Catalogues in Chromoscope

Astronomers love to catalogue the sky. We've been doing it as long as astronomy has existed. Perhaps the most famous astronomical catalogue is the Messier catalogue - compiled by Charles Messier so that he didn't mistake nebulae and galaxies for comets - but many thousands of catalogues now exist.

In the (not so) old days, catalogues were printed in books or journals. You'd visit the library, find the volume you needed, and go through transcribing the data for the objects you wanted. That was hard work and prone to transcription errors after staring at rows and rows of data. It makes your eyes go funny. I know that from experience.

These days, most important catalogues and data sets are compiled digitally, are published digitally, and end up on Vizier run by Centre de Données astronomiques de Strasbourg. The service is great because you can search specific catalogues and limit the search by position, magnitude, flux density or others parameter in the data set. It saves lots of time. Vizier even has web services and a set of command line tools to let power users interact with it.

This evening I decided to see if I could use those tools to help me convert Vizier catalogues into KML (the format used for Google Sky) so that I could pipe them into Chromoscope. It turns out that it isn't too tricky so I've added it to the development version of Chromoscope for testing.

My first test was my table of measurements of Compact Jodrell-Caltech Flat-spectrum (CJF) radio sources. Plotting the CJF sources in Chromoscope shows how the sample is limited by position on the sky (amongst other things). The limits are to objects above Declination 35 degrees (B1950) and Galactic latitudes greater than 10 degrees from the plane of The Galaxy.

Here are some other examples:

Thanks to Paul Woods and Chris Tibbs for helping me to test it this evening with some nice examples.

Posted in astro blog by Stuart on Monday 20th Jun 2011 (23:46 BST) | Permalink
[an error occurred while processing this directive]
[an error occurred while processing this directive]