VOSA. Help and Documentation

Version 7.5, July 2022

1. Introduction
2. Input files
2.1. Upload files
2.2. VOSA file format
2.3. Single object
2.4. Manage files
2.5. Archiving
2.6. Filters
3. Objects
3.1. Coordinates
3.2. Distances
3.3. Extinction
4. Build SEDs
4.1. VO photometry
4.2. SED
4.3. Excess
5. Analysis
5.1. Model Fit
5.2. Bayes analysis
5.3. Template Fit
5.4. Templates Bayes
5.5. Binary Fit
5.6. HR diagram
5.7. Upper Limits
5.8. Statistics
6. Save results
6.1. Download
6.2. SAMP
6.3. References
6.4. Log file
6.5. Plots
7. VOSA Architecture
8. Phys. Constants
9. FAQ
10. Use Case
11. Quality
11.1. Stellar libraries
11.2. VO photometry
11.3. Binary Fit Quality
12. Credits
12.1. VOSA
12.2. Th. Spectra
12.3. Templates
12.4. Isochrones
12.5. VO Photometry
12.6. Coordinates
12.7. Distances
12.8. Dereddening
12.9. Extinction
13. Helpdesk
14. About
. Excess calculation
. Total flux calculation
. VOphot quality info


VOSA uses some external services and theoretical models that you might want to cite or acknowledge if your science benefits from the use of this tool.

You can find below the description and, when appropiate, the bibliographic reference corresponding to all of them.

When you download the results obtained by VOSA two files will be included: info/refs.dat with the references to all the services used to obtain the results and info/refs.bibtex.bib with the bibtex entries corresponding to all those references.



  • Please include the following in any published material that makes use of VOSA:
    This publication makes use of VOSA, developed under the Spanish Virtual Observatory (https://svo.cab.inta-csic.es) project funded by MCIN/AEI/10.13039/501100011033/ through grant PID2020-112949GB-I00.

  • If your research benefits from the use of VOSA, we would appreciate if you could include the following reference in your publication:
    Bayo, A., Rodrigo, C., Barrado y Navascués, D., Solano, E., Gutiérrez, R., Morales-Calderón, M., Allard, F. 2008, A&A 492,277B.

Theoretical Spectra.

Template fit

Theoretical Isochrones and Evolutionary Tracks

VO Photometry

Object coordinates

  • Simbad
    • Acknowledgement
      This research has made use of the SIMBAD database, operated at CDS, Strasbourg, France

    • The SIMBAD astronomical database. The CDS reference database for astronomical objects
      Wenger et al. 2000, A&AS 143, 9W

Object distance VO services

  • GAIA DR2
    • Gaia Data Release 2. Summary of the contents and survey properties
      Gaia Collaboration et al. 2018, A&A 616, A1

    • The Gaia mission
      Gaia Collaboration et al. 2016, A&A 595, 1G

    • Gaia Data Release 2. Photometric content and validation
      Evans et al. 2018, A&A 616 A4

    • Acknowledgement
      This work has made use of data from the European Space Agency (ESA) mission Gaia (https://www.cosmos.esa.int/gaia), processed by the Gaia Data Processing and Analysis Consortium (DPAC, https://www.cosmos.esa.int/web/gaia/dpac/consortium). Funding for the DPAC has been provided by national institutions, in particular the institutions participating in the Gaia Multilateral Agreement.

  • GAIA DR3 (vizier)


Extinction properties VO services