Something Really Wants our Attention. One Object Released 1,652 Fast Radio Bursts in 47 Days
The energetic phenomena known as Fast Radio Bursts (FRBs) are one of the greatest cosmic mysteries today. These mysterious flashes of light are visible in the radio wave part of the spectrum and usually last only a few milliseconds before fading away forever. Since the first FRB was observed in 2007, astronomers have looked forward to the day when instruments of sufficient sensitivity would be able to detect them regularly.
That day has arrived with the completion of the 500-Meter FAST Radio Telescope (aka. Tianyan, “Eye of Heaven”). Since it commenced operations, this observatory has vastly expanded the number of detected FRBs. In fact, according to research led by the National Astronomical Observatories of the Chinese Academy of Sciences (NAO/CAS), the observatory detected a total of 1,652 independent bursts from a single source in 47 days.
The research, which recently appeared in the journal Science, was conducted by researchers from the Commensal Radio Astronomy FAST Survey (CRAFTS) project. CRAFTS includes researchers from the Cornell Center for Astrophysics and Planetary Science, the Max-Planck-Institut für Radioastronomie, the Commonwealth Scientific and Industrial Research Organisation (CSIRO), and multiple universities in China, Australia, and the U.S.
To break this phenomenon down, FBRs are highly energetic, producing a year’s worth of Solar output in the space of milliseconds. In rare cases, astronomers have found bursts that were repeating in nature, which has allowed them to conduct follow-up studies. While the origin of these bursts is still unknown, possible explanations range from hyper-magnetized neutron stars and black holes to cosmic strings left over from the Big Bang and even alien transmissions!
This exotic explanation is especially appealing where repeating FRBs are concerned, as repetition lends itself to artificial explanations. This includes the signal designated FRB 121102, which was originally detected in 2012 and is the first known repeater and the first well-localized FRB. Not only has this signal been traced to a dwarf galaxy 3 billion light-years away, but it is repeatedly bursting at pretty regular intervals.
Previous observations determined that it repeats on a 157-day cycle that consists of a 67-day inactive phase, followed by a 90-day period where it would repeatedly emit intense radio flares. In recent years, Pei Wang and the many institutions participating in the FAST telescope project have monitored FRB 121102’s and recorded several repeating bursts – one that consisted of 20 pulses in one day and another where 12 bursts were observed in two hours.
From these, Wang and his colleagues were able to refine estimates of FRB 121102’s cycle, which they now place at 156.1 days. But when they examined the backend data obtained by FAST during its commissioning phase, they noticed that FRB 121102 experienced a truly energetic period of activity. During the three months, running from Aug. 29th to Oct. 29th, 2019, FAST detected no less than 1,652 independent bursts in 59.5 hours spanning 47 days.
The Green Bank Telescope monitoring the galaxy for Fast Radio Bursts (FRBs). Credit: UC Berkeley
While the rate of radio pulses varied throughout this time, a record 122 bursts occurred during the peak hour – the highest event rate ever observed from an FRB. Based on the detected bursts, the researchers determined that they have a peak energy equivalence of 480 Nonillion (4.8 × 1037) ergs at 1.25 GHz, below which the detection of bursts is suppressed. As Dr. Wang said in a CAS Newsroom release:
“The total energy of this burst set already adds up to 3.8% of what is available from a magnetar and no periodicity was found between 1 ms and 1000 s, both of which severely constrains the possibility that FRB 121102 comes from an isolated compact object.”
They also determined that bursts’ energy distribution is bimodal in nature, meaning that they are distributed one of two ways, depending on the energy level. In other words, they found that weaker FRB pulses are more random while strong ones occur with greater consistency. Moreover, these latest results also allowed the team to investigate the range of theoretical causes and narrow them down.
For one, the lack of periodicity (or quasi-periodicity) of this repeating FRB challenges the notion that it results from a single rotating compact object (aka. a black hole
Did you miss our previous article…
Should We Send Humans to Venus?
NASA is preparing to send humans back to the Moon with the Artemis missions in the next few years as part of the agency’s Moon to Mars Architecture with the long-term goal of landing humans on the Red Planet sometime in the 2030s or 2040s. But what about sending humans to other worlds of the Solar System? And, why not Venus? It’s closer to Earth than Mars by several tens of millions of kilometers, and despite its extremely harsh surface conditions, previous studies have suggested that life could exist in its clouds. In contrast, we have yet to find any signs of life anywhere on the Red Planet or in its thin atmosphere. So, should we send humans to Venus?
“Yes, we should send humans to Venus,” Dr. Paul Byrne, who is an Associate Professor of Earth, Environmental, and Planetary Sciences at Washington University in St. Louis, tells Universe Today. “But first, let’s talk about what ‘sending humans to Venus’ actually means. The surface of Venus is hellish, so nobody would last long there nor volunteer to go. Above the clouds, the temperature and pressure are almost like a nice spring day here on Earth, so aside from tiny sulphuric acid cloud droplets you’d be okay (with a breathing apparatus).”
These “hellish” conditions that Dr. Byrne alludes to are the extreme conditions across the surface of Venus, including surface pressures 92 times that of Earth’s surface and average surface temperatures of approximately 464 degrees Celsius (867 degrees Fahrenheit). In contrast, Earth’s average surface temperatures are a calm 15 degrees Celsius (59 degrees Fahrenheit). These extreme pressures and temperatures have made landing on the surface of Venus even more difficult, as the former Soviet Union continues to be the only nation to have successfully landed on Venus’ surface, having accomplished this feat with several of their Venera and Vega missions. However, the longest mission duration for the lander was only 127 minutes (Venera 13), which also conducted the first sound recording on another planet.
Color images taken by the Soviet Union’s Venera 13 lander on the surface of Venus on March 1, 1982, with the lander surviving only 127 minutes due to Venus’s extreme surface conditions. (Credit: NASA)
“If we were to send humans to Venus, they’d be going in a spacecraft that would fly by the planet en route somewhere else,” Dr. Byrne tells Universe Today. “If we were to one day send humans actually to Venus itself for science and engineering purposes, then a cloud-based habitat is the way to go. Getting humans onto the Venus surface is going to require so much technology and expense that, for the foreseeable future, I don’t think anyone will think it worth doing.”
A 2015 study presented at the AIAA Space and Astronautics Forum and Exposition outlined a NASA study for the High Altitude Venus Operational Concept (HAVOC) mission that would involve a 30-day crewed mission using an airship equipped with solar panels within the upper atmosphere of Venus. This is because Venus’ upper atmosphere at approximately 50 kilometers (30 miles) above the surface exhibits much more hospitable conditions, including temperatures between 30 to 70 degrees Celsius (86 to 158 degrees Fahrenheit) and pressures very close to that of Earth. However, Dr. Byrne refers to HAVOC as an “unbelievably expensive concept”.
Artist rendition of proposed habitable airships traversing Venus’ atmosphere, which has been proposed as the High Altitude Venus Operational Concept (HAVOC) mission. (Credit: NASA)
As for using Venus while en route to another location in the Solar System, Venus has been used on several occasions to slingshot spacecraft to the outer Solar System as well as for exploration of the inner Solar System, such as Mercury and the Sun. For example, NASA’s Galileo and Cassini spacecraft used gravity assists
We Should Hit Peak Solar Activity Next Year
You may be familiar with the solar cycle that follows a 22 year process shifting from solar minimum to maximum and back again. It’s a cycle that has been observed for centuries yet predicting its peak has been somewhat challenging. The Sun’s current cycle is approaching maximum activity which brings with it higher numbers of sunspots on its surface, more flares and more coronal mass ejections. A team from India now believe they have discovered a new element of the Sun’s magnetic field allowing them to predict the peak will occur early in 2024.
The Sun is a gigantic sphere of plasma or electrically charged gas. One of the features of plasma is that if a magnetic field passes through it, the plasma moves with it. Conversely if the plasma moves, the magnetic field moves too. This magnetic field is just like Earth and is known as a dipole magnetic field. You can visualise it if you can remember your school science days with a bar magnet and iron filings.
A dipole magnetic field has two opposite but equal charges and at the start of the Sun’s cycle the field lines effectively run from the north pole to the south. As the Sun rotates, with the equator rotating faster than the polar regions, then the plasma drags the magnetic field lines with it, winding them tighter and tighter.
The field lines become stretched causing the magnetic field to loop up and through the visible surface of the Sun. This localised event prevents the convection of super heated gas from underneath and appears as a cooler area of the surface which appears dark. As the solar cycle starts, these sunspots appear around the polar regions and slowly migrate toward the equator as it progresses with peak activity occurring when the sunspots fade away as we head toward the start of another cycle.
Image of sunspots (Credit : NASA Goddard Space Flight Center // SDO)
On occasions the magnetic field of sunspots are disrupted and we can experience flares or coronal mass ejections hurling vast amounts of charged particles out into space. If they reach us here on Earth they give rise to the beautiful aurora displays but they do also have a rather negative impact to satellites, power grids and telecommunications systems.
