Barbara Ryden

Fat Bear Week comes but once a year. The final round of voting is today; make your vote count!

It's a rainy #Caturday here, and the cats are napping.

International Cat Day falls on a #Caturday this year! That means it is time to party like a cat.

A cat-approved book!

January 1921: NGC 584 is inconceivably distant. VP-elect has faith in America's moral fiber. July 2026: NGC 584 is at a distance of ~20 megaparsecs. Current VP is not regarded as an authority on moral fiber.

Since the cats have anti-parallel spins, they can both occupy the ground state. (Since they are cats, they are seldom in an excited state.)

Seen from certain angles, at occasional moments, the OSU campus is lovely.

Trim and Finn are recovering after their Caturday night party.

@benneholwerda.bsky.social is an authority. Pay attention to their words of wisdom!

Apparently, I am an author. It says so, right on my label.

Although my Friday lecture was on quasars, I decided to spread some Moon joy in the cover slide for the lecture. (The students seemed to tolerate the digression.)

"I'd like to get away from Earth awhile And then come back to it and begin over." For some reason, Robert Frost keeps running through my head today....

Now 285.

Happy #Caturday! Trim and Finn have each others' back, in a fine example of feline solidarity.

Finally... some "introverted astronomer" representation in the media!

Happy #Caturday. If you are in the path of a winter storm, Trim and Finn recommend that you keep warm.

Stellar Structure and Evolution: a very fine textbook.

It is not strictly required, when attending a meeting of the American Astronomical Society, to pose in front of the big AAS sign. However, I couldn't resist the opportunity. #aas247

I haven't quite decided if this is the ideal epigraph for chapter 8. Too Byronic, do you think, or just Byronic enough?

Happy Boxing Day from Finn the cat!

Happy #Solstice! I hope everyone in the northern hemisphere is keeping warm (preferably with the help of a cat).

I hope you are having a well-groomed #Caturday (perhaps with a little help from a friend).

Happy #Caturday! At this point, my cats' knowledge of physics is starting to catch up with mine.

#Caturday night.

Advice from Finn and Trim: get plenty of rest this #Caturday, to prepare you for the week ahead.

Happy Fat Bear Week to those who celebrate!

I'm not certain this is the best possible epigraph for a chapter on accretion, but I was feeling Rabelaisian when I chose it.

Happy #Caturday! May you have all the cat hugs you desire.

Happy #Caturday: may you dream of stars.

Roundhay Scene (1888)

For balance, a chapter that contains Maxwell's Equations must start with Maxwell's Poetry.

Remember to take some time to relax this #Caturday (in whatever posture suits your mood).

I continue my cinematic era with the epigraph to Chapter 4 of Astrophysical Gas Dynamics.

I cannot guarantee that I will stop crabbing. I will try, however, to stop doing it from pontoons.

Finn the cat is hanging out with his lobster. Happy #caturday!

Given 274 confirmed moons of Saturn, Lucy definitely has a point.

I am entering my cinematic era with the epigraph for Chapter 3 of Astrophysical Gas Dynamics.

I have chosen an epigraph for Chapter 2, and I think I have found a good illustration for the difference between Lagrangian and Eulerian observers. (I still have to negotiate the rights from the Shepard Trust, however.)

The latest volume in The Ohio State Astrophysics Series has been published! Thanks go to everyone in The Ohio State Astronomy Department, but especially to the students in the graduate dynamics class.

Opposing fascism and defying gender stereotypes: it's as American as apple pie, the Saturday Evening Post, and Norman Rockwell.

When a polar vortex is on its way, it is important to be prepared.

Are you attending #aas245? Stop by the Cambridge University Press display and get 30% off their featured books (including my latest, Celestial and Stellar Dynamics). Not attending? You can still get the discount online.