Every summer, we would meet once every year or two in Aspen Colorado, as the High-Z Supernova Search Team or as the ESSENCE Team. I am not sure of the year, but it was the early 2000s when this picture was taken at the Aspen Center for Physics. Weidong's expertise was valuable - he was recognized around the world as an expert in finding supernovae and measuring their light curves. He was also a warm, humble, and very intelligent friend. I am thinking about him on this third year since his death and I miss his.

In this photo you can see Alejandro Clocchiatti to the left, Bob Kirshner to the lowe right, Peter Garnavich at the upper left, and Adam Riess's beard at the top right.

I first met Weidong when he came to study English with my sister. She was thrilled to meet with this enthusiastic, young astronomer.  He taught her many things about his work while practicing English.  She would share their many discussions with me.  Later she also coached Ling. 

Over the years she became their "American Mother"  and I became their "American Auntie",  They were always ready to help her in any way.  Last year Weidong returned to China to be at his mother's death bed.  After he returned, Marilynn was dying.  Weidong spent many hours with her, first at home, and later in the hospital.  My sister kept telling me how much she appreciated his help.  She would say, "he is such a famous scientist but he will do anything to help me.  I am ashamed, I even ask him to take out the garbage!"  Weidong was very generous with his friends.  He also was quite modest about his intelligence and his accomplishments.  My world is a much lonelier place with out him.  He is missed.

As an undergraduate I spent a summer in sunny San Diego reducing images taken by KAIT and Nickel that Dr. Li (et. al.) graciously provided.  Today I find myself 1400 miles from home pursuing not only a PhD, but a career in science that I can only hope will be as influential as his.  The fact that I won’t get the chance to thank him in person for his work saddens me, but I feel my experience and drive is a living illustration of just how significant his influence on students was.  RIP Dr. Li, and thank you.

In 1996, my team at UC Berkeley completed the Katzman Automatic Imaging Telescope (KAIT) at Lick Observatory, a 0.76-meter robotic reflector whose purpose was to discover and monitor supernovae (exploding stars). Dick Treffers (my chief engineer) made most  of the hardware work correctly, and Michael Richmond (my graduate student) had written much of the software several years earlier.  We found our first supernova (SN 1997bs) in April 1997; see http://stupendous.rit.edu/richmond/kait/ngc3627.html .

But progress on our Lick Observatory Supernova Search (LOSS) was slow; I didn't have anyone dedicated full time to the project. So, I advertized for a postdoctoral researcher and was delighted when Weidong Li, a young graduate at the Beijing Astronomical Observatory, applied for the job. I knew that Weidong led a team that found SN 1996W and several other supernovae using a telescope quite similar to KAIT. (I think this makes him the first Chinese astronomer to discover a supernova since 1054 AD!) I offered him the position and was delighted when he accepted.

Weidong arrived at UC Berkeley in September 1997, and though it took him a few months to improve the software enough, in March 1998 he found SN 1998W and SN 1998Y, and LOSS really got going. The rest, as they say, is history: LOSS became, for about a decade, the world's most successful nearby supernova search, responsible for about 40% of those found each year; see http://astro.berkeley.edu/bait/public_html/kait.html . In total, it discovered almost 900 supernovae, many of which were quite young and thus scientifically most valuable. All of this was due to Weidong's incredible dedication, knowledge, ability, and enthusiasm. I have rarely met anyone as driven and passionate about their work; whenever there were problems with KAIT, for example, he would drive up to Lick Observatory and try to fix them, sometimes spending several days on the mountain with little sleep. If a really time-critical and exciting event came up, like a gamma-ray burst, he would stay up late at home, making sure KAIT conducted a thorough set of follow-up observations of the optical afterglow. I greatly admired him for all that he did.

Weidong became my right-hand man, leading LOSS and also collaborating with me on a very large number of research papers. I trusted him completely with everything KAIT did, and gave him nearly full authority in running LOSS. He
also played a large role (and in many cases the leading role) in mentoring many dozens of undergraduate students who checked the KAIT supernova candidates each day, as well as some graduate students and postdoctoral researchers
in my group. For example, he was the main advisor to Jesse Leaman, whose PhD thesis was the supernova rate in galaxies as derived from LOSS. Weidong and I were very proud that he played such a major part in developing the careers of so many young new scholars.

In public and technical presentations, I highlighted Weidong's enormous contributions, joking that my main goal each year was to secure his funding, and also that KAIT/LOSS would completely fall apart if he were to be "hit by a bus." I always worried that he might be lured away from me by another research group,
or by a higher paying nonacademic job... but I couldn't imagine that the world would lose him so suddenly, forever.

Weidong was a great astronomer and a wonderful friend. In many ways he was irreplaceable, and my research team will never be the same without him. He was also a very warm, generous, cheerful person who wanted to enrich the lives of others and make them happy. He had amazing spirit, and was tremendously excited about astronomy. It's difficult to believe that he is no longer with us, and his unexpected, tragic departure has created a hole in my heart that will never again be filled.

Farewell, my dear Weidong. We had an amazing 14 years doing science together, and I'll always cherish your memory.
 

"Weidong, do you like living here in the US?"

"Yes, a lot, but unfortunately here it is impossible to find those fresh, good snakes you can have in China!"

Weidong, we will miss you. 

I know Weidong from many meetings and scientific gatherings, I know his work, his enthusiasm, his professionality.  But here I will recall something about him that is not strictly related to science.  Five and half years ago, one day during the SN1006 millennium conference in Hangzhou, in Zhejiang province,  the conference organisers took the participants for a trip to the famous "Venice of the East", the marvellous and unique city of  Wuzhen.  It takes its nickname from the myriad of canals that cross it and make it so characteristic.  It rained a lot that day, which indeed reminded me of the real Venice, because most of the times I visited Venice it was raining (I also witnessed once one of the famous floods that make the water rise all over the town)!  We visited many historic places in Wuzhen that would have remained just as vestiges, reproductions, and museum pieces in my mind, were it not for the wise and authoritative explanations of Weidong, who would tell us details and meanings that are behind things and the relationship between  those remains and real history, past Chinese society and life. It is natural in these circumstances to speak with your Chinese native colleague about your own country and make comparisons.  In that occasion, we talked a lot with Weidong about East and West.  It was in that same occasion that he told me he had a daughter named Stella, the Italian word for  "star". It is also thank to this visit of Wuzhen and to the illuminating guidance of Weidong that I know something more about China - a country that I most love -  that is not just what a tourist learns and retains.   Weidong made that trip in a little, unique corner of Zhejiang province, a most authentic, instructive and unforgettable one. Thanks, Weidong.