Porting MESA to the Raspberry Pi Aug 18 2020, 17:44

It's long been my dream to run MESA on the Raspberry Pi family of single-board computers. This dream came a step closer in 2016, with the advent of ARMv8-based Raspberry Pi models that are capable of running 64-bit operating systems; and it finally moved within reach this summer, with the release of an 8GB version of the Raspberry Pi model 4B.

To get MESA up and running on Maple (my new Raspbery PI 4B/8GB computer, pictured right), I installed a custom 64-bit Gentoo Linux operating system (huge props to Sakaki for developing this version, and providing awesome accompanying documentation). I then ported the MESA SDK to run on this architecture and operating system (grab a copy of the SDK port here). I'm delighted to report that the latest development version of MESA compiles and executes without issue. A full run through the test suite takes a bit longer (1-2 days) than my 28-core Linux workstation, but the results are bit-for-bit identical.

Maple sets a number of records: it is the smallest, cheapest and lowest-power computer on which MESA has run. I'm hoping that the experience porting MESA to the ARM architecture (another first) will prove useful when Apple switches their desktop/laptop computers from Intel to ARM.

A Brief Statement Jun 5 2020, 18:26

Like many of my faculty, staff and student colleagues in the Department of Astronomy, I am deeply saddened and dismayed by the recent killing of George Floyd. This was not an isolated act, but rather just one further addition to the litany of heinous acts perpetrated against black and indigenous peoples in the United States. I stand in solidarity with the many movements fighting against such injustice, and fully recommit myself to hearing, supporting, promoting and following those from oppressed communities.

A stellar software ecosystem May 7 2018, 23:34

If takes a village to raise a child, it takes a whole software ecosystem to model a star. Frank Timmes has put together an informative graphic showing prominent parts of this ecosystem, including the GYRE and MESA software instruments that I'm helping develop. Also shown are some of the important ongoing and upcoming ground and space observatories that provide the empirical yardsticks that stellar models must match up against.

What shapes are things in Outer Space? May 1 2018, 09:00

Last week I was contacted by Gizmodo, who were looking for contributions to their 'Giz Asks' series on the question 'What shapes are things in Outer Space?'. This is how I began my response:

Most things in space—in particular, stars, planets, black holes and large asteroids—are spherical in shape, like a basketball. This is because the dominant force at the immense scales in space is gravity. For any sufficiently massive object, self-gravity—the gravitational pull of each part of the object on the other parts of the same object—tends to mold the object into the most compact form, and that happens to be a sphere.

Read my complete answer in the article, along with great write-ups by a number of other astronomers.

A Sterling Hall landscape for Stellarium Apr 30 2018, 13:44

As one of the components of the upcoming Astronomy 103 Online course, which will be running for the first time in Summer 2018, I've been creating a set of virtual planetarium tours using the popular (and free) Stellarium software. To provide students with a degree of immersion, I customized the landscape with a 360-degree panoramic image from the rooftop of Sterling Hall, home to the Department of Astronomy. This image was created by the awesome (and also free) Hugin panorama stitcher, from 8 separate photographs obtained using a Canon PowerShot ELPH 300 HS camera (although cell-phone cameras can now take impressive shots, I think traditional cameras still provide a superior result).

To try out the the image yourself, first download the landscape zip file. Then, in Stellarium, open up the View dialog (F4), select the Landscape tab, click on the Add/remove landscapes button, and then click on the Install a new landscape from a Zip archive button. Select the file you downloaded, and the Sterling Hall view should appear!