Arne Henden

Post date: 27-Mar-2009 16:48:52

Effective March 1, 2005, Dr. Arne Henden will assume the Directorship of the AAVSO.

The AAVSO's relationship with Henden began in 1997 when he provided photometry for variable star charts. Soon after, he became chief adviser to the AAVSO International High Energy Network. Since then, his association with the organization has grown to include advisory roles for the AAVSO Eclipsing Binary and RR Lyrae committees, three High Energy Astrophysics Workshops for Amateur Astronomers, the AAVSO Chart Team and also the publication of CCD Views.

As a scientist, Henden has been a co-author on over a hundred refereed publications, including 3 papers in the journal Nature. He has several papers in progress, mostly related to gamma-ray burst afterglow observations with various worldwide collaborations, and cataclysmic variables for the Sloan Digital Sky Survey (SDSS). In collaboration with Dr. R. H. Kaitchuck, he wrote the textbook Astronomical Photometry, widely regarded as a fundamental text for learning photometry.

Anyone who observes cataclysmic variables using AAVSO charts is aware of the collaboration of Arne and Bruce Sumner in providing hundreds of sequences upon which the latest AAVSO CV charts are based.

We're going to ask Arne about the role of visual and CCD observers in cataclysmic variable research, and the prospects of professional-amateur collaboration in the foreseeable future.

CVnet: Congratulations on your being appointed Director of the AAVSO! Two questions come to mind immediately. How will this impact your ability to contribute photometry for sequences for AAVSO charts, and will your being Director mean a shift in AAVSO policy towards CCD observing and away from the traditional role visual observers have played in the history of AAVSO?

Arne: Thank you for the congrats! Being Director will impact my ability to personally obtain photometry for sequences, though probably not as much as you might think. I will be moving my TASS camera down to our Flagstaff house (which we will keep for retirement) and setting it up for bright all-sky calibration. I am planning observing runs at my old NOFS stomping grounds, as well as submitting proposals to the national observatories for doing calibration work. Brian Skiff has implied that he is willing to do some all-sky photometry for the AAVSO. Of course, we intend to continue mentoring amateurs in becoming good all-sky photometrists.

As for shifting policy, my main goal has been and always will be to make amateur and small-college observatories more productive and generating higher quality, scientifically useful data. I've spent thousands of hours in calibrating fields, so that we have good sequences for both visual and CCD observers. I don't care whether an observer uses an expensive CCD camera or a pair of binoculars to measure a star; I just want the best results. There are many areas of variable-star astronomy where visual observations are valuable, and I don't see that changing much in the future. At the same time, CCD observations are still in their infancy and will be given a lot of attention since their complexity requires more care. So the shift will be in the sense of "more" rather than "less."

CVnet: Recently, the AAVSO seems to be more proactive in initiating observing campaigns and producing scientific papers based on observations of unusual or scientifically rewarding CV systems. Is this something you will be encouraging the AAVSO and its members to pursue in the future?

Arne: You bet. Campaigns have many beneficial aspects. Amateurs see real-time involvement with other observers (Aaron's chat room for the past BZ UMa outburst is a great example). Professionals come on-board with specific projects, get the data they need as well as an understanding of how valuable a resource amateurs can be. Papers highlight AAVSO results, giving free advertising to our organization. In addition, some science really does require the 24/7 type of monitoring, and campaigns provide that important database. Amateurs have the advantage of "numbers" (there are thousands out there) and worldwide geographic distribution.

Again, this is in addition to our normal monitoring activities, but I think campaigns are a lot of fun.

CVnet: As a co-author of the Sloan Digital Sky Survey (SDSS) CV papers, do you see follow up observations and long term monitoring of any or all of these systems as fertile ground for pro-am collaboration? Is this an area of research you will be encouraging AAVSO observers to get involved with?

Arne: Something over 100 new CVs have come out of the SDSS. Most of these are faint, low-accretion-rate systems. In quiescence, they are difficult for most amateurs to measure. However, most of the AAVSO CVs are also faint in quiescence; it is their bright outbursts that amateurs generally follow. I think it is a very important monitoring project to observe the SDSS CVs and determine their outburst behavior. I have so many projects clamboring for my attention that I never know which ones to highlight, but monitoring the SDSS CVs is an obvious new project for the AAVSO.

CVnet: What other areas of CV research do you see as fertile ground for pro-am collaboration, and how can visual and CCD observers contribute?

Arne: I have a few pet CV projects, such as predicting outbursts, looking at "stunted" outbursts, and following eclipsing systems. These would be primarily monitoring projects. However, I'm just one researcher, and the ideal future is to get many more professionals involved with the AAVSO and CV research. Outburst alerts for target-of-opportunity satellite observations have always been an important part of both visual and CCD observing programs. My goal here is to continue these opportunities, and to get more amateurs and professionals alike involved.

CVnet: As the new Director of the AAVSO, is there anything you would like to add regarding the future of CV research or the role CVnet can play?

Arne: Ah, the open-ended question! CVs are hot topics right now because interacting binaries are so prevalent in many areas of astrophysics. I think the future is bright (so to speak) and full of opportunity for the small-telescope observer. Surveys keep producing more and more lists of new objects that need followup observations, and with more objects come the rare cases that require even greater attention. CVnet is a useful invention at the right time, and I wish it well in disseminating information about CVs along with being a clearing-house for projects and providing instruction for observers. I'm glad that it has strong ties to the AAVSO.

For literally hundreds of references on the web, Google Search on "Arne Henden":

For links to abstracts and full papers, Search Results by author: