Profile 01 Alexey Tolstov

Name: ALEXEY TOLSTOV (Astronomer)
Hometown:  Cherepovets City, Northern European Russia
Position: Kavli IPMU Project Researcher
Recommended reading: Foundations of Radiation Hydrodynamics, by D. Mihalas and B. W. Mihalas
Favorite place in Japan: Ginkakuji (Temple of the Silver Pavillion), in Kyoto. When my family came to Japan, Kyoto was the first place we visited, and we stayed near the temple.

What can you tell us about your current research at Kavli IPMU?

In my research, I try to answer this question: how do massive stars die? The question is interesting not only for our understanding of the mechanism of supernova explosions, but also for our knowledge of the chemical composition of stellar evolution and the Universe.

In my work at Kavli IPMU, I’m mainly interested in Superluminous Supernovae, which are among the most luminous objects in the Universe. I am also interested in the so-called hypernovae, a supernova which release a huge amount of energy.

Another class of objects that I’m looking at are the first stars of the Universe. The explosions of first stars, too, are important for the evolution and chemical composition of the Universe.

As a theoretician, I build models to study these explosions. We then use X-ray, UV, optical and near-infrared observations to compare with the models in order to understand each scenario and to see which one fits the model best. In the case of Superluminous Supernovae, for example, there are several scenarios, but the scientific community still does not know which model is the best fit for them.

Can you say something about your experience of life at Kavli IPMU?

What I like about Kavli IPMU is that it is really international. Before I arrived, I had some concern that the supernova group here was quite small. But I found that there are a lot of visiting specialists, and that allows for many unique opportunities for fruitful discussions about supernovae.

Can you tell us something about your academic background?

I studied at the Moscow Institute of Physics and Technology (MIPT). The good thing about MIPT is that, by the time you are a 4th-year student, you are already involved in scientific research and activity for more than 50 percent of your time. For me, it was astrophysics.

I then joined for my Phd. the Institute for Theoretical and Experimental Physics (ITEP) in Moscow, which had a strong supernova group led by V. Imshennik and D. Nadyozhin, who are pioneers in building theoretical models for photon and neutrino emissions of supernovae. After that, I was a postdoc in Japan--at Kyoto University and RIKEN--before coming to Kavli IPMU.

What drew you to science, and your particular field, in the first place?

My way into research was a little bit complicated. Before science, I spent some years working in a software company in Moscow. After starting a family, I decided to study for my Phd. I just found science much more interesting than IT. And as I've liked physics since my childhood, I decided to come back to it.

What can you tell us about future projects?

There are many interesting objects observed recently by supernova surveys, so I’m going to continue with work on modeling them. Also, we plan to improve our models of light curves and spectra to make more realistic simulations. And, my collaborators and I have a number of different models of supernovae, as the number of observations is growing, so there is a need to build a catalog of them to give observers the opportunity to predict follow-up observations more accurately.

Where can we find your work?

You can find some links to my papers and short descriptions of my activities at and my profile at Kavli IPMU