Archiv: electromagnetic radiation


15.11.2019 - 18:07 [ Tuan Do, Astronomer at UCLA ‏/ Twitter ]

Here’s a timelapse of images over 2.5 hr from May from @keckobservatory of the supermassive black hole Sgr A*. The black hole is always variable, but this was the brightest we’ve seen in the infrared so far. It was probably even brighter before we started observing that night!

15.11.2019 - 18:04 [ arxiv.org ]

Unprecedented variability of Sgr A* in NIR

(05.08.2019)

The electromagnetic counterpart to the Galactic center supermassive black hole, Sgr A*, has been observed in the near-infrared for over 20 years and is known to be highly variable. We report new Keck Telescope observations showing that Sgr A* reached much brighter flux levels in 2019 than ever measured at near-infrared wavelengths. In the K$^\prime$ band, Sgr A* reached flux levels of $\sim6$ mJy, twice the level of the previously observed peak flux from $>13,000$ measurements over 130 nights with the VLT and Keck Telescopes. We also observe a factor of 75 change in flux over a 2-hour time span with no obvious color changes between 1.6 $\mu$m and 2.1 $\mu$m.

15.11.2019 - 18:00 [ universetoday.com ]

Milky Way’s Black Hole Just Flared, Growing 75 Times as Bright for a Few Hours

(13.08.2019)

Even though the black hole at the center of the Milky Way is a monster, it’s still rather quiet. Called Sagittarius A*, it’s about 4.6 million times more massive than our Sun. Usually, it’s a brooding behemoth. But scientists observing Sgr. A* with the Keck Telescope just watched as its brightness bloomed to over 75 times normal for a few hours.

15.11.2019 - 17:47 [ arxiv.org ]

The large-scale ionization cones in the Galaxy

(05.10.2019)

Our time-dependent Seyfert flare models adequately explain the observations and indicate the Seyfert flare event took place T_o = 3.5 +/- 1 Myr ago.

15.11.2019 - 17:32 [ ScienceAlert.com ]

Something in The Centre of Our Galaxy Colossally Erupted 3.5 Million Years Ago

(06.10.2019)

In 2013, astrophysicist Joss Bland-Hawthorn of the University of Sydney and the ARC Centre of Excellence for All Sky Astrophysics in 3 Dimensions (ASTRO 3D) and colleagues estimated that the event occurred between 1 and 3 million years ago.

Now, more observations taken using the Hubble Space Telescope – and therefore a bigger dataset – have provided even more compelling evidence for the event. And the team has been able to narrow down a timeframe for both when the event occurred, as well as its duration.

15.11.2019 - 17:29 [ arxiv.org ]

Fossil imprint of a powerful flare at the Galactic Centre along the Magellanic Stream

(21.09.2013)

Thus it is likely that the Stream emission arose from a `Seyfert flare‘ that was active 1-3 Myr ago, consistent with the cosmic ray lifetime in the Fermi bubbles. Sgr A* activity today is greatly suppressed (70-80 dB) relative to the Seyfert outburst…

15.11.2019 - 17:16 [ Forbes ]

The Milky Way’s Supermassive Black Hole Erupted Two Million Years Ago

(25.09.2013)

The key the astronomers found was actually discovered 20 years old, in the form of a strange glow that astronomers had noticed in the Magellanic Stream. The Magellanic Stream is composed of large clouds of gas – mostly hydrogen – that stretch for light years in the wake of the Milky Way’s two companion Galaxies, the Large and Small Magellanic Clouds. The Stream is about 2 billion years old.

„We didn’t understand the cause. Then suddenly we realised it must be the mark, the fossil record, of a huge outburst of energy from the centre of our Galaxy,“ remarked researcher Joss Bland-Hawthorn in a press release.

02.08.2019 - 17:56 [ theGuardian.com ]

Pentagon testing mass surveillance balloons across the US

The FCC documents show that Southcom’s balloons are carrying small, satellite-like vehicles housing sophisticated sensors and communication gear. One of those sensors is a synthetic aperture radar intended to detect every car or boat in motion on a 25-mile swath beneath the balloon.

The balloons also have advanced mesh networking technologies that allow them to communicate with one another, share data and pass it to receivers on the ground below.

