Month: March 2017

Enlarge / Artist's conception of the black hole in 47 Tucanae X9 siphoning matter off the white dwarf. (credit: NASA/CXC/M.Weiss)

In a study based on new observations from the Chandra X-ray Observatory, NuSTAR and Australia Telescope Compact Array, a team of researchers may have confirmed the presence of a black hole and a white dwarf star in the tightest orbit ever seen.

The system was observed in the 47 Tucanae globular cluster, is located about 16,700 light-years away in our own galaxy, and is the second-brightest globular cluster in the night sky. It’s also the site of the recent discovery of the first intermediate-mass black hole yet found. It’s a fertile ground for studying the role of black holes in globular clusters.

The system in question, 47 Tuc X9, is the brightest X-ray source in 47 Tuc’s core. Researchers initially thought its most massive constituent might be a so-called cataclysmic variable, a system whose brightness regularly increases and decreases. This occurs in a binary pair of stars in which material from the donor star (typically a white dwarf) falls onto the more massive (roughly Sun-mass) star, leading to the increased emissions.

Cisco Systems said that more than 300 models of switches it sells contain a critical vulnerability that allows the CIA to use a simple command to remotely execute malicious code that takes full control of the devices. There currently is no fix.

Cisco researchers said they discovered the vulnerability as they analyzed a cache of documents that are believed to have been stolen from the CIA and published by WikiLeaks two weeks ago.The flaw, found in at least 318 switches, allows remote attackers to execute code that runs with elevated privileges, Cisco warned in an advisory published Friday. The bug resides in the Cisco Cluster Management Protocol (CMP), which uses the telnet protocol to deliver signals and commands on internal networks. It stems from a failure to restrict telnet options to local communications and the incorrect processing of malformed CMP-only telnet options.

"An attacker could exploit this vulnerability by sending malformed CMP-specific telnet options while establishing a telnet session with an affected Cisco device configured to accept telnet connections," the advisory stated. "An exploit could allow an attacker to execute arbitrary code and obtain full control of the device or cause a reload of the affected device."

Enlarge / The 2016 summer minimum extent was the second lowest on record—compared here with the median extent between 1981 and 2010. (credit: NASA Earth Observatory)

Sea ice around Antarctica is very variable from year to year—we've seen the highest winter extents of the last few decades a few years ago, but record low extents have occurred in recent months. Although the trend of shrinking sea ice in the Arctic has been clearer, this doesn’t mean natural variability isn’t significant there, too. In any given year, a few storm systems can bring warm weather or blow sea ice around, deciding whether a new record low is reached. But can some meaningful portion of the Arctic trend over the last 40 years be blamed on longer-term variability?

It’s difficult to tease apart the human-caused and natural effects precisely here, so we haven’t had a great answer to that question. A new study led by the University of California, Santa Barbara’s Qinghua Ding worked out a different way to examine the question, looking for interesting patterns of atmospheric circulation.

The researchers looked for correlations between the summer sea ice low point in September and atmospheric conditions over the preceding summer months. They found a connection between the area of fastest sea ice loss—the Beaufort, Chukhchi, and East Siberian Sea side of the Arctic Ocean—and high-level atmospheric circulation over Greenland and northeastern Canada. High pressure systems in the upper troposphere there cause air to descend as it circles around the Arctic, warming as it comes down to a lower altitude.

Enlarge (credit: C-Span)

FBI Director James Comey said Monday that there was "no information" that President Donald Trump was wiretapped by President Barack Obama during the 2016 presidential election. The director, testifying before a House Permanent Select Committee on Intelligence, also said that the agency was probing whether there was collusion between the Trump campaign and the Russian government. The US intelligence community has suggested that Russia hacked the Democratic National Committee during the election to embarrass Trump's presidential rival, Hillary Clinton.

"I have been authorized by the Department of Justice to confirm that the FBI, as part of our counter-intelligence mission, is investigating the Russian government's efforts to interfere in the 2016 presidential election, and that includes investigating the nature of any links between individuals associated with the Trump campaign and the Russian government, and whether there was any coordination between the campaign and Russia’s efforts. As with any counter-intelligence investigation, this will also include an assessment of whether any crimes were committed," Comey said.

Moments later, in response to a question about Trump's claims on Twitter earlier this month that he was wiretapped by Obama during the election, Comey responded: "The department has no information that supports those tweets."

Gabriel O'Flaherty-Chan

If it's sufficiently fast and has a screen, someone will eventually get an old-school game emulator running on it. Over the weekend, iOS developer Gabriel O'Flaherty-Chan made that happen for the Apple Watch with a Game Boy emulator he calls "Giovanni."

Named for the leader of Team Rocket from the original Pokémon games, Giovanni runs Game Boy and Game Boy Color games on the Apple Watch Series 2 (the Series 1 hardware is presumably capable of the same performance, though the original Apple Watch is likely too slow). O'Flaherty-Chan used the existing Gambatte emulator as Giovanni's core, and then added Apple Watch-friendly controls. There's room for the select, start, and B buttons at the bottom of the screen; you tap the right side of the screen for the A button, while the left side of the screen is mapped to the control pad. Turning the Digital Crown up and down can also simulate the up and down buttons on the control pad.