Welcome to Sott.net
Fri, 09 Dec 2022
The World for People who Think

Strange Skies


Grey Alien

Extraterrestrial signal search is underway using the southern hemisphere's biggest radio telescope

MeerKAT telescope in South Africa,
© Danielle Futselaar / Breakthrough Listen / SARAO
Artist’s impression of the MeerKAT telescope in South Africa, and the Breakthrough Listen compute cluster, scanning the sky for possible signals (represented as binary codes) from extraterrestrial intelligence. One of the first targets to be observed by the new instrument will be the Alpha Centauri system, represented as the three stars towards the top right of the image.
Vanderbijlpark, South Africa - Breakthrough Listen - the initiative to find signs of intelligent life in the universe - announced today, at a conference organized by the South African Radio Astronomy Observatory (SARAO), the start of observations using a powerful new instrument deployed to the MeerKAT radio telescope in the remote Karoo region of South Africa. The new search for technosignatures - indicators of technology developed by extraterrestrial intelligence - expands the number of targets searched by a factor of 1,000.

The astronomers and engineers on the Breakthrough Listen team have spent the last three years developing and installing the most powerful digital instrumentation ever deployed in the search for technosignatures, and integrating the equipment with the MeerKAT control and monitoring systems in cooperation with SARAO engineers. The new hardware complements Listen's ongoing searches using the Green Bank Telescope in the USA, the Parkes Telescope in Australia, and other telescopes around the world. But while Listen's programs at the GBT and Parkes involve moving these thousand-ton-plus dishes to point at targets all over the sky, the program on MeerKAT usually won't mechanically move the antennas.

"MeerKAT consists of 64 dishes, which can see an area of the sky 50 times bigger than the GBT can view at once," explained Breakthrough Listen Principal Investigator Dr. Andrew Siemion. "Such a large field of view typically contains many stars that are interesting technosignature targets. Our new supercomputer enables us to combine signals from the 64 dishes to get high resolution scans of these targets with excellent sensitivity, all without impacting the research of other astronomers who are using the array."

Info

Study investigates a rare type Icn supernova

SN 2022ann
© Davis et al., 2022
Finder charts of SN 2022ann (right) and its host galaxy, SDSS J101729.72–022535.6 (center and left).
An international team of astronomers has conducted optical and near-infrared observations of a rare Type Icn supernova known as SN 2022ann. The results of the study, published November 9 on the preprint server arXiv, shed more light on the nature of this supernova and its unique properties.

Supernovae (SNe) are powerful and luminous stellar explosions. They are important for the scientific community as they offer essential clues into the evolution of stars and galaxies. In general, SNe are divided into two groups based on their atomic spectra: Type I and Type II. Type I SNe lack hydrogen in their spectra, while those of Type II showcase spectral lines of hydrogen.

Type Icn SNe are an extreme subtype of interacting stripped-envelope supernovae (SESN). They have strong, narrow oxygen and carbon lines but weak or absent hydrogen and helium lines, presenting additional complications to the stripping mechanism. They have narrow emission features indicative of circumstellar interaction.

To date, only five Type Icn SNe have been discovered, and SN 2022ann is the latest addition to the short list of this SN subtype. SN 2022ann was detected on January 27, 2022 in the faint host galaxy SDSS J101729.72-022535, at a distance of about 710 million light years.

Info

Machine learning autonomously identify 1,000 supernovae

Supernovae
© California Institute of Technology
Today's astronomical facilities scan the night sky deeper and faster than ever before. Identifying and classifying known and potentially interesting cosmic events is becoming impossible for one or a group of astronomers. Therefore, increasingly they train computers to do the work for them. Astronomers from the Zwicky Transient Facility collaboration at Caltech have announced that their machine-learning algorithm has now classified and reported 1000 supernovae completely autonomously.

"We needed a helping hand and we knew that once we train our computers to do the job, they would take a big load off our backs", says Christoffer Fremling, a staff astronomer at Caltech and the mastermind behind the new algorithm, dubbed SNIascore. "SNIascore classified its first supernova in April 2021 and a year and a half later we are hitting a nice milestone of 1000 supernovae without any human involvement".

Many of the current and most exciting scientific questions that astronomers are trying to answer require them to collect large samples of different cosmic events. As a result, modern astronomical observatories have become relentless data-generating machines that throw tens of thousands of alerts and images at astronomers every night. This is particularly true in the field of time-domain astronomy, in which researchers look for fast-changing objects, or transients, such as exploding and dying stars known as supernovae, black holes eating orbiting stars, asteroids, and more.

"The traditional notion of an astronomer sitting at the observatory and sieving through telescope images carries a lot of romanticism but is drifting away from reality," says Matthew Graham, the ZTF project scientist at Caltech.

Apart from freeing time for astronomers to pursue other science questions, the machine learning algorithm is much faster at classifying potential supernova candidates and sharing the results with the astronomical community. With SNIascore the process is shortened from 2-3 days to about 10 min, or near real-time. Such early identification of cosmic explosions is often critical to better study their physics.

