We now have a resource to help you identify the standard fields that you need for calibrations. Check it out here: ( https://www.aavso.org/apps/vsd/stdfields )
Standard fields are fields-of-view that contain stars with complete and careful photometry. You may have noticed in VSP and VPhot the option to have these stars displayed instead of the regular comp stars. This tool will help you find the fields by directing you to VSP with the chart and photometry ready for printing.
The fields are grouped into four categories. First there are the big fields that Arne Henden compiled for us to aid our transformation calibrations. Then there are the three sets put together by Arlo Landolt:
- UBVRI Photometric Standard Stars around the Sky at +50 deg Declination ,
- UBVRI Photometric Standard Stars Around the Celestial Equator: Updates and Additions
- UBVRI Photometric Standard Stars around the Sky at -50° Declination
This page presents almost 200 fields in a format where you can sort the lists by RA, Dec, FOV size and star count. With this you will be able to identify the fields you need.
This project built upon the work of Terry Bohlsen and Mike Simonsen to make the Landolt Standards available to us all: https://www.aavso.org/standard-stars-vsp .
So, go forth and calibrate!
This is a wonderful improvement on the Bohlsen-Simonsen table which, itself, was an important tool to help us gain access to the Landolt fields. Thank you!
This is a great addition to the existing system. I see a continued bright future for the AAVSO calibration efforts. Thanks to everyone with input on this project. Super work!
This is awesome. Thanks!
I'm seeing "out-of-range coordinates: 166.3875 -58.73" when I select NGC 3532 though. I'll let you know if I see other problems.
This is a very busy field and VSP was timing out on the render. I tweaked the page so that the mag limit would be 14.5 instead of 16; it now will render.
Please, anyone who spots a chart problem here should report it!
I've attached a modified version of your standard stars table. It contains a new column with the B-V range for each field. Another added column, Notes, marks the fields in which I discovered a problem, mostly inconsistencies between the Count column and the number of standards stars which appear in the charts.
The second file explains the Notes.
Thank you for making this happen George! This is a great resource for our observers!
Best wishes - clear skies,