The lifecycle of a star is regularly articulated as formation taking place inside vast clouds of gas and dust and then ending either as a planetary nebula or supernova explosion. In the last 70 years however, there seems to be a number of massive stars that are just disappearing! According to stellar evolution models, they should be exploding as supernova but instead, they just seem to vanish. A team of researchers have studied the behaviour of star VFTS 243 – a main sequence star with a black hole companion – and now believe it, like the others, have just collapsed, imploding into a black hole!
Continue reading “Hundreds of Massive Stars Have Simply Disappeared”First Light from Einstein Probe: A Supernova Remnant
On 9 January 2024, the Einstein probe was launched, its mission to study the night sky in X-rays. The first image from the probe that explores the Universe in these energetic wavelengths has just been released. It shows Puppis A, the supernova remnant from a massive star that exploded 4,000 years ago. The image showed the expanding cloud of ejecta from the explosion but now, Einstein will continue to scan the skies for other X-ray events.
Continue reading “First Light from Einstein Probe: A Supernova Remnant”The Brightest Gamma Ray Burst Ever Seen Came from a Collapsing Star
After a journey lasting about two billion years, photons from an extremely energetic gamma-ray burst (GRB) struck the sensors on the Neil Gehrels Swift Observatory and the Fermi Gamma-Ray Space Telescope on October 9th, 2022. The GRB lasted seven minutes but was visible for much longer. Even amateur astronomers spotted the powerful burst in visible frequencies.
It was so powerful that it affected Earth’s atmosphere, a remarkable feat for something more than two billion light-years away. It’s the brightest GRB ever observed, and since then, astrophysicists have searched for its source.
Continue reading “The Brightest Gamma Ray Burst Ever Seen Came from a Collapsing Star”This Supernova Lit Up the Sky in 1181. Here’s What it Looks Like Now
Historical astronomical records from China and Japan recorded a supernova explosion in the year 1181. It was in the constellation Cassiopeia and it shone as bright as the star Vega for 185 days. Modern astronomers took their cue from their long-gone counterparts and have been searching for its remnant.
But it took them time to find it because they were looking for the wrong thing.
Continue reading “This Supernova Lit Up the Sky in 1181. Here’s What it Looks Like Now”Finally, an Explanation for the “String of Pearls” in Supernova 1987A
Not long after the explosion of Supernova 1987a, astronomers were abuzz with predictions about how it might look in a few years. They suggested a pulsar would show up soon and many said that the expanding gas cloud would encounter earlier material ejected from the star. The collision would light up the region around the event and sparkle like diamonds.
Continue reading “Finally, an Explanation for the “String of Pearls” in Supernova 1987A”This is a 1.3 Gigapixel Image of a Supernova Remnant
Stars more massive than the Sun blow themselves to pieces at the end of their life. Usually leaving behind either a black hole, neutron star or pulsar they also scatter heavy elements across their host galaxy. One such star went supernova nearly 11,000 years ago creating the Vela Supernova Remnant. The resultant expanding cloud of debris covers almost 100 light years and would be twenty times the diameter of the full Moon. Astronomers have recently imaged the remnant with a 570 megapixel Dark Energy Camera (DECam) creating a stunning 1.3 gigapixel image.
Continue reading “This is a 1.3 Gigapixel Image of a Supernova Remnant”Finally! Webb Finds a Neutron Star from Supernova 1987A
I can remember seeing images of SN1987A as it developed back in 1987. It was the explosion of a star, a supernova in the Large Magellanic Cloud. Over the decades that followed, it was closely monitored in particular the expanding debris cloud. Predictions suggested there may be a neutron star or even a black hole at the core but the resolution of the telescopes was insufficient to pick anything up. Now we have the James Webb Space Telescope and using its more powerful technology, signs of a neutron star have been detected.
Continue reading “Finally! Webb Finds a Neutron Star from Supernova 1987A”Even if We Can’t See the First Stars, We Could Detect Their Impact on the First Galaxies
For a long time, our understanding of the Universe’s first galaxies leaned heavily on theory. The light from that age only reached us after travelling for billions of years, and on the way, it was obscured and stretched into the infrared. Clues about the first galaxies are hidden in that messy light. Now that we have the James Webb Space Telescope and its powerful infrared capabilities, we’ve seen further into the past—and with more clarity—than ever before.
The JWST has imaged some of the very first galaxies, leading to a flood of new insights and challenging questions. But it can’t see individual stars.
How can astronomers detect their impact on the Universe’s first galaxies?
Continue reading “Even if We Can’t See the First Stars, We Could Detect Their Impact on the First Galaxies”Gravitationally Lensed Supernovae are Another Way to Measure the Expansion of the Universe
Supernova are a fascinating phenomenon and have taught us much about the evolution of stars. The upcoming Nancy Grace Roman telescope will be hunting the elusive combination of supernovae in a gravitational lens system. With its observing field 200 times that of Hubble it stands a much greater chance of success. If sufficient lensed supernovae are found then they could be used to determine the expansion rate of the Universe.
Continue reading “Gravitationally Lensed Supernovae are Another Way to Measure the Expansion of the Universe”Giant Star Seen 150 Days Before it Exploded as a Supernova
Supernovae are relatively rare. It might not seem like it, but that’s because they’re so bright we can see them in other galaxies a great distance away. In fact, in 2022, astronomers spotted a supernova over 10 billion light-years away.
Any time astronomers spot a supernova, it’s an opportunity to learn more about these rare, cataclysmic explosions. It’s especially valuable if astronomers can get a good look at the progenitor star before it explodes.
Continue reading “Giant Star Seen 150 Days Before it Exploded as a Supernova”