milky way Archives

January 9, 2020January 10, 2020 by Brian Koberlein

A Huge Wave is Passing Through the Milky Way Unleashing New Stellar Nurseries

A wave structure of stellar nurseries in the Milky Way. Credit: Alyssa Goodman / Harvard University

Stars are formed within large clouds of gas and dust known as stellar nurseries. While star formation was once seen as a simple gravitational process, we now know it is a complex dance of interactions. When one star forms it can send shock waves through the interstellar medium that trigger other stars to form. Supernovae and galactic collisions can trigger the creation of stars as well. One way to study stellar formation is to look at where stars form within a galaxy.

January 6, 2020January 6, 2020 by Evan Gough

This is the Core of the Milky Way, Seen in Infrared, Revealing Features Normally Hidden by Gas and Dust

A composite infrared image of the core of the Milky Way galaxy. NASA/SOFIA/JPL-Caltech/ESA/Herschel

The world’s largest airborne telescope, SOFIA, has peered into the core of the Milky Way and captured a crisp image of the region. With its ability to see in the infrared, SOFIA (Stratospheric Observatory For Infrared Astronomy) is able to observe the center of the Milky Way, a region dominated by dense clouds of gas and dust that block visible light. Those dense clouds are the stuff that stars are born from, and this latest image is part of the effort to understand how massive stars form.

December 20, 2019February 17, 2023 by Matt Williams

100,000 Supernovae Exploded Near the Core of the Milky Way

Taken with the HAWK-I instrument on ESO’s Very Large Telescope in the Chilean Atacama Desert, this stunning image shows the Milky Way’s central region with an angular resolution of 0.2 arcseconds. This means the level of detail picked up by HAWK-I is roughly equivalent to seeing a football (soccer ball) in Zurich from Munich, where ESO’s headquarters are located. The image combines observations in three different wavelength bands. The team used the broadband filters J (centred at 1250 nanometres, in blue), H (centred at 1635 nanometres, in green), and Ks (centred at 2150 nanometres, in red), to cover the near infrared region of the electromagnetic spectrum. By observing in this range of wavelengths, HAWK-I can peer through the dust, allowing it to see certain stars in the central region of our galaxy that would otherwise be hidden.

Thanks to the latest generation of sophisticated telescopes, astronomers are learning things a great deal about our Universe. The improved resolution and observational power of these instruments also allow astronomers to address previously unanswered questions. Many of these telescopes can be found in the Atacama Desert in Chile, where atmospheric interference is minimal and the cosmos can be seen with greater clarity.

It is here that the European Southern Observatory (ESO) maintains many observatories, not the least of which is the Paranal Observatory where the Very Large Telescope (VLT) resides. Recently, an international team of astronomers used the VLT to study the center of the Milky Way and observed evidence of ancient starbursts. These indicate that the central region of our galaxy experienced an intense period of star birth in the past.

December 12, 2019December 12, 2019 by Evan Gough

Dark Matter Could Be A Source of Gamma Rays Coming from the Center of the Milky Way

A map of gamma ray emissions throughout the Milky Way galaxy, based on observations from the Fermi Gamma-ray Space Telescope. The inset depicts the Galactic Center Excess – an unexpected, spherical region of gamma ray emissions at the center of our galaxy, of unknown origin. Credit: NASA/T. Linden, U.Chicago

There’s a lot of mysterious goings-on at the center of the Milky Way. The supermassive black hole that resides there is chief among them. But there’s another intriguing puzzle there: an unexpected spherical region of intense gamma ray emissions.

A new study suggests that dark matter could be behind those emissions.

December 10, 2019December 10, 2019 by Evan Gough

This is the Milky Way’s Magnetic Field

A representation of how our Galaxy would look in the sky if we could see magnetic fields. The plane of the Galaxy runs horizontally through the middle, and the Galactic centre direction is the middle of the map. Red–pink colours show increasing Galactic magnetic field strengths where the direction is pointing towards the Earth. Blue–purple colours show increasing Galactic magnetic field strengths where the direction is pointing away from the Earth. The background shows the signal reconstructed using sources outside our Galaxy. The points show the current measurements for pulsars. The squares show the measurements from this work using LOFAR pulsar observations. Image Credit: Sobey et al, 2019.

