galaxies Archives

January 25, 2021January 25, 2021 by Andy Tomaswick

An Active Galaxy That Erupts Predictably Every 114 Days Or So

Computers are known for their ability to spot patterns. It’s what they are good at, and over the last 50+ years they have continued to improve. But they only know how to spot patterns if they know where to look for them in data. So sometimes, it falls to a human to truly see a pattern that no one expected to be there.

That is exactly what happened in the case of the discovery of the most consistent active galaxy yet discovered. Anna Payne, a graduate student at the University of Hawai’i at Manoa, was looking into data collected by the All Sky Automated Survey for Supernovae (ASAS-SN), and notice a strange feature about one of its galaxies, known as ESO 253-3: it was getting significantly brighter every 114 days.

January 23, 2021January 23, 2021 by Matthew Cimone

The Universe in Formation. Hubble Sees 6 Examples of Merging Galaxies

Newly released collage of six galaxy mergers used in the HiPEEC survey. Top Row Left to Right: NGC 3256, 1614, 4195 Bottom Row Left To Right: NGC 3690, 6052, 34 - Credit ESA/Hubble/NASA

^{Audio narration by the author is available above}

10 billion years ago, galaxies of the Universe were ablaze with the light of newly forming stars. This epic phase of history is known as “Cosmic Noon” – the height of all star creation. Galaxies like our Milky Way aren’t creating stars at nearly the rates they were in the ancient past. However, there is a time when galaxies in the present can explode with star formation – when they collide with each other. This recently published collage of merging galaxies by the Hubble HiPEEC survey (Hubble imaging Probe of Extreme Environments and Clusters) highlights six of these collisions which help us understand star formation in the early Universe.

January 11, 2021January 11, 2021 by Paul M. Sutter

This is the Fireworks Galaxy. It’s had ten Supernovae in the Last Century Alone

NGC 6946, also known as the Fireworks Galaxy due to the stupendous number of active supernovae. Image credit: ESA/Hubble & NASA, A. Leroy, K.S. Long

Say hello to NGC 6946, otherwise known as the Fireworks Galaxy. This little galaxy is the most prolific producer of supernovae in the known universe, popping off those incredible explosions roughly once a decade. It’s secret? An incredibly high rate of star formation.

November 30, 2020November 30, 2020 by Paul M. Sutter

Astronomers find a galaxy that had its dark matter siphoned away

Artist rendering of possible dark matter emissions from the Milky Way. Credit: Christopher Dessert, Nicholas L. Rodd, Benjamin R. Safdi, Zosia Rostomian (Berkeley Lab)

The galaxy NGC 1052-DF4 surprised scientists by having almost no dark matter to complement its stellar population. Recently a team of astronomers has provided an explanation: a nearby galaxy has stripped NGC 1052-DF4 of its dark matter, and is currently in the process of destroying the rest of it too.

November 17, 2020November 19, 2020 by Paul M. Sutter

The family tree of the Milky Way. The mergers that gave us the galaxy we see today

An edge-on view of a spiral galaxy. Credit: ESO

Galaxies build themselves up slowly over time by cannibalizing their neighbors. Using an advanced suite of computer simulations, researchers have now traced back the evolutionary history of our own Milky Way.

November 16, 2020November 16, 2020 by Matt Williams

New Horizons Saw the Universe With Even Less Light Pollution than Hubble’s View

Artist's impression of New Horizons' close encounter with the Pluto–Charon system. Credit: NASA/JHU APL/SwRI/Steve Gribben

In July of 2015, NASA’s New Horizons probe made history when it became the first mission ever to conduct a close flyby of Pluto. This was followed by the spacecraft making the first-ever encounter with a Kuiper Belt Object (KBO) – known as Arrokoth (aka. 2014 MU69) – on Dec.31st, 2018. In addition, its unique position in the outer Solar System has allowed astronomers to conduct rare and lucrative science operations.

This has included parallax measurements of Proxima Centauri and Wolf 359, the two closest stars to the Solar System. In addition, a team of astronomers led by the National Optical Astronomy Observatory (NOAO) and Southwest Research Institute (SwRI) used archival data from the probe’s Long Range Reconnaissance Imager (LORRI) to conduct measurements of the Cosmic Optical Background (COB).

October 30, 2020October 30, 2020 by Evan Gough

Galaxies Grew Quickly and Early On in the Universe

Artist's illustration of a galaxy in the early universe that is very dusty and shows the first signs of a rotationally supported disk. In this image, the red color represents gas, and blue/brown represents dust as seen in radio waves with ALMA. Many other galaxies are visible in the background, based on optical data from VLT and Subaru. Credit: B. Saxton NRAO/AUI/NSF, ESO, NASA/STScI; NAOJ/Subaru

The behaviour of galaxies in the early Universe attracts a lot of attention from researchers. In fact, everything about the early Universe is under intense scientific scrutiny for obvious reasons. But unlike the Universe’s first stars, which have all died long ago, the galaxies we see around us—including our own—have been here since the early days.

Current scientific thinking says that in the early days of the Universe, the galaxies grew slowly, taking billions of years to become what they are now. But new observations show that might not be the case.

September 30, 2020September 30, 2020 by Nancy Atkinson

A Galaxy has been Found That’s as Bright as a Quasar… But it’s Not a Quasar

Image of the region of the sky containing BOSS-EUVLG1 and artist`s drawing of the burst of star formation in BOSS-EUVLG1. Credit: DESI Legacy Imaging Surveys/Gabriel Pérez Díaz, SMM (IAC).

Astronomers have found a new type of galaxy that is very old, very distant and very bright in ultraviolet light. This is somewhat an unusual combination, and so when this bright galaxy was first detected, the team of researchers who found it first thought it was a quasar. But detailed study revealed it was actually a galaxy with some other unusual features, which contributes to its brightness: it is busy with star formation, it has almost no dust.

As of now, this galaxy – with the license plate-type name of BOSS-EUVLG1 – appears to be the only one of its kind.

September 26, 2020September 26, 2020 by Evan Gough

Gaia has Already Given Us 5 New Insights Into the Milky Way

The ESA's Gaia mission is currently on a five-year mission to map the stars of the Milky Way. Gaia has found evidence for a galactic collision that occurred between 300 million and 900 million years ago. Image credit: ESA/ATG medialab; background: ESO/S. Brunier.

The European Space Agency launched the Gaia mission in 2013. The mission’s overall goal was to discover the history of the Milky Way by mapping out the positions and velocities of one billion stars. The result is kind of like a movie that shows the past and the future of our galaxy.

The mission has released two separate, massive data sets for researchers to work through, with a third data release expected soon. All that data has spawned a stream of studies into our home galaxy.

Recently, the ESA drew attention to five new insights into the Milky Way galaxy. Allof these discoveries directly stemmed from the Gaia spacecraft.

September 14, 2020September 14, 2020 by Brian Koberlein

Small Amounts of Dark Matter are Creating Much Stronger Gravitational Distortions than Anyone Expected to See

A mosaic of telescopic images showing the galaxies of the Virgo Supercluster. It's part of the cosmic web in which a galaxy can exist during part of its evolution. Credit: NASA/Rogelio Bernal Andreo

Dark matter is difficult for astronomers to study, but that doesn’t keep them from trying. And with skill and determination, they continue to find exciting things about the invisible stuff.