Juliette Becker
@jcbecker.bsky.social
Currently trying to understand planet formation as a professor of astronomy at the University of Wisconsin-Madison
In Nick Marston's first first-author paper (accepted now to ApJ, and on arXiv here: arxiv.org/abs/2606.11330) he asks the question: do *all* super-puff exoplanets defy the expectations of core accretion? He modeled the interior structures of 34 cold super-puffs...
New first-author paper from Adam Distler, now accepted to ApJ, evaluates whether the inner edges of peas-in-a-pod (PIAP) multiplanet systems are affected by secular resonance crossings driven by the rotational evolution of the host star....
Paper day!!! 🎉 arxiv.org/abs/2604.07447 ⬇️ #exoplanets #astronomy It all starts with planets around really small stars (M dwarfs). There's some evidence that planets around these stars form fundamentally differently than around stars like our Sun. We think that planets around these stars may 1/
Super-Earth masses and stellar abundances from NIRPS reveal tentative evidence for water-rich formation around M dwarfs
Tracing the compositional link between terrestrial super-Earths and their host stars provides clues to their dominant formation pathway. By constraining the stellar abundances of refractory elements, we can predict the core mass fractions (CMFs) of their super-Earths. The level of agreement between this prediction and the planetary CMF derived from their masses and radii can reveal past formation processes, like mantle stripping and water-rich formation plus sequestration in the planet's core. Here, we present the first results from the Near Infrared Planet Searcher (NIRPS) GTO CMF subprogram: an intensive radial velocity campaign to refine masses and compute host stellar abundances of three hot super- Earths around M dwarfs (GJ 1132 b, GJ 1252 b, and LTT 3780 b), calculating masses of $1.69 \pm 0.15M_\oplus$, $1.54 \pm 0.18M_\oplus$, and $2.34 \pm 0.10M_\oplus$ respectively. We measure the CMFs of these and six further hot super-Earths with precise masses already available in the literature to 10-15% precision. We compare these to CMF predictions made from measuring the Fe, Mg, and Si abundances of their host stars measured from the NIRPS spectra. We find that the CMFs of these planets are smaller than expected from their host stellar abundances, to a statistically significant degree. This discrepancy is suggestive of significant reservoirs of water, and while these planets are too hot to harbor surface water, they likely have interior water mass fractions of $\sim$1%.
arxiv.org
New paper led by University of Wisconsin-Madison undergrad alum Coleman Nelson finds TOI-700d is robustly habitable, while TOI-700e sits on the edge: iopscience.iop.org/article/10.1...
Dynamical Interactions and Habitability in the TOI-700 Multi-planet System
Dynamical Interactions and Habitability in the TOI-700 Multi-planet System, Nelson, Coleman, Becker, Juliette
iopscience.iop.org
New ApJ paper: Can inner planets survive when a giant becomes a hot/warm Jupiter via high-eccentricity tidal migration? Usually no. Survival requires the giant’s periastron to stay >14 mutual Hill radii away. Observed systems with hot Jupiters + inner planets are inconsistent...
Warm Jupiter Tidal Migration Can Spare Inner Planets; Hot Jupiter Tidal Migration May Not
Warm Jupiter Tidal Migration Can Spare Inner Planets; Hot Jupiter Tidal Migration May Not, Becker, Juliette
iopscience.iop.org
AbSciCon will be in Madison, WI in May 2026! Please consider submitting an abstract to session 39, Dynamical Environments of Habitable Worlds, led by Joseph Livesey. Hope to see you all there!
Interested in coming to UW-Madison and working with WiCOR on questions related to the origin of life? Apply for this new postdoctoral fellowship opportunity. Applications due November 15th!
Wisconsin Center for Origins Research@wicor.bsky.social · 9mo agoWiCOR seeks a #postdoctoral fellow to participate in Center #research in any discipline related to our two main research questions: 1. How do habitable planets form? 🪐 2. How does life emerge on habitable planets? 🧬 Full information at: wicor.wisc.edu/postdoc/ Apply by Nov 15 🔭 🧪 #postdoc #hiring
Mean motion resonances (familiar from planetary systems) also govern how stellar-mass BHs migrate and merge in AGN disks. Marguerite Epstein-Martin (applying to postdocs THIS FALL) has a new paper “Mean Motion Resonances in AGN Disks” (arxiv.org/abs/2510.128...). #exoplanets
Mean Motion Resonances in AGN Disks
Mean motion resonances (MMRs) are a generic outcome of convergent migration for bodies embedded in accretion disks around a central mass. Long studied in planetary systems, the same phenomenon should ...
