Press release: On the trail of the mysteries of the Universe: cosmic data open to all

No. 79 - 03.06.2026

HETDEX project researchers make dataset from night sky observations publicly accessible

Following the completion of the largest survey of the early Universe to date, the team behind the Hobby-Eberly Telescope Dark Energy Experiment (HETDEX) has made its extensive dataset available to the public. With half a petabyte of data, researchers and astronomy enthusiasts alike can now investigate how the first galaxies formed and evolved, measure the distribution of stars and gas, map the cosmos, and explore objects that are difficult to find in conventional databases. The data is based on observations of the night sky in West Texas using one of the world’s largest telescopes: the Hobby-Eberly Telescope. It is operated by the University of Göttingen and LMU Munich in Germany, as well as the University of Texas at Austin and Pennsylvania State University both in the US. The release of the data was announced in The Astrophysical Journal Supplement Series.

“The Hobby-Eberly Telescope enables us to carry out cutting-edge research in astrophysics,” says Professor Ansgar Reiners at Göttingen University. Between 2017 and 2024, it surveyed an area of the night sky at the McDonald Observatory in Texas equivalent to the surface area of around 2,000 full moons, thereby creating a map of the distant Universe. Researchers in the HETDEX project are using this data to solve the mystery of dark energy – the unknown factor causing the Universe to expand at an ever-increasing rate.

To achieve this, the team is mapping the positions of over a million ancient galaxies, whilst also collecting data on the entire space in between. Professor Karl Gebhardt, HETDEX project leader at the University of Texas at Austin, explains: “We don’t select specific objects to observe. Instead, we point one of the world’s largest telescopes at the sky and see what’s out there. We are confident that extraordinary discoveries are hidden in the data.”

HETDEX uses a technique known as spectroscopy, which involves breaking light down into its constituent wavelengths. The researchers look for spectral lines in the spectra that provide information about an object’s chemical composition, its motion through space, and its distance from Earth. The newly published database contains 600 million spectra from an epoch in the Universe known as “Cosmic Noon”, which took place 10 to 12 billion years ago – an extremely early stage in the cosmic evolution of our Universe which is around 13.8-billion years old.

“HETDEX offers an exceptionally broad and detailed spectroscopic insight into the Universe from a time when most stars and galaxies were only just forming,” say Gebhardt, and Professor Wolfram Kollatschny at Göttingen University. “The telescope and its instruments capture tens of thousands of spectra simultaneously. This allows galaxies to be mapped across enormous cosmic volumes in a way that was previously impossible.” Professor Jens Niemeyer at Göttingen University gives an idea of what’s to come: “In just a few months’ time, measurements made with unprecedented precision about the mysterious dark energy – the accelerated expansion of the Universe – will be presented.”

Data and further information: https://hetdex.org/data-results/

Original publication: Erin Mentuch Cooper et al. HETDEX Public Data Release 1: Source Catalogue 2 and Data Cubes from ∼ 90 deg2 of Integral-Field Optical Spectroscopy. The Astrophysical Journal Supplement Series (2026). DOI: 10.3847/1538-4365/ae6068

Contact:

Professor Wolfram Kollatschny

University of Göttingen

Institute for Astrophysics and Geophysics

Friedrich-Hund-Platz 1, 37077 Göttingen, Germany

Tel: +49 (0)551 39-25065

Email: wkollat@astro.physik.uni-goettingen.de