ESO Archives

August 17, 2023August 17, 2023 by Nancy Atkinson

This Brown Dwarf is 2,000 Degrees Hotter Than the Sun

exoplanet hot jupiter transiting its star — This artist’s impression shows an ultra-hot exoplanet as it is about to transit in front of its host star. Credit: ESO

Astronomers have discovered an intense binary star system located about 1,400 light years away. It contains a brown dwarf with 80 times the mass of Jupiter which is bound closely with an incredibly hot white dwarf star. Observations have shown the brown dwarf is tidally locked to the white dwarf, allowing the daytime surface temperatures on the brown dwarf to reach 8,000 Kelvin (7,700 Celsius, 14,000 Fahrenheit) — which is much hotter than the surface of the Sun, which is about 5,700 K (5,427 C, 9,800 F). The brown dwarf’s nightside, on the other hand, is about 6,000 degrees K cooler.

July 11, 2023July 12, 2023 by Nancy Atkinson

The Biggest Telescope in the World is Half Built

This image, taken in late June 2023, shows a night view of the construction site of ESO’s Extremely Large Telescope at Cerro Armazones, in Chile's Atacama Desert. Credit: ESO.

The European Southern Observatory continues to build the largest telescope in the world, the Extremely Large Telescope (ELT). Construction of the telescope began in 2014 with flattening the top of a mountain named Cerro Armazones in Chile’s Atacama Desert.

ESO just announced that progress on construction has crossed the 50% mark. The remaining work should take another five years. When it finally comes online in 2028, the telescope will have a 39-meter (128 ft) primary mirror of 798 hexagonal segments, making it the largest telescope in the world for visible and infrared light. The new telescope should help to answer some of the outstanding questions about our Universe, such as how the first stars and galaxies formed, and perhaps even be able to take direct images of extrasolar planets.

March 14, 2023March 14, 2023 by Matt Williams

Warm Carbon Increased Suddenly in the Early Universe. Made by the First Stars?

While previous studies have suggested a rise in warm carbon, much larger samples – the basis of the new study – were needed to provide statistics to accurately measure the rate of this growth.

According to the most widely-accepted model of cosmology, the Universe began roughly 13.8 billion years ago with the Big Bang. As the Universe cooled, the fundamental laws of physics (the electroweak force, the strong nuclear force, and gravity) and the first hydrogen atoms formed. By 370,000 years after the Big Bang, the Universe was permeated by neutral hydrogen and very few photons (the Cosmic Dark Ages). During the “Epoch of Reionization” that followed, the first stars and galaxies formed, reoinizing the neutral hydrogen and causing the Universe to become transparent.

For astronomers, the Epoch of Reionization still holds many mysteries, like when certain heavy elements formed. This includes the element carbon, a key ingredient in the formation of planets, an important element in organic processes, and the basis for life as we know it. According to a new study by the ARC Center of Excellence for All Sky Astrophysics in 3 Dimensions (ASTRO 3D), it appears that triply-ionized carbon (C iv) existed far sooner than previously thought. Their findings could have drastic implications for our understanding of cosmic evolution.

March 2, 2023March 2, 2023 by Matt Williams

A Very Young Star is Forming Near the Milky Way's Supermassive Black Hole

Artist's impression of a young, massive star orbiting Sagittarius A*. Credit: University of Cologne

Since the 1930s, physicists and radio engineer Karl Jansky reported discovering a persistent radio source coming from the center of our galaxy. This source came to be known as Sagittarius A* (Sgr A*), and by the 1970s, astronomers determined that it was a supermassive black hole (SMBH) roughly four million times the mass of our Sun. Since then, astronomers have used increasingly-advanced radio telescopes to study Sgr A* and its surrounding environment. This has led to many exotic discoveries, such as the many “Stars stars” and gaseous “G objects” that orbit it.

The study of these objects and how the powerful gravity of Sgr A* has allowed scientists to test the laws of physics under the most extreme conditions. In a recent study, an international team of researchers led by the University of Cologne made a startling discovery. Based on data collected by multiple observatories, they observed what appears to be a newly-formed star (X3a) in the vicinity of Sgr A*. This discovery raises significant questions about how young stellar objects (YSOs) can form and survive so close to an SMBH, where they should be torn apart by violent gravitational forces.

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.

December 8, 2022December 8, 2022 by Evan Gough

Astronomers Have Found Two Temperate Super-Earths Orbiting a Nearby Red Dwarf

The telescopes of the SPECULOOS Southern Observatory gaze out into the stunning night sky over the Atacama Desert, Chile. ©ESO/P.Holárek

A team of astronomers has found two Super-Earths orbiting a red dwarf about 114 light-years away. The star, named LP 890-9, is the second coolest star found that hosts planets. Both the planets are likely temperate, and one of them “… is the second-most favourable habitable-zone terrestrial planet known so far,” according to the paper presenting the results.

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.

May 2, 2022May 2, 2022 by Matt Williams

This is it! On May 12th we’ll see the Event Horizon Telescope’s Image of the Milky Way’s Supermassive Black Hole

This image contains a collage of ESO’s telescopes at various sites in Chile.

In April of 2019, the international astronomical consortium known as the Event Horizon Telescope (EHT) made headlines worldwide when it announced the first-ever image of a black hole. Specifically, the image showed the glowing disk surrounding the supermassive black hole (SMBH) at the center of the M87 galaxy. In 2021, they followed up on this by acquiring an image of the core region of the Centaurus A galaxy and the radio jet emanating from it.

But in what is sure to be the most exciting announcement yet, the European Southern Observatory (ESO) and researchers from the EHT will announce the results of their survey that examined the SMBH at the center of our very own Milky Way Galaxy – Sagittarius A*! The results will be shared as part of a press conference on Thursday, May 12th, starting at 03:00 PM CEST (08:00 EDT; 05:00 PDT). The event will take place at the ESO Headquarters in Munich, Germany, and live-streamed via an ESO webcast.