Hubble finds the first black hole hiding in the Omega Centauri star cluster

the gist

Omega Centauri is a massive globular cluster of stars, and astronomers expected it to contain many black holes left by exploded stars. Evidence for them had been scarce for years. Using archival data from the Hubble Space Telescope along with observations from the James Webb Space Telescope, a team has now identified its first stellar-mass black hole. The discovery helps confirm that the cluster likely holds a larger hidden population of such objects.

so what

The find strengthens the idea that dense star clusters hide many black holes that are hard to detect. It also shows how combining archival and new observations from different telescopes can answer long-standing questions.

more on this

background

Omega Centauri (ω Cen, NGC 5139, or Caldwell 80) is a globular cluster in the constellation of Centaurus that was first identified as a non-stellar object by Edmond Halley in 1677. Located at a distance of 17,090 light-years (5,240 parsecs), it is the largest known globular cluster in the Milky Way at a diameter of roughly 150 light-years. It is estimated to contain approximately 10 million stars, with a total mass of 4 million solar masses, making it the most massive known globular cluster in the Milky Way.

Omega Centauri is very different from most other galactic globular clusters to the extent that it is thought to have originated as the core remnant of a disrupted dwarf galaxy. There is evidence of an intermediate-mass black hole in the dense core of this cluster, although this is disputed.

From Wikipedia: Omega Centauri (CC BY-SA 4.0) ↗

see

ESO, CC BY 4.0, via Wikimedia Commons

Pablo Carlos Budassi, CC BY-SA 4.0, via Wikimedia Commons

KPNO/NOIRLab/NSF/AURA/Blythe Guvenen, CC BY 4.0, via Wikimedia Commons

ESA/Hubble · CC BY 4.0

Image: ESA/Hubble

source: ESA/Hubble ↗

historyWikipediaclassic1336–1565 · Karnataka, India

Hampi was once one of the world's largest cities, until its Vijayanagara capital was destroyed in 1565

the gist

Hampi is a UNESCO World Heritage Site in Karnataka, India, with more than 1,600 surviving remains spread over 4,100 hectares. It was the capital of the Vijayanagara Empire from 1336 to 1565. Travellers from Persia and Portugal described it as a prosperous, wealthy and grand city with temples, markets and farms along the Tungabhadra River. By 1500 it was estimated to be the world's second-largest city after Beijing, and probably India's richest at the time. In 1565 a coalition of Muslim sultanates defeated the Vijayanagara Empire, its capital was conquered and destroyed, and the city was left in ruins. Hampi remains a religious centre, with the active Virupaksha Temple at its heart.

how it works

The city was built around a fortified core with temples, markets and water structures along the river, supplied by an extensive network of roads and waterworks. When the empire fell, the city was not rebuilt, so its stone monuments were left standing.

so what

Hampi shows how quickly a great city can vanish after a military defeat, and how a ruined capital can remain sacred. Its ruins give historians a view of medieval South Asia that few other sites can match.

fun fact

The name Hampi comes from Pampa, an old name for the Tungabhadra River.

From Wikipedia, the free encyclopedia · text CC BY-SA 4.0

Image: Wikimedia Commons

source: Wikipedia ↗

2 min

politicsshortCNA2:01

False allegations about Singapore’s hand in Indonesia’s markets and a made-up meeting

from CNA

CNA Verify has found close to 400 posts pushing falsehoods tying Singapore to Indonesia’s stock market rout and to a secret meeting that never took place. Together, they drew nearly 12 million views, and some were circulated by accounts that appeared to be working in concert, across multiple social media platforms.

Here’s how the disinformation campaign targeting Singapore was uncovered.

on YouTube: CNA ↗