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Direct web query of VSX/VSP

ldj's picture
ldj
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Joined: 2010-07-25

I'm a planetarium software author (ECU) and I'd like to update it so users can do an aavso query of an object.

I used to use: http://www.aavso.org/cgi-bin/searchcharts3.pl?name=VARNAME

but it no longer works.

I see that VSX in the about page says:

"Querying the Database

Web-based tools for querying VSX in various ways are available to the public. The public data returned in a query transaction contains all the accumulated data for the most recent revision level for each star in the recordset, including details of all modifications made to the data, and references to support those changes. Previous revisions may also be viewed. The public interface does not include the means for modifying the data in any way, but a form for sending suggestions for modification to the Project Administrator is made available."

Is there documentation for this?

Also, since we keep being told: "VSP is not a planetarium program" :-), I'd like to better integrate it with one, as that is what many of us use to plan our observations. It would be really nice to click on a star in the planetarium and press a button and up comes a VSP chart.

Can I bring up a VSP chart from an appropriately formatted web link? If so, where can I get the documentation?

--- Dave

VSP HTTP GET Specification
RWG's picture
RWG
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Joined: 2010-08-01

Hello Dave

I sent you the HTTP GET Specification for VSX.

And I do advocate to reintroduce again the old VSP interface as it was at the old
AAVSO web site and publish a specification on how to use it.
All old VSP links are broken including all the ones in older AAVSO alert notices
and special notices (using the URL parameter: pickname=) and
especially the ones from VSX.

CS
Wolfgang

VSP HTTP Get Spec Link
David Benn's picture
David Benn
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Joined: 2010-07-29

Hi Wolfgang

Would it be possible to post a link here in the forum (or attach it if it's a Word doc/PDF) to the VSP HTTP GET specification?

Thanks.

Regards,

David Benn

VSX HTTP GET spec
RWG's picture
RWG
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Joined: 2010-08-01

It originates from the longe gone Bugzilla page:
http://www.aavso.org/bugzilla/attachment.cgi?id=5&action=view
So parts might be outdated. The last time I checked all parameters, a few of the hi vs. low range values had to be reversed to get what I expected.

A recent example I stiched together is:
All vars and suspects in VSX that are brighter than 6.5 mag at max:
http://www.aavso.org/vsx/index.php?view=results.get&coords=180.0+0.0&format=d&size=420&unit=1&geom=b&order=5&maxhi=-30&maxlo=6.5


___________________________________________________________________________

 

 VSX HTTP GET Specification

 

This is the preliminary specification for HTTP GET queries at VSX. The IP address for the server is temporary and will eventually become vsx.aavso.org, but not right now. The common portion of the URL is:

http://www.aavso.org/vsx/index.php?view=results.get

Following this root URL, any workable combination of the below described name/value pairs may be appended. They do not need to appear in the URL in the order given here, and they do not all need to be present. Selective absence and presence of these values from the URL are what make for all the different search types. All non-numeric argument values may include the SQL wildcard character (%) in order to create wildcard searches, but the character must be URL-encoded as %25. Spaces must be URL-encoded with the whitespace replacement character (the plus sign). Plus (+) characters present in designations or coordinates must be URL-encoded as %2B.

&coords

The central J2000 RA/DEC coordinates for a radius search, expressed sexagesimally (by default), or in decimal degrees if format is set to d. Northern hemisphere coordinates must have the plus (+) sign URL-encoded as %2B. Space characters between all other figures must be replaced with the URL whitespace character (+). The order argument (which see) must also be included in the query string with its value set to 9 in order to prompt VSX to display distances from the central coordinates in the results listing. Default is empty string (no radius search).

&ident

Object identification for name searches. Space characters must be replaced with the URL whitespace character (+). Other special characters may also need to be URL-encoded. Default is empty string (no name search).

&constid

The numeric constellation ID for constellation-bound searches. See http://www.sai.msu.su/groups/cluster/gcvs/gcvs/iii/constel.dat for codes. Default is 0 (not bounded by constellation).

&format

Explicit specification for format of coords. For sexagesimal, this value should be s. For decimal degrees, this value should be d. Default is s (sexagesimal).

&geom

The geometry for central coordinate-based searches. For radius searches, this value should be r. For box searches, this value should be b. Default is r (radius search).

&size

For box searches (geom=b), the width of the box. For radius searches (geom=r), the radius of the circle. Expressed in the units specified by unit (see next). Default is 10.0.

&unit

The unit of measurement used for the value given in size (see above). For arc degrees, this value should be 1. For arc minutes, this value should be 2. For arc seconds, this value should be 3. Default is 2 (arc minutes).

