A brilliant flash of blue light briefly outshined its host galaxy before fading away — but then it exploded again, and again.
On September 7, 2022, an automatic telescope picked up a blazing dot of blue light some 1,000 times brighter than a typical supernova. The brilliant blue flare lasted only days before it faded away, but not before an automated system had put astronomers on alert.

The system designated the event AT2022tsd, but it some came to be called the "Tasmanian Devil." It joined the short list of a special class of objects discovered in 2018 known as luminous fast blue optical transients (LFBOTs). Astronomers think these explosive flares are a special kind of supernova, but they could also be stars ripped apart in the intense gravitational field surrounding a neutron star or black hole. The devil, as they say, is in the details.

But while the Tasmanian Devil's discovery was a welcome surprise, the real bombshell came 100 days later. In December that year, Anna Ho (Cornell University) and colleagues were reviewing routine images that had monitored the fading flare when, to their bewilderment, they found a red-colored burst almost as bright as the original blue one, and in the same position on the sky.

Scouring for more data, both in the archive and then with new observations, the astronomers found another outburst — and then another, and another. The energy of each one of these outbursts is equivalent to that released from an exploding star. Overall, at least 14 flares followed the first one, Ho and colleagues report in Nature, and it's likely there were many more they missed.

"An event like this has never been witnessed before," says team member Jeff Cooke (Swinburne University of Technology and the ARC Centre of Excellence in Gravitational Wave Discovery, Australia).

"Indeed, optical flares following an explosive transient like the Tasmanian Devil — with luminosity similar to supernovae, but only lasting a minute or two — are a completely new (and unexpected) discovery," agrees Ashley Chrimes (ESA), who wasn't involved with the study.

Astronomers from the Liverpool John Moores University have performed photometric and spectroscopic observations of a recently discovered nova, known as AT 2023prq. Results of the observational campaign, published in the November issue of the Research Notes of the American Astronomical Society (AAS), shed more light on the nature of this nova.

A nova is a star experiencing a sudden increase in brightness and slowly returning to its original state, a process that could last many months. Such an outburst, which releases an immense amount of energy, is the result of the accretion process in a close binary system containing a white dwarf and its companion. Studying novae is crucial in advancing our knowledge about fundamental astrophysical processes, including stellar evolution.

AT 2023prq (other designation ZTF23aaxzvrr) was detected by the Zwicky Transient Facility (ZTF) on August 15, 2023, in the halo of the Andromeda galaxy (or Messier 31, M31). It had an r′-band magnitude of 17.13 and shortly after its detection, follow-up observations of this nova commenced in order to get more insights into its properties.

Astronomers Michael Healy-Kalesh and Daniel Perley from the Liverpool John Moores University in Liverpool, UK, were among the first to observe AT 2023prq after it was identified. They used the Liverpool Telescope (LT) and various other ground-based facilities to monitor the nova until the end of August 2023.

WHAT ARE MYSTERIOUS 'BRIGHT NIGHTS'?

A phenomenon rarely seen in centuries might have just appeared in the night sky over Colorado--a "Bright Night." Philosophers and scientists have reported Bright Nights for literally thousands of years. It's when an otherwise dark and moonless night fills with a soft glow, allowing observers to see distant mountains or read a newspaper. Pliny the Elder, an Army commander in ancient Rome, described the phenomenon as a "nocturnal sun" (~ 113 BCE).


In the modern world, Bright Nights are seldom seen. Most of our planet's human population lives in cities, and even rural landscapes are somewhat lit by distant urban bulbs. The "nocturnal sun" has been overwhelmed.

Or has it? Enter Aaron Watson, an experienced night-sky photographer who regularly visits the darkest of dark-sky sites in remote parts of Colorado. On multiple occasions this year he has photographed red auroras and green airglow invisible from any ordinary countryside. Last month, he was at one of his favorite inky-dark sites when he may have experienced a modern Bright Night.

In 2023, amateur astronomer Dana Patchick was looking through images from the Wide-field Infrared Survey Explorer archive and discovered a diffuse, circular object in the constellation of Cassiopeia. He found this apparent nebula was interesting because it was bright in the infrared portion of the spectrum, but virtually invisible in the colors of light visible to our eyes. Dana added this item to the database of the Deep Sky Hunters amateur astronomers group, believing it was a planetary nebula - the quiet remnant of stars in mass similar to the sun. He named it PA 30.

However, professional astronomers who picked it up from there realized that this object is far more than it first seemed. It is, they now believe, the remnant of a lost supernova observed in 1181. And an extremely rare type at that.

