NOTICE: This site is no longer being actively maintained
On October 1, 2019 NOAO joined with Gemini Observatory and Rubin Observatory operations to create a new organization, NSF’s NOIRLab. The content of this site is being migrated to our new domain: The public site has been launched and is the main web portal for the public and media. Many links on this site may redirect you to the new site. For now, scientists and astronomers can still find information about Kitt Peak, CTIO, and CSDC on the old site ( October 28, 2020

NOAO < NEWS < David S. De Young

David S. De Young

NOAO is deeply saddened to announce the death of Dr. David De Young on December 2, 2011. Dave, an astronomer with tenure, arrived at NOAO in 1980 and had recently retired at the end of September 2011. His outstanding efforts to promote the quality of research, from the telescopes and from the staff, will be greatly missed.

Dave was born in Colorado Springs, Colorado, and earned his BA from the University of Colorado in 1962 and his PhD in physics and astronomy from Cornell University in 1967. He joined the National Radio Astronomy Observatory (NRAO) in 1969 as an Assistant Scientist. He was hired to bring theoretical expertise to NRAO, but quickly became involved in observing and analysis. He was promoted to Associate Scientist in 1972 and to Scientist with Tenure in 1974. He left NRAO to join NOAO (then Kitt Peak National Observatory) in 1980.

“Throughout his career, Dave was motivated by a deep commitment to the science,” says Sidney Wolff, past NOAO Director. “We all remember him saying repeatedly at TAC meetings, ‘Where’s the physics?’ It was Dave who established the basic TAC processes that are still used today—processes that ensure a fair and open discussion of each proposal and its merits. I also valued his thoughtful advice. I could discuss any issue with him, no matter how sensitive or difficult, explore options for what to do, and yet know that the conversation would remain completely confidential.”

Dave was instrumental in the development and deployment of the virtual observatory: as Project Scientist for the National Virtual Observatory development project (2002-2009), as Project Scientist for the Virtual Astronomical Observatory operational facility (2010-2011), as chair of the International Virtual Obsevatory Alliance (IVOA, 2007-2008) and as chair of the IVOA Committee on Science Priorities (2008-2011). Dave was unrelenting in his push to keep the VO efforts focused on science capabilities and not dominated by technology for its own sake. In accord with his own interests in theory, he was also a strong advocate for the integration of theoretical simulations into the VO. Many of his VO colleagues throughout the world have expressed their sadness at Dave’s passing, and the next meeting of the IVOA Interoperability Workshop will be dedicated to Dave’s memory.

Among other accomplishments, he authored a book The Physics of Extragalactic Radio Sources (2004). He had over 120 scientific publications.

Dave’s service activities to NOAO included acting as Chairman of the two KPNO telescope Time Allocation Committees, membership on the NOAO IPAC Committee, membership on the WIYN Board of Directors, membership on the WIYN Scientific Advisory Committee, membership on the NOAO Management Committee, supervisor of the NOAO Tucson library, member or chairman of the ad hoc KPNO Personnel and Post-Doctoral Selection Committees, Chairman of the AURA Strategic Planning Committee, co-author of the AURA education and outreach proposal to the NSF, membership on the AURA interim team for the SOFIA proposal, and membership on various ad hoc NOAO committees such as NOAO 2000 and the AURA-sponsored Albuquerque Workshop.

Dave served as Associate Director of KPNO from 1982 to 1987 and as Associate Director of NOAO from 1988 until 1993.

He was very involved with the Aspen Center for Physics beginning with an astrophysics workshop that he attended there in 1972 and continuing for his entire career. He was very influential in promoting the astrophysics program at the Center and obtained NASA support for the early summers. He served on the Board of Trustees beginning in 1974 and held positions including Scientific Secretary, 1980-81; President, 2001-2004; and Chair of the Executive Committee, 2001-04. Dave was an avid runner, and he would arrive in Aspen every summer in time to run in the July Fourth race.

Dave’s main research interest was in active galactic nuclei. He also carried out extensive numerical modeling of airflow over Mauna Kea and Cerro Pachón in order to facilitate site selection for the Gemini Project, and he did numerical simulations of airflow in telescope enclosures and around mirror cells to assist the Gemini project in enclosure and telescope design. . More recently, Dave was the co-chair at NOAO for the site survey working group for the Thirty Meter Telescope (TMT) project. This group initiated the survey of sites in Northern Chile for TMT and the computational analysis of individual peaks including candidates in Chile, Mexico, and Hawaii.

He is survived by his wife Mary Ellen, and two children: a son Christopher and a daughter Lynn.

Comments submitted by friends and colleagues:

From Steve Ridgway

Dave was my go-to theorist since the early 1980’s. More often, we interacted on management and policy questions, and I appreciated his astute observations always expressed precisely and with complete frankness.

