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Mysterious Kilonova Explosion Afterglow Potentially Spotted for First Time – SciTechDaily

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An artist’s conception illustrates the aftermath of a “kilonova,” a powerful event that happens when two neutron stars merge. Credit: X-ray: NASA/CXC/Northwestern Univ./A. Hajela et al.; Illustration: NASA/CXC/M.Weiss

Strange ‘sonic boom’ accompanied unprecedented event.

  • Mysterious X-rays observed 3.5 years after the merger of two neutron stars
  • Astrophysicists believe a kilonova afterglow or materials falling into a <span class="glossaryLink" aria-describedby="tt" data-cmtooltip="
    black hole
    A black hole is a place in space where the pull of gravity is so strong not even light can escape it. Astronomers classify black holes into three categories by size: miniature, stellar, and supermassive black holes. Miniature black holes could have a mass smaller than our Sun and supermassive black holes could have a mass equivalent to billions of our Sun.

    ” data-gt-translate-attributes=”["attribute":"data-cmtooltip", "format":"html"]”>black hole might have caused the X-ray emission

  • Either scenario would be the first for the field
  • The kilonova afterglow was likely produced by a shock similar to a sonic boom, generated by expanding debris from the merger

For the first time, <span class="glossaryLink" aria-describedby="tt" data-cmtooltip="

Northwestern University
Established in 1851, Northwestern University (NU) is a private research university based in Evanston, Illinois, United States. Northwestern is known for its McCormick School of Engineering and Applied Science, Kellogg School of Management, Feinberg School of Medicine, Pritzker School of Law, Bienen School of Music, and Medill School of Journalism.&nbsp;

” data-gt-translate-attributes=”["attribute":"data-cmtooltip", "format":"html"]”>Northwestern University-led astronomers may have detected an afterglow from a kilonova.

A kilonova occurs when two neutron stars — some of the densest objects in the universe — merge to create a blast 1,000 times brighter than a classical nova. In this case, a narrow, off-axis jet of high-energy particles accompanied the merger event, dubbed GW170817. Three-and-a-half years after the merger, the jet faded away, revealing a new source of mysterious X-rays.

As the leading explanation for the new X-ray source, astrophysicists believe expanding debris from the merger generated a shock — similar to the sonic boom from a supersonic plane. This shock then heated surrounding materials, which generated X-ray emissions, known as a kilonova afterglow. An alternative explanation is materials falling toward a black hole — formed as a result of the <span class="glossaryLink" aria-describedby="tt" data-cmtooltip="

neutron star
A neutron star is the collapsed core of a large (between 10 and 29 solar masses) star. Neutron stars are the smallest and densest stars known to exist. Though neutron stars typically have a radius on the order of just 10 – 20 kilometers (6 – 12 miles), they can have masses of about 1.3 – 2.5 that of the Sun.

” data-gt-translate-attributes=”["attribute":"data-cmtooltip", "format":"html"]”>neutron star merger — caused the X-rays.

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Either scenario would be a first for the field. The study was published on February 28, 2022, in The Astrophysical Journal Letters.

“We have entered uncharted territory here in studying the aftermath of a neutron star merger,” said Northwestern’s Aprajita Hajela, who led the new study. “We are looking at something new and extraordinary for the very first time. This gives us an opportunity to study and understand new physical processes, which have not before been observed.”

Hajela is a graduate student at Northwestern’s Center for Interdisciplinary Exploration and Research in Astrophysics (CIERA) and in the Department of Physics and Astronomy in the Weinberg College of Arts and Sciences.

On August 17, 2017, GW170817 made history as the first neutron-star merger detected by both <span class="glossaryLink" aria-describedby="tt" data-cmtooltip="

gravitational waves
Gravitational waves are distortions or ripples in the fabric of space and time. They were first detected in 2015 by the Advanced LIGO detectors and are produced by catastrophic events such as colliding black holes, supernovae, or merging neutron stars.

” data-gt-translate-attributes=”["attribute":"data-cmtooltip", "format":"html"]”>gravitational waves and electromagnetic radiation (or light). Since then, astronomers have been using telescopes around the world and in space to study the event across the electromagnetic spectrum.