The Guest Star

In early August of 1181 CE, a "guest star" appeared in the constellation we now know as Cassiopeia. To the Chinese astronomers of the time, it was known as Chuanshe. They, and Japanese astronomers recorded the appearance of the star and state that it remained visible for 185 days, unmoving with respect to other stars.

In 1971, astronomers first realized that this "guest star" was almost certainly a supernova due to how long it remained visible in the night sky. This made the initial observation an extremely rare reporting of a historical supernova.

Supernovae are believed to occur, on average, about once per century in galaxies like the Milky Way but, because they may be obscured if they are on the far side of the galaxy and obscured by the heavy dust lanes, not all will be visible to us. Ultimately, this made SN 1181 one of less than a dozen suspected supernovae in recorded history prior to the rise of modern astronomy. And of those, only four had been conclusively tied to an observational remnant. While astronomers are confident that these historical supernovae were indeed supernovae, without having an identified remnant, it is impossible to determine the type of supernovae.

Previously, SN 1181 had been potentially associated with a pulsar known as 3C 58, but attempts at determining the age of this object suggested it was far too old to be associated with the Chinese records.

Every now and then a comet or asteroid comes to our solar system from interstellar space. We have observed two interstellar objects in recent years, Oumuamua in 2017, and Borisov in 2019. One would assume then that in the past at least some interstellar objects have struck Earth. But we've never found an interstellar meteorite. A new study argues that this is because the Oort cloud is much more active than we thought.

The Oort cloud is a halo of icy material on the outermost edge of the solar system, where the Sun's gravity is barely strong enough to hold them in a stellar orbit. When another star passes somewhat near the Sun, members of the Oort cloud can be nudged toward the inner solar system, where they can become long-period comets. We have never observed the Oort cloud, but we know it's there because comets can approach the Sun from every direction, not just the orbital plane of the planets.

Astronomers can distinguish between Oort cloud objects and interstellar objects by their orbits. Interstellar objects have a hyperbolic orbit, meaning that if you traced their path purely under the gravitational influence of the Sun, it would continue on to interstellar space, never to return. Oort cloud objects, on the other hand, have an orbital path that is closed. They may travel to the most distant region of space, but they are gravitationally bound to the Sun.

WHAT JUST HAPPENED?

Two CMEs hit Earth over the weekend--one on Saturday, Nov. 4th, another on Sunday, Nov. 5th. The double blow sparked a strong G3-class geomagnetic storm with auroras as far south as Colorado (+40.1N) and Texas (+33.6N). The storm is now subsiding with isolated periods of minor G1-class storming expected through Nov. 6th. Aurora alerts: SMS Text

NOT ALL THE LIGHTS WERE AURORAS

At the apex of the storm, bright lights danced across the skies of northern Europe. Not all the lights were auroras. "To our utter amazement we observed a striking phenomenon," reports Martin McKenna of Swatragh, N. Ireland. "It was STEVE!"

"We were blown away by the intensity of the purple beam," continues McKenna."We could see it plainly with the naked eye, swelling and flickering in brilliance with delicate structures like those seen within a feather. My mate Conor likened it to a celestial funnel cloud or tornado changing form in real time."

Alaskans and visitors may be able to see an artificial airglow in the sky created by the High-frequency Active Auroral Research Program during a four-day research campaign that starts Saturday.

Scientists from the University of Alaska Fairbanks, Cornell University, University of Colorado Denver, University of Florida and Georgia Institute of Technology will conduct a variety of experiments at the UAF-operated research site.

The experiments will focus on the ionosphere, the region of the atmosphere between about 30 and 350 miles above the Earth's surface.

Scientists will investigate ionosphere mechanisms that cause optical emissions. They'll also try to understand whether certain plasma waves — gas so hot that electrons get knocked off atoms — amplify other very low frequency waves. And they'll investigate how satellites can use plasma waves in the ionosphere for collision detection and avoidance.

Each day, the airglow could be visible up to 300 hundred miles from the HAARP facility in Gakona. The site lies about 200 miles northeast of Anchorage and 230 miles southeast of Fairbanks, or about 300 to 350 kilometers.

HAARP creates airglow by exciting electrons in Earth's ionosphere, similar to how solar energy creates natural aurora, with on and off pulses of high-frequency radio transmissions. HAARP's Ionospheric Research Instrument, a phased array of 180 high-frequency antennas spread across 33 acres, can radiate 3.6 megawatts into the upper atmosphere and ionosphere.

