Astronomers find 72 bright and fast explosions

Gone in a (cosmological) flash: a team of astronomers found 72 very bright, but quick events in a recent survey and are still struggling to explain their origin. Miika Pursiainen of the University of Southampton will present the new results on Tuesday 3 April at the European Week of Astronomy and Space Science.

The scientists found the transients in data from the Dark Energy Survey Supernova Programme (DES-SN). This is part of a global effort to understand dark energy, a component driving an acceleration in the expansion of the Universe.

DES-SN uses a large camera on a 4-metre telescope in the Cerro Tololo Inter-American Observatory (CTIO) in the Chilean Andes. The survey looks for supernovae, the explosion of massive stars at the end of their lives. A supernova explosion can briefly be as bright as a whole galaxy, made up of hundreds of billions of stars.

Pursiainen and his collaborators found the largest number of these quick events to date. Even for transient phenomena, they are very peculiar: while they have a similar maximum brightness to different types of supernovae they are visible for less time, from a week to a month. In contrast supernovae last for several months or more.

The events appear to be both hot, with temperatures from 10,000 to 30,000 degrees Celsius, and large ranging in size from several up to a hundred times the distance from Earth to Sun (the Earth is 150 million kilometres from the Sun). They also seem to be expanding and cooling as they evolve in time, as would be expected from an exploding event such as a supernova.

There is still debate on the origin of these transients. One possible scenario is that the star sheds a lot of material before a supernova explosion, and in extreme cases could be completely enveloped by a shroud of matter.

The supernova itself may then heat the surrounding material to very high temperatures. In this case astronomers see the hot cloud rather than the exploding star itself. To confirm any of this, the team will need a lot more data.

Pursiainen comments: "The DES-SN survey is there to help us understand dark energy, itself entirely unexplained. That survey then also reveals many more unexplained transients than seen before. If nothing else, our work confirms that astrophysics and cosmology are still sciences with a lot of unanswered questions!"

For the future, the team plan to continue their search for transients, and estimate how often they take place compared with more 'routine' supernovae.

Related Links
Royal Astronomical Society
Stellar Chemistry, The Universe And All Within It

Tweet

Thanks for being there;
We need your help. The SpaceDaily news network continues to grow but revenues have never been harder to maintain.

With the rise of Ad Blockers, and Facebook - our traditional revenue sources via quality network advertising continues to decline. And unlike so many other news sites, we don't have a paywall - with those annoying usernames and passwords.

Our news coverage takes time and effort to publish 365 days a year.

If you find our news sites informative and useful then please consider becoming a regular supporter or for now make a one off contribution.

SpaceDaily Monthly Supporter
$5+ Billed Monthly

paypal only

SpaceDaily Contributor
$5 Billed Once

credit card or paypal

A Runaway Star in the Small Magellanic Cloud
Flagstaff AZ (SPX) Mar 30, 2018
Astronomers have discovered a rare "runaway" star that is speeding across its galaxy at 300,000 miles per hour (at that speed it would take about half a minute to travel from Los Angeles to New York). The runaway star (designated J01020100-7122208) is located in the Small Magellanic Cloud, a close neighbor of the Milky Way Galaxy, and is believed to have once been a member of a binary star system. When the companion star exploded as a supernova, the tremendous release of energy flung J010201 ... read more