ALMA Observatory Archives

January 9, 2024January 9, 2024 by Scott Alan Johnston

Young Stars in the Outskirts of Galaxies Finally Have an Explanation

Star formation is well understood when it happens in the populous centers of galaxies. From our vantage point on Earth, within the Milky Way, we see it happening all around us. But when newborn stars are birthed in the empty outskirts of galactic space, it requires a new kind of explanation. At the 243rd meeting of the American Astronomical Association yesterday, astronomers announced that they have observed, for the first time, the unique molecular clouds that give rise to star formation near the remote edges of galaxies.

January 3, 2024January 3, 2024 by Evan Gough

The Oldest Known Spiral Galaxy Has Ripples Like the Surface of a Pond

This simulation illustrates a galaxy disk being disturbed, leading to the propagation of a seismic ripple throughout the disk. (Credit: Bland-Hawthorn and Tepper-Garcia, University of Sydney).

Astronomers have detected pond-like ripples across the gaseous disk of an ancient galaxy. What caused the ripples, and what do they tell us about the distant galaxy’s formation and evolution? And whatever happened, how has it affected the galaxy and its main job: forming stars?

November 17, 2023November 17, 2023 by Evan Gough

ALMA Takes Next-Level Images of a Protoplanetary Disk

This ALMA image of the young star HL Tauri shows rings of dust surrounding the star. The line patterns show the orientation of polarized light. It's the deepest dust polarization image of any protoplanetary disk captured thus far, revealing details about the dust grains in the disk. Credit: NSF/AUI/NRAO/B. Saxton/Stephens et al.

The ESO’s Atacama Large Millimeter/submillimeter Array (ALMA) is perched high in the Chilean Andes. ALMA is made of 66 high-precision antennae that all work together to observe light just between radio and infrared. Its specialty is cold objects, and in recent years, it has taken some stunning and scientifically illuminating images of protoplanetary disks and the planets forming in them.

But its newest image supersedes them all.

November 9, 2023November 9, 2023 by Matt Williams

Sometimes Compact Galaxies Hide Their Black Holes

Illustration of an active quasar. What role does its dark matter halo play in activating the quasar? Credit: ESO/M. Kornmesser — Illustration of an active quasar. New research shows that SMBHs eat rapidly enough to trigger them. Credit: ESO/M. Kornmesser

Quasars, short for quasi-stellar objects, are one of the most powerful and luminous classes of objects in our Universe. A subclass of active galactic nuclei (AGNs), quasars are extremely bright galactic cores that temporarily outshine all the stars in their disks. This is due to the supermassive black holes in the galactic cores that consume material from their accretion disks, a donut-shaped ring of gas and dust that orbit them. This matter is accelerated to close to the speed of light and slowly consumed, releasing energy across the entire electromagnetic spectrum.

Based on past observations, it is well known to astronomers that quasars are obscured by the accretion disk that surrounds them. As powerful radiation is released from the SMBH, it causes the dust and gas to glow brightly in visible light, X-rays, gamma-rays, and other wavelengths. However, according to a new study led by researchers from the Centre for Extragalactic Astronomy (CEA) at Durham University, quasars can also be obscured by the gas and dust of their entire host galaxies. Their findings could help astronomers better understand the link between SMBHs and galactic evolution.

September 12, 2023September 12, 2023 by Brian Koberlein

Do The Gaps in Protoplanetary Disks Really Indicate Newly Forming Planets?

Artist depiction of a protoplanetary disk in which planets are forming. Credit: ESO/L. Calçada

Roughly 5 billion years ago Earth was in the process of forming. Gas and dust gathered with the young Sun’s protoplanetary disk, likely nudged a bit by the resonant gravitational pull of Jupiter and other large worlds. One can imagine that as Earth formed it swept its orbit clear of debris, leaving a gap in the disk visible from light years away. While we know this tale is reasonably accurate, the idea that planets such as Earth always clear gaps in a protoplanetary disk likely isn’t.

