Gamma Ray Bursts Archives

March 24, 2022March 24, 2022 by Brian Koberlein

New Radio Images of Bizarre “Odd Radio Circles” Which are Vastly Bigger Than the Milky Way

Artist depiction of an Odd Radio Circle. Credit: CSIRO

In radio astronomy, circle-shaped objects are fairly common. Since diffuse ionized gas often emits radio light, objects such as supernova remnants, planetary nebulae, and even star-forming regions can create circular arcs of diffuse gas. But in 2019 astronomers began to discover radio circles they couldn’t explain, in part because they are so large.

July 13, 2021July 12, 2021 by Paul M. Sutter

Exploding Material From a Gamma-ray Burst Scrambled Nearby Magnetic Fields

Artist’s impression of a gamma-ray burst shining through two young galaxies in the early Universe. Credit: ESO

A team of astronomers has found that giant, organized magnetic fields can help drive some of the most powerful explosions in the universe. But when all is said and done, the shock wave from that blast scrambles any magnetic fields in a matter of minutes.

April 8, 2021April 8, 2021 by Brian Koberlein

An Intermediate-Mass Black Hole Discovered Through the Gravitational Lensing of a Gamma-ray Burst

An intermediate mass black hole lenses light around it. Credit: Carl Knox, OzGrav

Black holes come in three sizes: small, medium, and large. Small black holes are of stellar mass. They form when a large star collapses at the end of its life. Large black holes lurk in the centers of galaxies and are millions or billions of solar masses. Middle-sized black holes are those between 100 to 100,000 solar masses. They are known as Intermediate Mass Black Holes (IMBHs), and they are the kind we least understand.

November 18, 2020November 18, 2020 by Brian Koberlein

Astronomers think they’ve seen a magnetar form for the first time; the collision of two neutron stars

Artist view of a kilonova producing a magnetar. Credit: NASA, ESA, and D. Player (STScI)

A magnetar is a neutron star with a magnetic field thousands of times more powerful than those of typical neutron stars. Their fields are so strong that they can generate powerful, short-duration events such as soft gamma repeaters and fast radio bursts. While we have learned quite a bit about magnetars in recent years, we still don’t understand how neutron stars can form such intense magnetic fields. But that could soon change thanks to a new study.

September 27, 2020June 20, 2023 by Matt Williams

Beyond “Fermi’s Paradox” X: What is the Firstborn Hypothesis?

Artist's impression of an exoplanet orbiting a low-mass star. Credit: ESO/L. Calçada

Welcome back to our Fermi Paradox series, where we take a look at possible resolutions to Enrico Fermi’s famous question, “Where Is Everybody?” Today, we examine the possibility that the reason for the Great Silence is that we are “early to the party”!

In 1950, Italian-American physicist Enrico Fermi sat down to lunch with some of his colleagues at the Los Alamos National Laboratory, where he had worked five years prior as part of the Manhattan Project. According to various accounts, the conversation turned to aliens and the recent spate of UFOs. Into this, Fermi issued a statement that would go down in the annals of history: “Where is everybody?“

This became the basis of the Fermi Paradox, which refers to the disparity between high probability estimates for the existence of extraterrestrial intelligence (ETI) and the apparent lack of evidence. Since Fermi’s time, there have been several proposed resolutions to his question, which includes the Firstborn Hypothesis that states that humanity could be the first intelligent life to emerge in our galaxy.

May 29, 2020May 29, 2020 by Evan Gough

A New Kind of Supernova Explosion has been Discovered: Fast Blue Optical Transients

Artist's conception illustrates the differences in phenomena resulting from an "ordinary" core-collapse supernova explosion, an explosion creating a gamma-ray burst, and one creating a Fast Blue Optical Transient. Credit: Bill Saxton, NRAO/AUI/NSF

For the child inside all of us space-enthusiasts, there might be nothing better than discovering a new type of explosion. (Except maybe bigger rockets.) And it looks like that’s what’s happened. Three objects discovered separately—one in 2016 and two in 2018—add up to a new type of supernova that astronomers are calling Fast Blue Optical Transients (FBOT).

March 23, 2020 by Matt Williams

NASA Chooses 4 New Astronomy Space Missions for Additional Study

Hot stars burn brightly in this image from NASA's Galaxy Evolution Explorer, showing the ultraviolet side of a familiar face. At approximately 2.5 million light-years away, the Andromeda galaxy, or M31, is our Milky Way's largest galactic neighbor. The entire galaxy spans 260,000 light-years across -- a distance so large, it took 11 different image segments stitched together to produce this view of the galaxy next door. The bands of blue-white making up the galaxy's striking rings are neighborhoods that harbor hot, young, massive stars. Dark blue-grey lanes of cooler dust show up starkly against these bright rings, tracing the regions where star formation is currently taking place in dense cloudy cocoons. Eventually, these dusty lanes will be blown away by strong stellar winds, as the forming stars ignite nuclear fusion in their cores. Meanwhile, the central orange-white ball reveals a congregation of cooler, old stars that formed long ago. When observed in visible light, Andromeda's rings look more like spiral arms. The ultraviolet view shows that these arms more closely resemble the ring-like structure previously observed in infrared wavelengths with NASA's Spitzer Space Telescope. Astronomers using Spitzer interpreted these rings as evidence that the galaxy was involved in a direct collision with its neighbor, M32, more than 200 million years ago. Andromeda is so bright and close to us that it is one of only ten galaxies that can be spotted from Earth with the naked eye. This view is two-color composite, where blue represents far-ultraviolet light, and orange is near-ultraviolet light.

