What is a typical day in the life of an Astronomer?

The typical day in the life of an astronomer is a very broad question, because there are many kinds of astronomy to do and that’s a wonderful thing. When many people think of astronomy they picture someone with a telescope on dark nights, outside looking through lenses. This is more and more a fair description of amateur or backyard astronomy (Still wonderful and valuable, never let the word amateur be negative!) but less and less the truth behind professional astronomy.
Astronomy for many astronomers is much like doing physics for a living. You will spend much of your time developing mathematical models that fit HUGE amounts of data. That data will come from X-Ray, Microwave, Visible, Gamma and UV frequencies among others. This could be modeling of E&M gravitation systems quantum signatures, etc. There is really very little in the way of limits to what a astronomer has in their grab bag of tools to learn by observation. Especially in today’s age of trying to come to better understanding of dark matter, which often will bring an astronomers head out of the sky so to speak and down to a particle collider.
In some cases there is not even any observation, but model building. Some astronomers / physicists will spend time doing research for building new models that will be looked for by other people for how stars would spin into one another or how to look at galactic rotations.
You may instead develop the front end detection equipment much like an experimental physicist. This could mean you spend time design bigger better or smarter telescopes. Many of which have become individually smaller, while the array of telescopes that talk to one another become bigger. There could be very interesting and complex math for interference and Fourier analysis.
In general many astronomers are joined with a university of some kind, and are professors in their own right, so of course there will be the act of teaching or guidance for other up and coming students as well. There are MANY scientific roads to walk under the umbrella of “Astronomer,” and the competition at times can be tough, but it is an extremely rewarding field filled with a lifetime of discovery that can largely be what you make of it.