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DevAnn #3: The tools to access AAVSO resources

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SGEO's picture
DevAnn #3: The tools to access AAVSO resources

Well, the rumors are true: changes are coming to the AAVSO website and server infrastructure. This may/will have an impact on any software that you have written that queries directly for information and charts. This is the topic of the Developer Announcement that is coming out today: we want developers to be aware that change is coming and to work with us here in this forum to sort out the issues.

Tell us here, or in an email direct to, what mechanisms your software uses. For example, I know that the TransformApplier calls ""+ sd->CHART+ "/?format=xml" to fetch the photometry of a chart. Knowing this HQ can make sure this mechanism continues to work in the future. And if it has to change, give you the details of how it will change.

The AAVSO is meant to be a resource to the professional/amateur community, to help them do good science. Help us here help you.

And if you have a new idea of information that will help you do science, bring that too!


WAB's picture
Tools to Access AAVSO Resources

Thanks for the head's up. It's greatly appreciated.

Using MPO Canopus, this is a sample call to get photometry data for a U GEM field that is 20x20 arcminutes with a limiting mag of 16. Note the resulting XML includes the parth to a chart as well.

The field (Name or RA/Dec), FOV, Limiting mag, and orientation are the allowed user inputs.


Thanks for trying to avoid breaking code, but it happens sometimes.

Brian D. Warner

clkotnik's picture

Just to add to the VSP service call that I use format=JSON.


clkotnik's picture
APASS via Vizier

Using the python astroquery package I query APASS data from Vizier as catalog "II/336".


Way to go!

I love it that you guys are doing such a great job of keeping your data consumers appraised of potential API changes. Thank you!


Eric Dose
Eric Dose's picture
my current API calls...

Pylcg 1.00 (code at has 3 API calls, example URLs given here:

  • retrieves observations for plotting (essential):
  • shows VSX record for star in browser:
  • shows observations in browser:


Photrix, my daily planning and processing system (code at has 2 API calls, example URLs given here:

  • retrieves chart by chart ID (occasional need):
  • retrieves observations to prioritize targets not recently observed (daily need, 300 targets):

Please prepend "https//www." to each of the above URLs (omitted to prevent forum sw from corrupting them).

Hope this helps. E-mail me if I can clarify anything, and thanks for the opportunity to comment.

Herr_Alien's picture
API calls I use

1) I use the VSP API ( ), to get photometry data or chart, for two web applications (Extinction-o-Meter and Variable Stars Atlas)

2) I use the web service that powers the old observations planner ( service URL , planner URL to power my own version of the planner ( Variable Stars Observations Planner ; this alternative planner can provide a customized view of the atlas mentioned above).

dhdeangelis's picture
API calls I use

Hi and thanks for this initiative. I use custom scripts that 1) download observations for plotting light curves and 2) get charts for visual use. The API calls are:

Download observations:"$star"&fromjd=$firstdate&tojd=$lastdate&delimiter=,

(in bold are variables)

This scheme is also used in LCplot, a freely available Perl program that can be run locally to plot light curves of variable stars.

Download charts:$star&fov=$fov{$chartType}&maglimit=$maglim{$chartType}&north=$north{$chartType}&east=$east{$chartType}&format=json)

(again, my variables in bold)

The script then parses the JSON file to get the image URI and download it.

In my experience so far the API works fine, is fast and very reliable for my purposes.

Thanks again and will be nice to hear how this work evolves!

Hernán [DHEB]

dks's picture
My API calls

I use several API calls for my personal data analysis workflow, so it's not a big deal if the APIs change - I just need the ability to get the same data:

Retrieve comparison stars<>&dec=<>&charttitle=&chartc...

Plot charts<>&title=<>&fov=<>&resolution=<>&mag...

Generate light curves:

Retrieve data from VSX:<>

Shawn (DKS)

njsg's picture
Yup I use a call to get

Yup I use a call to get charts and comp star data:

I assume you will let us know if and how these things will change?



rberg's picture
Call to retrieve chart and photometry table

Similarly to others, I use the following code, embedded in an iframe within a script, to retrieve and display a chart whose parameters are posted in an HTML form, to include the name and others as shown:

src='.....//" + varName + 
              "&charttitle=" + varTitle +  "&fov=" + varFOV + 
              "&maglimit=" +  varLimit +  "&ccdtable=on'


Thanks for asking.


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