Category Archives: Astronomy

There are thousands of near-Earth asteroids in the inner solar system, as depicted in this graphic. Some known and some unknown. Another asteroid discovered by the same astronomer to discover 2022 EB5 in early March made a close pass with Earth in the early hours of March 25, 2022. Image via NASA/ JPL-Caltech/ Wikimedia Commons.Another asteroid whizzes past Earth overnight

Overnight on March 24-25, 2022, another small asteroid raced toward Earth, unseen until hours before its closest approach. Hungarian astronomer Krisztin Srneczky, same astronomer who first spotted asteroid 2022 EB5 earlier this month hours before it hit Earth near Iceland, found this new asteroid, too. He caught it just hours before it sped by Earth. This asteroid is labeled Sar2594. Its close encounter with Earth came at 8:10 UTC or 3:10 a.m. CDT.

This time, instead of a collision, the space rock slipped through Earths shadow.

It passed at a distance of about 5,400 miles (8,700 km). Thats in contrast to the moons distance of 238,900 miles (384,000 km).

Sar2594 is categorized as a Near-Earth Object, or NEO. It raced by at about 40,265 miles an hour (18 km/s).

Sar2594 now has an official designation: 2022 FD1. Srneczky says the asteroid is about 2-4 meters in size. This could put it in the running for the smallest asteroid known. The current record holder is 2015 TC25, which is approximately 6 feet or 2 meters in diameter.

The asteroids flyby of Earth changed its course. Srneczky and Tony Dunn share charts and simulations of 2022 FD1s inclination:

Bottom line: Another asteroid whizzes past Earth hours after discovery. The asteroid, Sar2594, was discovered by the same astronomer, Krisztin Srneczky, who discovered 2022 EB5, which impacted near Iceland earlier this month.

Kelly Kizer Whitt has been a science writer specializing in astronomy for more than two decades. She began her career at Astronomy Magazine, and she has made regular contributions to AstronomyToday and the Sierra Club, among other outlets. Her childrens picture book, Solar System Forecast, was published in 2012. She has also written a young adult dystopian novel titled A Different Sky. When she is not reading or writing about astronomy and staring up at the stars, she enjoys traveling to the national parks, creating crossword puzzles, running, tennis, and paddleboarding. Kelly lives with her family in Wisconsin.

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Whoa! Another asteroid whizzes past Earth hours after discovery - EarthSky

image:An artistic impression of the high-frequency retrograde (HFR) vorticity waves. These waves appear as swirling motions near the equator of the Sun. The rotation in the north is always anti-symmetric to the rotation in the southern hemisphere. These mysterious waves move in the opposite direction to the sun's rotation, which is to the right, three times faster then what is allowed by hydrodynamics alone. view more

Credit: NYU Abu Dhabi

Abu Dhabi, UAE: Researchers from NYU Abu Dhabis (NYUAD) Center for Space Science have discovered a new set of waves in the Sun that, unexpectedly, appear to travel much faster than predicted by theory.

In the study, Discovery of high-frequency-retrograde vorticity waves in the Sun, published in the journal Nature Astronomy, the researchers led by Research Associate Chris S. Hanson -- detailed how they analyzed 25 years of space and ground-based data to detect these waves. The high-frequency retrograde (HFR) waves - which move in the opposite direction of the Suns rotation - appear as a pattern of vortices (swirling motions) on the surface of the Sun and move at three times the speed established by current theory.

The interior of the Sun and stars cannot be imaged by conventional astronomy (e.g. optical, x-ray etc.), and scientists rely on interpreting the surface signatures of a variety of waves to image the interiors. These new HFR waves may yet be an important puzzle piece in our understanding of stars.

Complex interactions between other well known waves and magnetism, gravity or convection could drive the HFR waves at this speed. If the HFR waves could be attributed to any of these three processes, then the finding would have answered some open questions we still have about the Sun, said Hanson. However, these new waves dont appear to be a result of these processes, and thats exciting because it leads to a whole new set of questions.

This research was conducted within NYUADs Center for Space Science in collaboration with the Tata Institute of Fundamental Research (TIFR) and New York University, using NYUAD and TIFRs computational resources. By studying the Suns interior dynamics - through the use of waves - scientists can better appreciate the Sun's potential impact on the Earth and other planets in our solar system.

The very existence of HFR modes and their origin is a true mystery and may allude to exciting physics at play, said Shravan Hanasoge, a co-author of the paper. It has the potential to shed insight on the otherwise unobservable interior of the Sun.

Image caption: An artistic impression of the high-frequency retrograde (HFR) vorticity waves. These waves appear as swirling motions near the equator of the Sun. The rotation in the north is always anti-symmetric to the rotation in the southern hemisphere. These mysterious waves move in the opposite direction to the sun's rotation, which is to the right, three times faster then what is allowed by hydrodynamics alone.

