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Charts and Sequences Team On A Mission

Posted by SXN on April 8, 2013 - 3:23pm

Compared to the pace of even five years ago, the speed at which the charts and sequences team addresses new and revised sequences is simply astonishing. One of the important factors in this NASCAR paced activity is APASS, the all sky survey nearing completion. Every time a data release is made available the team re-examines its lists of requests and reports to see what else can be fixed or created anew in light of the latest photometric data available.

The fact that we can easily select comparison stars with the right characteristics by using SeqPlot, a brilliant tool created by Arne Henden and Sara Beck, decreases the transition time from raw data to complete sequences from days to hours. Not only does the user interface clearly identify the stars most likely to be useful, it converts the selections made by the user into a file formatted to load into the comp star database automatically. 

While we refer to it as the Automated Chart Plotter, there is still a lot of work that goes on behind the scenes to make these automated charts available. There are real people who work tirelessly day after day, reducing data from the survey, loading it into the data base, selecting the stars for sequences, documenting the work that is done, updating the lists of sequences created and revised and checking off the requests for new sequences and updating the entries in the chart error tracking tool, CHET.

Tom Bretl is the one who is addressing most of the reports to CHET. He scans the list often, searches the data to see if photometry exists to make or revise sequences, uploads the resulting files to the database, documents the work done, both in email to the team and on our update spreadsheet maintained in Google Drive and sends out notifications to the users that the work has been completed. The amount of work he has done in the last several years is simply awesome. In 2011 the Director saw fit to honor Tom with a special award whose citation reads, “In recognition of his outstanding volunteer efforts in the creation of new and revised sequences for AAVSO program stars. In just a few short years, he has elevated the use of photometric resources, AAVSO software and tools, and the guidelines for sequence creation to an art form. Not only is he a conscientious, reliable and valued volunteer, he has become the most prolific member of the charts and sequences team in this decade, producing sequences for over 500 variable stars since 2009. Tom is well liked and respected by all the members of the team. His energy and enthusiasm are infectious, and it is an honor to work with him.”

Of the 479 reports currently residing in CHET only 129 remain unresolved. If you’ve had reports in CHET that were recently addressed it’s probably Tom Bretl who made it happen. Say hi to Tom and his wife Donna and thank him personally at the next AAVSO meeting.

Tim Crawford is responsible for setting up the process for requesting new sequences via another spreadsheet he maintains in Google Drive. Tim wrote to me last week to give me an update on the status of requests for sequences, “After taking advantage of DR7 and a just completed audit I note the following:

Requests Received To Date: 596
Open FOV's no Sequence: 43 (~ 7.2% of all requested)
Sequences created but need improving: 15 (~2.7% of created sequences)
This means that we have now completed ~93% of all requests with a sequence!”

I have seen many times where a request for a sequence has come in, been distributed to the sequence team mail list and a few hours later a message appears saying it has already been handled. I think the first chair of the Chart Committee, David Pickering, would have been amazed and very proud to see how far we’ve come and how efficient the AAVSO chart process has become in the last decade.

This is not the only volunteer activity Tim engages in for the AAVSO. He also serves on the speakers’ bureau, has been the chair of the council nominating committee twice, and has been my right hand man in the mentor program for years. In recognition of his achievements and spirit, Tim was awarded the William Tyler Olcott Award in 2012 “for his many years of patiently mentoring observers, giving inspirational talks to astronomy clubs and societies, and his tireless creation of comparison star sequences for observers.”

Another stand out among the incredible members of this team is Jim Jones. Jim has taken on the role of creating sequences in near real time for all the new transients (mostly CVs) that get picked up by surveys and followed by CBA, VSNET and CVnet observers. You may have seen his announcements on those mail lists telling observers of the availability of sequences, often before they even have a chance to request them! Just yesterday an observer mentioned the need for a sequence on our own forum and within hours Jim had sent me a new sequence for the star to upload to the DB.

Sebastian Otero is another highly valued member of the team. We rely on him heavily for information on bright variable stars and southern hemisphere targets as well as his expertise and efficiency with all things regarding VSX and its ties to our work and the database. Although it was a team effort to create all the sequences for the new AAVSO Binocular Program, I think it is fair to say we would not have attained such excellent results without Sebastian’s knowledge and input.

Sebastian is another member of the team who has been recognized for his contributions and high quality of work. He was given the Director’s Award in 2009 in recognition of his “unique ability to achieve high precision visual estimates and his mentoring of others to help them reach their visual observing potential, and of his contributions to reviewing submissions to the International Variable Star Index (VSX) and guiding observers through the submission process.”

Another important job the team performs admirably is checking and creating or revising sequences for campaign targets, like the current list of CVs being observed by HST, and the subjects of alert notices and special notices, like supernovae, novae and unusual activity of other stars or variable objects.

I am extremely proud of this team of volunteers and staff and the high quality and tremendous quantity of work they do. These are the kind of outstanding individuals that make the AAVSO as a whole such a great organization. I’m proud to lead such a team of incredible people creating a legacy that one day will be an important chapter in the next centennial history of the AAVSO chart making process.






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