milky way galaxy Archives

April 7, 2020 by Matt Williams

WFIRST Will Use Relativity to Find More Exoplanets!

Using the microlensing metthod, a team of astrophysicists have found the first extra-galactic planets! Credit: NASA/Tim Pyle

In 2025, NASA’s next-generation telescope, the Wide-Field Infrared Survey Telescope (WFIRST), will take to space and join in the search for extrasolar planets. Between its 2.4-meter (8 ft) telescope, 18 detectors, 300-megapixel camera, and the extraordinary survey speed it will offer, the WFIRST will be able to scan areas of the sky a hundred times greater than the Hubble Space Telescope.

Beyond its high-sensitivity and advanced suite of instruments, WFIRST will also rely on a technique known as Gravitational Microlensing to search for and characterize exoplanets. This is essentially a small-scale version of the gravitational lensing technique, where the gravitational force of a massive object between the observer and the target is used to focus and magnify the light coming from a distant source.

March 4, 2020March 4, 2020 by Matt Williams

The Disk of the Milky Way is Warped Because it Already Collided With Another Galaxy

Credit and Copyright: Stefan Payne-Wardenaar; Magellanic Clouds: Robert Gendler/ESO

For decades, astronomers have been trying to understand why the Milky Way galaxy is warped the way it is. In recent years, astronomers have theorized that it could be our neighbors, the Magellanic Clouds, that are responsible for this phenomenon. According to this theory, these dwarf galaxies pull on the Milky Way’s dark matter, causing oscillations that pull on our galaxy’s supply of hydrogen gas.

However, according to new data from the European Space Agency’s (ESA) star-mapping Gaia Observatory, it is possible that this warp is the result of an ongoing collision with a smaller galaxy. These findings confirm that the warp in our galaxy is not static, but subject to change over time (aka. precession), and that this process is happening faster than anyone would have thought!

January 18, 2020January 18, 2020 by Matt Williams

More Mysterious Space Blobs Have Been Found Near the Center of the Milky Way

Artist’s impression of G objects, with the reddish centers, orbiting the supermassive black hole at the center of our galaxy. The black hole is represented as a dark sphere inside a white ring (above the middle of the rendering). Credit: Jack Ciurlo

At the center of our galaxy lies a region where roughly 10 million stars are packed into just 1 parsec (3.25 light-years) of space. At the center of this lies the supermassive black hole (SMBH) known as Sagittarius A*, which has a mass of over 4 million Suns. For decades, astronomers have been trying to get a better look at this region in the hopes of understanding the incredible forces at work and how they have affected the evolution of our galaxy.

What they’ve found includes a series of stars that orbit very closely to Sagittarius A* (like S1 and S2), which have been used to test Einstein’s Theory of General Relativity. And recently, a team from UCLA’s Galactic Center Orbits Initiative detected a series of compact objects that also orbit the SMBH. These objects look like clouds of gas but behave like stars, depending on how close they are in their orbits to Sagittarius A*.

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 11, 2019December 15, 2019 by Matt Williams

This Galaxy Has Been Home to 5 Supernovae in the Last 20 Years

Some of the most dramatic events in the Universe occur when certain stars die — and explode catastrophically in the process. Such explosions, known as supernovae, mainly occur in a couple of ways: either a massive star depletes its fuel at the end of its life, become dynamically unstable and unable to support its bulk, collapses inwards, and then violently explodes; or a white dwarf in an orbiting stellar couple syphons more mass off its companion than it is able to support, igniting runaway nuclear fusion in its core and beginning the supernova process. Both types result in an intensely bright object in the sky that can rival the light of a whole galaxy. In the last 20 years the galaxy NGC 5468, visible in this image, has hosted a number of observed supernovae of both the aforementioned types: SN 1999cp, SN 2002cr, SN2002ed, SN2005P, and SN2018dfg. Despite being just over 130 million light-years away, the orientation of the galaxy with respect to us makes it easier to spot these new ‘stars’ as they appear; we see NGC 5468 face on, meaning we can see the galaxy’s loose, open spiral pattern in beautiful detail in images such as this one from the NASA/ESA Hubble Space Telescope.

When stars die, they don’t die quietly but prefer to go out with a bang! This is known as a supernova, which occurs when a star has expended all of its fuel and undergoes gravitational collapse. In the process, the outer layers of the star will be blown off in a massive explosion visible from billions of light-years away. For decades, NASA has been monitoring galaxies beyond the Milky Way and detected numerous supernova taking place.

For instance, over the past 20 years, the Hubble Space Telescope has been monitoring the galaxy NGC 5468 – an intermediate spiral galaxy located roughly 130 million light-years from Earth in the constellation Virgo. In that time, this galaxy has experienced 5 supernovae and, thanks to its orientation (perpendicular to our own), astronomers have been able to study this galaxy and its supernovae in glorious detail.

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.

October 3, 2019October 4, 2019 by Matt Williams

Earth, Solar System, Milky Way. Are they Getting More or Less Massive Over Time?

Artist's impression of the Milky Way Galaxy. Credit: ESO

According to the most widely-accepted cosmological models, the first galaxies began to form between 13 and 14 billion years ago. Over the course of the next billion years, the cosmic structures we’ve all come to know emerged. These include things like galaxy clusters, superclusters, and filaments, but also galactic features like globular clusters, galactic bulges, and Supermassive Black Holes (SMBHs).

However, like living organisms, galaxies have continued to evolve ever since. In fact, over the course of their lifetimes, galaxies accrete and eject mass all the time. In a recent study, an international team of astronomers calculated the rate of inflow and outflow of material for the Milky Way. Then the good folks at astrobites gave it a good breakdown and showed just how relevant it is to our understanding of galactic formation and evolution.

July 17, 2019July 17, 2019 by Matt Williams

Gaia Mission is Mapping Out the Bar at the Center of the Milky Way

Credit: Data: ESA/Gaia/DPAC, A. Khalatyan(AIP) & StarHorse team; Galaxy map: NASA/JPL-Caltech/R. Hurt (SSC/Caltech)

Despite the many advancements made in the field of astronomy, astronomers still struggle to get an accurate assessment of the Milky Way Galaxy. Because we are embedded in its disk, it is much more difficult to assess its size, structure, and extent – unlike galaxies located millions (or billions) of light-years away. Luckily, thanks to improved instruments and tireless efforts, progress is being made all the time.

For instance, a team of astronomers recently combined the latest data obtained by the ESA’s Gaia observatory with the infrared and optical observations of other telescopes to start mapping the bar-shaped collection of stars at the center of our Milky Way. This constitutes the first time in history that astronomers have been able to make direct measurements of this barred structure.

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.