William Thompson

Paper accepted to AJ! 🥳
Updated preprint coming to an arxiv server near you.

New position, same institution!

First day as a Plaskett Fellow 😎

Last day as a Herzberg fellow 🥲

Very nice!

To make it work, I had to pass “--overcommit”
Story of my life…

Probably nothing compared to TESS and Kepler though!

#exoplanets As we speak, Octofitter is running on nearly 20,000 cores 😅 maybe a record for most exoplanet orbit fits run in parallel?

Unless it’s SQL!

These changes are breaking---See sefffal.github.io/Octofitter.j... for details. Thanks! [4/4]

We have a new concept of “observation variables” that makes it easy to model out instrument systematics like RV offsets and northangle/platescale uncertainties. This plugs into our improved cross-validation capabilities to test how different subsets of data impact results. [3/4]

We have a new API for constructing models and specifying priors, with much simpler syntax. It’s now really easy to e.g. add priors on mutual inclination between two bodies and other dynamical constraints. [2/4]

Octofitter v7, now released! This release overhauls the modelling syntax and add some powerful new capabilities for advanced users. [1/4]

(Octofitter is a package for Bayesian modelling of exoplanet orbits)

Relative brightness maps of Antares over the course of a year, showing the changing brightness and shapes of convective cells in the stellar photosphere.

The brightest star in Scorpius, Antares, is nearing the end of its 15 million year life. It's so large that the orbits of Mercury, Venus, Earth and Mars would be inside the star. 🔭🧪

Pilate et al. published brightness maps of the star, showing gigantic convective cells.

arxiv.org/abs/2507.08614

Direct imagers, what is your expectation for how speckles behave at high spectral resolution? Do they vary smoothly with wavelength?

We have an R11,000 cube at 10^-7 contrast to share soon, but I’m curious to hear people’s expectations first #instrumentation #exoplanets.

a plot of a planet's position vs the star in 2D indicated as coloured lines. The line colour goes towards red or blue as the planet is in front of the star or behind. It is blue on the left, red on the right, and green, indicating 0, at the top and bottom. The separation is about 1000 milliarcseconds left or right increasing to about 1300 at top or bottom, creating an oval.

Position of Epsilon Eridani b in-front/behind the star, and phase angle over time for those interested. Updated pre-print should be ready soon!

🔭 #exoplanets

There’s something very special about the gulf islands 🏝️

Our JWST DDT was accepted 🥳

Gorgeous!

Found some beautiful Neptune data digging through the Keck Observatory Archives! The pole isn't nearly as visible now as it was back in 2002.

Thank you!

I was honoured today to give the Plaskett medal award talk to open this years Canadian Astronomical Society meeting in Halifax! Great to share our work on #exoplanets imaging and modelling 🔭

Astonishing new videos of the Sun show coronal "rain" in (pink-tinted) hydrogen-alpha light. Obtained with advanced adaptive optics research supported by NSF, the National Solar Observatory, and New Jersey Institute of Technology. Details and more videos in the link in the first comment below.

Link: sefffal.github.io/Octofitter.j...
Change log: github.com/sefffal/Octo...

Fig. credits:
* arxiv.org/abs/2504.11127
* arxiv.org/abs/2502.05359
* arxiv.org/abs/2502.20561

Thanks to:
* Dori Blakley
* Eric Nielsen
* William Roberson
* Zach Langford
* Eric Agol
* Sarah Blunt
* Clarissa R Do Ó

Octofitter v6 just released! 🐙

* Overhauled Hipparcos / Gaia modelling
* Multi-planet epicycle approximation
* Include astrometric jitter, north angle, and plate-scale uncertainties
* Dynamical priors (prevent crossing)
* Celerite gaussian processes
Much more!

(fig. credit in reply) #exoplanets 🔭

Thank you @bhaveshrajpoot.bsky.social !

Check out our short update on JWST mid-infrared observations of the closest Sun-like star, Alpha Centauri A!
iopscience.iop.org/article/10.3...

Credit: Jason Wang/William Thompson/Christian Marois/Quinn Konopacky

Access the video and related data here:

jasonwang.space/orbits.html

Unfortunately no, although we used to have a little LED to act as a planet 😅
Now we just inject fake planets with software when we need to.