Hajime Kawahara
@hajimekawahara.bsky.social
soprano sax https://youtu.be/oSr2Mtm3rhs ; astronomer (exoplanet)
New paper out: Differentiable Microlensing Modeling (led by Shota Miyazaki) arxiv.org/abs/2510.02639
microJAX: A Differentiable Framework for Microlensing Modeling with GPU-Accelerated Image-Centered Ray Shooting
We introduce microJAX, the first fully differentiable implementation of the image-centered ray-shooting (ICRS) algorithm for gravitational microlensing. Built on JAX and its XLA just-in-time compiler,...
arxiv.org
October 7, 2025 at 12:17 AM
New paper out: Differentiable Microlensing Modeling (led by Shota Miyazaki) arxiv.org/abs/2510.02639
Last week, I gave an intensive course (exoplanets and inference) at Tohoku University. I am sharing the lecture materials here. github.com/HajimeKawaha...
GitHub - HajimeKawahara/exoinference: This is a handout on exoplanets and Bayesian inference.
This is a handout on exoplanets and Bayesian inference. - HajimeKawahara/exoinference
github.com
September 20, 2025 at 2:56 PM
Last week, I gave an intensive course (exoplanets and inference) at Tohoku University. I am sharing the lecture materials here. github.com/HajimeKawaha...
ExoJAX 2.2.0 has been released! We continue to modularize the entire codebase. The differentiable thermochemical equilibrium code ExoGibbs is now under development, and ExoJAX can already be coupled with it. github.com/HajimeKawaha...
Release version 2.2.0 · HajimeKawahara/exojax
The main target for version 2.2.0 is the capability of differentiable TCE (thermal chemical equilibrium). Note that we are developing the differentiable TCE package ExoGibbs.
Equilibrium Retrieval
...
github.com
September 20, 2025 at 11:13 AM
ExoJAX 2.2.0 has been released! We continue to modularize the entire codebase. The differentiable thermochemical equilibrium code ExoGibbs is now under development, and ExoJAX can already be coupled with it. github.com/HajimeKawaha...
Our paper, led by Shotaro Tada, is out. Atmospheric asymmetry not only affects the central time of the transit but also induces chromatic variations in duration, can be used to know differences in the atmosphere between the dayside and nightside near the limb. arxiv.org/abs/2503.08988
March 15, 2025 at 12:48 PM
Our paper, led by Shotaro Tada, is out. Atmospheric asymmetry not only affects the central time of the transit but also induces chromatic variations in duration, can be used to know differences in the atmosphere between the dayside and nightside near the limb. arxiv.org/abs/2503.08988
Reposted by Hajime Kawahara
*Newly Dr.* Kathryn Jones (+me and Kevin Heng) asks: "Planets show a sharp surge in brightness when directly opposite the Sun, and this peak is sharper for solid planets than for gas planets. Could we use this to detect rocky surfaces with JWST or HWO?" 🧪🔭🪐
tl;dr: no.
arxiv.org/abs/2502.14629
tl;dr: no.
arxiv.org/abs/2502.14629
February 21, 2025 at 3:22 PM
*Newly Dr.* Kathryn Jones (+me and Kevin Heng) asks: "Planets show a sharp surge in brightness when directly opposite the Sun, and this peak is sharper for solid planets than for gas planets. Could we use this to detect rocky surfaces with JWST or HWO?" 🧪🔭🪐
tl;dr: no.
arxiv.org/abs/2502.14629
tl;dr: no.
arxiv.org/abs/2502.14629