13.07.2019 - 16:40 [ EOS.org ]

The Thermosphere Responds to a Weaker Than Normal Solar Cycle

The cooling near solar minimum is natural and specific to the thermosphere. The cooling thermosphere does not affect the troposphere, the layer of the atmosphere closest to Earth’s surface where people live. The temperatures we experience on the ground do not get colder because of this solar cycle. NASA and other climate researchers continue to see a warming trend in the troposphere. These two effects are ongoing but unrelated.

Nitric oxide and carbon dioxide play important roles in cooling the thermosphere.

16.06.2019 - 11:31 [ Christina H Koch, current resident of the International @Space_Station / Twitter ]

Years ago at the South Pole, I looked up to the aurora for inspiration through the 6-month winter night. Now I know they’re just as awe inspiring from above. #nofilter

(10.06.2019)

30.05.2019 - 15:49 [ Harvard.edu ]

Cosmic-ray volleys from the Galactic Center and their recent impact on the earth environment

Authors: Laviolette, P. A.
Journal: Earth, Moon, and Planets (ISSN 0167-9295), vol. 37, March 1987, p. 241-286.

29.04.2019 - 10:50 [ Phys.org ]

Rapid destruction of Earth-like atmospheres by young stars

(24.04.2019)

The high energy radiation is important because it is absorbed high in the atmosphere of a planet, causing the gas to be heated. For the Earth, the gas is heated to temperatures of more than 1000 degrees Celsius in the upper region known as the thermosphere. This is the region in which spacecraft such as satellites and the International Space Station fly. When orbiting young stars with high activity levels, the thermospheres of planets are heated to much higher temperatures which, in extreme cases, can cause the gas to flow away from the planet.

06.03.2019 - 14:09 [ cnet.com ]

Google looks to leave passwords behind for a billion Android devices

(25.2.2019) Google and the Fast Identity Online Alliance said Monday that Android is now FIDO2-certified, meaning its devices can use fingerprints and security keys for logging in to accounts instead of passwords. The certification was unveiled at Mobile World Congress in Barcelona, Spain.

06.03.2019 - 14:03 [ Wikipedia ]

FIDO Alliance

FIDO supports a full range of authentication technologies, including biometrics such as fingerprint and iris scanners, voice and facial recognition, as well as existing solutions and communications standards, such as Trusted Platform Modules (TPM), USB security tokens, embedded Secure Elements (eSE), smart cards, and near field communication (NFC).[2] The USB security token device may be used to authenticate using a simple password (e.g. four-digit PIN) or by pressing a button.

06.03.2019 - 14:00 [ theRegister.co.uk ]

Microsoft: You looking at me funny? Oh, you just want to sign in

(21.11.2018) Microsoft’s corporate veep of all things identity, Alex Simons, trumpeted that the 800 million people who use a Microsoft account will now be able to sign in without username or password.

06.03.2019 - 13:54 [ cbronline.com ]

Android Gets FIDO2 Support: Death to Passwords?

(28.2.2019) The FIDO2 standard comprises the World Wide Web Consortium’s (W3C) Web Authentication specification and the corresponding Client to Authenticator Protocol (CTAP) from FIDO Alliance. Together these initiatives create an ecosystem of compliant devices that can easily authenticate themselves to online services.

03.03.2019 - 13:16 [ Wikipedia ]

The Thing (listening device)

The Thing, also known as the Great Seal bug, was one of the first covert listening devices (or „bugs“) to use passive techniques to transmit an audio signal. It was concealed inside a gift given by the Soviet Union to W. Averell Harriman, the United States Ambassador to the Soviet Union, on August 4, 1945. Because it was passive, needing electromagnetic energy from an outside source to become energized and activate, it is considered a predecessor of Radio-Frequency Identification (RFID) technology.

03.03.2019 - 12:48 [ theRegister.co.uk ]

Met lab claims ‚biggest breakthrough since Watergate‘: Power lines act as police informers

(1.6.2010) ENF relies on frequency variations in the electricity supplied by the National Grid. Digital devices such as CCTV recorders, telephone recorders and camcorders that are plugged in to or located near the mains pick up these deviations in the power supply, which are caused by peaks and troughs in demand. Battery-powered devices are not immune to to ENF analysis, as grid frequency variations can be induced in their recordings from a distance.

