SALT celebrates two decades of astronomical breakthroughs

The Southern African Large Telescope (SALT) has reached a monumental milestone, celebrating twenty years since its inauguration. The observatory, situated at the South African Astronomical Observatory site in Sutherland, Northern Cape, has solidified its reputation as Africa’s Giant Eye on the Sky, contributing significantly to global astronomy.

The National Research Foundation (NRF) will host a prestigious gathering to celebrate this landmark anniversary on Monday. High-profile speakers will include NRF Board chair Prof Mosa Moshabela, and the Deputy Minister of Science, Technology and Innovation, Nomalungelo Gina, who will highlight SALT’s impressive record of scientific achievements and transformative role in the African continent's space science development.

Constructed in the late 1990s with a financial commitment from the South African government, SALT was envisioned to be a flagship for the new South Africa. Upon its completion in 2005, it underwent a rigorous performance verification phase, leading to full scientific operations starting in September 2011. Despite challenges, SALT has fully realised its immense potential as a world-leading astronomical observatory.

As the largest single optical telescope in the Southern Hemisphere, measuring 11 metres, SALT can capture light from distant celestial objects that are a billion times fainter than what can be seen with the naked eye. Over its two decades of operation, SALT has set numerous astronomical milestones and forged lasting international partnerships.

• Kilonova of GW170817 (2017): SALT participated in a pivotal multi-messenger event, being one of the first telescopes to record the optical afterglow of a neutron star merger. This observation helped validate models regarding heavy element synthesis.
• Exoplanet Microlensing (2019): SALT was instrumental in a campaign employing gravitational microlensing, aiding in the characterisation of new exoplanets through rapid follow-up spectroscopy.
• Eight Super-Hot Stars Unveiled (2020): Astronomers identified eight new extremely hot sub-dwarf stars using SALT, providing significant insights into stellar evolution.
• “Peekaboo” Galaxy Discovery (2022): SALT played a crucial role in characterising a tiny galaxy, revealing its primordial conditions and low metallicity, offering glimpses into the early universe.
• Four-Star Multi-Stellar System (2023): SALT and the University of Canterbury’s partnership led to the discovery of an unusual quadruple star system, testing theories of multi-star formation.

As astrophysics continues to evolve, SALT remains at the forefront, ensuring South Africa’s competitiveness in global astronomy well into the 21st century. Its achievements underscore the commitment to advancing space science on the African continent, reinforcing SALT’s status as an indispensable asset for researchers and scholars worldwide.