Binary stars are ubiquitous; yet it remains unclear how wide-orbit stellar companions influence the formation of hot Jupiters, particularly around M dwarfs. Here, we first report the discovery of TOI-5628Ab, a giant planet transiting a midtype M dwarf ( M _* = 0.36 ± 0.02 M _⊙ ) every 4.34 days, accompanied by an associated white dwarf TOI-5628B ( M _WD = 0.59 ± 0.16 M _⊙ ) at a projected distance of about 2500 au. Using TESS, ground-based photometry, and SPIRou radial velocities, we constrain the planet radius to 0.74 ± 0.04 R _J and mass to 0.09 ± 0.04 M _J , with a 3 σ upper limit of 0.22 M _J . Building on this system, we further conduct a homogeneous systematic search for comoving stellar companions with projected semimajor axes between 100 and 10,000 au around all M dwarfs with confirmed giant planets with periods smaller than 10 days and radii larger than 0.7 R _J , as well as a group of field M stars with stellar properties similar to the planet sample, based on the stellar kinematics from Gaia DR3. We measure a stellar multiplicity of 34.2% ± 9.5% for M dwarfs hosting short-period giant planets, which is substantially higher than the fraction of 5.3% ± 3.7% for the field M stars by approximately a factor of 6. Our results suggest that wide-orbit stellar companions tend to promote the formation of short-period gas giants around M stars with masses 0.21 ≤ M _* ≤ 0.64 M _⊙ , and high-eccentricity migration may play an important role in producing such systems.
We present updated transit timing measurements for three hot Jupiters (Qatar-4 b, HAT-P-18 b, and CoRoT-1 b) by leveraging data collected from the MicroObservatory Telescope Network, a network of small, robotic ground-based telescopes, and the NASA Transiting Exoplanet Survey Satellite (TESS). By combining these data with archival published results, we present the most precise orbital solutions to date for all three systems, allowing for precise transit time predictions for future missions. We report an updated mid-transit time for Qatar-4 b of 2458919.5838 ± 0.000089 BJD_TDB and an updated orbital period of 1.80536560 ± 0.00000021 days. For HAT-P-18 b, we find a mid-transit time of 2459743.85340 ± 0.000022 BJD_TDB and an updated orbital period of 5.50802957 ± 0.00000012 days. For CoRoT-1 b, we report a mid-transit time of 2456268.99083 ± 0.000099 BJD_TDB and an updated orbital period of 1.50896846 ± 0.000000071 days. Our results demonstrate improvements over recently published ephemerides, with reductions of 36.4
Binary stars are ubiquitous, yet it remains unclear how wide-orbit stellar companions influence the formation of hot Jupiters, particularly around M dwarfs. Here, we first report the discovery of TOI-5628Ab, a giant planet transiting a mid-type M dwarf (M_∗=0.36±0.02 M_⊙) every 4.34 days, accompanied by an associated white dwarf TOI-5628B (M_ WD=0.59±0.16 M_⊙) at a projected distance of about 2,500 AU. Using TESS, ground-based photometry and SPIRou RVs, we constrain the planet radius to 0.74±0.04 R_J and mass to 0.09±0.04 M_J, with a 3σ upper limit of 0.22 M_J. Building on this system, we further conduct a homogeneous systematic search for co-moving stellar companions with projected semi-major axis between 100 and 10,000 AU around all M dwarfs with confirmed giant planets with periods smaller than 10 days and radii larger than 0.7 R_J, as well as a group of field M stars with stellar properties similar to the planet sample, based on the stellar kinematics from Gaia DR3. We measure a stellar multiplicity of 34.2±9.5% for M dwarfs hosting short-period giant planets, which is substantially higher than the fraction of 5.3±3.7% for the field M stars by approximately a factor of 6. Our results suggest that wide-orbit stellar companions tend to promote the formation of short-period giant planets around M stars with masses 0.21 ≤ M_∗≤ 0.64 M_⊙, and high-eccentricity migration may play an important role in producing such systems.
