Scientific Tutorials

 The latest tutorials to learn how to use VO-enabled tools for your research:

  • Abell 1656: The Coma Cluster of Galaxies [ for ASTERICS, last update Apr 2019]
    This tutorial uses the advanced VO functionalities of Aladin (interactive sky atlas), TOPCAT (tools to work on catalogs) and Cassis (interactive spectrum analyzer) to study interactively the Coma cluster of galaxies. The user can visualize the Coma cluster of galaxies and build a subset of these galaxies with Aladin. With TOPCAT, they can analyze this subset. Finally, they can study an HST power spectrum with Cassis. (If needed the complementary Jupyter notebook can be downloaded here.)
  • Discovery of Brown Dwarfs mining the 2MASS and SDSS databases [ for ASTERICS, last update Apr 2019]
    This tutorial uses the advanced VO functionalities of Aladin (interactive sky atlas), TOPCAT (tools to work on catalogs) and STILTS to find brown dwarfs in 2MASS and SDSS surveys using three differents methods. The user learns about the filtering, cross-matching and visualization functions of Aladin and TOPCAT as well as about the implementation of scripts for Aladin and STILTS to repeat several time the same steps leading to the identification of the brown dwarfs in these surveys. (If needed the complementary Jupyter notebook can be downloaded here.)
  • The CDS tutorial [ASTERICS VO School, Nov 2018]
    This tutorial describes the basis of the VO program hosted at CDS. The three major VO programs are described: SIMBAD (astronomical database), VizieR (catalog service) and Aladin (interactive sky atlas). The user gets familiar with the programs 1) searching for the galaxy NGC4039 through the CDS portal to get direct access to SIMBAD, VizieR and Aladin, 2) comparing the sky coverage between SDSS and GALEX surveys using Aladin and 3) selecting interacting galaxies with Aladin. (If needed a complementary Jupyter notebook can be downloaded here.)
  • Determination of stellar physical parameters using VOSA [ASTERICS VO School, Nov 2018]
    This tutorial uses the advanced VO functionalities of VOSA (VO Sed Analyzer) and TOPCAT to determine empirically the masses and radii of stars surrounded by planets. The user needs to register to get access to the functionalities of VOSA (online tool). They can then upload a list of objects to study, build their SEDs and analyze them (by fitting models). Using the interoperability between VOSA and TOPCAT, the user can compare the empiral values obtained with VOSA to those published in papers.
  • Accessing and cross matching big datasets with ADQL [ASTERICS VO School, Nov 2018]
    This tutorial allows the user to get familiar with ADQL (Astronomical Data Query Language) and TAP (Table Access Protocol)  through using GAIA data. ADQL and TAP are widely used in VOs to handle large datasets that cannot be handled locally.
  • Electromagnetic follow-up of gravitational-wave events [ASTERICS VO School, Nov 2018]
    This online tutorial uses mostly Aladin functionalities to locate the sources of latest gravitational wave events on the sky
  • Exploring Gaia with TopCAT and STILTS [ASTERICS VO School, Nov 2018]
    This tutorial uses TOPCAT and STILTS to study the Pleiades open star cluster.  The user starts with getting TGAS data for the Pleiades and identifies its as a comoving subset. In a second step, the user matches HST data with Gaia observations using the interoperability of TOPCAT with VizieR to access the catalogs. The cross-match is refined using a color-magnitude diagram. The user can also use the TAP (Table Access Protocole) service of TOPCAT to run scripts for Gaia data. Finally, the user can upload the full TGAS catalog and investigate it with STILTS.
  • Advanced usage of HiPS and MOCs [ for ASTERICS, updated June 2018 for VO School Nov 2018]
    This is a hands-on tutorial demonstrating an advanced usage of Hierarchical Progressive Surveys (HiPS) and Multi-Order Coverage (MOC) maps in Aladin. Using this document, you will learn how to handle a problem like : I have an image survey. I would like to select regions in my observations that are above a given threshold in another survey (e.g. at low extinction), retrieve objects from very large catalogs (e.g. Gaia + WISE) in these non-trivial shapes and not-necessarily-connected regions, and combine them to visualise some quantities (e.g. color magnitude diagram).
  • Classifying the SEDs of Herbig Ae/Be stars [ASTERICS VO School, Nov 2017]
    Herbig Ae/Be stars are 2-8 solar mass. These stars show Balmer emission lines in their stellar spectrum and infrared excess due to circumstellar dust. They roughly fall into two groups: Group I sources have a relatively strong far-IR flux. Group II sources show a similar near-IR excess as group I sources but their flux falls off strongly towards the far-IR. In this tutorial, you will learn how to use VO tools and services to access observed photometric SEDs and spectra in the near and far infrared of different stellar objects. You will compare the stars and classified them.
  • Multi-instrument, multi-wavelength study of high energy sources with the virtual Observatory [ASTERICS VO School, Nov 2016]
    This tutorial makes extensive use of the cross-matching and selection (based on criteria) functionalities of the VO tools to study high energy sources observed at different photon energy bands and with various instruments. The user queries SIMBAD to get HESS sources and overlays them on a Fermi LAT image in Aladin. They then cross-match HESS sources with the Fermi LAT catalog that they download from VizieR via its interoperability with TOPCAT. Applying selection criteria with TOPCAT functionalities, they can identify different classes of objects in a color-color diagram to finally get SEDs for the objects of interest.
  • Handling gravitational-wave sky maps for EM-followUP observations [ASTERICS VO School, Nov 2016]
    This tutorial uses the functionalities of Aladin to visualize probability sky maps. It also makes extensive use of the MOC (Multi-Order Coverage) capabilities of Aladin to query a given region of the sky and access the catalogs with information in that region via the interoperability with VizieR. Finally the additional interoperability with TOPCAT permits sending the data available in that region to the latter for further studies.

Previous (versions of) tutorials: