DevAnn #3: The tools to access AAVSO resources

Affiliation
American Association of Variable Star Observers (AAVSO)
Thu, 02/14/2019 - 14:47

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 aavso.org 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 aavso@aavso.org, what mechanisms your software uses. For example, I know that the TransformApplier calls "http://www.aavso.org/apps/vsp/api/chart/"+ 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!

George
 

Affiliation
American Association of Variable Star Observers (AAVSO)
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.

<https://www.aavso.org/apps/vsp/api/chart/?star=U%20GEM&title=U%20GEM%20…;

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

Brian D. Warner

Affiliation
American Association of Variable Star Observers (AAVSO)
APASS via Vizier

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

Cliff

Affiliation
American Association of Variable Star Observers (AAVSO)
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!

-Christopher

Affiliation
American Association of Variable Star Observers (AAVSO)
my current API calls...

Pylcg 1.00 (code at https://github.com/edose/pylcg) has 3 API calls, example URLs given here:

  • retrieves observations for plotting (essential): aavso.org/vsx/index.php?view=api.delim&ident=AL+CEP&tojd=2458529.34228&fromjd=2458029.34228&delimiter=@@@
  • shows VSX record for star in browser: aavso.org/vsx/index.php?view=results.get&ident=AL+CEP
  • shows observations in browser: aavso.org/apps/webobs/results?star=AL+CEP

 

Photrix, my daily planning and processing system (code at https://github.com/edose/photrix) has 2 API calls, example URLs given here:

  • retrieves chart by chart ID (occasional need): aavso.org/apps/vsp/api/chart/X15912AW/?format=json
  • retrieves observations to prioritize targets not recently observed (daily need, 300 targets): aavso.org/apps/webobs/results/?star=AC+Cnc&num_results=200&obs_types=vis+ccd

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.

Affiliation
American Association of Variable Star Observers (AAVSO)
API calls I use

1) I use the VSP API ( https://www.aavso.org/apps/vsp/api/chart&nbsp;), 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 http://www.aavso.org/cgi-bin/obs_planner_web.pl , planner URL https://www.aavso.org/observation-planning) 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).

Affiliation
Svensk Amator Astronomisk Forening, variabelsektionen (Sweden) (SAAF)
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:

https://www.aavso.org/vsx/index.php?view=api.delim&ident="$star"&fromjd=$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:

https://www.aavso.org/apps/vsp/api/chart/?star=$star&fov=$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]

Affiliation
American Association of Variable Star Observers (AAVSO)
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

http://www.aavso.org/apps/vsp/api/chart/?ra=<>&dec=<>&charttitle=&chart…

Plot charts

http://www.aavso.org/vsp/chart?star=<>&title=<>&fov=<>&resolution=<>&ma…

Generate light curves:

https://www.aavso.org/LCGv2/index.htm?DateFormat=Julian&RequestedBands=…@@@

Retrieve data from VSX:

https://www.aavso.org/vsx/index.php?view=results.get&ident=<&gt;

Shawn (DKS)

Affiliation
American Association of Variable Star Observers (AAVSO)
LCGv2 url parameter for contributors

Hi,

Are there any parameter in the url expresion for sellect some contributor to mark it on the ligth curve?

&obscode=  is a filter that only show this observator datas

 

thx

Jordi

Affiliation
American Association of Variable Star Observers (AAVSO)
LCGv2 url parameter for contributors

Hello Jordi,

Yes, you should be able to add the parameter &obscode= to show only one person's observations, but there is not currently a way to show everyone's observations with just one person's observations marked using the URL. You can only do this manually by clicking on the orange square to the left of any person's observer code in the table.

Best wishes,
Sara

 

Affiliation
American Association of Variable Star Observers (AAVSO)
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='.....//www.aavso.org/cgi-bin/vsp.pl?name=" + varName + 
              "&charttitle=" + varTitle +  "&fov=" + varFOV + 
              "&maglimit=" +  varLimit +  "&ccdtable=on'

 

Thanks for asking.

Dick