In 2003, Bailey and Slater [A review of astronomy education research, Astron. Educ. Rev. 2, 20 (2003)] published a review of astronomy education research (AER) to survey the field, identify areas of robust coverage, and uncover gaps in the research to help guide future researchers. While our review is not intended as a direct comparison to their original work, we aim to update the field's progress since that time. After initially considering more than 450 works, primarily peer-reviewed publications, we focused on research conducted in undergraduate settings or related to non-K-12-teaching adults, such as planetarium professionals, participants in massive open online courses, and citizen scientists. We identified seven broad categories of research, continuing several categories from the original study, such as student understanding and efficacy of instructional strategies, while also introducing new topics, such as authentic research experiences. These findings demonstrate the evolution of AER over the past two decades. The largest body of research remains focused on the efficacy and implementation of instructional strategies. Progress has also been made in exploring technology use (e.g., simulations) in introductory astronomy classrooms and integrating active learning into fully online courses. Notably, course-based undergraduate research experiences have emerged as a new focus in AER. Moving forward, future research should better incorporate educational theory (e.g., mechanisms of learning) and explore the unique educational opportunities offered within astronomy.
Massive open online courses (MOOCs) experienced a resurgence in popularity due to the COVID-19 pandemic. In this work, we studied participants in an astrobiology MOOC offered on Coursera since April 2019. Using a modified version of the Science Motivation Questionnaire II, we examined the primary motivational factors of the participants, how those factors related to demographics and course performance, and how participants in our MOOC compared to those in a general astronomy MOOC as well as traditional undergraduate students. Participants in the astrobiology MOOC were more highly motivated when compared to the general astronomy MOOC across all five motivational factors we surveyed: intrinsic, career, grade, self-determination, and self-efficacy. Compared to the undergraduate population, astrobiology MOOC participants reported higher motivations in all the factors except for career and grade. We found that demographics had some impact on these results, with older participants reporting lower career and grade motivations and female participants having generally higher motivations compared to males. Despite this, male participants and those older than 40 were more likely to complete the course. As the astrobiology MOOC was initially offered prior to the COVID-19 pandemic, we also looked at the impact the pandemic had on these results. The demographics of participants changed significantly, with the percentage of participants under the age of 30 and the percentage of those identifying as full-time students doubling compared to prepandemic. The motivations of participants also changed, with participants showing more career and grade motivation since the pandemic. Interestingly, the increase in younger and more full-time student participants has continued even with the return of in-person learning. This suggests that the pandemic introduced MOOCs to a new population of learners who have continued to utilize them in the years since.
Previous studies conclusively show that pencil-and-paper lecture-tutorials (LTs) are incredibly effective at increasing student engagement and learning gains on a variety of topics when compared to traditional lecture. LTs in astronomy are post-lecture activities developed with the intention of helping students engage with conceptual and reasoning difficulties around a specific topic with the end goal of them developing a more expert-like understanding of astrophysical concepts. To date, all astronomy LTs have been developed for undergraduate courses taught in-person. Increases in online course enrollments and the COVID-19 pandemic further highlighted the need for additional interactive, research-based, curricular materials designed for online classrooms. To this end, we developed and assessed the efficacy of an innovative, interactive LT designed to teach planet formation in asynchronous, online, introductory astronomy courses for undergraduates. We utilized the Planet Formation Concept Inventory to compare learning outcomes between courses that implemented the new online, interactive LT, and those that used either a lecture-only approach or utilized a standard pencil-and-paper LT on the same topic. Overall, learning gains from the standard pencil-and-paper LT were statistically indistinguishable from the in-person implementation of the online LT and both of these conditions outperformed the lecture-only condition. However, when implemented asynchronously, learning gains from the online LT were lower and not significantly above the lecture-only condition. While improvements can be made to improve the online LT in the future, the current discipline ideas still outperform traditional lecture, and can be used as a tool to teach planet formation effectively.
Here we present an analysis of 14 transit light curves of the hot Jupiter HAT-P-54 b. Thirteen of our datasets were obtained with the 6-inch MicroObservatory telescope, Cecilia, and one was measured with the 61-inch Kuiper Telescope. We used the EXOplanet Transit Interpretation Code (EXOTIC) to reduce 49 datasets in order to update the planet's ephemeris to a mid-transit time of 2460216.95257 +/- 0.00022 BJD_TBD and an updated orbital period of 3.79985363 +/- 0.00000037 days. These results improve the mid-transit uncertainty by 70.27 mid-transit time can help to ensure the efficient use of expensive, large ground- and space-based telescope missions in the future. This result demonstrates that amateur astronomers and citizen scientists can provide meaningful, cost-efficient, crowd-sourcing observations using ground-based telescopes to further refine current mid-transit times and orbital periods.
