What if Earth-sized HZ worlds don’t have exactly Earth-like climate feedbacks? Climate Chaos, Snowballs, run-aways - but also many temperate yet not-Earth-like worlds! Congrats to Chaucer Langbert on this cool study!
arxiv.org/abs/2602.10369 @uarizonalpl.bsky.social @stewardobservatory.bsky.social
Pandora spacecraft in front of an exoplanet
It's happening!!! Pandora is going to space in just over 16 hours (if all goes well). Pandora is going to help us study exoplanet atmospheres, even when their host stars are misbehaving. I am headed up to Vandenberg to watch the launch shortly, and will make a thread about the mission/launch here!
Ever wondered how many bins to choose when making a histogram of data? The answer is that you shouldn't choose a number of bins yourself! ☄️ #astrocode
Here's a little notebook explaining how to make less biased histograms:
I'm very happy I woke up at 4am this morning to catch 3I/ATLAS right before its closest approach to Earth (today!) This interstellar visitor is traveling over 60 km/s ☄️
At 269 million km (1.8 AU), I took a series of 2.5 min exposures with my Seestar 🔭
The application for the ESO Summer Research Programme 2026 has just opened!
It‘s a six week programme in Garching close to Munich where pre-Ph.D students can work on a hands-on project.
Working at @eso.org is a fabulous experience, so please help me spread the word ✨
🔗 eso.org/sci/meetings...
Cloudy with a Chance of Starships takes readers on an irreverent expedition through the marvelous world of astrobiology, using as a guide the most important equation in science since E=mc2. With an irresistible blend of wit, insight, and the latest cutting-edge research, Seven Rasmussen looks at the thrilling possibilities of life in the cosmos through the lens of the Drake equation, a seven-variable mathematical expression that calculates the number of civilizations in our galaxy that humans could potentially contact. First proposed in 1961 by astrobiologist and SETI scientist Frank Drake, the equation begins with simple and well-known numbers such as the rate of star formation in the Milky Way and the fraction of stars with planetary systems. It then wades into thornier topics such as the number of planets with environments suitable for life, the fraction of suitable planets on which life appears, and the likelihood of intelligent life emerging on a planet and becoming technological. It concludes with the truly unknowable average lifetime of a civilization. While we will never resolve all its variables, the Drake equation offers an invaluable road map to the questions and challenges that lie before us in our quest for alien life.
the day is finally here: you can order my debut non-fiction, CLOUDY WITH A CHANCE OF STARSHIPS: HOW THE DRAKE EQUATION REVEALS THE ODDS OF LIFE IN THE COSMOS from B&N!!
www.barnesandnoble.com/w/cloudy-wit...
⭐️✨🔭Please help us get the message out about the 7th annual international ASPIRE program at @api.uva.nl. This summer 2026 school provides astronomy research experience for talented MSc students from countries where opportunities to move into a PhD program are limited. Applications are due 17 Dec! ⭐️✨🔭
Equating giant planet occurrence rate of ~20% to the disk fraction, that means a timescale of ~10 Myr for giant planet formation!
Their input source selection in the Sco-Cen region, showing stars with (blue) and without (orange) disks.
The fraction of young stars with disks as a function of age, based on three different selection methods. All show that many stars appear to have disks to ages well beyond ~10 million years, with a median lifetime of ~5 million years!
New paper led by Fabian Polnitzcky & with @sratzenboeck.bsky.social + @joaoalves.bsky.social: based on the ages of stars with infrared excess in Sco-Cen, it seems planet-forming disks last around twice as long as previous estimates suggest - giving twice as long for planets to form. 🔭☄️ #exoplanets
Any chance you can get density measurements for these planets from radial velocity masses?
That would really nail it down, otherwise it could also be planet engulfment/scattering/mergers etc.
Thanks, that is indeed a more complete one because it includes the directly imaged planets!
Thanks for the pointer, that may be what I will end up doing!
Question for the #exoplanets crowd:
Does any one know where to find an updated version of this plot?
I'm looking for the "standard" exoplanet mass vs. semi-major axis plot, but with an overlay of which planets have a spectroscopic measurement of their atmosphere
wasp-planets.net/2020/09/29/w...
Enjoyed giving a UofA Origins talk on how protoplanetary disks evolve – featuring new results from ALMA and JWST. The recording is available here 👇
youtu.be/mdgGgnjVbb0
@uarizonalpl.bsky.social @stewardobservatory.bsky.social
Big congrats to Jennifer Burt, Xavier Dumusque, and Sam Halverson on finishing their epic (instant classic) Annual Reviews of Astronomy & Astrophysics article "Precise Radial Velocities"!
arxiv.org/abs/2511.01954
contains some great new graphics for talks on
#exoplanets #EPRV #DopplerSpectroscopy
An image of the Gaia spacecraft logo in red with text above it that says Gaia DR3 IDs.
The NASA #Exoplanet Archive now has Gaia DR3 IDs! This should hopefully make your work and planning observations easier!
exoplanetarchive.ipac.caltech.edu
w/ Oli Shorttle, @johannateske.bsky.social & Eliza Kempton we reviewed our current understanding and prospects for peaking on the inside of small #exoplanets in "Constraining exoplanet interiors using observations of their atmospheres": www.science.org/stoken/autho... & arxiv.org/abs/2510.08844 🔭🧪⚒️☄️
And finally, you can read the entire paper here, soon to be published in ApJ:
arxiv.org/abs/2509.14101
19 /🧵
Jupiter and Earth, size to scale
Solar system-like architectures appear for a small range of initial disk masses around F and G stars, but are not a common feature around K and M stars.
Perhaps we are somewhat special among #exoplanets?
18 /🧵
Water mass fraction vs disk mass for planets within the habitable zone
While the mid mass architecture is most efficient at depositing water directly in the habitable zone:
It's pebble snow!
#exoplanets
17/🧵
Water mass fraction vs disk mass for planets within an orbital period of 100 days
The low-mass architectures are quite efficient at creating water-worlds close to the star.
16 /🧵
The bimodel pattern in core mass vs semi-major axes is consistent across stellar mass
The architectures are remarkably consistent across stellar mass, with the location and size of planets shifting with snow line and disk mass
15 /🧵
Mid mass architecture with giant planet cores at the snow line and water-rich smaller planets in the habitable zone
The mid mass architectures form a bimodal distribution:
Giant planet cores at the initial snow line location,
and a second peak with smaller, water-rich #exoplanets in the habitable zone!
14/🧵
Drumbeat
And…
13/🧵
Low mass architecture with watery super-earth cores growing inside of the snow line
Low mass disks from predominantly planetary cores closer in, possible precursors to super-earths or waterworlds.
12/🧵
High mass architecture with planet cores growing outside of the snow line
The main results is there are three growth modes:
High mass disks form exclusively giant planet cores outside the snow line
11/🧵
Snow line locations for different stellar masses and disk mass fractions
And explored a large range of stellar mass and disk mass to identify trends
10/🧵
Plot of planet core mass vs semi-major axis with 50 planetary seeds and a moving snow line
And a snow line that moves in over time
9/🧵
Plot of planet core mass vs semi-major axis with 100 planetary seeds
Sean added two components:
Pebble filtering from 100s of planetary cores growing simultaneously
8/🧵
And the code from Ormel & Liu 2018 that calculates planet growth from the pebble flux.
i.astro.tsinghua.edu.cn/~cormel/NewS...
7/🧵
