A5038790536- Stellar, planetary, and galactic studies
- Astro and Planetary Science
- Astrophysics and Star Formation Studies
- Astronomy and Astrophysical Research
- Gamma-ray bursts and supernovae
- High-pressure geophysics and materials
- Families in Therapy and Culture
- Scientific Research and Discoveries
- Geomagnetism and Paleomagnetism Studies
- Geophysics and Gravity Measurements
- Planetary Science and Exploration
The University of Texas at Austin
1995-2024
University of Pennsylvania
2021
California University of Pennsylvania
2020
We present the direct imaging discovery of a giant planet orbiting young star AF Lep, 1.2 $M_{\odot}$ member 24 $\pm$ 3 Myr $\beta$ Pic moving group. Lep was observed as part our ongoing high-contrast program targeting stars with astrometric accelerations between Hipparcos and Gaia that indicate presence substellar companions. Keck/NIRC2 observations in $L'$ Vector Vortex Coronagraph reveal point source, b, at ${\approx}340$ mas which exhibits orbital motion 6-$\sigma$ level over course 13...
Abstract The orientation between a star’s spin axis and planet’s orbital plane provides valuable information about the system’s formation dynamical history. For non-transiting planets at wide separations, true stellar obliquities are challenging to measure, but lower limits on spin–orbit orientations can be determined from difference inclination of rotational companion’s (Δ i ). We present results uniform analysis rotation periods, inclinations, cool stars (SpT ≳ F5) hosting directly imaged...
Abstract Tidal heating on Io due to its finite eccentricity was predicted drive surface volcanic activity, which subsequently confirmed by the Voyager spacecraft. Although activity in is more complex, theory volcanism can be driven runaway melting tidal increases as mantle thickness decreases. We show that this mechanism generic for a composite planetary body with liquid core and solid mantle, provided (i) rigidity, μ , comparable central pressure, i.e., /( ρ gR P ) ≳ 0.1 density...
Abstract Transiting giant planets provide a natural opportunity to examine stellar obliquities, which offer clues about the origin and dynamical histories of close-in planets. Hot Jupiters orbiting Sun-like stars show tendency for obliquity alignment, suggests that obliquities are rarely excited or tidal realignment is common. However, distribution less clear at wider separations where mechanisms not expected operate. In this work, we uniformly derive line-of-sight inclinations 47 cool ( T...
Abstract With a dynamical mass of 3 M Jup , the recently discovered giant planet AF Lep b is lowest-mass imaged with direct measurement. Its youth and spectral type near L/T transition make it promising target to study impact clouds atmospheric chemistry at low surface gravities. In this work, we present JWST/NIRCam imaging b. Across two epochs, detect in F444W (4.4 μ m) signal-to-noise ratios 9.6 8.7, respectively. At planet’s separation 320 mas during observations, coronagraphic throughput...
Abstract The large-scale structure of the solar system has been shaped by a transient dynamical instability that may have triggered interaction giants planets with massive primordial disk icy debris. In this work, we investigate conditions under which could coalesced into using analytic and numerical calculations. particular, perform simulations system’s early evolution account for viscous stirring collisional damping within disk. We demonstrate if would sufficient to maintain temperate...
With a dynamical mass of $3 \, M_\mathrm{Jup}$, the recently discovered giant planet AF Lep b is lowest-mass imaged with direct measurement. Its youth and spectral type near L/T transition make it promising target to study impact clouds atmospheric chemistry at low surface gravities. In this work, we present JWST/NIRCam imaging b. Across two epochs, detect in F444W ($4.4 \mathrm{\mu m}$) S/N ratios 9.6 8.7, respectively. At planet's separation $320 \mathrm{mas}$ during observations,...
The orientation between a star's spin axis and planet's orbital plane provides valuable information about the system's formation dynamical history. For non-transiting planets at wide separations, true stellar obliquities are challenging to measure, but lower limits on spin-orbit orientations can be determined from difference inclination of rotational companion's ($Δi$). We present results uniform analysis rotation periods, inclinations, cool stars (SpT $\gtrsim$ F5) hosting directly imaged...
We present the direct imaging discovery of a giant planet orbiting young star AF Lep, 1.2 $M_{\odot}$ member 24 $\pm$ 3 Myr $β$ Pic moving group. Lep was observed as part our ongoing high-contrast program targeting stars with astrometric accelerations between Hipparcos and Gaia that indicate presence substellar companions. Keck/NIRC2 observations in $L'$ Vector Vortex Coronagraph reveal point source, b, at ${\approx}340$ mas which exhibits orbital motion 6-$σ$ level over course 13 months. A...
Transiting giant planets provide a natural opportunity to examine stellar obliquities, which offer clues about the origin and dynamical histories of close-in planets. Hot Jupiters orbiting Sun-like stars show tendency for obliquity alignment, suggests that obliquities are rarely excited or tidal realignment is common. However, distribution less clear at wider separations where mechanisms not expected operate. In this work, we uniformly derive line-of-sight inclinations 47 cool...
Tidal heating on Io due to its finite eccentricity was predicted drive surface volcanic activity, which subsequently confirmed by the $\textit{Voyager}$ spacecrafts. Although activity in is more complex, theory volcanism can be driven runaway melting tidal increases as mantle thickness decreases. We show that this mechanism generic for a composite planetary body with liquid core and solid mantle, provided (i) rigidity, $\mu$, comparable central pressure, i.e. $\mu/ (\rho g R_{\rm...
We present the quantifiable limits of observation artificial megastructures within TESS data. characterize observability using a ratio in-transit RMS residuals and out-of-transit residuals. measure percent difference in circularity (a non-circularity index) by summing object’s pixels that do not fall pixel area planet. have determined an threshold our index to be O = 3. At this threshold, given simulated standard noise (gaussian with zero mean deviation dependent upon individual star’s...