This week we continue our round of thanks to participants to the HOYS project. We have a short description of the group at the Astrolab IRIS observatory in Belgium, who has contributed about 6.5% of all images in our database.

HOYS Participant: Astrolab IRIS observatory

By Siegfried Vanaverbeke, Franky Dubois, Ludwig Logie, Steve Rau

A couple of years ago in 2018 I was viewing some YouTube videos and came across a talk by Dr. Dirk Froebrich on a project called “HOYS-CAPS”. HOYS stands for “Hunting Outbursting Young Stars”. I was searching for projects to be executed on the 68 cm telescope of the Astrolab IRIS observatory in Belgium (see above image). This is a public observatory located near Ypres in Belgium and our group of four people involved in photometry (Franky Dubois, Ludwig Logie, Steve Rau and me) had been actively involved in research projects in stellar photometry and exoplanet science since 2014.

The main purpose of the project is to obtain long-term light curves of young stellar objects in a whole sample of open stellar clusters. From the photometric data, we hope to infer crucial properties of the circumstellar disks that orbit the protostars in the very early stage of their formation when planet formation is ongoing and protostars are still evolving toward the main sequence. We also look at the properties of the protostars themselves including their rotational periods and spot activity.

The project seemed very suitable for our purposes because the targets are distributed all over the sky so that there would always be a number of open stellar clusters that could be imaged with the telescope when the weather permits. I exchanged a number of emails with Dirk and finally we met for the first time at the public observatory Mira in Grimbergen near Brussels during the 4th European Variable Star meeting in September 2019 where Dirk was giving a talk about the project. I then invited him to present his talk again at the annual meeting of the Flemish astronomy organization VVS later that year at the start of October.

Our main observer Franky Dubois began taking images and after a period of testing the data processing pipeline on the project website he has been observing HOYS targets almost every clear night. Meanwhile Franky has build up his own private observatory ADONIS and now contributes CCD images from his home in Langemark. In total our group has now contributed about 6500 images to HOYS. I have been analysing data from the HOYS database and the project has resulted in several publications already with the team led by Dirk at the University of Kent.