We are looking at something new and extraordinary for the very first time.”
Aprajita Hajela, astrophysicist

Using <span class="glossaryLink" aria-describedby="tt" data-cmtooltip="

NASA
Established in 1958, the National Aeronautics and Space Administration (NASA) is an independent agency of the United States Federal Government that succeeded the National Advisory Committee for Aeronautics (NACA). It is responsible for the civilian space program, as well as aeronautics and aerospace research. It's vision is &quot;To discover and expand knowledge for the benefit of humanity.&quot;

” data-gt-translate-attributes=”["attribute":"data-cmtooltip", "format":"html"]”>NASA’s Chandra X-ray Observatory, astronomers observed X-ray emissions from a jet moving very close to the speed of light produced by the neutron star merger. Starting in early 2018, the jet’s X-ray emission steadily faded as the jet continued to slow and expand. Hajela and her team then noticed from March 2020 until the end of 2020, the decline in brightness stopped, and the X-ray emission was approximately constant in brightness.

This was a significant clue.

“The fact that the X-rays stopped fading quickly was our best evidence yet that something in addition to a jet is being detected in X-rays in this source,” said Raffaella Margutti, astrophysicist at the University of California at Berkeley and a senior author of the study. “A completely different source of X-rays appears to be needed to explain what we’re seeing.”

The researchers believe a kilonova afterglow or black hole are likely behind the X-rays. Neither scenario has ever before been observed.

“This would either be the first time we’ve seen a kilonova afterglow or the first time we’ve seen material falling onto a black hole after a neutron star merger,” said study co-author Joe Bright, also from the University of California at Berkeley. “Either outcome would be extremely exciting.”

To distinguish between the two explanations, astronomers will keep monitoring GW170817 in X-rays and radio waves. If it is a kilonova afterglow, the X-ray and radio emissions are expected to get brighter over the next few months or years. If the explanation involves matter falling onto a newly formed black hole, then the X-ray output should stay steady or decline rapidly, and no radio emission will be detected over time.

“Further study of GW170817 could have far-reaching implications,” said study co-author Kate Alexander, a CIERA postdoctoral fellow at Northwestern. “The detection of a kilonova afterglow would imply that the merger did not immediately produce a black hole. Alternatively, this object may offer astronomers a chance to study how matter falls onto a black hole a few years after its birth.”

The study, “Evidence for X-ray emission in excess to the jet afterglow decay 3.5 years after the binary neutron star merger GW170817: A new emission component,” was supported by NASA, the National Science Foundation, the U.S. Department of Energy and the Royal Astronomical Society.

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May's possible meteor storm offers chance to listen to 'shooting stars' on the radio – Space.com

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“Shooting stars” from the tau Herculids meteor shower may be visible late this month, but you might want to listen for them instead.

Excitement among meteor enthusiasts is building as we get closer to the much-anticipated meteor outburst that might be produced by a concentrated trail of dusty debris from the nucleus of comet Schwassmann-Wachmann 3 (SW 3) late Monday night into early Tuesday morning (May 30 to 31). 

Even if you can’t get a good view of the show because of clouds or light pollution, you can “observe” the meteor shower a different way: by listening to it on the radio!

Related: Meteor shower guide 2022: Dates and viewing advice

Under certain conditions, meteors can reflect radio waves in the same way the ionosphere propagates transmissions between widely separated ham-radio operators. The ionosphere usually reflects frequencies below 30 megahertz (MHz), but it’s transparent to higher frequencies, such as the FM broadcast band (88 to 108 MHz).  

Such high-frequency (short-wavelength) radio signals generally pass unimpeded through the atmosphere in straight lines; they cannot follow the curvature of the Earth to reach a listener beyond the horizon. Yet when certain layers of the upper atmosphere become ionized, they can reflect the signals back to the ground far away. The lowest such layer, 60 to 70 miles (96 to 112 kilometers) up, is called the E layer of the ionosphere, and that’s the altitude where most meteors are seen.   

So, as a meteoroid vaporizes as it passes through Earth’s atmosphere, it briefly ionizes air molecules along its path. Forming an expanding column or cylinder several miles or more in length, these ions can scatter and reflect radio waves, in much the same way a high-altitude jet reflects sunlight and leaves a glowing contrail against the darkening sky after sunset. But because the ion trails disperse rapidly, the reflected radio waves generally last only a few seconds.  

Tiny particles tend to vaporize at the bottom of the E layer. Large particles, in contrast, begin to flame higher up. And predictions for the particles shed from comet SW 3 suggest that a majority of these will be large. Such meteors produce longer-lasting ionization, and because they start to “flame on” higher up, they can reflect signals from more distant transmitters. 