Grey Alien

Prepare for alien encounter now before it's too late, warn scientists

Team at University of St Andrews says Earth needs to work on communicating with extraterrestrials as first contact could happen any day.
Alien Probe
© The Telegraph, UK
An alien probe as depicted in Star Trek.
Aliens could get in touch tomorrow and we must know what to say to them, scientists have warned, as they launched a new research hub to prepare humanity for first contact.

The University of St Andrews has joined forces with the UK SETI (Search for Extraterrestrial Intelligence) Research Network to establish protocols and procedures if aliens are found.

The team warn that although there are measures in place for dealing with threats posed by asteroid impacts, there is no agreed response if a radio signal were picked up from another intelligent lifeform.

The Seti Post-Detection Hub will bring together experts from around the world to decide how to decipher methods, enact space law and anticipate societal impacts.

Dr John Elliott, honorary research fellow in the School of Computer Science at St Andrews and coordinator of the Hub, said: "Will we ever get a message from ET? We don't know. We also don't know when this is going to happen.

"But we do know that we cannot afford to be ill prepared - scientifically, socially, and politically rudderless - for an event that could turn into reality as early as tomorrow and which we cannot afford to mismanage.

"We need to coordinate our expert knowledge not only for assessing the evidence but also for considering the human social response, as our understanding progresses and what we know and what we don't know is communicated. And the time to do this is now."

Info

Polarized x-rays from a magnetar in Cassiopeia constellation observed for the first time

A signature in the X-ray light emitted by a highly magnetised dead star known as a magnetar suggests the star has a solid surface with no atmosphere, according to a new study by an international collaboration co-led by UCL researchers.
Magnetar
© ESO/L. Calçada
Artist’s impression of a magnetar in the star cluster Westerlund 1.
The study, published in the journal Science, uses data from a NASA satellite, the Imaging X-ray Polarimetry Explorer (IXPE), which was launched last December. The satellite, a collaboration between NASA and the Italian Space Agency, provides a new way of looking at X-ray light in space by measuring its polarisation - the direction of the light waves' wiggle.

The team looked at IXPE's observation of magnetar 4U 0142+61, located in the Cassiopeia constellation, about 13,000 light years away from Earth. This was the first time polarised X-ray light from a magnetar had been observed.

Magnetars are neutron stars - very dense remnant cores of massive stars that have exploded as supernovae at the ends of their lives. Unlike other neutron stars, they have an immense magnetic field - the most powerful in the universe. They emit bright X-rays and show erratic periods of activity, with the emission of bursts and flares which can release in just one second an amount of energy millions of times greater than our Sun emits in one year. They are believed to be powered by their ultra-powerful magnetic fields, 100 to 1,000 times stronger than standard neutron stars.

Bizarro Earth

Unexpected solar flare caused radio blackouts in Australia and New Zealand

The flare was accompanied by a coronal mass ejection that missed Earth.
Solar Flare
© NASA Goddard
A past solar flare seen erupting from the sun on June 20, 2013
A surprise solar flare has burst from an area of dense magnetism on the sun's surface, causing a temporary radio blackout in parts of Australia and all of New Zealand.

The M5-class, medium-strength solar flare was recorded by NASA's Solar Dynamics Observatory as it erupted from the sunspot AR3141 at 7:11 p.m. ET on Sunday (Nov. 6). The flare created a rush of radiation that ionized Earth's atmosphere, according to spaceweather.com.

Sunspots are dark regions on the sun's surface where powerful magnetic fields, created by the flow of electrical charges, knot into kinks before suddenly snapping. The resulting release of energy launches bursts of radiation called solar flares and explosive jets of solar material called coronal mass ejections (CMEs). A CME did accompany this flare, but it was not aimed at Earth.

The solar flare erupted unexpectedly and took scientists by surprise. "Our apologies there was no alert for this event. The flare was impulsive," the solar activity tracking website SpaceWeatherLive wrote on Twitter.

The National Oceanic and Atmospheric Administration (NOAA) classifies solar flares in five categories — A, B, C M and X — based on the intensity of the X-rays they release, with each level having 10 times the intensity of the last. TK

Better Earth

Mysterious & unexplained blue auroral phenomenon photographed over Sweden

blue aurora
© Claudio Comi
The blue ribbon over Lake Tornetrask.
Yesterday in Sweden, sky watchers were puzzled when a strange ribbon of blue light appeared during a geomagnetic storm. "It didn't look like any auroras I have ever seen before," says Chad Blakley, the director of Lights over Lapland. One of his tour guides, Miquel Such, video-recorded the phenomenon.

A G1-class geomagnetic storm was underway on Nov. 3rd when the blue ribbon appeared. Webcams saw it first at 1615 UT (5:15 p.m. local Abisko time). It rapidly brightened to naked-eye visibility, then sank below the horizon 30 minutes later. The whole time, regular green auroras danced around and seemingly in front of it: movie [video can be found below]

But what was it?

