WASHINGTON: Astronomers have detected in the stellar halo that represents the Milky Way’s outer limits a group of stars more distant from Earth than any known within our own galaxy — almost halfway to a neighbouring galaxy.
The researchers said these 208 stars inhabit the most remote reaches of the Milky Way’s halo, a spherical stellar cloud dominated by the mysterious invisible substance called dark matter that makes itself known only through its gravitational influence. The furthest of them is 1.08 million light-years from Earth. A light year is the distance light travels in a year, 5.9 trillion miles (9.5 trillion km).
These stars, spotted using the Canada-France-Hawaii Telescope on Hawaii’s Mauna Kea mountain, are part of a category of stars called RR Lyrae that are relatively low mass and typically have low abundances of elements heavier than hydrogen and helium. The most distant one appears to have a mass about 70% that of our sun. No other Milky Way stars have been confidently measured farther away than these.
An undated illustration shows the Milky Way galaxy’s inner and outer halos. A halo is a spherical cloud of stars surrounding a galaxy. NASA, ESA, and A. Feild (STScI).— Reuters
The stars that populate the outskirts of the galactic halo can be viewed as stellar orphans, probably originating in smaller galaxies that later collided with the larger Milky Way.
“Our interpretation about the origin of these distant stars is that they are most likely born in the halos of dwarf galaxies and star clusters which were later merged — or more straightforwardly, cannibalized — by the Milky Way,” said Yuting Feng, an astronomy doctoral student at the University of California, Santa Cruz, who led the study, presented this week at an American Astronomical Society meeting in Seattle.
“Their host galaxies have been gravitationally shredded and digested, but these stars are left at that large distance as debris of the merger event,” Feng added.
The Milky Way has grown over time through such calamities.
“The larger galaxy grows by eating smaller galaxies — by eating its own kind,” said study co-author Raja GuhaThakurta, UC Santa Cruz’s chair of astronomy and astrophysics.
Containing an inner and outer layer, the Milky Way’s halo is vastly larger than the galaxy’s main disk and central bulge that are teeming with stars. The galaxy, with a supermassive black hole at its centre about 26,000 light years from Earth, contains perhaps 100 billion–400 billion stars including our sun, which resides in one of the four primary spiral arms that make up the Milky Way’s disk. The halo contains about 5% of the galaxy’s stars.
Dark matter, which dominates the halo, makes up most of the universe’s mass and is thought to be responsible for its basic structure, with its gravity influencing visible matter to come together and form stars and galaxies.
The halo’s remote outer edge is a poorly understood region of the galaxy. These newly identified stars are almost half the distance to the Milky Way’s neighbouring Andromeda galaxy.
“We can see that the suburbs of the Andromeda halo and the Milky Way halo are really extended — and are almost ‘back-to-back,'” Feng said.
The search for life beyond the Earth focuses on rocky planets akin to Earth orbiting in what is called the “habitable zone” around stars. More than 5,000 planets beyond our solar system, called exoplanets, already have been discovered.
“We don’t know for sure, but each of these outer halo stars should be about as likely to have planets orbiting them as the sun and other sun-like stars in the Milky Way,” GuhaThakurta said.
In order to provide children with technical education and training, Sindh Governor Kamran Tessori has made the decision to set up IT classes for 50,000 children.
The governor urged the youth to play a vital part in the nation’s growth during a ceremony held here on Thursday.
“Pakistan has an abundance of skill. We will have to play our role in the development of the country. We will have to work to improve our economy,” the governor said.
He urged the overseas Pakistanis to invest in Pakistan and play their role in making the country prosperous.
Addressing the youth of the country, Kamran Tessori said, “Pakistan should be our priority. We need to do everything for Pakistan.
The New York-based cybersecurity firm Wiz has discovered a cache of sensitive data from the Chinese artificial intelligence business DeepSeek that was mistakenly exposed to the public internet.
In a blog post released on Wednesday, Wiz reported that examinations of DeepSeek’s infrastructure revealed that the company had inadvertently exposed over a million lines of unencrypted data. The materials were digital software keys and chat logs that seemingly documented prompts transmitted from consumers to the company’s complimentary AI assistant.
The chief technical officer of Wiz stated that DeepSeek promptly safeguarded the data following the notice from his organisation.
“It was removed in under an hour,” stated Ami Luttwak. “However, this was exceedingly easy to locate, leading us to believe we are not the sole discoverers.”
DeepSeek did not promptly respond to a request for comment.
DeepSeek’s rapid success after the introduction of its AI helper has exhilarated China and incited concern in America. The Chinese company’s evident capacity to rival OpenAI’s skills at a significantly reduced cost has raised concerns regarding the viability of the business models and profit margins of U.S. AI behemoths like Nvidia and Microsoft.
By Monday, it surpassed the U.S. competitor ChatGPT in downloads from Apple’s App Store, prompting a worldwide decline in technology stocks.
WhatsApp has initiated testing of a bulk channel administration feature on iOS for select beta users, enabling the simultaneous selection of many channels, hence enhancing the efficiency of managing following channels.
This essential update enables users to perform bulk activities, including muting many channels simultaneously, designating them as read, and altering notifications. If the chosen channels are muted, users will now have the option to activate notifications. Users can swiftly silence unmuted channels in one action.
Additionally, this feature enables users to unfollow many channels simultaneously, thereby optimizing the process of decluttering their channel list. This change is particularly beneficial for users that oversee numerous subscriptions, as reported by WABetaInfo.
Previously, users were required to manage each channel individually, rendering tasks such as muting or designating channels as read laborious and time-consuming.
The functionality provides enhanced flexibility and control over channel subscriptions, enabling users to efficiently manage notifications. The solution streamlines laborious operations for consumers who subscribe to numerous channels, hence enhancing their entire experience.
Accessibility The bulk management feature is presently accessible exclusively to a limited number of beta testers who installed the latest WhatsApp beta for iOS using the TestFlight application. WhatsApp, owned by Meta, plans to expand the feature’s availability to a larger user base in the next weeks.
This update demonstrates WhatsApp’s dedication to enhancing user experience by offering a clear and efficient method for managing channels and notifications.