Home » Observatories » Solar Observatory
Solar Observatory

ESAC Solar Observatory (Helios) 

Since 12th of Jun 2023 we have resumed daily operation of the observatory.

WATCH the Latest SUN (web) !

The ESAC Solar Observatory (Helios) was installed at ESAC in 2012.


External view Internal view Sun H-alpha Sun visible   Portable RA h-alpha (only special events) Portable RA visible (only special events)

Use of the observatory for Educators and Students

You can see the latest Sun images in For Educators - Latest Sun. Images are stored in a public archive where they can be downloaded for Educational use.

With these images you can do some of our interactive scientific cases for secondary schools, see the list of scientific cases.

For visits to the Observatory and Student Control of the telescopes, please contact us.

Where is it located?

The Helios Observatory is located in the European Space Astronomy Centre (ESAC). 

Google Maps link.

What can we observe?

The Sun!

Sun photos from CESAR observatory (ESA/CESAR)

WATCH the Latest SUN (web)

Txt file with best images:

Current status

The observatory is operated on work days from the ESAC site. See the images here!


Technical specifications

It consists of a 3 meter remotized classical dome with sliding window (ScopeDome 3M). The enclosure protects the following observing equipment from the weather, being the main equipment two solar telescopes:

  • TS Photoline Apo, for visible (white-light):
    • Aperture: 72mm
    • Focal Length: 432mm
    • Solar Filter: Astrozap Solar Filter + Baader Solar Continuum
  • A SkyWatcher EQ8-R mount.
  • The observing cameras:
    • 2 QHY5-II-M planetary cameras with a 1/2 CMOS sensor.
  • The electronic boards that control the dome and gear mechanisms.
  • An AAG CloudWatcher weather station (standing in a pole outside the dome), for automatic door opening and closure depending on the rain and wind conditions. Cloud cover is also checked but the dome will not close if cloudy.
  • A master computer that controls the operating of the dome, cameras, link connections to the servers.
  • Cameras to check the conditions from outside and inside the dome.
  • A UPS to power the observatory in case of power line interruptions.




Link to the news

Click for full resolution

Click for full resolution