ESO Archives

May 20, 2023May 20, 2023 by Andy Tomaswick

ESO is Using a New System to Allocate Telescope Time. It’s Working Well

ESO's Very Large Telescope is composed of four Unit Telescopes (UTs) and four Auxiliary Telescopes (ATs). Seen here is one of the UTs firing four lasers which are crucial to the telescope's adaptive optics systems. To the right of the UT are two ATs, these smaller telescopes are moveable and work in tandem with the other telescopes to create a unique and powerful tool for observing the Universe.

Most astronomers know the struggle of getting time on the world’s most powerful telescopes. Even though this observing time might literally be the most important thing to their career prospects, there are always more studies than there is time available to perform them. Typically, each telescope system has a panel of experts that determine which proposals will get observational time and which won’t. However, the European Southern Observatory (ESO), based in Germany but with observational telescopes in Chile, decided to try a new proposal review method – peer review.

May 19, 2023May 19, 2023 by Matt Williams

The Largest Explosion Ever Seen in the Universe

Artist impression of a black hole accretion. Credit: John A. Paice.

Throughout recorded history, humans have looked up at the night sky and witnessed the major astronomical events known as a “supernova.” The name, still used by astronomers, referred to the belief that these bursts of light in the “firmament” signaled the birth of a “new star.” With the birth of telescopes and modern astronomy, we have since learned that supernovae are what occur at the end of a star’s lifecycle. At this point, when a star has exhausted its hydrogen and helium fuel, it experiences gravitational collapse at its center.

This leads to a tremendous explosion that can be seen billions of light-years distant, releasing tremendous amounts of energy and blowing the star’s outer layers off. Thanks to an international team of astronomers led by the University of Southhampton, the most powerful cosmic explosion has been confirmed! The stellar explosion, AT2021lwx, took place about 8 billion light-years away in the constellation Vulpecula and was over ten times brighter than any supernova ever observed and 100 times brighter than all the stars in the Milky Way combined!

April 26, 2023April 26, 2023 by Matt Williams

The Next Generation of Telescopes Will Tell Us About the Weather on Other Worlds

This artist’s rendering shows the Extremely Large Telescope in operation on Cerro Armazones in northern Chile. The telescope is shown using lasers to create artificial stars high in the atmosphere. Image: ESO/E-ELT

The field of astronomy is about to be revolutionized, thanks to the introduction of Extremely Large Telescopes that rely on primary mirrors measuring 30 meters (or more) in diameter, adaptive optics (AO), coronographs, and advanced spectrometers. This will include the eponymously-named Extremely Large Telescope (ELT), the Giant Magellan Telescope (GMT), and the Thirty Meter Telescope (TMT). These telescopes will enable astronomers to study exoplanets using the Direct Imaging (DI) method, which will yield valuable data on the composition of their atmospheres.

According to a new study by a team of researchers from Ohio State University (OSU), these telescopes will also allow astronomers to study “ultracool objects,” like very low-mass stars (VLMs), brown dwarfs, and exoplanets. In addition to being able to visualize magnetic starspots and determine the chemical compositions of these objects, ELTs will be able to reveal details about atmospheric dynamics and cloud systems. These types of studies could reveal a wealth of information about some of the least-studied objects in our Universe and significantly aid in the search for life beyond our Solar System.

February 25, 2023February 25, 2023 by Matt Williams

Astronomers Suspected There Should Be a Planet Here, and Then They Took a Picture of it

Direct images of AF Lep b, acquired by the SPHERE instrument on the VLT. Credit: ESO/Paranal Observatory

To date, astronomers have confirmed 5,272 exoplanets in 3,943 systems using a variety of detection methods. Of these, 1,834 are Neptune-like, 1,636 are gas giants (Jupiter-sized or larger), 1,602 are rocky planets several times the size and mass of Earth (Super-Earths), and 195 have been Earth-like. With so many exoplanets available for study (and next-generation instruments optimized for the task), the process is shifting from discovery to characterization. And discoveries, which are happening regularly, are providing teasers of what astronomers will likely see in the near future.

For example, two international teams of astronomers independently discovered a gas giant several times the mass of Jupiter orbiting a Sun-like star about 87.5 light-years from Earth. In a series of new papers that appeared in Astronomy & Astrophysics, the teams report the detection of a Super-Jupiter orbiting AF Leporis (AF Lep b) using a combination of astrometry and direct imaging. The images they acquired using the Spectro-Polarimetric High-contrast Exoplanet REsearch instrument (SPHERE) have since become the ESO’s Picture of the Week.