Hundreds of thousands of undergraduates enroll in general education science courses to fulfill university core requirements. However, many of these lecture-based courses fail to foster high-level data literacy skills. This work details the design, implementation, and analysis of a new climate change-based classroom activity for college students that pairs data interpretation with participation in an online citizen science project called Floating Forests (http://floatingforests.org). We pilot tested our activity in introductory geoscience and biology courses at six universities (∼1,500 students) during the 2020–2021 academic year. Additionally, we developed and validated a survey to assess how engagement with our activity impacted students’ self-reported changes across four factors: (1) perceptions of the impacts of climate change, (2) data literacy self-efficacy, (3) beliefs about the value of citizen science, and (4) beliefs about science engagement. In a pre- to post-test comparison, students who utilized our activity in their courses showed statistically significant increases (p < 0.05) across all four factors. These results highlight the potential benefit of implementing data-driven, citizen science-based activities in introductory-level undergraduate courses.
We present an updated ephemeris and physical parameters for the exoplanet WASP-77 A b. In this effort, we combine 64 ground- and space-based transit observations, 6 space-based eclipse observations, and 32 radial velocity observations to produce the most precise orbital solution to date for this target, aiding in the planning of James Webb Space Telescope (JWST) and Ariel observations and atmospheric studies. We report a new orbital period of 1.360029395 +- 5.7e-8 days, a new mid-transit time of 2459957.337860 +- 4.3e-5 BJDTDB (Barycentric Julian Date in the Barycentric Dynamical Time scale; arXiv:1005.4415) and a new mid-eclipse time of 2459956.658192 +- 6.7e-5 BJDTDB. Furthermore, the methods presented in this study reduce the uncertainties in the planet mass to 1.6654 +- 4.5e-3 Mjup and orbital period to 1.360029395 +- 5.7e-8 days by factors of 15.1 and 10.9, respectively. Through a joint fit analysis comparison of transit data taken by space-based and citizen science-led initiatives, our study demonstrates the power of including data collected by citizen scientists compared to a fit of the space-based data alone. Additionally, by including a vast array of citizen science data from ExoClock, Exoplanet Transit Database (ETD), and Exoplanet Watch, we can increase our observational baseline and thus acquire better constraints on the forward propagation of our ephemeris than what is achievable with TESS data alone.
Using the EXOplanet Transit Interpretation Code (EXOTIC), we reduced 52 sets of images of WASP-104 b, a Hot Jupiter-class exoplanet orbiting WASP-104, in order to obtain an updated mid-transit time (ephemeris) and orbital period for the planet. We performed this reduction on images taken with a 6-inch telescope of the Center for Astrophysics | Harvard & Smithsonian MicroObservatory. Of the reduced light curves, 13 were of sufficient accuracy to be used in updating the ephemerides for WASP-104 b, meeting or exceeding the three-sigma standard for determining a significant detection. Our final mid-transit value was 2457805.170208 +/- 0.000036 BJD_TBD and the final period value was 1.75540644 +/- 0.00000016 days. The true significance of our results is in their derivation from image sets gathered over time by a small, ground-based telescope as part of the Exoplanet Watch citizen science initiative, and their competitive results to an ephemeris generated from data gathered by the TESS telescope. We use these results to further show how such techniques can be employed by amateur astronomers and citizen scientists to maximize the efficacy of larger telescopes by reducing the use of expensive observation time. The work done in the paper was accomplished as part of the first fully online Course-Based Undergraduate Research Experience (CURE) for astronomy majors in the only online Bachelor of Science program in Astronomical and Planetary Sciences.
Course-Based Undergraduate Research Experiences (CUREs) have been shown to provide students with a variety of learning benefits including better conceptual understanding, improved critical thinking and data literacy skills, and increased interest in pursuing scientific careers. Additionally, CUREs provide students with opportunities to participate in authentic research experiences that have a broader impact outside of the classroom. Despite the numerous benefits, the field of astronomy has lagged behind disciplines like biology and chemistry when it comes to including CUREs in the curriculum. Not limited to astronomy, however, is the lack of research opportunities and courses offered to students enrolled in undergraduate degree programs online. In the Fall of 2020, Arizona State University (ASU) introduced the nation’s first online bachelor’s degree program in astronomy and planetary sciences (APS). To make research accessible to a more diverse population of learners, it is imperative that students in this program have access to the same opportunities to participate in authentic research as those in the parallel in-person program. In this work, we describe the development, implementation, and assessment of a fully online CURE for astronomy majors as part of the APS program. We conducted a mixed methods analysis consisting of a Likert style survey administered pre- and postcourse as well as student interviews at the conclusion of the semester. Survey results from the course’s first two offerings (N=24) indicated that students’ research self-efficacy and science identity both improved. An exoplanet-specific multiple-choice assessment (N=26) showed statistically significant improvements in conceptual understanding postcourse. Additionally, student interview (N=11) responses relayed that students felt a stronger sense of belonging to both ASU and the larger astronomy community after participation in the course. The results from this study are encouraging and suggest that student participation in this online CURE led to similar improvements across a variety of outcomes previously identified in studies of in-person CUREs spanning multiple disciplines.