Since 1958, the NASA Explorer Program has conducted low-cost missions that were deemed relevant to the goals of the Science Mission Directorate (SMD), particularly where the study of our Sun and the deeper cosmic mysteries are concerned. Recently, the Explorer Program selected four missions that they considered to be well-suited to these goals, two of which will be selected for launch in the coming years.

Consisting of two astrophysics Small Explorer (SMEX) and two Missions of Opportunity (MO) proposals, these missions are designed to study cosmic explosions and the debris they leave behind, as well as monitor how nearby stellar flares may affect the atmospheres of orbiting planets. After detailed evaluations, two of these missions will be selected next year and will take to space sometime in 2025.

January 15, 2020January 16, 2020 by Matt Williams

It Takes Two Stars to Make a Gamma Ray Burst

Artist’s impression of gamma-ray burst with orbiting binary star. Credit: University of Warwick/Mark Garlick

In 1967, NASA scientists noticed something they had never seen before coming from deep space. In what has come to be known as the “Vela Incident“, multiple satellites registered a Gamma-Ray Burst (GRB) that was so bright, it briefly outshined the entire galaxy. Given their awesome power and the short-lived nature, astronomers have been eager to determine how and why these bursts take place.

Decades of observation have led to the conclusion that these explosions occur when a massive star goes supernova, but astronomers were still unsure why it happened in some cases and not others. Thanks to new research by a team from the University of Warwick, it appears that the key to producing GRBs lies with binary star systems – i.e. a star needs a companion in order to produce the brightest explosion in the Universe.

September 11, 2019September 11, 2019 by Evan Gough

Hubble Has Looked at the 2017 Kilonova Explosion Almost a Dozen Times, Watching it Slowly Fade Away

An artistic rendering of two neutron stars merging. Credit: NSF/LIGO/Sonoma State/A. Simonnet

In 2017, LIGO (Laser-Interferometer Gravitational Wave Observatory) and Virgo detected gravitational waves coming from the merger of two neutron stars. They named that signal GW170817. Two seconds after detecting it, NASA’s Fermi satellite detected a gamma ray burst (GRB) that was named GRB170817A. Within minutes, telescopes and observatories around the world honed in on the event.

The Hubble Space Telescope played a role in this historic detection of two neutron stars merging. Starting in December 2017, Hubble detected the visible light from this merger, and in the next year and a half it turned its powerful mirror on the same location over 10 times. The result?

The deepest image of the afterglow of this event, and one chock-full of scientific detail.

November 22, 2018 by Matt Williams

Massive Triple Star System Creates this Bizarre Swirling Pinwheel of Dust. And it Could be the Site of a Gamma Ray Burst

The VISIR instrument on ESO’s VLT captured this stunning image of a newly-discovered massive binary star system. Nicknamed Apep after an ancient Egyptian deity, it could be the first gamma-ray burst progenitor to be found in our galaxy. Apep’s stellar winds have created the dust cloud surrounding the system, which consists of a binary star with a fainter companion. With 2 Wolf-Rayet stars orbiting each other in the binary, the serpentine swirls surrounding Apep are formed by the collision of two sets of powerful stellar winds, which create the spectacular dust plumes seen in the image. The reddish pinwheel in this image is data from the VISIR instrument on ESO’s Very Large Telescope (VLT), and shows the spectacular plumes of dust surrounding Apep. The blue sources at the centre of the image are a triple star system — which consists of a binary star system and a companion single star bound together by gravity. Though only two star-like objects are visible in the image, the lower source is in fact an unresolved binary Wolf-Rayet star. The triple star system was captured by the NACO adaptive optics instrument on the VLT. Credit: ESO/Callingham et al.

When stars reach the end of their lifespan, many undergo gravitational collapse and explode into a supernova, In some cases, they collapse to become black holes and release a tremendous amount of energy in a short amount of time. These are what is known as gamma-ray bursts (GRBs), and they are one of the most powerful events in the known Universe.

Recently, an international team of astronomers was able to capture an image of a newly-discovered triple star system surrounded by a “pinwheel” of dust. This system, nicknamed “Apep”, is located roughly 8,000 light years from Earth and destined to become a long-duration GRB. In addition, it is the first of its kind to be discovered in our galaxy.

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