January 10, 2023July 11, 2023 by Nancy Atkinson

Need a Project? You can Build a Paper Model of the Extremely Large Telescope

Paper model of the Extremely Large Telescope. Credit: ESO

The Extremely Large Telescope (ELT) will be the world’s largest optical/near-infrared telescope. It is under construction on top of a mountain named Cerro Armazones in the Atacama Desert of northern Chile. Now you can build your own slightly smaller, incredibly lower cost version of your own ELT – using paper.

November 23, 2022November 23, 2022 by Nancy Atkinson

A New Instrument Gives the Very Large Telescope an Even Sharper View of the Cosmos

ERIS, the Very Large Telescope’s newest infrared eye on the sky, reveals the inner ring of the galaxy NGC 1097 in stunning detail, in this comparison view. Credit: ESO/ERIS team.

The Very Large Telescope (VLT) at Cerro Paranal in northern Chile, is undoubtedly one of the premier ground-based observatories. But a new infrared instrument recently installed on the telescope has made the VLT even better.

The Enhanced Resolution Imager and Spectrograph (ERIS) was delivered to Chile in December, 2021 and the first test observations were carried out beginning in February of this year. ESO, the European Organization for Astronomical Research in the Southern Hemisphere, an international organization which coordinates the use of VLT and several other observatories, says this infrared instrument “will be able to see further and in finer detail, leading the way in Solar System, exoplanet and galaxy observations.”

November 10, 2022November 10, 2022 by Nancy Atkinson

A New View of the Cone Nebula From the Very Large Telescope

The Cone Nebula is part of a star-forming region of space, NGC 2264, about 2500 light-years away. This image was released on the occasion of ESO’s 60th anniversary. Credit: ESO

Here’s a dramatic and spectacular new view of the Cone Nebula, as seen by the Very Large Telescope (VLT). This nebula is part of a distant star-forming region called NGC 2264, which about 2,500 light-years away. Its pillar-like appearance is a perfect example of the shapes that can develop in giant clouds of cold molecular gas and dust, known for creating new stars.

August 23, 2022August 23, 2022 by Nancy Atkinson

Rare “Red Sprites” Seen From ESO’s La Silla Observatory in Chile

This picture, taken from ESO’s La Silla Observatory in Chile, shows bright red streaks known as red sprites. Credit: Zdenek Bardon/ESO.

This new image taken of the skies above Chile’s Atacama Desert near the European Southern Observatory’s (ESO) La Silla Observatory, shows bright red streaks in the sky known as red sprites. Red sprites are large-scale electrical discharges that occur high above thunderstorm clouds, usually triggered by the discharges of positive lightning between an underlying thundercloud and the ground. However, the red sprites appear high in Earth’s atmosphere, sometimes 50-90 km in altitude.

February 12, 2022February 12, 2022 by Matt Williams

A THIRD Planet Found Orbiting Nearby Proxima Centauri

This artist’s impression shows Proxima d, a planet candidate recently found orbiting the red dwarf star Proxima Centauri, the closest star to the Solar System. The planet is believed to be rocky and to have a mass about a quarter that of Earth. Two other planets known to orbit Proxima Centauri are visible in the image too: Proxima b, a planet with about the same mass as Earth that orbits the star every 11 days and is within the habitable zone, and candidate Proxima c, which is on a longer five-year orbit around the star.

In August of 2016, astronomers with the European Southern Observatory (ESO) announced that they had discovered an exoplanet orbiting in neighboring Proxima Centauri. Based on Radial Velocity measurements (aka. Doppler Photometry), the discovery team estimated that the planet was roughly the same size and mass as Earth and orbited with Proxima Centauri’s Circumsolar Habitable Zone (HZ). In 2020, this planet was confirmed by follow-up observations.

In that same year, a second exoplanet (Proxima c) roughly seven times the mass of Earth (a Super-Earth or mini-Neptune) was confirmed. As if that wasn’t enough, an international team of astronomers with the ESO recently announced that they detected a third exoplanet around Proxima Centauri – Proxima d! This Mars-sized planet orbits about halfway between its host star and Proxima b and is one of the lightest exoplanets ever discovered.

February 11, 2022February 11, 2022 by Matt Williams

Astronomers Measure the Layers of an Exoplanet's Atmosphere

An artist's conception of the hot Jupiter WASP-79b. (Image credit: NASA)

The number of planets discovered beyond our Solar System has grown exponentially in the past twenty years, with 4,919 confirmed exoplanets (and another 8,493 awaiting confirmation)! Combined with improved instruments and data analysis, the field of study is entering into an exciting new phase. In short, the focus is shifting from discovery to characterization, where astronomers can place greater constraints on potential habitability.

In particular, the characterization of exoplanet atmospheres will allow astronomers to determine their chemical makeup and whether they have the right characteristics to support life. In a new study led by the University of Lund, an international team of researchers characterized the atmosphere of one of the most extreme exoplanets yet discovered. This included discerning what could be several distinct layers that have particular characteristics.