&vtype

The variability type. Used to limit search to only stars of specified variability type. Typically, this can be set to a standard GCVS variable type abbreviation (see http://www.sai.msu.su/groups/cluster/gcvs/gcvs/iii/vartype.txt), but VSX holds in its database many different non-standard variable types taken from other catalogs. Default is empty string (no limitation to variability type).

&stype

The spectral type. Used to limit search to only stars of specified spectral type. Default is empty string (no limitation to spectral type).

Range values

The following pairs of query string arguments are used to perform searches on values greater then, less then, or between given values. Including one value from the pair establishes only an upper or lower limit, and including both established a complete range.

&maxhi
&maxlo

The upper and lower limits to a search within a range of maximum magnitudes. Defaults are empty strings.

&minhi
&minlo

The upper and lower limits to a search within a range of minimum magnitudes. Defaults are empty strings.

&perhi
&perlo

The upper and lower limits to a search within a range of periods. Defaults are empty strings.

&ephi
&eplo

The upper and lower limits to a search within a range of epochs. Defaults are empty strings.

&riselo
&risehi

The lower and upper limits to a search within a range of rise times. Defaults are empty strings.

&yrlo
&yrhi

The lower and upper limits to a search within a range of outburst years. Defaults are empty strings.

Additional Fields

&filter

A comma-delimited list of the values representing which class of objects should be included in the search results. This allows for filtering in/out proven variables, suspected variables, and/or non-variables. The value for proven variables is 0, for suspected variables is 1, and for non-variables is 2. For example, if you wanted to search for only proven variables, the value should be set to 0. If you wanted to search for all classes of objects, the value should be set to 0,1,2. Defaults to 0,1 (includes proven and suspected variables, but not non-variables).

&order

A value representing the desired sort order for the search results. The sort order values are as follows:

1 ? by GCVS name sequence

2 ? alphabetical by name

3 ? by R.A.

4 ? by Dec.

5 ? by maximum magnitude

6 ? by variable type

7 ? by spectral type

8 ? by constellation

9 ? by angular separation from central coordinates

Default is 1 (by GCVS name sequence).

Notes

There is a limit of 9999 records that can be returned from any HTTP GET query of VSX.

Thanks for the VSX http get
David Benn's picture
David Benn
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Joined: 2010-07-29

Thanks for the VSX http get spec Wolfgang. I'd like to remove (eventually) all direct database access to VSX, AID etc from VStar, using web services or http get.

Regards,

David

VSP HTTP GET Specification
RWG's picture
RWG
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Joined: 2010-08-01

There is now also a HTTP GET Specification for VSP on the homepage.

CS
Wolfgang

Getting B1950 coordinates from a VSX get query
David Benn's picture
David Benn
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Joined: 2010-07-29

Further to this old thread, is there a way to get B1950 coordinates from a VSX get query or if these are required, should one just convert from the J2000 coordinates?

David

Only J2000
wlp's picture
wlp
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Joined: 2010-08-05

Hi David,

A HTTP GET query in VSX will only give J2000 coordinates, but you have the B1950 coordinates if you go to the individual detail sheet of an object, by following the link provided by the result from the GET query.

Patrick

VOTable
David Benn's picture
David Benn
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Joined: 2010-07-29

Hi Patrick

I meant to say that this is a VOTable query, e.g.

   http://www.aavso.org/vsx/index.php?view=query.votable&ident=R+Car

that I want to programatically process.

David

VOTable
wlp's picture
wlp
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Joined: 2010-08-05

Hi David,

I don't see much use for 1950 coordinates anymore.  You should probably calculate them yourself.

Patrick

J2000 vs B1950 coords for HJD conversion
David Benn's picture
David Benn
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Joined: 2010-07-29

Hi Patrick

Okay. The context is that I have code for conversion of JD to HJD using B1950 coordinates. I'm not otherwise interested in B1950. If I can find a suitable algorithm and validate it against test data for using J2000 coordinates instead for HJD conversion, I'll happily use J2000 instead.

One possible source is:

  http://articles.adsabs.harvard.edu//full/1972PASP...84..784L/0000784.000.html

Do you have any more suitable suggestions?

Thanks.

David

Heliocentric correction
wlp's picture
wlp
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Joined: 2010-08-05

Hi David,

There are a few online HJD calculators around which work with J2000 coordinates, most with the source code available.  Here are links to just a few: http://mira.aavso.org/pipermail/aavso-discussion/2009-July/033152.html, http://britastro.org/computing/applets_dt.html, http://search.cpan.org/~rcreager/Astro-Time-HJD-0.02/HJD.pm.

Patrick

Thanks Patrick.  David
David Benn's picture
David Benn
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Joined: 2010-07-29

Thanks Patrick. 

David

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