Around 1987 I was putting an addition on my house and Dave came over to give me a hand lifting a heavy beam into place over a set of large windows. We chatted about French cooking and other mutual interests. I still recall details of that visit when I look out those windows.

Sarah Emery

Dave was more than a colleague, he was a beloved friend. One of my favorite things about VO meetings was knowing I would see his bright smile and enjoy his company. Dave was a gentleman, a deep appreciator of beauty and life, and a truly sensitive and wise soul. I will miss him more than I can say.

John Salzer, on behalf of the WIYN Board of Directors

The WIYN family notes with sadness the passing of Dave De Young. Dave was a member of the WIYN Board of Directors in the mid-90s, during the time when the telescope was first being commissioned and used for science. This was also a period of time when WIYN was being operated in queue mode for a significant fraction of the time. This represented one of the first large-scale experiments with this observing mode (particularly at the National Observatory). As a member of the Board at that time, Dave had a hand in defining and overseeing this experiment.

One former Board member describes Dave’s participation in WIYN this way: “Dave was always thoughtful and sagacious…. It was a time when NOAO was the strongest partner, and he helped continue the tone set by Sidney (Wolff) and Caty (Pilachowski) of NOAO being a gentle, gracious, and helpful giant, making everything work…”

A faculty member at one of the WIY universities had this to say: “I always thought Dave had an observer’s approach to things and was well aware of the kinds of practical issues that often shape an observing program as much or more than the science. This is probably because Dave had chaired the KPNO allocation committee for so long. This also meant that he had sound advice for us on how to allocate WIYN telescope time in a fair way that maximized the science, and we had many discussions on this topic. Dave always had a deep interest in WIYN activities, and his service on the WIYN BOD and committees was critical in the early days of WIYN.”

Caty Pilachowski

Dave and I were colleagues and friends at NOAO for more than 20 years, and I continue to value all of the many things he taught me. He served as a prime example of what a theorist should be, especially at a national observatory. His broad knowledge of astronomy, and most particularly his deep knowledge of so many fields of astronomy was and is an inspiration. His insight about the key scientific questions in diverse areas and his ability to articulate the importance of science served both the observatory and the community well as he chaired the Telescope Allocation Committee. His insistence on rigor and quality, and the value he placed on feedback from the TAC to proposers, helped many of us learn to focus and to improve our own approaches to research. “Where’s the science?” was a refrain often heard as he challenged us to do better. His firm conviction of the importance of a national observatory and of the value of telescope access based on scientific merit sustained the high scientific quality and productivity at NOAO telescopes through the past three decades. His unfailing support of research by the NOAO scientific staff encouraged us always to find time for research, to think bigger, and to challenge ourselves. Dave De Young’s legacy is the science we continue carry out at the national observatories.

Buell Jannuzi

Earlier this year I wrote to Dave De Young upon the occasion of the his retirement. Rereading my letter now, it seems appropriate to repeat portions of it here. I wrote in early October,

“Dear Dave,

Thank you.

Thank you for your major contributions as a leader, both scientifically and as a manager, of the National Observatory. Since I first noticed the existence of the National Observatory (while in graduate school), I’ve associated you with the activities of NOAO. Whether you were serving as a leader of KPNO, or scouting potential KPNO post-docs at AAS meetings, or participating in a Science Conference, you always represented NOAO well and with class.

As your colleague since 1995, I’ve particularly appreciated how you, as our “resident theorist” among a group of observers, always worked to keep us focused on science and understanding the physics that underlies everything we study.

Thank you for being such a vital and positive influence on the science scene of Tucson. You helped build science bridges across Cherry Avenue from which we all benefited.

Finally, thank you for the support and guidance you have given me over my career. Like many at NOAO, I sometimes would feel overwhelmed by the non-science aspects of our job. Often this feeling was lightened by talking with you. Your interest in my work, your encouragement for me to attend summer or winter meetings at the Aspen Center for Physics (where you also have had such a wonderful impact), always helped restore my passion for astrophysics and science in general.

Thank you,


I will greatly miss having Dave as a colleague, but am grateful to have been able to work with him for the past 16 years.

Meg Urry

I knew Dave for many years, and always looked to him as one of the leading theorists for AGN physics — especially radio jets, one of my own interests. He was unfailingly kind, thoughtful, focused on doing the physics right. Our paths crossed many times, though we never collaborated directly. I hesitated to write something here until I figured out what to say. But I think it is just this: I will miss Dave, and our field is emptier without him.

Merry Maisel

Dave served on the time allocation committee at the San Diego Supercomputer Center for many years, and it was always a delight to have him in town. He was a percipient critic of computing proposals who always knew the difference between doing new physics and just “turning the crank,” as he called it. We are all the losers…

We invite you to submit your memories of Dr. De Young.