The amount of ultraviolet irradiation and ablation experienced by a planet depends strongly on the temperature of its host star. Of the thousands of extrasolar planets now known, only six have been found that transit hot, A-type stars (with temperatures of 7,300–10,000 kelvin), and no planets are known to transit the even hotter B-type stars. For example, WASP-33 is an A-type star with a temperature of about 7,430 kelvin, which hosts the hottest known transiting planet, WASP-33b (ref. 1); the planet is itself as hot as a red dwarf star of type M (ref. 2). WASP-33b displays a large heat differential between its dayside and nightside2, and is highly inflated–traits that have been linked to high insolation3,4. However, even at the temperature of its dayside, its atmosphere probably resembles the molecule-dominated atmospheres of other planets and, given the level of ultraviolet irradiation it experiences, its atmosphere is unlikely to be substantially ablated over the lifetime of its star. Here we report observations of the bright star HD 195689 (also known as KELT-9), which reveal a close-in (orbital period of about 1.48 days) transiting giant planet, KELT-9b. At approximately 10,170 kelvin, the host star is at the dividing line between stars of type A and B, and we measure the dayside temperature of KELT-9b to be about 4,600 kelvin. This is as hot as stars of stellar type K4 (ref. 5). The molecules in K stars are entirely dissociated, and so the primary sources of opacity in the dayside atmosphere of KELT-9b are probably atomic metals. Furthermore, KELT-9b receives 700 times more extreme-ultraviolet radiation (that is, with wavelengths shorter than 91.2 nanometres) than WASP-33b, leading to a predicted range of mass-loss rates that could leave the planet largely stripped of its envelope during the main-sequence lifetime of the host star (ref. 6)

The KELT Follow-Up Network And Transit False-Positive Catalog: Pre-Vetted False Positives For TESS

The Kilodegree Extremely Little Telescope (KELT) project has been conducting a photometric survey of transiting planets orbiting bright stars for over 10 years. The KELT images have a pixel scale of ~23\u27\u27 pixel⁻¹—very similar to that of NASA\u27s Transiting Exoplanet Survey Satellite (TESS)—as well as a large point-spread function, and the KELT reduction pipeline uses a weighted photometric aperture with radius 3\u27. At this angular scale, multiple stars are typically blended in the photometric apertures. In order to identify false positives and confirm transiting exoplanets, we have assembled a follow-up network (KELT-FUN) to conduct imaging with spatial resolution, cadence, and photometric precision higher than the KELT telescopes, as well as spectroscopic observations of the candidate host stars. The KELT-FUN team has followed-up over 1600 planet candidates since 2011, resulting in more than 20 planet discoveries. Excluding ~450 false alarms of non-astrophysical origin (i.e., instrumental noise or systematics), we present an all-sky catalog of the 1128 bright stars (6 \u3c V \u3c 13) that show transit-like features in the KELT light curves, but which were subsequently determined to be astrophysical false positives (FPs) after photometric and/or spectroscopic follow-up observations. The KELT-FUN team continues to pursue KELT and other planet candidates and will eventually follow up certain classes of TESS candidates. The KELT FP catalog will help minimize the duplication of follow-up observations by current and future transit surveys such as TESS

Emotion in pre-service teachers: Relations among self- and observer-reports on classroom videos and voice parameter analyses

Video-based reflective practices have long been part of teacher education. Frequently the feedback or focus is about content or organisation of the material, but enhancing one’s level of emotional mindfulness has also been suggested as a means to improve performance in teaching and a speaker understands of how they may be perceived by the audience. The affective component of teaching has been argued to be a key predictor of pupil engagement. The effects of emotion on vocal expression is apparent in everyday speech but can also be characterised by using voice analysis software (PRAAT). The aim of the current research was to inform reflective practice and test links among various indices of emotional state in pre-service teachers (PSTs) giving lessons to school children. Participants were 54 PSTs in teacher training at 3 regional universities. Participants worked in small 60 groups and alternated between being the Teaching PST and Observing PST. Several emotion measures were used in repeated measures designs. Teaching PSTs completed the Positive and Negative Affect Schedule (PANAS) before and after each lesson. Emotion checklists completed by Teaching and Observer PSTs for segments of recorded lessons were evaluated to determine the level of individual emotions and profiles of blended emotions. Observer PSTs also rated the affect of Teaching PSTs during the lessons. The points of concordance and disparity between the Teaching and Observer PST ratings were used to inform the reflective exercises overseen by mentor teachers. The affect/emotion ratings were also used to help characterise various voice parameters (e.g., fundamental frequency, intensity variability) as calculated by PRAAT software. Preliminary results indicate that the method for recording emotion during teaching was feasible and did not intrude significantly on the classroom. Concordance between Teaching and Observing PST reports was not always high but the discussions about differences were considered fruitful in terms of assisting reflection. The similarity between PANAS scores and ratings of emotion for teaching segments was also variable. Our voice analyses to decode emotion effects indicated that laboratory reports about emotion-parameter links may not apply well to recordings in naturalistic settings that evoke blended and fluid emotional reaction