arxiv.org
Some hot Jupiters might not have traveled far. New simulations by UW-Madison recent undergrad alum Devansh Mathur show that if enough solid material is funneled inward, both a hot Jupiter and its inner companions could form in situ. Accepted to PASP: arxiv.org/abs/2510.135... #exoplanets
Investigating the Formation of Planets Interior to in situ Hot Jupiters
The population of hot Jupiters with adjacent planetary companions is small but growing, and inner companions appear to be a nearly ubiquitous outcome within this subset of the exoplanet census. While ...
arxiv.org
Published this week in ApJ by UW-Madison undergraduate Eva Stafne: General relativity might save life on planets orbiting white dwarfs. GR-driven orbital precession can suppress tidal heating that would otherwise trigger a runaway greenhouse. arxiv.org/abs/2509.26421 #exoplanets
General Relativity Can Prevent a Runaway Greenhouse on Potentially Habitable Planets Orbiting White Dwarfs
Planets orbiting in the habitable zones of white dwarfs have recently been proposed as promising targets for biosignature searches. However, since the white dwarf habitable zone resides at 0.01 - 0.1 ...
arxiv.org
When stars die, could life begin? White dwarfs could possibly host planets with oceans, making them worth considering in the search for life. I wrote about the science (and surprises) of white dwarf planets at The Conversation. theconversation.com/earth-size-s...
Earth-size stars and alien oceans – an astronomer explains the case for life around white dwarfs
Could tiny stars a fraction the size of our solar system’s Sun have habitable planets orbiting them? A new study says it’s possible.
theconversation.com
Two weeks until abstracts (and requests for travel support) are due for this fall's GLEAM! gleam.astro.wisc.edu/overview/ I hope to see you here!
Overview
GLEAM 2025 is a two-day meeting (Nov 6/7) focused on new results in exoplanet science and planetary evolution. The event is aimed at undergraduate and graduate students, postdocs, and faculty and will...
gleam.astro.wisc.edu
Juliette Becker@jcbecker.bsky.social · last yr.We’re so happy to host GLEAM 2025 at UW–Madison this Fall, Nov 6–7! gleam.astro.wisc.edu Join us for two days of exoplanets & community with a view of the shores of Lake Mendota. No registration fee. Travel support available. Abstracts & Travel Support Requests due Sept 5th. #exoplanets
We’re so happy to host GLEAM 2025 at UW–Madison this Fall, Nov 6–7! gleam.astro.wisc.edu Join us for two days of exoplanets & community with a view of the shores of Lake Mendota. No registration fee. Travel support available. Abstracts & Travel Support Requests due Sept 5th. #exoplanets
Definition question: Everyone in the field seems to use P~10 days as the boundary between "Hot" and "Warm" Jupiters in the literature. Does anyone know where this boundary actually came from (did a single person come up with it, and if so who / what paper)?
#AAS246 Chambliss Student Award Winners The AAS is pleased to announce the Chambliss Astronomy Achievement Student Award winners from the 246th AAS meeting in Anchorage, Alaska, in June 2025. Congratulations, all! aas.org/posts/news/2... 🔭
AOS Prof. Hannah Zanowski studies polar oceanography, and she's now bringing that expertise to WiCOR, where she focuses on planetary oceanography by modeling early Earth and exoplanet conditions to understand what ultimately makes a planet habitable after it forms. ls.wisc.edu/news/from-ea...
From Earth to Exoplanets: Studying Oceans Across the Universe
ls.wisc.edu
Congratulations, Irene, on this excellent (and very complete) paper!!
Irene Vargas-Salazar, PhD@irinipocket.bsky.social · last yr.🚨 Paper day!!! 🚨 Excited to announce that this project I’ve been working on these last few years has been published! Read more at : arxiv.org/abs/2506.13004 More info in the 🧵
'Baby' stars are typically surrounded by disks loaded with gas, but it isn't long before that mass starts to drift away. #UWMadison astronomers say that might mean gas giants like Jupiter need to form earlier than rocky planets like ours. news.wisc.edu/measuring-ga...
Measuring gases around young stars, astronomers unlock major clues to planet formation
UW–Madison astronomers and international collaborators have produced the most accurate measurement of the gases swirling around young stars and their changing mass over time. The discovery offers clue
news.wisc.edu
Hycean planets (ocean worlds with H-rich atmospheres) are thought to be promising spots for life, particularly around M-dwarfs, with the habitable zone being much wider than it is for terrestrial planets. But there's a twist...
