Ioonos

IOONOS: What made you want to become an astrophysicist?

Catherine Cesarsky: I liked math at school but when I reached university I found it a little bland. I then chose to add physics and when I had to pick a speciality for my postgraduate diploma I chose astrophysics. I stayed in this field and to this day I am still very happy I did!
As soon as I could access research, I soon realised how much I enjoyed it. It's beyond anything I could have imagined. The Universe is full of surprises and the technical progress of our era is such that we discover new things every day.

IOONOS: Could you describe your career path?

Catherine Cesarsky: I studied physics for five years at the University of Buenos Aires (Bachelor’s degree, postgraduate diploma) with some astrophysics, and then I obtained a doctoral degree (five years) in astronomy in the United States, at Harvard.
Before I joined the ESO, I ran an astrophysics department at the Commissariat à l’énergie atomique (CEA), then I joined the Department of physical science. I am today the president of the scientific programme comity of the CNES* (French space agency).

IOONOS: Has your job changed over the years?

Catherine Cesarsky: Everything has changed since I first started out! What happens today has nothing in common with what happened 10 years ago! There is a real explosion of knowledge today. Also different techniques and work methods have appeared over the years.
Internet means we can work with people all over the world. Before, there were just two or three people working on a project but now, teams of 15 or 20 people are international and it works tremendously well. Moreover, we don’t need to know the instruments so much.
In prior days, astronomers would spend nights in clod frozen domes (so as not to damage the telescope no heating was allowed), with their eyes stuck to the instrument… Today, we are comfortably sat in front of screens; there is no need for us to be near the telescope.

IOONOS: What future do you think is in store for astrophysicists?

Catherine Cesarsky: Astronomers, or astrophysicists, of my generation feel that they are living in a golden age, as if there were no chance of it getting better and better… I only half believe that; we are far from having understood everything and everyone knows that the more you know, the less you really know! I am certain that things will continue to improve and be more and more addictive!

IOONOS: What advice would you give a young person who is interested in your profession?

Catherine Cesarsky: You need a solid grounding in math and physics. Physics and more physics! And if you are interested in instrumental aspects then you need to study engineering.
Just studying maps of the sky doesn’t lead you anywhere. You must work hard from a very young age, don’t miss your chance, especially in France, where you won’t be given a second chance.

IOONOS: What is your most emotional memory as an astrophysicist?

Catherine Cesarsky: That would have to be the very first time I went to the observatory of Paranal, Chile. At that time I didn’t work for the ESO. But it was most certainly due to the feeling I had that day that I accepted the job I was offered later on when I was offered it.
I worked for a long time and with many people on the Isocam, a space instrument on board a satellite. And I must admit that when the first image from my infrared camera reached us, showing that everything was working, I was over the moon!
When I was theoretical physician at the very beginning of my career, I had been trying to resolve a problem for a very long time. And one night, it happened in a flash that enabled me to resolve everything all at once. We were a team but it was me who had the answer that meant we could solve the problem once and for all!