Oct 16, 2017

In detecting star collision for first time, astronomers see a new era

An artist's depiction of neutron star merger. Credit: NSF / LIGO / Sonoma State University / A. Simonnet

Scientists announced today they've detected the collision of two neutron stars 130 million years ago. It's the first time one of the massive mergers has been witnessed, and that light detected with telescopes has been combined with gravitational waves detection to observe a cosmic event.

What it means: "This result provides definitive evidence for the first time that heavy elements like platinum and gold, are produced in these collisions," David Reitze, executive director of the LIGO Laboratory, whose founders will collect the Nobel Prize in physics this year. The so-called "multi-messenger astronomy" allows researchers to view events in both light and sound, and will be used to better understand the structure of stars, the rate of expansion of the universe and other fundamental questions in physics.

What they saw: 130 million years ago, two dense neutron stars — with masses 1.6 and 1.1 times those of our sun crammed into about 10-mile-wide spaces — merged. The highly energetic event sent ripples across space and time that physicists working with the Laser Interferometer Gravitational-Wave Observatory (LIGO) and Virgo detectors observed on Aug. 17, 2017. The collision, which occurred relatively close to Earth, released high-energy, gamma-ray light that was also then seen by 70 optical, X-ray, radio, ultraviolet, infrared, and gamma-ray telescopes around the world and in space over the following days.

What's next: Dozens of papers are being published today by the more than 3500 researchers involved in the work. The LIGO and Virgo detectors have finished their current run and will be offline for a year while researchers try to optimize them. "[They are] currently working at a fraction of their sensitivity. We expect to increase the overall network sensitivity by about a factor of 2," said LIGO spokesperson David Shoemaker. That would open up 8 times more space for surveying and, they hope, observing other events like supernovae.

Go deeper: Quanta's Katia Moskvitch has the play-by-play of the detection.

Go deeper

The growing coronavirus recession threat

Illustration: Aïda Amer/Axios

In just a matter of weeks, top economists and investment bank analysts have gone from expecting the coronavirus outbreak to have minimal impact on the U.S. economy to warning that an outright recession may be on the horizon.

What's happening: The spread of confirmed coronavirus cases in Europe, the Middle East and the U.S., and the speed at which they are being discovered has set the table for the outbreak to have a larger and much costlier impact.

Mass shooting in Milwaukee: What we know

Milwaukee Mayor Tom Barrett in 2012. Photo: John Gress/Corbis via Getty Images

Six people died in a shooting at the Molson Coors Brewing Company in Milwaukee on Wednesday, including the gunman, Mayor Tom Barrett told reporters at a Wednesday evening press conference with local police.

Details: All of the victims worked at the brewery complex, as did the shooter who died of "an apparent self-inflicted gunshot wound," police confirmed in a statement late Wednesday.

Go deeperArrowUpdated 8 hours ago - Politics & Policy

Coronavirus updates: South Korea case count tops 2,000

Data: The Center for Systems Science and Engineering at Johns Hopkins, the CDC, and China's Health Ministry. Note: China numbers are for the mainland only and U.S. numbers include repatriated citizens.

33 people in California have tested positive for the coronavirus, and health officials are monitoring 8,400 people who have recently returned from "points of concern," Gov. Gavin Newsom said Thursday.

The big picture: COVID-19 has killed more than 2,850 people and infected over 83,000 others in some 50 countries and territories. The novel coronavirus is now affecting every continent but Antarctica, and the WHO said Wednesday the number of new cases reported outside China has exceeded those inside the country for the first time.

Go deeperArrowUpdated 8 hours ago - Health