Check out this 12-paper series out today from the AGE-PRO collaboration. Congrats to everyone (including Coco Zhang from UW Madison) on the huge amount of work that went into this interesting result!! It might take me a while to read all 12 papers though! public.nrao.edu/news/alma-pl...
ALMA Reveals Lives of Planet-Forming Disks - National Radio Astronomy Observatory
An international team of astronomers has unveiled groundbreaking findings about the disks of gas and dust surrounding nearby young...
public.nrao.edu
Ready to roll at #AAS246! I’ll be giving a talk on Tuesday afternoon in the AGN session and two of my students will be presenting in other AGN sessions as well!
Check out our new paper in PASP!
Publications of the Astronomical Society of the Pacific (PASP)@paspjournal.bsky.social · last yr.A recent open-access @paspjournal.bsky.social article assesses the impact of episodic FU Orionis outbursts on the evolution and migration of planetary systems, providing an avenue for the observed prevalence of low-mass, iron-rich ultra short-period planets. iopscience.iop.org/article/10.1....
A recent open-access @paspjournal.bsky.social article assesses the impact of episodic FU Orionis outbursts on the evolution and migration of planetary systems, providing an avenue for the observed prevalence of low-mass, iron-rich ultra short-period planets. iopscience.iop.org/article/10.1....
Why do some Hot Jupiters have nearby companions while others appear alone? Our new paper led by Thomas MacLean (senior UG off to Stanford) explores how stellar spin-down and system architectures affect the visibility of inner & outer companions. Read more: arxiv.org/abs/2505.11637
Three-Dimensional Orbital Architectures and Detectability of Adjacent Companions to Hot Jupiters
The orbital properties of the (as-yet) small population of hot Jupiters with nearby planetary companions provide valuable constraints on the past migration processes of these systems. In this work, we...
arxiv.org
Jim Lattis and I will be on Madison's local NPR affiliate tomorrow afternoon from noon - 1pm, as a part of the Larry Meiller Show. We'll talk about exoplanets, the search for life, and the new WiCOR center at UW. Locals can listen on FM 88.7, or online www.wpr.org/shows/larry-...
The Larry Meiller Show
Join us every weekday from 11:00 to 1:00 when we discuss the environment, consumer issues, nature, books, gardening, home improvement and so much more. Our expert guests share their knowledge and take...
wpr.org
Can FU Orionis outbursts scorch planets into becoming iron-rich and ultra-short-period? We model how extreme heat & turbulence during these events can strip planetary mantles — reshaping planetary composition & sizes forever. arxiv.org/abs/2504.16772
Thermal Evolution and Mass Loss on Short-Period, Low-Mass Planets During FU Orionis Outbursts
Ultra-short-period (USP) planets represent a unique class of exoplanets characterized by their tight orbits and relatively low masses, with some also exhibiting unusually high iron fractions. Previous...
arxiv.org
I would like to highlight that this work was led by UW-Madison Astronomy post-bac student Alyssa Jankowski, and also featured contributions by Zijun He, a high school student at Madison West High School. Congratulations to both of them on their accomplishments!
Publications of the Astronomical Society of the Pacific (PASP)@paspjournal.bsky.social · last yr.In a recent open-access article published in @paspjournal.bsky.social the ambiguous age and tidal history for the ultra-hot Jupiter TOI-1937Ab is assessed through a suite of tidal evolution simulations and analysis of the system's transit timing variations. iopscience.iop.org/article/10.1...
Check out Alyssa Jankowski’s first first-author paper (just accepted to PASP) on TOI-1937 Ab—a massive ultra-hot Jupiter that could be inspiraling due to tidal forces! arxiv.org/abs/2503.158... For those hiring - Alyssa is applying to grad schools and post-bac positions now. #exoplanets
The Ambiguous Age and Tidal History for the Ultra-Hot Jupiter TOI-1937Ab
Ultra-short-period (USP) planets are a rare but dynamically significant subset of the exoplanet sample, and understanding their dynamical histories and migration processes is necessary to build a comp...
arxiv.org
Join WiCOR on March 3 & 4 for seminars from Dr. Jon Arenberg: NASA’s James Webb Space Telescope March 3 @ 12 pm, 6515 Sterling Hall The Importance of Communication March 4 @ 10 am, 4421 Sterling Hall