On the ground, the meteor’s presence is signaled by the momentary enhancement of FM reception from a distant station.

How to listen for meteors on the radio 

For this radio method to work, find a frequency where no nearby FM station is broadcasting.  You will have a better chance of success by scanning the low-frequency end of the FM band, below 91.1 MHz. Why there? Because that’s where the lower-power stations, chiefly run by colleges, are found, and they’re usually free from local interference from the high-power commercial stations. In fact, unless you live in a very unpopulated region of the country, your chances of finding an open frequency free of interference above 91.1 MHz is rather small, so you’ll need to tune to a distant station on a clear frequency below 91.1 MHz.  

FM Atlas, published from 1970 to 2010, provided listings of all FM stations in North America, with the unique feature of frequency-by-frequency maps. Bruce Elving, publisher of the FM Atlas, was a longtime proponent and expert in all things FM. He died in 2011, but as a tribute to his love and dedication to FM radio, the 21st and final edition of FM Atlas (2010) is available for free, courtesy of AmericanRadioHistory.com. You can also see a complete listing of AM and FM stations in the 2010-2011 edition of the M Street Directory. 

What do meteors sound like?  

Normally, when you’re tuned in to an “empty” radio frequency, you just hear a hissing noise. But as meteors zip through the atmosphere, a distant or silent station will abruptly “boom in” for anywhere from a fraction of a second to several seconds. You might also hear what initially sounds like a “pop” or a whistle, and then as the ionization trail dissipates, the station will quickly fade away. Because of their height, meteors best reflect signals from stations 800 to 1,300 miles (1,300 to 2,100 km) from you. 

When should you listen for meteors? 

The best time to listen is when the radiant is 45 degrees above the horizon as seen from a point midway between you and the transmitter. At the predicted peak time for Tuesday morning’s potential meteor outburst, parts of Maine and the Canadian provinces of New Brunswick, Nova Scotia and Prince Edward Island will have the radiant close to that preferred altitude, while eastern New York, New England and southern Quebec will not be far behind, at about 50 to 55 degrees. 

Also, it is best to tune to a station located in a direction perpendicular to the radiant. Because the SW 3 radiant will be near the brilliant orange star Arcturus in the constellation Boötes, which will be toward the western part of the sky, the better listening directions will be to the north and south of you. 

Most meteors are heard but not seen 

If you are watching for meteors while monitoring your radio, most of the time, you will hear a “ping” of reception, but you won’t see a corresponding meteor streak in the sky. Recall that most of the meteors you hear are roughly halfway between you and the radio station — about 400 to 650 miles (650 to 1,050 km) away. So they are occurring either near the horizon or just below it. Back in the 1970s, members of the Nippon Meteor Society in Japan who made extensive records of radio meteors noted that only 20% to 40% of meteors heard on the radio were simultaneously observed visually. 

What if you can’t find a clear frequency? 

Related stories:

Particularly in large metropolitan areas, finding a clear or empty FM frequency may be all but impossible, even below 91.1 MHz. In many ways, finding a clear frequency seems to go hand in hand with trying to find a dark sky free of light pollution. You’ll probably have a much better chance in rural or country locations. 

But if you can’t find a clear FM frequency, don’t despair. You can still listen for meteors on livemeteors.com. A Yagi antenna in the Washington, D.C., metro area constantly detects 55- or 61-MHz analog TV signals in Ontario reflected off of meteor trails. When a meteor passes over — ping!there is an echo. It’s the next best thing to having free access to a giant government radar! 

Good luck, and good listening!

Joe Rao serves as an instructor and guest lecturer at New York’s Hayden Planetarium (opens in new tab). He writes about astronomy for Natural History magazine (opens in new tab), the Farmers’ Almanac (opens in new tab) and other publications. Follow us on Twitter @Spacedotcom (opens in new tab) and on Facebook (opens in new tab)

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Paragon Humidity Control Technology Flies on Boeing's CST-100 Starliner – Benzinga – Benzinga

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TUCSON, Ariz. , May 27, 2022 /PRNewswire/ — Paragon Space Development Corporation (Paragon) is excited to announce that its Humidity Control Subassembly (HCS) has been successfully tested and operated on the Boeing CST-100 Starliner Orbital Flight Test-2 prior to its successful landing on Wednesday, May 25th.  Boeing’s CST-100 Starliner successfully docked with the International Space Station (ISS) for the first time on May 20, 2022 after lifting off May 19th from Florida. The HCS platform was developed by Paragon under a fixed price development and production contract to Boeing and is built upon Paragon’s patented technology as well as decades worth of time-tested experience and knowledge focused on development of life support systems for extreme environments. 

