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Behind the Scenes with the Chart Team

Posted by SXN on December 20, 2010 - 10:50am

It's been another year of incredible activity from the charts and sequences team. Together they have revised or created hundreds of new sequences for AAVSO charts in the past twelve months. I can't tell you enough about how much work these guys do for the AAVSO. I can tell you a little about who they are. 

 
Our most prodigious sequence analyst by far is Tom Bretl. He has personally improved hundreds of sequences this year alone. I surrender my obsessive compulsive chart crown to Tom gladly. I sat with Tom and his wife, Donna, at the AAVSO fall banquet, and he seemed so normal! You'd never know from appearances... The banquet might have been the only time Donna has seen Tom in a couple years, and we were still talking about variable stars and charts!
 
Tom manages to observe nearly all the stars he does sequences for and obviously spends all his cloudy nights working at the computer planning his attack on the rest of the sequences. The emails he sends to the sequence team list, with his analysis of the photometry, suggestions for improvements, photometry files of stars to upload to the comp star DB and charts displaying the changes represent hours of careful work.
 
A good deal of the inspiration to make improvements to sequences comes from our unofficial "Visual Inspector Gadget", Bob Stine. Bob has entered more chart 'suggestions' into CHET in the last three years than any other five people combined. He is an unapologetic supporter of visual observers of red stars. What else would you expect from an observer with the initials SRB?
 
He lets us know when the the comp star soup is not quite right. He doesn't like his comps too red or too blue, but somewhere in between. We try to keep Bob happy, but he keeps finding things to improve. He's kind of a pain in the butt really, which should make him an excellent member of council! 
 
Another team member who I can't say enough about is Tim Crawford.  He has taken on the task of updating all the sequences for the eclipsing binary program as photometry becomes available. He also does sequences for transient objects, alert notice objects and just about anything else we come up with that absolutely has to get done. Tim has tons of energy, an infectious smile and a wry sense of humor. I call him on the phone sometimes just to share a laugh. Tim also volunteers as a mentor and speaker for the speakers bureau.
 
Robert Fidrich is our Hungarian binocular and bright variable expert. He concentrates primarily on the brighter variables visible in binoculars and small telescopes. He has a nearly encyclopedic knowledge of the existing charts and sequences used by AAVSO, BAAVSS and HAA-VSS, the Hungarian variable star observers. It's great having active observers making the revisions to sequences because we get feedback right away, and continuous suggestions for improvements. Robert is an active observer and also a mentor for observers in Europe.
 
Our newest member, Sherrill Shaffer, is one of the bravest people I've met. He sent an email asking if he could help, read the tutorials on the sequence team site, downloaded SeqPlot and jumped into the deep end with the sharks all in about one week. Many people never get the hang of the work. Others find it too time consuming or daunting. Some find out it's not as glamorous as it sounds and find other things to do. He's learned the ropes quickly and has progressed faster than anyone I can remember. He's doing all this while still a relatively new observer, building his own program of binocular and bright variables. He also enjoys spending time with Zapper, flagging discrepant data in the AID. Yup, he's a keeper.
 
The teams' expertise extends into the southern hemisphere also. Sebastian Otero helps guide the team on matters pertaining to bright star photometry south of the celestial equator and he is also an expert advisor on the use of ASAS and other data sets to derive photometry from until APASS South fills in the holes for us. Sebastian is a legendary observer and his opinion in VSO matters is respected among the team members. Sebastian also does invaluable work in support of VSX, moderating the discussions and vetting submissions.
 
Mati Morel is a contributor from down under. Whenever a nova or unusual transient appears in the southern sky Mati quickly supports observers by supplying sequences from the best available photometry. He has been working on charts for the RASNZ and indirectly, the AAVSO, for decades. He co-authored a paper on the history of the RASNZ charts, 'The VSS RASNZ Variable Star Charts: a Story of Co-Evolution', in the JAAVSO volume 38 number 1. It's is a great story told by someone who was there for most of it.
 
I met Keith Graham when the AAVSO spring meeting was held in Rockford, Illinois. We hit it off right away, and have been friends ever since. Keith worked on Vance Petreiw's Comp DB Team that cataloged all the comparison stars on all the AAVSO charts, the precursor to the current DB VSP uses to plot charts. Once VSP came online, Keith asked if he could help out making charts and we welcomed him to the sequence team. He puts in time when he can, but since retiring he doesn't seem to have as much time to work on charts. That seems to be a recurring theme with a lot of our people. Once they retire, they become more busy than ever! He is an active observer, and as a retired teacher, he is a valuable CCD mentor in the mentor program.
 
Jim Jones is another part-time contributor. He contributes when he can and has done some good work on sequences. Another active observer who works on sequences on cloudy nights when he can.
 
Almost none of this valuable work would be possible if it weren't for the amazing program SeqPlot, programmed by AAVSO's Sara Beck. SeqPlot displays star fields with stars plotted in three colors, red, blue and green based on their magnitudes and colors. Green stars have middle of the road B-V colors we can use for comp stars. Red stars red and blue stars are blue. Not only does it make selecting the comparisons easier, it sends the photometric measurements to a text file in the proper format to load into the comp star DB with the click of a button. Sara continues to make improvements and adds a new feature once in a while just to keep us on our toes. 
 
SeqPlot is based on a program our Director, Arne Henden, created long ago, and of course SeqPlot would be impossible without all the photometric data loaded into it from our APASS Survey, SRO calibrations, a thousand little patches of sky calibrated by Arne at USNO and all the other photometric data it now contains. Another person who makes this all happen is our Science Director, Matthew Templeton. He does a lot of the work loading the data into the DB that SeqPlot utilizes to do its job.
 
As proud as I am of all these people and the work we have done, we are just the latest group of AAVSOers working to bring the best possible charts with the best available photometry to our observers, so they can acquire the best possible data. This is a challenge AAVSO teams have been working on for a hundred years. 
 
It takes a special breed to do all this work and have fun at the same time.
 
Sometime soon we will have what every chart maker before us has only dared to dream of---an all sky photometric database down to 17th magnitude from which we can make variable star charts. It's a good time to be on the 'chart committee', as it has been referred to historically. We have some fantastic tools, and just the right kind of people to put them to use.
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