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About NYU Abu Dhabi

http://www.nyuad.nyu.edu

NYU Abu Dhabi is the first comprehensive liberal arts and research campus in the Middle East to be operated abroad by a major American research university. NYU Abu Dhabi has integrated a highly selective undergraduate curriculum across the disciplines with a world center for advanced research and scholarship. The university enables its students in the sciences, engineering, social sciences, humanities, and arts to succeed in an increasingly interdependent world and advance cooperation and progress on humanitys shared challenges. NYU Abu Dhabis high-achieving students have come from over 115 countries and speak over 115 languages. Together, NYU's campuses in New York, Abu Dhabi, and Shanghai form the backbone of a unique global university, giving faculty and students opportunities to experience varied learning environments and immersion in other cultures at one or more of the numerous study-abroad sites NYU maintains on six continents.

Discovery of high-frequency-retrograde vorticity waves in the Sun

24-Mar-2022

Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.

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NYU Abu Dhabi researchers discover a mysterious, new type of wave in the Sun whose speed defies explanation - EurekAlert

Dr. Amruta Jaodand;Division of Physics, Mathematics and Astronomy,California Institute of Technology

Transitional millisecond pulsars (tMSPs) switch between a low-mass X-ray binary (LMXB) and a radio millisecond pulsar (RMSP) state, establishing a firm evolutionary link between the two source classes. tMSPs provide a great avenue to study the low-level accretion processes that spin-up pulsars to millisecond periods. Systematic, multi-wavelength observational campaigns over the last decade have resulted in surprising finds such as: i) persistent, multi-year-long, low-level (Lx <10^34 ergs/s) accretion state with coherent pulsations; ii) extremely stable, bi-modal X-ray light curves; iii) radio outflows, and iv) uninterrupted pulsar spin down in the X-rays. In this unique state, we have now found the first known UV millisecond pulsar with a dedicated multi-wavelength campaign involving the Hubble space telescope. In my talk I will review observational understanding of tMSPs while highlighting key finds which reveal how these systems have altered our understanding of low level accretion and pulsed emission in neutron stars.

Biography:Dr. Amruta Jaodand is a postdoctoral reseacher in the NuSTAR group at Caltech's Division of Physics, Mathematics and Astronomy. Previously, she did her PhD at University of Amsterdam. She works on observational investigations of various neutron stars such as millisecond pulsars, magnetars, gravitational wave engines and X-ray binaries with a deeper expertise in transitional millisecond pulsars and multi-wavelength gravitational wave follow up. As a PI, she has won observational time and funding for ~30 proposals spanning observatories such as XMM, NuStar, Swift, Green Bank Telescope, ZTF and VLA etc. Another interest of hers is astroinformatics in the era of large scale datasets. To that effect she has worked for the past five years in bringing together EU and American astronomers through multiple conferences to probe machine learning and visualisation approaches.

22 MAR 2022: Physics and Astronomy Colloquium3:30pm, Online via ZoomZoom Link:https://uiowa.zoom.us/j/94392147007Meeting ID: 943 9214 7007, No passcode

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Physics & Astronomy Colloquium - Dr. Amruta Jaodand | Physics and Astronomy | The University of Iowa - The University of Iowa

An IDAS LPS-D2 filter suitable for two-inch push-fit telescope camera accessories with an M48 0.75 connection thread. The filter has male and female threads on either side, hence it is stackable with other filters and M48 adaptors. The LPS-D2 is also available in 52mm and Canon APS-C clip-filter formats. All images: Ade Ashford.At a glance

Type: light-pollution suppression filter for low-/high-pressure sodium vapour and LED lightsCoating technology: Ion-Gun Assisted Deposition (IGAD)Suitability: DSLR and astro camerasConnection thread: M48 0.75 (male and female on either side, hence stackable)Substrate thickness: 2.5mmDiameter of filter glass: 49mmPrice: 175 (M48 and 52mm); 185 (Canon APS-C clip filter)Manufacturer: ICAS Enterprises, JapanSupplier: rothervalleyoptics.co.uk

Light pollution is a regrettable fact of life for most of us. By night, the sky over our cities and towns even villages is increasingly awash with the glare of unnecessary or misdirected artificial light. This is not only a tremendous waste of energy, but it upsets nocturnal ecosystems and harms human health, disturbed sleep patterns and the disruption of natural circadian rhythms.

For almost three decades, Tokyo-based ICAS Enterprises IDAS Division has been responsible for manufacturing some of the worlds most respected interference filters for suppressing light pollution for astronomers. Their LPS-D1 filter made its debut in 1991 at a time when the main sources of artificial illumination in our towns and cities were low- and high-pressure sodium vapour and mercury vapour lamps. Fortunately for astronomers, both sodium (Na) and mercury (Hg) vapour lamps share a common characteristic: they typically emit light in specific and largely narrow wavelength bands of the spectrum so-called emission lines that can be removed by an interference filter.

The LPS-D1 was designed for one-shot CCD/CMOS colour cameras and DSLRs to eliminate the glow from low-pressure sodium and high-pressure mercury street lights, while substantially reducing the peak intensities of high-pressure sodium light emissions. Both the IDAS D1 and P2 filters pass the desirable spectral lines of hydrogen-beta, oxygen-III, hydrogen-alpha light from nebulae, plus diatomic carbon (C2, the so-called Swan bands) from comets. The LPS-P2 is virtually identical to the D1 except for a slightly greater red sensitivity encompassing sulphur-II emissions.