At the Metropolitan Police’s digital forensics lab in Penge, south London, scientists have created a database that has recorded these deviations once every one and a half seconds for the last five years.

13.02.2019 - 12:56 [ National Security Agency ]

TEMPEST: A Signal Problem

(1972) Now, let´s go back to the beginning. During World War II, the backbone systems for Army und Navy secure teletypewriter communications were one-time tapes and the primitive crypto-equipment SIGTOT. For encrypting, the Services used a Bell-telephone mixing device, called 131-B2. When one of these mixers was being tested in a Bell laboratory, a researcher noticed, quite by accident, that each time the machine stepped, a spike appeared on an oscilloscope in a distant part of the lab. After he examined these spikes more carefully, he found that he could read the plain text of the message being enciphered by the machine.

13.02.2019 - 12:44 [ Wim van Eck / radio-utopie.de ]

Electromagnetic Radiation from Video Display Units: An Eavesdropping Risk?

(1985) In February, 1985, we carried out an eavesdropping experiment in London, in cooperation with the British Broadcasting Corporation. Part of the results were shown in the programme „Tomorrow’s World.“ A small van was equipped with a 10 metre high pump mast to which a VHF band III antenna was clamped (10 dB gain). The received signal was fed through an antenna, amplified (18 dB) and displayed on a television screen inside the van.

For obvious reasons we cannot give information on the data picked up during the experiment. The results can be
summarized as follows:

• It is possible to eavesdrop on the video display units or terminals in buildings from a large distance, using a car fitted up for the purpose.

• Although the experiment was carried out in broad daylight and many people watched us, nobody asked what we were doing.

13.02.2019 - 12:38 [ Universität Tel Aviv ]

Stealing Keys from PCs using a Radio: Cheap Electromagnetic Attacks on Windowed Exponentiation

(April 2015) Q1: What information is leaked by the electromagnetic emanations from computers?

This depends on the specific computer hardware. We have tested numerous laptop computers, and found the following:
In almost all machines, it is possible to tell, with sub-millisecond precision, whether the computer is idle or performing operations.
On many machines, it is moreover possible to distinguish different patterns of CPU operations and different programs.
Using GnuPG as our study case, we can, on some machines:
distinguish between the spectral signatures of different RSA secret keys (signing or decryption), and fully extract decryption keys, by measuring the laptop’s electromagnetic emanations during decryption of a chosen ciphertext.

03.11.2018 - 20:34 [ WikiLeaks / Twitter ]

What are the effects of refugee publisher @JulianAssange being exposed to eighteen signal jammers (3 clusters, six antennas per cluster) in a confined space 24/7 for seven months? This paper offers a glimpse

03.11.2018 - 20:32 [ Journal of Biomedial Physics & Engineering ]

Exposure to Radiofrequency Radiation Emitted from Common Mobile Phone Jammers Alters the Pattern of Muscle Contractions: an Animal Model Study

These findings support early reports which indicated a wide variety of non-thermal effects of electromagnetic radiation on amphibians including the effects on the pattern of muscle extractions.

26.07.2018 - 14:51 [ National Security Agency ]

TEMPEST: A Signal Problem

(1972) Now, let´s go back to the beginning. During World War II, the backbone systems for Army und Navy secure teletypewriter communications were one-time tapes and the primitive crypto-equipment SIGTOT. For encrypting, the Services used a Bell-telephone mixing device, called 131-B2. When one of these mixers was being tested in a Bell laboratory, a researcher noticed, quite by accident, that each time the machine stepped, a spike appeared on an oscilloscope in a distant part of the lab. After he examined these spikes more carefully, he found that he could read the plain text of the message being enciphered by the machine.

26.07.2018 - 14:42 [ Wikipedia ]

The Thing (listening device)

The Thing, also known as the Great Seal bug, was one of the first covert listening devices (or „bugs“) to use passive techniques to transmit an audio signal. It was concealed inside a gift given by the Soviets to the US Ambassador to Moscow on August 4, 1945. Because it was passive, being energized and activated by electromagnetic energy from an outside source, it is considered a predecessor of RFID technology.