The Milky Way galaxy has its own magnetic field. It’s extremely weak compared to Earth’s; thousands of times weaker, in fact. But astronomers want to know more about it because of what it can tell us about star formation, cosmic rays, and a host of other astrophysical processes.

December 8, 2019December 8, 2019 by Matt Williams

A New Way to Measure the Age of the Milky Way

Artist’s impression of the warped and twisted Milky Way disk. Credit: Chen Xiaodian/Kavli Institute of Astronomy and Astrophysics

Like many other spiral galaxies in the Universe, the Milky Way Galaxy consists of two disk-like structures – the thin disk and the thick disk. The thick disk, which envelopes the thin disk, contains about 20% of the Milky Way’s stars and is thought to be the older of the pair based on the composition of its stars (which have greater metallicity) and its puffier nature.

However, in a recent study, a team of 38 scientists led by researchers from Australia’s ARC Centre of Excellence for All Sky Astrophysics in Three Dimensions (ASTRO-3D) used data from the now-retired Kepler mission to measure starquakes in the Milky Way’s disk. From this, they have revised the official estimates on the age of the Milky Way’s thick disk, which they conclude is around 10 billion years old.

September 18, 2019September 18, 2019 by Evan Gough

This Astrophotographer Makes the World Turn and the Sky Stand Still

Photographer Eric Brummel has created a stunning time-lapse of the Milky Way. Time-lapses of the Milky Way are not rare, but Eric has turned convention on its head. Instead of the Milky Way moving across the night sky, it’s the Earth that’s in motion.

August 13, 2019August 13, 2019 by Evan Gough

Milky Way’s Black Hole Just Flared, Growing 75 Times as Bright for a Few Hours

Illustration of the supermassive black hole at the center of the Milky Way. Credit: NRAO/AUI/NSF — Illustration of the supermassive black hole at the center of the Milky Way. It's huge, with over 4 times the mass of the Sun. But ultramassive black holes are even more massive and can contain billions of solar masses. Image Credit: Credit: NRAO/AUI/NSF

Even though the black hole at the center of the Milky Way is a monster, it’s still rather quiet. Called Sagittarius A*, it’s about 4.6 million times more massive than our Sun. Usually, it’s a brooding behemoth. But scientists observing Sgr. A* with the Keck Telescope just watched as its brightness bloomed to over 75 times normal for a few hours.

July 26, 2019July 26, 2019 by Evan Gough

What Did the Early Milky Way Look Like?

The Milky Way 10 billion years ago and the Milky Way today. Image Credit: Gabriel Pérez Díaz, SMM (IAC)

In the very early days of our Universe, just over 13 billion years ago, there was very little structure. There were stars, and they were forming at a rapid rate, kicking off what’s known as the Stelliferous Era. But the enormous, majestic galaxies that we see today, including our Milky Way galaxy, hadn’t formed yet.

June 26, 2019June 26, 2019 by Matt Williams

The Most Efficient Way to Explore the Entire Milky Way, Star by Star

Modelling galactic settlement. Credit: ESA/ACT

It seems like the stuff of dreams, the idea that humanity will one day venture beyond the Solar System and become an interstellar species. Who knows? Given enough time and the right technology (and assuming there’s not some serious competition), we might even be able to colonize the entire Milky Way galaxy someday. And while this seems like a far-off prospect at best, it makes sense to contemplate what a process like this would entail.

That’s what a think tank from the ESA’s Advanced Concepts Team (ACT) managed to do recently. As part of the tenth annual Global Trajectory Optimization Competition (GOTC X), they created a simulation that showed how humanity could optimally colonize the Milky Way. This was in keeping with the competition’s theme of “Settlers of the Galaxy“, which challenged teams to find the most energy-efficient way of settling as many star systems as possible.