Early warning before a star explodes

Dr. Eran Ofek, one of the Krill Prize winners decided to return to Israel after six years at Caltech. He is currently researching how supernova explosions can be predicted in the Department of Astrophysics at the Weizmann Institute

When Eran Ofek was 11 years old, he happened to hear about the activities of the Israel Astronomical Society and the observatory in Givatayim and joined them. "If I had known about it earlier, I would have joined earlier" he says in an interview with the Hedaan website, following his winning the Krill Prize, a prize awarded by the Wolf Foundation to outstanding researchers and senior researchers before the tenure stage.

Today, after studying all his degrees at Tel Aviv University, and when he returned about three years ago from a six-year post-doctorate at Caltech, he studies the same type of supernovae in which he specialized in the astrophysics department at the Weizmann Institute.

Dr. Ofek studies type IIn supernovae, the uniqueness of which is that the material emitted during the explosion of the star that creates the supernova collides with additional material that probably got there before the explosion. Observational evidence of these collisions has been known for many years but what Ofek and its partners are currently investigating is whether the events in which this material was ejected from the star were violent events or a slow shedding of the outer layers of that star. "We suspected that these were explosions and not the calm way, and indeed we discovered that a month to a few years before the supernova event, smaller explosions occurred in supernovae of this type.

By the way, how do you check retroactive data? It's very simple to search the data of robotic telescopes that are constantly watching the sky and are updated about every star in their field of view.

At Caltech he started the work on these supernovae and also studied the phenomenon of "Shock Brakes", which makes it possible to determine what type of star exploded in the supernova. Type IIn supernovae are a good place to test this hypothesis, where the phenomenon looks completely different than in normal supernovae. In this way it is also possible to learn what the material surrounding the supernovae that was damaged in the explosion is.

Gamma radiation bursts, and the most important thing I did at Caltech: measuring the eclipse that the rocks in the Oort cloud, the most distant region of the solar system, make on stars they pass in front of. These defects are very short. The length of a typical eclipse is a tenth of a second, they are very rare and have to look for long periods to capture such an eclipse. However, there are those who do this - the Hubble Space Telescope. In order to photograph areas in space for long periods of time, one of his cameras locks onto two certain stars (in each area). We went through data that was collected over a period of 15 years and was not supposed to be used for research at all, and we discovered two such deficiencies. I am currently building an optimal telescope system that will be able to discover these phenomena at a much higher rate.
Although Ofek is an observational astronomer, he does not make the observations himself: ""Most of the information I receive is collected by robotic telescopes or from other people. I was even responsible for the robotization of one of the telescopes. They work completely autonomously without human intervention and the entire operation is done automatically. These are huge information systems. Our main telescope is a telescope located on Mount Plumer and which is characterized by an extremely wide field of view.

A childhood dream that continues to come true
Dr. Ofek turned a hobby into a profession, in which he was awarded the Creel Award. "I was a member of the Astronomy Society from a young age, maybe sixth grade. I didn't know the observatory before. If I had known, I would have done something about it, I remember that I would have waited for the brochures every star of light, I would have gone down every day to check the mail to see if the issue had arrived.
"I was a guide at the observatory for many years. One of the things I really liked to do was track variable stars and send the reports to the American Variable Star Association. Then I studied for all degrees at Tel Aviv University, but already in my first degree and even before that I helped professors at Tel Aviv University with their research.

Why did you return to the Weizmann Institute? Is this not a place for observational astronomy?
"I had offers from all the places I wanted to go, Tel Aviv, Jerusalem, the Weizmann Institute - there was always astrophysics there, but mainly very little theoretical. A few years later, Avishai Gal-Yam, the observatory astronomer, arrived and I was the second observatory. I felt that the amount of resources that would be available to me there would be the most significant. I don't have the comparison but I'm pretty sure it does. They put help and resources at my disposal, and I still have them at my disposal, which would have been very difficult, even with a good will, to put them in other places."
"The return was not easy, you always have to get used to the Israeli culture again, it's not easy, about its advantages and disadvantages, it's even very difficult, it's much easier to get used to the American culture than to the Israeli culture even after you've been there."

What is your reaction to winning the Krill Award?
"This is a very appreciated award. I've heard quite a bit about him, and I know winners from previous years. It is distributed by the Wolf Foundation to young scientists before the tenure stage and I am happy for the win, it makes me feel that I am doing work that people value."

A prestigious award

The Krill Prize is a prize awarded in Israel, since 2005, by the Wolf Foundation for excellence in scientific research. The award, in the amount of $10,000, is intended for leading researchers who are outstanding academic faculty members, at the rank of lecturer or senior lecturer who have not yet received tenure, who are employed at one of the universities in Israel. Every year, the foundation awards ten Krill prizes in the following fields: exact sciences, life sciences, medicine, agriculture and engineering.

The "Keril Awards for Excellence in Scientific Research" have been awarded by the Wolf Foundation since 2005. The awards are financed from the estate of the late donor Avraham Hirsch Keril Shlanger (1912 - 2007).

For the full list of 2015 Krill Award winners