There is a critical need for research-based active learning instructional materials for the teaching and learning of STEM in online courses. Every year, hundreds of thousands of undergraduate non-science majors enroll in general education astronomy courses to fulfill their institution’s liberal arts requirements. When designing instructional materials for this population of learners, a central focus must be to help learners become more scientifically and data literate. As such, we developed a new, three-part, curricular model that was used to inform the creation of active-learning instructional materials designed for use in online courses to help introductory astronomy students improve their ability to make evidence-based conclusions when presented with a variety of data representations, while increasing their self-efficacy with respect to engaging meaningfully in science. We conducted a pilot study of these instructional materials at nine different colleges and universities to better understand whether students’ engagement with these materials lead to increases in self-efficacy, and whether faculty who implemented the materials were able to easily incorporate our active learning materials into their existing online astronomy courses. Overall, we found a statistically significant improvement in students' self-efficacy after engaging with our instructional materials in their online courses. The results of the item-by-item analysis indicated that students’ beliefs improved most on the questions that assessed their ability to make meaningful contributions to scientific research, and their confidence using data representations to interpret an array of scientific questions. The instructor feedback emphasized that our curriculum development model could successfully inform the creation of instructional materials that were easy to implement in existing online astronomy classes, and supported course learning objectives, creating the potential for widespread dissemination and use at the undergraduate level.
We present the results from the first two years of the Planet Hunters TESS (PHT) citizen science project, which identifies planet candidates in the TESS (Transiting Exoplanet Survey Satellite) data by engaging members of the general public. Over 22 000 citizen scientists from around the world visually inspected the first 26 sectors of TESS data in order to help identify transit-like signals. We use a clustering algorithm to combine these classifications into a ranked list of events for each sector, the top 500 of which are then visually vetted by the science team. We assess the detection efficiency of this methodology by comparing our results to the list of TESS Objects of Interest (TOIs) and show that we recover 85 per cent of the TOIs with radii greater than 4 R⊕ and 51 per cent of those with radii between 3 and 4 R⊕. Additionally, we present our 90 most promising planet candidates that had not previously been identified by other teams, 73 of which exhibit only a single-transit event in the TESS light curve, and outline our efforts to follow these candidates up using ground-based observatories. Finally, we present noteworthy stellar systems that were identified through the Planet Hunters TESS project.
The discovery and characterisation of planets orbiting distant stars has shed light on the origin of our own Solar System. It is important that college-level introductory astronomy students have a general understanding of the planet formation process before they are able to draw parallels between extrasolar systems and our own Solar System. In this work, we introduce the Planet Formation Concept Inventory (PFCI), an educational research tool used to assess student learning on the topic of planet formation. The PFCI Version 3 was administered to N = 561 students pre-instruction and N = 374 students post-instruction. Here, we present a Classical Test Theory (CTT) analysis of the PFCI Version 3. Ultimately, we conclude that the PFCI is a reliable and valid instrument that can differentiate experts from novices, and can be used to assess college-level introductory astronomy students' learning on the topic of planet formation. Initial findings on class normalised gain scores indicate that the PFCI may be capable of assessing the effectiveness of different instructional models. In the future, we recommend a national study of the PFCI to discern its ability to provide insight regarding the ascribed characteristics of learners and the effectiveness of different instructional strategies being used to teach this topic.
The topic of solar system formation has become essential to the teaching of astrobiology due to the discovery of more than 3700 exoplanets, some orbiting within their host star's habitable zone. The architecture of planetary systems is more easily understood when students are able to comprehend how solar systems form. There has yet to be a study that addresses the topic of planet formation at the college level using a large sample of introductory astronomy students. We collected responses from students in 13 introductory astronomy and planetary science courses (n=1050) at the University of Arizona, who each completed 1 of 6 short-answer questions on the topic of planet formation. The questions were administered on the first day of the Fall 2016 and Spring 2017 semesters before any relevant material was taught. After analyzing their responses, we found that the most common misconception students held was that our Solar System formed as a direct result of the Big Bang, but a substantial percentage of students lacked a more general understanding of fundamental astronomical topics (gravity, definitions of a planet and solar system, density, and the physical processes associated with solar system formation). This lack of foundational knowledge prevented students from explaining and understanding the process of planet formation at a scientific level.
