Çağatay Kerem Dönmez

Çağatay Kerem Dönmez

Who are you?

A PhD student in Physics in Middle East Technical University (METU). It is located in Ankara, the capital of Turkey.

Also working as a research assistant in my department since 2019.


What do you do in school? Splitting atoms? Self-torture?

Well, I am working in the field of astrophysics, currently concentrated on binary neutron stars in X-rays.


So you mean, self-torture???

No, not really... Maybe?

Well, a neutron star is basically the immensely compacted core of a huge dead star. I think there is no word in any language to properly explain how "immensely" it is compacted: The material of a neutron star is in average 100 000 000 000 000 times denser than water! Consequently, a typical neutron star has a mass comparable to Sun, yet is 10 km in size.

Even though we often think of stars as single entities, many of them has companions: in such binary systems the star pair rotates around each other. When a neutron star is in a binary system and when the conditions are right (i.e. the companion is huge or unstable, or the stars are very close), the neutron star may steal matter from its companion. Because the neutron star is so heavy and dense, the infalling matter accelerates wildly and gains an incredible amount of energy. Due to the violent interactions between the infalling matter and the neutron star, lots of high-energy X-rays are produced (Okaay, other types of "light" are produced as well, but right now X-rays are my bread and butter). By observing those X-rays, you can understand the physics behind those weird objects better. It is basically what we do.

In order to observe X-rays, one needs to send a space telescope spesifically manufactured to detect X-rays:

  • It needs to be sent into space because, luckily, Earth's atmosphere blocks all X-rays coming from the outer space.
  • It needs to be a special type of telescope, because you cannot manipulate X-rays like visible light. For example, you can create a lens to focus visible light, but X-rays rather pass through or be absorbed by such a lens!
So, scientists come with different designs for different purposes; and there are numerous X-ray space observatories orbiting the Earth. Securing some observation time from these telescopes are extremely hard, but thankfully, most of the data are publicly available immediately, or after a proprietary period.


Any actual work, or just slacking?

As of February 2022, I have two published articles:

My defended my master's thesis in February 2019, titled The Spectral and Temporal Properties of MAXI J1409-619.


Meh. Tell me more about yourself.

Born in an industrial, mid-sized city called Karadeniz Ereğli on the coast of Black Sea. Spent my life there until university.

My undergrad degree is actually in electrical and electronics engineering. I studied in Bilkent University (again in Ankara), was graduated in 2015.

I'm a casual


How to find you?

I am often at my office, Z22, at the Department of Physics. It is on the ground floor, at the middle of the long corridor.

However, due to the ongoing pandemic, trespassers may be shot. You can also reach me from:

If somehow you need my exact address, here it is:


That's all?

Yep. But hopefully, I'll add more details. You may check on here again later.