The airglow, if visible, will appear as a faint red or possibly green patch. Because of the way the human eye operates, the airglow might be easier to see when looking just to the side.

In the heart of Wood Green, a forgotten suburban corner of North London, lay a dingy room steeped in shadows, where a solo hacker wasted no time to wash, shave, meet anyone, or sometimes even eat. He had just accessed classified military and NASA networks, where UFO Research and secret technologies were hidden.

Gary McKinnon got his first computer at age 14. It was the Atari 400, which proved to be a capable device for learning to write code in Basic. Inspired by the movie WarGames, where Matthew Broderick acted as a young hacker breaching into the Pentagon, McKinnon left school at 17, worked as a hairdresser, and later found sporadic work in tech support.

And he was dying to find out what critical information about UFOs the US government was hiding.

"I got interested in them when I saw one," McKinnon said in one interview. "A very decent light in the sky."

Between 2001 and 2002, around the time when the 9/11 attacks happened, he managed to infiltrate 97 military and NASA computers and wreak complete havoc in the US government's systems.

Countless late-night hacking sessions trying to reveal dark secrets forever changed his life, filling it with rejection, accusations, horrors, and even more unanswered questions. Are we really not alone in this seemingly vastly empty cosmic space?

Accused of perpetrating "the biggest military computer hack of all time," in 2002, McKinnon faced extradition to the US, decades in jail, and millions in fines.

On July 19, 1952, Palomar Observatory was undertaking a photographic survey of the night sky. Part of the project was to take multiple images of the same region of sky, to help identify things such as asteroids. At around 8:52 that evening a photographic plate captured the light of three stars clustered together. At a magnitude of 15, they were reasonably bright in the image. At 9:45 pm the same region of sky was captured again, but this time the three stars were nowhere to be seen. In less than an hour they had completely vanished.

Stars don't just vanish. They can explode, or experience a brief period of brightness, but they don't vanish. And yet, the photographic proof was there. The three stars are clearly in the first image, and clearly not in the second. The assumption then is that they must have suddenly dimmed, but even that is hard to accept. Later observations found no evidence of the stars to dimmer than magnitude 24. This means they likely dimmed by a factor of 10,000 or more. What could possibly cause the stars to dim by such an astounding amount so quickly?

One idea is that they are not three stars, but one. Perhaps a star happened to brighten for a short time, such as a fast radio burst from a magnetar. While this happened, perhaps a stellar-mass black hole passed between it and us, causing the flare to gravitationally lens as three images for a brief time. The problem with this idea is that such an event would be exceedingly rare, but other photographic images taken during the 1950s show similar rapid disappearances of multiple stars. In some cases, the stars are separated by minutes of arc, which would be difficult to produce by gravitational lensing.

New artificial intelligence tool removes humans from entire search, discovery process.
A fully automated process, including a brand-new artificial intelligence (AI) tool, has successfully detected, identified and classified its first supernova.

Developed by an international collaboration led by Northwestern University, the new system automates the entire search for new supernovae across the night sky — effectively removing humans from the process. Not only does this rapidly accelerate the process of analyzing and classifying new supernova candidates, it also bypasses human error.

The team alerted the astronomical community to the launch and success of the new tool, called the Bright Transient Survey Bot (BTSbot), this week. In the past six years, humans have spent an estimated total of 2,200 hours visually inspecting and classifying supernova candidates. With the new tool now officially online, researchers can redirect this precious time toward other responsibilities in order to accelerate the pace of discovery.

"For the first time ever, a series of robots and AI algorithms has observed, then identified, then communicated with another telescope to finally confirm the discovery of a supernova," said Northwestern's Adam Miller, who led the work. "This represents an important step forward as further refinement of models will allow the robots to isolate specific subtypes of stellar explosions. Ultimately, removing humans from the loop provides more time for the research team to analyze their observations and develop new hypotheses to explain the origin of the cosmic explosions that we observe."

"We achieved the world's first fully automatic detection, identification and classification of a supernova," added Northwestern's Nabeel Rehemtulla, who co-led the technology development with Miller. "This significantly streamlines large studies of supernovae, helping us better understand the life cycles of stars and the origin of elements supernovae create, like carbon, iron and gold."

Miller is an assistant professor of physics and astronomy at Northwestern's Weinberg College of Arts and Sciences and a member of the Center for Interdisciplinary Exploration and Research in Astrophysics (CIERA). Rehemtulla is an astronomy graduate student in Miller's research group.