March 10, 2023March 10, 2023 by Evan Gough

Water’s Epic Journey to Earth Began Before the Sun Formed

This artist’s impression shows the planet-forming disc around the star V883 Orionis. New research shows how water starts its journey in the gas cloud that forms the star, and eventually ends its journey on Earth. Image Credit: ESO/L. Calçada

The origins of Earth’s water is a complicated mystery that scientists have been untangling for decades. Life is impossible without water, so the origin of Earth’s life-giving water is a foundational question. As the power of our telescopes grows, researchers have made meaningful headway on the question.

Previous research uncovered links between Earth’s water and the Solar System’s comets and icy planetesimals. But newer research follows the chain back even further in time to when the Sun itself had yet to form.

January 11, 2023January 11, 2023 by Evan Gough

This Star is Blasting Out a Concentrated Jet of Material at 500 km/s

A team of astronomers was studying the masers around oddball star MWC 349A when they discovered something unexpected: a previously unseen jet of material launching from the star’s gas disk at impossibly high speeds. Image Credit: ALMA (ESO/NAOJ/NRAO), M. Weiss (NRAO/AUI/NSF)

MWC 349A is a star about 3,900 light-years away in the constellation Cygnus. It’s huge, about 38 times as massive as the Sun. It’s actually a binary star and may even be a triple star. It’s an oddball and one of the brightest sources of radio emission in the sky.

One of the star’s unusual features is its natural maser. MWC 349A’s natural maser played a central role in a new discovery: the young star emits a blistering jet of material travelling at 500 km/sec (310 m/sec.) That discovery could help astronomers understand massive stars and their complexity.

November 29, 2022November 29, 2022 by Evan Gough

Baby Gas Giants Cast Shadows on Their Siblings

A computer-generated image depicting a dark protostellar disk seen edge-on at 90 degrees to jets (orange) emanating from the poles of a young star. Such disks are thought to be the precursors of planetary systems, with planets forming as the dust coalesces. RIKEN researchers may have spotted embryos of gas giant planets in one protostellar disk. Credit: Mark Garlick/Science Photo Library

A team of astronomers has caught glimpses of gas giants forming around a very young star.

The nascent giants are having a chilling effect on their potential siblings.

May 12, 2022May 12, 2022 by Evan Gough

We’ve Now Seen Planet-Forming Disks Around Hundreds of Young Stars. What Do They Tell Us?

ALMA's high-resolution images of nearby protoplanetary disks, which are results of the Disk Substructures at High Angular Resolution Project (DSHARP). The observatory is often used to look for planet birth clouds like these and the one around HD 169142. Credit: ALMA (ESO/NAOJ/NRAO), S. Andrews et al.; NRAO/AUI/NSF, S. Dagnello

Is our Solar System comparable to other solar systems? What do other systems look like? We know from exoplanet studies that many other systems have hot Jupiters, massive gas giants that orbit extremely close to their stars. Is that normal, and our Solar System is the outlier?

One way of addressing these questions is to study the planet-forming disks around young stars to see how they evolve. But studying a large sample of these systems is the only way to get an answer. So that’s what a group of astronomers did when they surveyed 873 protoplanetary disks.

November 26, 2020November 26, 2020 by Evan Gough

Astronomers See a Newly Forming Planetary Disk That’s Continuing to Feed On Material from its Nebula

This false-colour image shows the filaments of accretion around the protostar [BHB2007] 1. The large structures are inflows of molecular gas (CO) nurturing the disk surrounding the protostar. The inset shows the dust emission from the disk, which is seen edge-on. The "holes" in the dust map represent an enormous ringed cavity seen (sideways) in the disk structure. Image Credit: MPE

Over the last few years, astronomers have observed distant solar systems in their early stages of growth. ALMA (Atacama Large Millimeter/submillimeter Array) has captured images of young stars and their disks of material. And in those disks, they’ve spotted the tell-tale gaps that signal the presence of growing young planets.

As they ramped up their efforts, astronomers were eventually able to spot the young planets themselves. All those observations helped confirm our understanding of how young solar systems form.

But more recent research adds another level of detail to the nebular hypothesis, which guides our understanding of solar system formation.