“It’s really quite an accomplishment to have the HCS aboard this historic mission – the first truly new humidity control technology developed in 60 years of human spaceflight. It is a testament to the excellent work and dedication of our team at Paragon, and that of our partners at Boeing,” said Grant Anderson, Paragon’s President and CEO. “Our team is excited that the HCS system passed its debut flight to the ISS and will support the transport of humans back and forth for years to come.”

The HCS will provide essential life support functionality for next generation human spaceflight operations and is the most recent spaceflight technology fielded by Paragon for the ever-expanding human spaceflight market. Paragon’s HCS technology is being integrated into the Northrop Grumman HALO module and will provide contingency life support capability during crewed Artemis missions to–and around–the Moon.

“As humanity accelerates into space, with new missions ahead and new technological, exploration and scientific goals to achieve, it will be systems like the HCS that make it all possible. Without life support and environmental controls, you don’t have human spaceflight – it’s really that simple,” noted Barry Finger, Paragon’s VP of Engineer, adding that, “With Boeing’s vision and stick-to-it approach, as well as that of all the partners on this fantastic team, we all made the difficult a reality – and that is what we at Paragon see as our strength.”

For over 29 years, Paragon has been on the forefront of systems designed for extreme environments in sea, land, air, and space. Paragon has a successful history of providing design, analysis and/or hardware on every human space program of record since 1999. Paragon has grown their design, analysis, manufacturing, and operational capabilities to support the most current and forward-leaning civil and commercial space programs. For more information and other news, visit www.paragonsdc.com.

Media Contact: Leslie Haas, 520-382-4814, 337368@email4pr.com.

View original content to download multimedia:https://www.prnewswire.com/news-releases/paragon-humidity-control-technology-flies-on-boeings-cst-100-starliner-301556421.html

SOURCE Paragon Space Development Corporation

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NASA Moves Forward With Next-Gen Solar Sail Project – ExtremeTech

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Getting from point A to point B in the solar system is no simple feat, and inefficient, heavy rockets aren’t always the best way. Therefore, NASA has announced it is moving ahead with a new solar sail concept that could make future spacecraft more efficient and maneuverable. The Diffractive Solar Sailing project is now entering phase III development under the NASA Innovative Advanced Concepts (NIAC) program, which could eventually lead to probes that use solar radiation to coast over the sun’s polar regions. 

The concept of solar sails is an old one — they were first proposed in the 1980s. The gist is that you equip a vessel with a lightweight sail that translates the pressure from solar radiation into propulsion. The problem is that a solar sail has to be much larger than the spacecraft it’s dragging along. Even a low-thrust solar sail would need to be almost a square kilometer, and you need to keep it intact over the course of a mission. Plus, you have little choice but to fly in the direction of sunlight, so you have to make tradeoffs for either power or navigation. Futuristic diffractive light sails could address these shortcomings. 

This work is being undertaken at the Johns Hopkins University Applied Physics Laboratory under the leadership of Amber Dubill and co-investigator Grover Swartzlander. The project progressed through phase I and II trials, which had the team developing concept and feasibility studies on diffractive light sails. The phase III award ensures $2 million in funding over the next two years to design and test the materials that could make diffractive light propulsion a reality. 

A standard lightsail developed by the Planetary Society in 2019.

A diffractive light sail, as the name implies, takes advantage of a property of light known as diffraction. When light passes through a small opening, it spreads out on the other side. This could be used to make a light sail more maneuverable so it doesn’t need to go wherever the solar winds blow. 

The team will design its prototypes with several possible mission applications in mind. This technology most likely won’t have an impact on missions to the outer solar system where sunlight is weaker and the monumental distances require faster modes of transportation. However, heliophysics is a great use case for diffractive lightsailing as it would allow visiting the polar regions of the sun, which are difficult to access with current technology.

A lightsail with the ability to essentially redirect thrust from a continuous stream of sunlight would be able to enter orbit over the poles. It may even be possible to maneuver a constellation of satellites into this difficult orbit to study the sun from a new angle. In a few years, NASA may be able to conduct a demonstration mission. Until then, it’s all theoretical.

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