Enhancing science and mathematics teacher education: Evaluating an enhancement module for science pre-service teachers

Copyright © 2017 Inderscience Enterprises Ltd. Motivated and well-trained science and mathematics teachers are a requirement for sustaining an industrialised economy. The Australian government has funded several projects to satisfy this requirement designed to improve pre-service teacher (PST) education in regional and rural Australia. One such project uses a collaboration nexus model with lesson feedback and Reflection Module in an iterative process using a repeated sequence comprised of an Enhancement Module, a subsequent Teaching Lesson and a Reflection Module. This paper reports on qualitative investigations of the effectiveness of the collaboration nexus in the Enhancement Module and comments on the value of the iterative process. Results from small-scale trials with PSTs indicate that the module positively engages participants, PSTs, university scientists and specialist educators. The module and its iterations appear to be effective in grounding PST education in targeting regional contexts relevant to the daily lives of both PSTs and their classroom students

A giant planet undergoing extreme-ultraviolet irradiation by its hot massive-star host

The amount of ultraviolet irradiation and ablation experienced by a planet depends strongly on the temperature of its host star. Of the thousands of extrasolar planets now known, only six have been found that transit hot, A-type stars (with temperatures of 7,300-10,000 kelvin), and no planets are known to transit the even hotter B-type stars. For example, WASP-33 is an A-type star with a temperature of about 7,430 kelvin, which hosts the hottest known transiting planet, WASP-33b (ref. 1); the planet is itself as hot as a red dwarf star of type M (ref. 2). WASP-33b displays a large heat differential between its dayside and nightside, and is highly inflated-traits that have been linked to high insolation. However, even at the temperature of its dayside, its atmosphere probably resembles the molecule-dominated atmospheres of other planets and, given the level of ultraviolet irradiation it experiences, its atmosphere is unlikely to be substantially ablated over the lifetime of its star. Here we report observations of the bright star HD 195689 (also known as KELT-9), which reveal a close-in (orbital period of about 1.48 days) transiting giant planet, KELT-9b. At approximately 10,170 kelvin, the host star is at the dividing line between stars of type A and B, and we measure the dayside temperature of KELT-9b to be about 4,600 kelvin. This is as hot as stars of stellar type K4 (ref. 5). The molecules in K stars are entirely dissociated, and so the primary sources of opacity in the dayside atmosphere of KELT-9b are probably atomic metals. Furthermore, KELT-9b receives 700 times more extreme-ultraviolet radiation (that is, with wavelengths shorter than 91.2 nanometres) than WASP-33b, leading to a predicted range of mass-loss rates that could leave the planet largely stripped of its envelope during the main-sequence lifetime of the host star

The KELT Follow-up Network and Transit False-positive Catalog: Pre-vetted False Positives for TESS

The Kilodegree Extremely Little Telescope (KELT) project has been conducting a photometric survey for transiting planets orbiting bright stars for over ten years. The KELT images have a pixel scale of ~23"/pixel---very similar to that of NASA's Transiting Exoplanet Survey Satellite (TESS)---as well as a large point spread function, and the KELT reduction pipeline uses a weighted photometric aperture with radius 3'. At this angular scale, multiple stars are typically blended in the photometric apertures. In order to identify false positives and confirm transiting exoplanets, we have assembled a follow-up network (KELT-FUN) to conduct imaging with higher spatial resolution, cadence, and photometric precision than the KELT telescopes, as well as spectroscopic observations of the candidate host stars. The KELT-FUN team has followed-up over 1,600 planet candidates since 2011, resulting in more than 20 planet discoveries. Excluding ~450 false alarms of non-astrophysical origin (i.e., instrumental noise or systematics), we present an all-sky catalog of the 1,128 bright stars (6<V<10) that show transit-like features in the KELT light curves, but which were subsequently determined to be astrophysical false positives (FPs) after photometric and/or spectroscopic follow-up observations. The KELT-FUN team continues to pursue KELT and other planet candidates and will eventually follow up certain classes of TESS candidates. The KELT FP catalog will help minimize the duplication of follow-up observations by current and future transit surveys such as TESS.Comment: Accepted for publication in AJ, 21 pages, 12 figures, 7 table