The COVID-19 pandemic presents a remarkable opportunity to put to work all of the research that has been undertaken in past decades on the elicitation and structural estimation of subjective belief distributions as well as preferences over atemporal risk, patience, and intertemporal risk. As contributors to elements of that research in laboratories and the field, we drew together those methods and applied them to an online, incentivized experiment in the United States. We have two major findings. First, the atemporal risk premium during the COVID-19 pandemic appeared to change significantly compared to before the pandemic, consistent with theoretical results of the effect of increased background risk on foreground risk attitudes. Second, subjective beliefs about the cumulative level of deaths evolved dramatically over the period between May and November 2020, a volatile one in terms of the background evolution of the pandemic.

We convey our experiences developing and implementing an online experiment to elicit subjective beliefs and economic preferences. The COVID-19 pandemic and associated closures of our laboratories required us to conduct an online experiment in order to collect beliefs and preferences associated with the pandemic in a timely manner. Since we had not previously conducted a similar multi-wave online experiment, we faced design and implementation considerations that are not present when running a typical laboratory experiment. By discussing these details more fully, we hope to contribute to the online experiment methodology literature at a time when many other researchers may be considering conducting an online experiment for the first time. We focus primarily on methodology; in a complementary study we focus on initial research findings.

We observed the 2 July 2019 total solar eclipse with a variety of imaging and spectroscopic instruments recording from three sites in mainland Chile: on the centerline at La Higuera, from the Cerro Tololo Inter-American Observatory, and from La Serena, as well as from a chartered flight at peak totality in mid-Pacific. Our spectroscopy monitored Fe X, Fe XIV, and Ar X lines, and we imaged Ar X with a Lyot filter adjusted from its original H-alpha bandpass. Our composite imaging has been compared with predictions based on modeling using magnetic-field measurements from the pre-eclipse month. Our time-differenced sites will be used to measure motions in coronal streamers.

Children and their parents who are exposed to medical life-threat due to illness or injury are at risk for developing symptoms of posttraumatic stress. However, the prevention, detection, and treatment needed are often not available in the acute care settings of the hospital. The National Child Traumatic Stress Network and the Substance Abuse and Mental Health Services Administration have created a set of materials for use by hospital health providers and families that is available for download free from the National Child Traumatic Stress Network website, www.nctsn.org.

By reprocessing the NICMOS coronagraphic archive using improved PSF subtraction methods, we have obtained new images of 5 debris disks, all previously unseen using classical PSF subtractions. Three of the disks are edge on and two appear to be ring like, one of which is extremely asymmetric.

Their stellar hosts are nearby, young F and G type stars (40-90 pc, 12–30 Myr), including one that is a close analog to the young sun at roughly the age at which terrestrial planets were assembling. This is a 25% increase in the sample of debris disks seen in scattered light. Analysis and modeling of the disk geometries is in process. Given these systems' youth, proximity, and brightness (V = 7.2 to 8.5), these will be superb targets for investigating planet formation, and are perfect targets for studies with GPI, SPHERE and JWST.

The Archival Legacy Investigation of Circumstellar Environments (ALICE) project (AR-12652) is currently conducting a comprehensive and consistent reprocessing of HST-NICMOS coronagraphic survey data to search for point sources and disks using advanced PSF subtraction. The KLIP algorithm (Karhunen-Loève Image Projection) was developed for this project, and has proven very effective at processing the hundreds of selected archival images. This project has already been very successful with numerous detections of previously unseen point sources and several resolved debris disks that we are currently following up by multiple avenues. We give an overview of the project including preliminary scientific results with companion candidates and improved images of known disks

Transits of Mercury and Venus across the face of the Sun are rare. The 20th century had 15 transits of Mercury and the 21st century will have 14, the two most recent occurring on 15 November 1999 and 7 May 2003. We report on our observations and analysis of a black-drop effect at the 1999 and 2003 transits of Mercury seen in high spatial resolution optical imaging with NASA’s Transition Region and Coronal Explorer (TRACE) spacecraft. We have separated the primary contributors to this effect, solar limb darkening and broadening due to the instrumental point spread function, for the 1999 event. The observations are important for understanding historical observations of transits of Venus, which in the 18th and 19th centuries were basic for the determination of the scale of the solar system. Our observations are in preparation for the 8 June 2004 transit of Venus, the first to occur since 1882. Only five transits of Venus have ever been seen – in 1639, 1761, 1769, 1874, and 1882. These events occur in pairs, whose members are separated by 8 years, with an interval between pairs of 105 or 122 years. Nobody alive has ever seen a transit of Venus.

The black-drop effect bedeviled attempts to determine the Astronomical Unit from the time of the transit of Venus of 1761, until dynamical determinations of the AU obviated the need for transit measurements. By studying the 1999 transit of Mercury, using observations taken from space with NASA's Transition Region and Coronal Explorer (TRACE), we have fully explained Mercury's black-drop effect, with contributions from not only the telescope's point-spread function but also the solar limb darkening. Since Mercury has no atmosphere, we have thus verified the previous understanding, often overlooked, that the black-drop effect does not necessarily correspond to the detection of an atmosphere. We continued our studies with observations of the 2004 transit of Venus with the TRACE spacecraft in orbit and with ground-based imagery from Thessaloniki, Greece. We report on preliminary reduction of those data; see http://www.transitofvenus.info for updated results. Such studies are expected to contribute to the understanding of transits of exoplanets. Though the determination of the Astronomical Unit from studies of transit of Venus has been undertaken only rarely, it was for centuries expected to be the best method. The recent 8 June 2004 transit of Venus provided an exceptionally rare opportunity to study such a transit and to determine how modern studies can explain the limitations of the historical observations.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

Using the Near Infrared Camera and Multi-Object Spectrometer (NICMOS) on the Hubble Space Telescope we have conducted a coronagraphic imaging survey of 18 main sequence stars with large infrared excesses, searching for circumstellar dust (debris) in scattered light. Dusty disks with radial and hemispheric brightness anisotropies and complex morphologies, both possibly indicative of dynamical interactions with unseen planetary mass companions, were spatially resolved and imaged around three young (≲ 10Myr old) stars. From these observations we describe the debris systems around: a) HR 4796A (A0V), a 70 AU radius ring less than 14 AU wide with unequal ansal flux densities; b) HD 141569A (Herbig Ae/Be), a 400 AU radius disk with a 40 AU wide gap; and c) TW Hya (K7 T-Tauri), a pole-on circularly symmetric disk with a radial break in its surface density of scattering particles. Additionally, our non-detection of scattered light and high precision photometry of a fourth system of similar age, HD 98800 A/B, coupled with mid and thermal IR measurements, greatly constrain a likely model for the debris about the B component.

AMS radiocarbon results from the World Ocean Circulation Experiment in the Pacific Ocean show dramatic changes in the inventory and distribution of bomb-produced 14C since the time of the GEOSECS survey (8/73–6/74). Near-surface Δ14C values for the eastern portion of both the northern and southern subtropical gyres decreased by 25–50‰, with the change being greater in the north. Equatorial near-surface values have increased by ca. 25‰. Changes in the 250–750-m depth range are dramatically different between the northern and southern basins. The intermediate and mode waters of the southern basin have increased by as much as 75‰ since GEOSECS. Waters of similar density in the northern hemisphere are not exposed to the Southern Ocean circulation regime and are significantly less ventilated, showing maximum changes of ca. 50‰.