Deep inside the Sun, a dynamo mechanism is driving all this. It is created by the energy from the movement of plasma and it is this that is responsible for the flipping of the Sun’s magnetic poles where the north pole becomes south and the south pole becomes north which happens every 11 years or so. It’s another aspect of the solar cycle.
It’s been known since the 1930’s that the rate of rise the sunspot cycle relates to its strength with stronger cycles taking less time to reach peak. In the paper published in the Monthly Notices of the Royal Astronomical Society Letters; Priyansh Jaswal, Chitradeep Saha and Dibyendu Nandy from the Indian Institutes of Science Education and Research announced their findings. They discovered that the rate of decrease in the Sun’s dipole magnetic field also seems to relate to the rise of the present cycle.
The team have looked back through archives and have shown how the observation of the dipole decrease rate along with observations of sunspots can predict the peak of activity with better accuracy than before. They conclude the current cycle is expected to peak somewhere between early 2024 and September next year. Being able to better predict the peak of activity will help understand the likely intensity of space weather events here on Earth providing us more warning to be able to prepare.
Source : Solar activity likely to peak next year, new study suggests
The post We Should Hit Peak Solar Activity Next Year appeared first on Universe Today.
The Solar Radius Might Be Slightly Smaller Than We Thought
Two astronomers use a pioneering method to suggest that the size of our Sun and the solar radius may be due revision.
Our host star is full of surprises. Studying our Sun is the most essential facet of modern astronomy: not only does Sol provide us with the only example of a star we can study up close, but the energy it provides fuels life on Earth, and the space weather it produces impacts our modern technological civilization.
Now, a new study, titled The Acoustic Size of the Sun suggests that a key parameter in modern astronomy and heliophysics—the diameter of the Sun—may need a slight tweak.
The study out of the University of Tokyo and the Institute of Astronomy at Cambridge was done looking at data from the joint NASA/ESA Solar Heliospheric Observatory (SOHO’s) Michelson Doppler Imager (MDI) imager. The method probes the solar interior via acoustics and a cutting edge field of solar physics known as helioseismology.
A cutaway diagram of the Sun. NASA/ESA/SOHO
‘Hearing’ the Solar Interior
How can you ‘hear’ acoustic waves on the Sun? In 1962, astronomers discovered that patches on the surface of the Sun oscillate, or bubble up and down, like water boiling on a stove top. These create waves that ripple in periodic 5-minute oscillations across the roiling surface of the Sun.
A view of the Sun, courtesy of SOHO’s MDI instrument. Credit: NASA
What’s more, astronomers can use what we see happening on the surface of the Sun to model the solar interior, much like terrestrial astronomers use seismic waves traveling through the Earth to model its core. Thanks to helioseismology, we can even ‘see’ what’s going on on the solar farside, and alert observers of massive sunspots before they rotate into view.
Solar farside modeling using helioseismology. Credit: NSF/GONG
The study looked at p-mode waves as they traversed the solar interior. Previous studies relied on less accurate f-mode waves, which are surface waves considerably shorter than the solar radius.
The study defines the solar radius (half the diameter) as 695,780 kilometers… only slightly smaller than the generally accepted radius of 696,000 kilometers obtained by direct optical measurement. This is only smaller by a few hundredths of a percent, or 100-200 kilometers.
An artist’s conception of SOHO in space. Credit: ESA/SOHO
The solar radius is a deceptively simple but crucial factor in astronomy. The Sun is a glowing ball of hydrogen and helium plasma without a distinct surface boundary. The photosphere—the glowing visible layer we see shining down on us on a sunny day—is what we generally refer to as the surface of the Sun.
The Solar Radius: A Brief
Did you miss our previous article…
Fashion4 days ago
EDM6 days ago
Canned Cocktails And Perfume: Espresso Martini’s Are All The Rage
Tech6 days ago
The Download: OpenAI’s wild year, and tech’s cult of personality
EDM4 days ago
Swedish House Mafia To Play Virtual Concert In Roblox
Baller Awards6 days ago
BRIT Awards change rules for 2024 after diversity row
EDM5 days ago
PLS&TY Launches Anticipated “Proper Manners” Radio Show + Drops Stellar “Party In My Head” Remix Package
Baller Awards6 days ago
Sharib Hashmi on hosting the Filmfare OTT Awards 2023: ï¿½I look forward to entertaining the audienceï¿½
EDM7 days ago
KANJI Dives Into Melodic Bass With Debut Single ‘Runaway’