arXiv subjects

Cole Smith

Publications and source records attributed to Cole Smith.

3 recordsLinked to original sources

arXiv2026

JWST MIRI reveals a potential atmosphere on the ultra-hot rocky planet TOI-431b

An open question in exoplanet science is whether rocky exoplanets extremely close in to their host stars, `lava worlds', can retain significant atmospheres. Thermal emission observations via secondary eclipse can be used to determine whether a rocky exoplanet possesses an atmosphere. It is expected that an atmosphere could increase the planet's albedo and/or redistribute heat away from the dayside, reducing the secondary eclipse depth measured. Recent eclipse observations of lava planets, rocky planets hot enough to have liquid magma surfaces, have suggested the presence of atmospheres. Here, we present a single JWST MIRI/LRS partial secondary eclipse of the lava planet TOI-431b. We measure an eclipse depth of 81 $\pm$ 16 ppm, which corresponds to a brightness temperature of $1967^{+237}_{-253}$ K and a brightness temperature ratio R = $0.81\pm0.10$, being 1.2 $\sigma$ higher than the value reported by Spitzer. The observed brightness temperature ratio is 1.8$\sigma$ below that of a zero-albedo, zero heat redistribution bare rock (R=1). Given that magma pools are expected to have low albedos, we find that our results are best explained by the presence of an atmosphere. Future work to measure the exact composition of TOI-431b's atmosphere and improve models of lava planet atmospheres would better constrain the nature and evolution of lava planets.

astro-ph.EP↗

arXiv2026

Evidence for an Atmosphere on the Ultra-Short Period super-Earth HD 3167 b

'Lava worlds'-Earth-sized planets hot enough (Teq >~ 1100 K) to melt their dayside silicate surfaces-have emerged as promising candidates for atmospheric detection and characterization. Thermal emission observations show an apparent dichotomy: the hottest lava worlds have colder daysides than the temperature of a maximally emitting bare rock, indicating the likely presence of thick and/or reflective atmospheres while the coldest ones do not. However, where in instellation flux this potential bifurcation occurs is uncertain. We present a JWST MIRI LRS eclipse of the ultra-short period (USP) lava world HD 3167 b (Teq = 1786 K, R = 1.6 Rearth, P = 0.96 d) that helps bridge this gap. We measure the white light eclipse depth to be 38 +/- 11 ppm, more than 5 sigma lower than the expected eclipse depth of a dark, maximally hot bare rock. We use this to derive a dayside brightness temperature that is best explained by the presence of an atmosphere that cools the dayside by reflecting incoming starlight and/or efficiently redistributing heat to the planet's nightside. An atmosphere is further compatible with the planet's slight under-density compared to an Earth-like composition. The corresponding dayside emission spectrum is not precise enough to constrain atmospheric composition, motivating follow-up spectroscopic observations with JWST NIRSpec. Lastly, we use our observation and existing data to refine key planetary parameters of the HD 3167 system. HD 3167 b is currently the least irradiated USP super-Earth with evidence for an atmosphere.

astro-ph.EP↗

arXiv2020

Robotic Room Traversal using Optical Range Finding

Consider the goal of visiting every part of a room that is not blocked by obstacles. Doing so efficiently requires both sensors and planning. Our findings suggest a method of inexpensive optical range finding for robotic room traversal. Our room traversal algorithm relies upon the approximate distance from the robot to the nearest obstacle in 360 degrees. We then choose the path with the furthest approximate distance. Since millimeter-precision is not required for our problem, we have opted to develop our own laser range finding solution, in lieu of using more common, but also expensive solutions like light detection and ranging (LIDAR). Rather, our solution uses a laser that casts a visible dot on the target and a common camera (an iPhone, for example). Based upon where in the camera frame the laser dot is detected, we may calculate an angle between our target and the laser aperture. Using this angle and the known distance between the camera eye and the laser aperture, we may solve all sides of a trigonometric model which provides the distance between the robot and the target.

cs.RO↗