AAVSO: American Association of Variable Star Observers

Standard Fields

Standard stars in the Comp Star Database (VSD) are those that are meant for filter/color transformation and extinction coefficient determination. They are available when you select "Standard Field" in the Variable Star Plotter (VSP). They are grouped into small fields-of-view so they can be easily imaged and their magnitudes have been determined with high precision and accuracy.

Our collection of available standard fields now includes:

  • Standard open cluster fields for transformation calibration compiled by Arne Henden (M67 and 5 others)
  • Landolt fields compiled by Arlo Landolt. These fields contain fewer stars, but are selected to cover the whole sky. The fields are published in 3 papers with standards at -50 Dec, equator and +50 Dec. Terry Bohlsen and Mike Simonsen added the first two sets of Landolt stars. George Silvis recently completed the last set. The annoucement for this new feature is here

Below you will find a table of all the fields of standard stars available in VSD. For each field you can click on the field name and see the related VSP chart and table of photometry. There are a lot of fields! To help you choose an appropriate field the table is sortable by any column so you can quickly find what you need.
The columns are

  • Id : 1000 series are the standard cluster fields, 2000 series are the -50 Dec Landolt fields, 3000 are the equatorial Landolt fields, and 4000 are the +50 Dec Landolt fields
  • RA : Right Acension in hours
  • Dec : Declination in degrees
  • Fov : Field of view size in arc minutes
  • Count : Number of stars in the field
  • Name : Common name or that assigned in the Landolt papers. If the name includes "SFn" then it is a subset of a larger field