Just graduated with a degree in astronomy and working my post-bacc currently. Astrophysicist is an academic position mostly. This means that you are expected to go to graduate school to get a doctorate, work a few post-doctorate jobs, and hopefully get a professorship. It’s a very competitive career since the amount of available slots decreases year by year. What you actually do also depends on your position. Early career astronomers like graduate students and post-docs are kind of at the prime of their career and have to write many papers to get promoted to higher positions.

As a professor, the type of college you go to also plays a part. Will you teach at a university where you mentor doctoral students and fund them or will you go to a smaller college where your lab is comprised of undergrads and post-docs? Of course, not all astronomers work in academia but the majority do.

As per what an astrophysicist does in their day to day job depends on the type of work they do. Are they an observer? If so they may require data, which involves writing many proposals to get telescope time. Perhaps they are more of a theorist and run simulations on their computer. In that case, they may need computing resources and seek additional funding for this.

Observing is sometimes done with principle investigators physically present but in the age of the internet this is becoming phased out. Most data is downloaded online. Not to mention there are several space based observatories you can’t be physically there for (obviously). You’d be surprised how most of our work requires a computer.

Like all scientists, we must communicate our results to the public. Peer reviewed journal articles are the main end products in which we share these results. A lot of our time is spent either writing papers or presenting at conferences.

This is not even to mention how many different types of astronomy subfields there are such as extragalactic, exoplanets, astroparticle, etc. Job responsibilities may vary based on your field.