Comment: A variety of unusual and unexplained phenomena has been appearing in our skies in recent years, with other, formerly rare, activity increasing in both frequency and intensity. Taken together, it's clear that there is a great shift afoot on our planet, part of which is reflected in our changing, cooling, atmosphere: Also check out SOTT radio's:


Fireball 5

Large, 'potentially hazardous' asteroid will zip through Earth's orbit on Halloween

The asteroid's upper size estimate is just short of the world's tallest building.
Asteroid
© Science Photo Library - ANDRZEJ WOJCICKI via Getty Images
An artist's impression of a near-Earth asteroid.
A newly discovered, "potentially hazardous" asteroid almost the size of the world's tallest skyscraper is set to tumble past Earth just in time for Halloween, according to NASA.

The asteroid, called 2022 RM4, has an estimated diameter of between 1,083 and 2,428 feet (330 and 740 meters) — just under the height of Dubai's 2,716-foot-tall (828 m) Burj Khalifa, the tallest building in the world. It will zoom past our planet at around 52,500 mph (84,500 km/h), or roughly 68 times the speed of sound.

At its closest approach on Nov. 1, the asteroid will come within about 1.43 million miles (2.3 million kilometers) of Earth, around six times the average distance between Earth and the moon. By cosmic standards, this is a very slender margin.

NASA flags any space object that comes within 120 million miles (193 million km) of Earth as a "near-Earth object" and classifies any large body within 4.65 million miles (7.5 million km) of our planet as "potentially hazardous." Once flagged, these potential threats are closely watched by astronomers, who study them with radar for signs of any deviation from their predicted trajectories that could put them on a devastating collision course with Earth.

Info

Lost star catalog of ancient times comes to light

Technology may have revealed a piece of the long-lost works of Greek astronomer Hipparchus, one of the greatest astronomers of antiquity.
Ancient Star Catalogue
© Peter Malik
Historians have found what appears to be a piece of an ancient star catalog in a folio from the Codex Climaci Rescriptus, shown here.
Around 130 BC, the great Greek astronomer Hipparchus drew up the very first star catalog ever, containing descriptions and coordinates of some 850 naked-eye stars in the northern sky.

At least, that's what later sources say - copies of Hipparchus's list have never been found. Until now, that is. Writing in the Journal of the History of Astronomy, three European scientists claim to have uncovered a small part of the long-lost catalog. "I felt nothing short of awe when I first heard about it," says astronomy historian and writer William Sheehan.

In the 2nd century AD, Claudius Ptolemy compiled a catalog of 1,025 stars in 48 constellations to include in his magnum opus, Almagest. Ptolemy also hinted at the existence of an earlier listing, some scholars have suggested that Ptolemy's work was based not on his own observations but on Hipparchus's catalog.

Hipparchus was born around 190 BC in Nicaea, in what is now northwestern Turkey, but he carried out most of his astronomical work on the island of Rhodes. He made the first estimates of the distances and sizes of the Moon and the Sun, and was the first to discover precession: the slow wobble in the orientation of the Earth's spin axis. According to astronomy historian Bradley Schaefer (Louisiana State University), Hipparchus was "arguably the best and greatest astronomer in the world before Copernicus."

"Only one of his many books, The Commentaries, has survived," says Schaefer, "with the most important loss being his influential star catalog." That's why scientists are elated about the new find. "It [...] illuminates a crucial moment in the birth of science, when astronomers shifted from simply describing the patterns they saw in the sky to measuring and predicting them," astronomy historian James Evans (University of Puget Sound, Washington) told Nature.

Peter Williams (Cambridge University, UK) and Victor Gysembergh and Emmanuel Zingg (Sorbonne University, Paris) studied the Codex Climaci Rescriptus, a 9th- or 10th-century manuscript from the Saint Catherine's Monastery on the Sinai peninsula in Egypt. The codex, which is now kept at the Museum of the Bible in Washington, D.C., contains Christian texts in Syriac.

Cassiopaea

Red Alert: massive stars sound warning they are about to go supernova

Supergiant star Betelgeuse
© European Southern Observatory/L. Calçada
This artist’s impression shows the supergiant star Betelgeuse as it was revealed thanks to different state-of-the-art techniques on ESO’s Very Large Telescope (VLT), which allowed two independent teams of astronomers to obtain the sharpest ever views of the supergiant star Betelgeuse. They show that the star has a vast plume of gas almost as large as our Solar System and a gigantic bubble boiling on its surface. These discoveries provide important clues to help explain how these mammoths shed material at such a tremendous rate.
Astronomers from Liverpool John Moores University and the University of Montpellier have devised an 'early warning' system to sound the alert when a massive star is about to end its life in a supernova explosion. The work was published in Monthly Notices of the Royal Astronomical Society.

In this new study, researchers determined that massive stars (typically between 8 and 20 solar masses) in the last phase of their lives, the so-called 'red supergiant' phase, will suddenly become around a hundred times fainter in visible light in the last few months before they die. This dimming is caused by a sudden accumulation of material around the star, which obscures its light.