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Supporting the Sequence Team

The work of the Sequence Team is dear to the hearts of every variable star observer. They establish the comparison star "sequences" (lists of stars) that are used to make an observation. It's very important work because the quality of the sequence has a direct effect on the quality of the observation. As such, their work has historical importance. It can also be very challenging because it involves delving deeply into various databases and knowing the strengths and weakness of each. Also, when selecting a sequence one is limited to the stars that nature gave us, so there is a subjective, almost artistic, aspect to it. 

Ask anyone who has been around a while and you'll hear about how much better our sequences are these days. Much of that is thanks to the work of the Sequence Team.

The team has many tools at their disposal. A relatively new tool is SeqPlot (right), written by staff member Sara Beck, which can show star fields and relative star colors. The sequence team can use it on most fields to automatically select new sequences and save them to a format which is later uploaded to the database that  the Variable Star Plotter uses.

For a sample of some recent work by the Sequence Team, visit:

Our webmaster recently launched a recoded version of the CHart Error Tracking Tool (CHET). CHET allows you to submit an error on a chart or sequence and track the error as the Sequence Team investigates it. Also, here are guidelines and the procedure for how to request comparison stars for a field in the sky.

Staff member Mike Simonsen is the fearless leader of the team. They are always looking for more members. Contact Mike or the AAVSO if you'd like more information.

Below are the current, active members of the Sequence Team (click their name to visit their web site user pages). If you see them at an AAVSO meeting or any other function, be sure to thank them!

Tom Bretl







Tim Crawford

Robert Fidrich

Jim Jones

Mati Morel








Sebastian Otero


Mike Simonsen


Bob Stine

AAVSO 49 Bay State Rd. Cambridge, MA 02138 617-354-0484