Using Keck/HIRES spectra (Delta v similar to 7 km s(-1)) we analyze forbidden lines of [O I] 6300 angstrom, [O I] 5577 angstrom. and [S II] 6731 angstrom. from 33 T Tauri stars covering a range of disk evolutionary stages. After removing a high-velocity component (HVC) associated with microjets, we study the properties of the low-velocity component (LVC). The LVC can be attributed to slow disk winds that could be magnetically (magnetohydrodynamic) or thermally (photoevaporative) driven. Both of these winds play an important role in the evolution and dispersal of protoplanetary material. LVC emission is seen in all 30 stars with detected [O. I] but only in two out of eight with detected [S. II], so our analysis is largely based on the properties of the [O. I] LVC. The LVC itself is resolved into broad (BC) and narrow (NC) kinematic components. Both components are found over a wide range of accretion rates and their luminosity is correlated with the accretion luminosity, but the NC is proportionately stronger than the BC in transition disks. The full width at half maximum of both the BC and NC correlates with disk inclination, consistent with Keplerian broadening from radii of 0.05 to 0.5 au and 0.5 to 5 au, respectively. The velocity centroids of the BC suggest formation in an MHD disk wind, with the largest blueshifts found in sources with closer to face-on orientations. The velocity centroids of the NC, however, show no dependence on disk inclination. The origin of this component is less clear and the evidence for photoevaporation is not conclusive.
We present a detailed analysis of narrow of NaI and KI absorption resonance lines toward nearly 40 T Tauri stars in Taurus with the goal of clarifying their origin. The NaI 5889.95 angstrom line is detected toward all but one source, while the weaker KI 7698.96 angstrom line in about two thirds of the sample. The similarity in their peak centroids and the significant positive correlation between their equivalent widths demonstrate that these transitions trace the same atomic gas. The absorption lines are present towards both disk and diskless young stellar objects, which excludes cold gas within the circumstellar disk as the absorbing material. A comparison of NaI and CO detections and peak centroids demonstrates that the atomic and molecular gas are not co-located, the atomic gas is more extended than the molecular gas. The width of the atomic lines corroborates this finding and points to atomic gas about an order of magnitude warmer than the molecular gas. The distribution of NaI radial velocities shows a clear spatial gradient along the length of the Taurus molecular cloud filaments. This suggests that absorption is associated with the Taurus molecular cloud. Assuming the gradient is due to cloud rotation, the rotation of the atomic gas is consistent with differential galactic rotation while the rotation of the molecular gas, although with the same rotation axis, is retrograde. Our analysis shows that narrow NaI and KI absorption resonance lines are useful tracers of the atomic envelope of molecular clouds. In line with recent findings from giant molecular clouds, our results demonstrate that the velocity fields of the atomic and molecular gas are misaligned. The angular momentum of a molecular cloud is not simply inherited from the rotating Galactic disk from which it formed but may be redistributed by cloud-cloud interactions.
The Tharsis region of Mars is covered in volcanic flows that can stretch for tens to hundreds of kilometers. Radar measurements of the dielectric properties of these flows can provide information regarding their composition and density. SHARAD (shallow radar), a sounding radar on the Mars Reconnaissance Orbiter, detects basal interfaces beneath flows in some areas of Tharsis northwest and west of Ascraeus Mons, with additional detections south of Pavonis Mons. Comparisons with 12.6 cm ground‐based radar images suggest that SHARAD detects basal interfaces primarily in dust or regolith‐mantled regions. We use SHARAD data to estimate the real relative permittivity of the flows by comparing the measured time delay of returns from the subsurface with altimetry measurements of the flow heights relative to the surrounding plains. In cases where the subsurface interface is visible at different depths, spanning tens of meters, it is also possible to measure the loss tangent (tan δ) of the material. The permittivity values calculated range from 7.6 to 11.6, with an average of 9.6, while the mean loss tangent values range from 7.8 × 10−3 to 2.9 × 10−2 with an average of 1.0 × 10−2. These permittivity and loss tangent estimates for the flows northwest of Ascraeus Mons, west of Ascraeus Mons, and south of Pavonis Mons are consistent with the lab‐measured values for dense, low‐titanium basalt.