arXiv subjects

David Makowski

Publications and source records attributed to David Makowski.

3 recordsLinked to original sources

arXiv2026

Preparing for the Early eVolution Explorer: Detecting the Primordial, Transiting Exoplanet Population

The close-in small planet population may be formed either with hydrogen/helium dominated envelopes or with water-rich interiors. Both scenarios reproduce the present day planet population in mass, radius, and periods, and are difficult to differentiate with the mature planet demographic. Hydrogen/Helium `gas-dwarfs' have low mean molecular weight atmospheres, while `water-worlds' have envelopes that are significantly heavier, and as such these two scenarios have different evolution tracks that diverge in the first ~50 Myr of their evolution. We show that a low Earth orbit multi-band photometric survey mission, within the scope of the NASA Small Explorers Program (SMEX), can determine the frequency of young close-in planets at the 5% level and definitively differentiate between the competing `gas-dwarf' and `water-world' hypotheses. We simulate a 2.5 year mission capable of simultaneous multi-band near-ultraviolet (NUV), optical, and near infrared (NIR) wide field photometry. Such a mission would perform a photometric survey of 30 different stare-fields selected to probe the young star population. The mission will yield ~100 transiting planets in young star clusters and associations with ages <50 Myr. In comparison, only 20 such planets are known from K2 and TESS today.

astro-ph.EP↗

arXiv2025

TESS Discovers a Second System of Transiting Exocomets in the Extreme Debris Disk of RZ Psc

We present the TESS discovery of only the second system of transiting exocomets with a sufficient number of events to measure the size distribution in the RZ Psc system, enabling comparisons with the $\beta$ Pictoris and Solar System size distributions. Twenty-four transits with absorption depths (AD) of 1--20\% were observed across three TESS sectors of the 20-50 Myr K0V star, detected as part of our TESS survey of extreme debris disks identified by their IR excess. We discover that the ADs (and hence exocomet radii) follow a broken power-law cumulative frequency distribution not previously seen in extrasolar contexts but similar to that observed in Solar System Kuiper Belt Object sizes, with power-law slopes above and below the break of $\gamma_\mathrm{AD>break}$=2.32$\pm$0.12 and $\gamma_\mathrm{AD<break}$=0.11$\pm$0.04, respectively. We derive size distributions of 1--7~km from two independent lines of evidence. We use the RZ Psc exocomet rate to predict exocomet yields for the Early eVolution Explorer (EVE) NASA astrophysics Small Explorer (SMEX) mission concept to obtain simultaneous photometry of 10$^4$ young stars in NUV, optical, and NIR bands. Assuming occurrence rates scaled from RZ Psc, EVE would detect 590 exocomets from $\approx$70 young systems in the optical band, with $\approx$120 simultaneous 5$\sigma$ detections in all three bands. These data would enable grain sizes of 200--700~nm and graphite--olivine compositions of dozens of events to be distinguished at 2.5--3$\sigma$, as well as a 4$\sigma$ determination of the accuracy of the Herschel-derived M-debris disk fraction.

astro-ph.EP↗

arXiv2023

Impact of the Ukrainian crisis on the global food security

Using global wheat trade data and a network model for shock propagation, we study the impact of the Ukrainian crisis on food security. Depending on the level of reduction in Ukrainian wheat exports, the number of additional individuals falling under the minimum dietary energy requirement varies from 1 to 9 millions, and reaches about 4.8 millions for a $50\%$ reduction in exports. In the most affected countries, supply reductions are mainly related to indirect trade restrictions.

physics.soc-ph↗