The 4-metre Multi-Object Spectroscopic Telescope (4MOST) facility in Chile obtained its first light on October 18.

This milestone is a crucial step in the life of any telescope marking the moment it is ready to begin its scientific journey. Once fully operational, 4MOST will investigate the formation and evolution processes of stars and planets, the Milky Way and other galaxies, black holes and other exotic objects, and of the Universe as a whole.

4MOST is installed on the VISTA telescope at the European Southern Observatory’s (ESO) Paranal Observatory where is it is designed to be the most powerful spectroscopic survey facility in the southern hemisphere.

4MOST does not simply take images of the sky; it records spectra, capturing the light of each object in every individual colour. With this capability, it can unravel the light of 2,400 celestial objects simultaneously into 18,000 colour components, allowing astronomers to study their detailed chemical composition and properties.

Lancaster PhD student Andrew Milligan and Professor Isobel Hook of Lancaster University are members of the commissioning team for the 4MOST instrument. Their work involves travel to Chile to take part in the on-site work at the telescope.

In preparation for this, Andrew has gained experience with night-time telescope observations and created parts of the 4MOST commissioning software. He has also been performing critical work on automating the classification of this massive number of objects to ensure the purest possible sample of type Ia supernovae for cosmology.

©ESO/B. Tafreshi (twanight.org)

Lancaster University is a founding member of the Time Domain Extragalactic Survey (TiDES), a dynamic constituent of 4MOST designed to capitalize on another revolutionary new telescope, the US National Science Foundation/Department of Energy led Vera C. Rubin Observatory. Every time 4MOST observes, TiDES will use a handful of its fibres to observe recently discovered “transient” objects discovered in Rubin’s Legacy Survey of Space and Time (LSST).

Andrew said: "I am excited that we will soon see supernova spectra as 4MOST begins taking scientific data over the coming months. TiDES aims to observe over 30,000 supernovae and over 200,000 host galaxies. These observations will help make the most precise measurement in history of the properties of dark energy."

TiDES constitutes part of the UK’s in-kind contribution that secures UK astronomers rights to access the Rubin data via the LSST:UK consortium.

Lancaster academic staff, research associates and students have undertaken critical work in performing preparatory 4MOST survey simulations, creating TiDES data flow infrastructure and commissioning the 4MOST instrument.

Professor Hook recently returned from the first phase of 4MOST commissioning in Chile, prior to the First Light event.

She said: "The VISTA site at Paranal is exceptional for astronomy and it's the ideal home for the 4MOST instrument. It was wonderful to see the full instrument installed on the telescope and ready to start scanning the night sky".

Other Lancaster university members of TiDES include Lydia Makrygianni, Christopher Duffy, Georgios Dimitriadis, Brooke Simmons and Mathew Smith.