Skip to main content

Featured post

Online sales can generate 780,000 service opportunities in Pakistan.

Nearest black hole to Earth discovered

Astronomers have a new candidate in their search for the nearest black hole to Earth.
It's about 1,000 light-years away, or roughly 9.5 thousand, million, million km, in the Constellation Telescopic.
That might not sound very close, but on the scale of the Universe, it's actually right next door.
Scientists discovered the black hole from the way it interacts with two stars - one that orbits the hole, and the other that orbits this inner pair.
Normally, black holes are discovered from the way they interact violently with an accrediting disc of gas and dust. As they shred this material, copious X-rays are emitted. It's this high-energy signal that telescopes detect, not the black hole itself.
So this is an unusual case, in that it's the motions of the stars, together known as HR 6819, that have given the game away.
"This is what you might call a 'dark black hole'; it's truly black in that sense," said Dietrich Baade, emeritus astronomer at the European Southern Observatory (ESO) organisation in Garching, Germany.
"We think this may be the first such case where a black hole has been found this way. And not only that - it's also the most nearby of all black holes, including the accreting ones," he told BBC News.
One of the fascinating aspects of this story is that it's possible see HR 6819 with just the naked eye - assuming you have access to the southern sky. No telescope or binoculars are needed, although conditions are tricky at the moment because the star system is only now emerging from behind the Sun.
Scientists had begun the study of HR 6819 many years ago when looking for what's termed a Be star. This is a star that rotates so rapidly that it nearly tears itself apart, and the outer object in this pairing is a good example.
But a series of circumstances meant the investigation was never carried through to completion - until very recently.
Studies using the 2.2m telescope at La Silla Observatory in Chile reveal the inner of the two visible stars to be orbiting an unseen object every 40 days.
Presumed to be a black hole, this object has a likely mass of at least four times that or our Sun.
Astronomers have spotted only a couple of dozen black holes in our Milky Way Galaxy to date, nearly all of which strongly interact with their accretion discs.
But statistics tell us there must be many, many more out there.
"In the Milky Way, the idea is that there should be about 100 million black holes. So there should be perhaps a couple more that are closer by still," Marianne Heida, a postdoctoral fellow at ESO, told BBC News

Comments

Popular posts from this blog

NCC meeting will decide future of lockdown this week

ISLAMABAD - Minister for Planning, Development and Reforms, Asad Umar on Sunday said the National Coordination Committee on Corona-virus would decide about the future course of lock-down after analysis and observations to be presented by National Command and Operation Centre (NCOC). The meeting would be held this week with Prime Minister Imran Khan in the chair, to decide the post-May, 9 scenarios in the country. Addressing a televised press briefing here, Asad Umar said the NCOC would share all its analysis about corona-virus in the meeting of NCC. “We do not follow the West blindly and the future decisions would also be taken according to our own ground realities,” he remarked. He said keeping in view the growing number of deaths in the country, the people should adopt strict protective measures against COVID-19. He said for the last six days, on average, 24 people were dying of the disease daily but still, the disease had not proven to be as chronic as in Europe and the ...

IAF MiG-29 crashes near Hoshiarpu in Punjab

HOSHIARPUR - An Indian Air Force (IAF) fighter jet has crashed in Punjab today (Friday). According to media reports, the Russian made fighter jet has reportedly crashed in the Rurkee Kalan village in Hoshiarpur district of Punjab, however, the pilots ejected before the plane went down. As per reports, after the mayday situation, the pilots crashed the plane in an open field. The aircraft had developed a technical snag and the pilot ejected safely as he was unable to control the aircraft. The pilot has been rescued by a helicopter. A court of inquiry has been ordered to investigate the cause of accident," the IAF said.

Indian troops martyr key freedom activist in occupied Kashmir

SRINAGAR - In occupied Kashmir, Indian forces martyred one of top freedom activists Riyaz Naikoo and his associate Aadil Ahmed during a cordon and search operation in Pulwama district, on Wednesday. Naikoo, who is considered as successor of Burhan Muzzafar Wani, was gunned down by Indian troops during a "fake encounter" in his native village at Beighpora Awantipore in the district last night. According to Kashmir Media services, the authorities have suspended mobile internet services in the entire occupied territory and curfew like restrictions have been imposed. The 22-year-ol Wani was killed on July 8, 2016, in what many human rights defenders see as an extrajudicial killing.