Eric Agol

Kareem El-Badry Named a 2025 MacArthur Fellow Kareem El-Badry Named a 2025 MacArthur Fellow

Congratulations to @kelbadry.bsky.social for becoming a McArthur genius!!! 🤩🥳

www.caltech.edu/about/news/k...

🔭🧪🎢

Yes, during my sabbatical there in 2017.

Yall check this out, it’s the top coolest thing I’ve seen in a while, closed form autodiffable representation of optical interferometry, enormously powerful. Yes!!

So exhausting..

The statue of Pasteur in Paris faces the Invalides where Napoleon is buried. This is apt as one fought germs, while the other fought Germans.

Excellent review paper on prospects for high-precision photometry of exoplanet systems with JWST by Sarah Millholland & Joshua Winn: www.pnas.org/doi/10.1073/...

Not only did this paper get published, but the author, Thomas Count Dracula, received the “Best Author of the Month” award. www.easpublisher.com/article/arti... h/t @bluewhalenews.bsky.social

Astronomy 🔭 and physics ⚛️ GRFP applications are due Nov 14! Only seniors and 1st-year grad students can apply now (no second years).

Today Sept 27, 2025. It marks a special mathematical date because the numerals of the date form perfect squares.
Written as 09/27/2025, it becomes 9,272,025, which is the square of 3,045.
When written in the European format 27/09/2025, it becomes 27,092,025, the square of 5,205.

Can an expert tell me if these error bars are accurate? arxiv.org/abs/2509.17454

Congrats to Univ of Washington's Prof. Josh Krissansen-Totton (former UCSC postdoc!) on being selected for the AGU Ronald Greeley Early Career Award in Planetary Sciences
www.agu.org/user-profile...

A High-Precision, Differentiable Code for Solar System Ephemerides We present jorbit, a python/JAX library designed to enable modern data-driven numerical studies of the solar system. Written entirely in JAX, an auto-differentiable and optionally GPU accelerated lang...

A High-Precision, Differentiable Code for Solar System Ephemerides (Cassese et al in press) arxiv.org/abs/2509.19549

Did you try l’Industrie pizzeria? I didn’t get to eat there since the line was too long, but apparently it is worth the wait!

On the 🔭🧪 postdoc job market? Excited about science with Rubin and big surveys? Come join us at DiRAC. I’m so excited that we’re able to offer a few of these Fellowship positions this year!

Please share, LMK if you have Q’s!

aas.org/jobregister/...

On 9/16/25, celebrate a date of mathematical beauty Pythagorean Triple Square Day, as one man affectionately calls 9/16/25, is a day like no other this century.

Pythagorean Triple Square Day, as one man affectionately calls 9/16/25, is a day like no other this century.

YouTube video by AAS AAS Journal Author Series: Richard Zeebe and David Hernandez on 2025AJ....170...71Z

youtu.be/Jx5SxWqpjjI
🔭
AAS Journal Author Series: Richard Zeebe and David Hernandez on 2025AJ....170...71Z

Richard Zeebe (University of Hawaii at Manoa) and David Hernandez (Yale University) chat about their article on stellar flybys of the solar system and their (lack of) effect on the Earth.

Sorry Google and @wikipedia.org but this is not correct. Half of the Nobel prize was awarded to Penrose for the mathematical theory of black holes; the other half to Genzel & Ghez for their study of Sgr A*. (Thanks
@nytgames.bsky.social
Connections for alerting me to this!)

My very first observational project involved an Arp galaxy!

TIL that I study “space balls” (71 down in Sunday’s NYT crossword).

How do they know that it is not an interstellar gas cloud posing as a shark for attention?

Rocky Worlds DDT Updates: Final Target List and Virtual Information Session

The Rocky Worlds DDT has published our final target list. Join us for an information session on September 15 to learn more about the 9 targeted planets and the goals of the program.

🔭 #exoplanets

If a title includes a question mark, the answer usually is 'no.'

That was a ground-breaking discovery!

Yes, and I miswrote above - the density of the star would be lower, not higher, if you assumed that there were a single short-period planet instead of a chain of identical planets.

First JWST Thermal Phase Curves Of Temperate Terrestrial Exoplanets Reveal No Thick Atmosphere Around TRAPPIST-1 b and c - Astrobiology We report JWST/MIRI 15 μm phase curves of TRAPPIST-1 b and c,

astrobiology.com/2025/09/firs...

Yes - the transit duration would be longer, so one would infer a larger density for the star (if you could measure the impact parameter and orbital eccentricity vector). I would also expect the RV of the star to be dramatically reduced.

If this were a transiting planet system, and one modeled it as a single transiting planet w/ P = 0.039 years, one would infer the wrong density for the star (I don't think there would be TTVs...). Would this be worth searching for based on transiting planets with anomalous host-star densities?

Announcement of Opportunity Find in-depth information about the NASA Hubble Fellowship Program (NHFP) and its requirements.

Hey #exoplaneteers (and other early career folks) - applications for the 2026 NASA Hubble Fellowship Program are open!

www.stsci.edu/stsci-resear...

Illustration of a planet silhouetted in front of a star. The star shows a large eruption on one side, near 2 o’clock, and more wisps of red coming from its southern hemisphere. Two more planets appear in the background at right. The words “Artist’s Concept” are at the bottom left.

The exoplanet TRAPPIST-1 d intrigues astronomers looking for possibly habitable worlds beyond our solar system because it is similar in size to Earth, rocky, and resides in an area around its star where liquid water on its surface is theoretically possible. (1/5) 🧵 🔭 🧪