As many of us up and down the United Kingdom and around the world are now acutely aware, the nature of street lighting is rapidly changing. The mellow yellow glow of low-pressure sodium light is being replaced with the energy-efficient yet brilliant white glare of light-emitting diodes (LEDs). I never thought that I would lament the passing of sodium street lights, but at least their light was relatively easy to mitigate. White LEDs, on the other hand, emit what is largely a continuous spectrum across a swathe of wavelengths (or colours, if you prefer) which is far harder to filter out.

If you consult the accompanying graph that shows the spectral profile of a typical white LED in blue, you will see immediately that it emits its greatest intensity of light almost 98 per cent transmittance in a well-defined peak at a wavelength close to 463 nanometres (nm), which is 4.63 107 metres, or 0.000463mm. Thus, the peak emission of a typical white LED is actually in the violet end of the blue region of the visible spectrum, at wavelengths that research has shown disrupts human circadian rhythms by keeping our brains in an awake state.

After the initial peak intensity, the white LEDs transmittance rapidly drops to around nine per cent at a wavelength of about 486nm in the bluegreen part of the spectrum. Thereafter, the transmittance rises steeply to a secondary, broader peak intensity of 53 per cent at about 560nm in the yellow part of the visible spectrum before gradually tailing off to zero in the far-infrared. If we were to use a conventional IDAS LPS-D1 or P2 filter on a white LED, then its peak intensity and much of its broader secondary intensity would not be filtered out. Clearly, we need another type of interference filter.

I was able to obtain data for the LPS-D2 filter based on a laboratory analysis rather than just rely on the design specification. The accompanying graph is a plot of the filters transmission versus wavelength in yellow, superimposed with that of a typical white LED in cyan. Where the white LEDs light intrudes into the D2 filters transmission curve is shown in green. Furthermore, the graphic shows the emission spectra of desirable nebula light (vertical dashed green lines), plus residual sources of light pollution that we wish to remove or mitigate (vertical red dashed lines). At the top and bottom of the graphic we see a continuous spectrum showing the approximate colour that corresponds to a specific wavelength; V = violet, B = blue, G = green, and so on.

The IDAS LPS-D2 is clearly very effective at removing the initial and most intense transmission spike from a typical white LED centred around 463 nanometres. However, when we come to capturing the desirable emission spectra of nebulae and comets in the blue green part of the spectrum hydrogen-beta, oxygen-III and diatomic carbon the intrusion of the LEDs light rises from a transmission of nine per cent at the hydrogen-beta line to around 30 per cent at the Swan bands of diatomic carbon. Note that some high-pressure mercury light pollution at 436nm and 546nm will also be passed by the LPS-D2 filter. Similarly, the second transmission peak of the LPS-D2 encompasses some of the white LEDs secondary peak light at around 52 per cent transmittance, so your white balance will have some strong green dominance. Fortunately, low-pressure sodium light pollution is fully suppressed and by the hydrogen-alpha and sulphur-II emission lines the white LEDs transmission is down to just 18 and 13 per cent, respectively.

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Beating the LED streetlights: IDAS light-pollution suppression LPS-D2 filter Astronomy Now - Astronomy Now Online

A mysterious, repeating radio signal in the Milky Way that baffled astronomers could be an object so rare, only one other has ever been tentatively identified.

According to a paper by astrophysicist Jonathan Katz of Washington University at St. Louis, uploaded to preprint server arXiv, and yet to be peer-reviewed, the signal named GLEAM-X J162759.5523504.3 could be a white dwarf radio pulsar.

"Since the early days of pulsar astronomy there has been speculation that a rotating magnetic white dwarf might show pulsar-like activity," Katz wrote in his paper.

"The recently discovered periodic radio transient GLEAM-X J162759.5523504.3 is a candidate for the first true white dwarf pulsar. It has a period of 18.18 minutes (1091 s) and its pulses show low frequency (72215 MHz) emission with a brightness temperature 1016 K implying coherent emission. It has no binary companion with which to interact. It thus meets the criteria of a classical pulsar, although its period is hundreds of times longer than any of theirs."

When a star dies, there are a range of outcomes, once it has ejected its outer material and core, no longer supported by the outward pressure of fusion, it collapses under its own gravity.

If the precursor star is over around 30 times the mass of the Sun, the core collapses into a black hole.

A precursor star between eight and 30 times the mass of the Sun results in a neutron star, around 20 kilometers (12 miles) across and up to around 1.4 times the mass of the Sun.

The core of a precursor star less than eight times the mass of the Sun will collapse into a white dwarf, packing mass up to 1.5 times that of the Sun into a ball between the sizes of Earth and the Moon.

Pulsars are a subset of neutron stars. They're neutron stars that rotate insanely fast, and angled in such a way that beams of bright radio waves shooting from the magnetic poles sweep past Earth on every rotation on the scale of seconds down to milliseconds. (Here's what that sounds like transcribed into audio.)

Scientists have wondered if similar behavior might be observed in white dwarf stars, and in 2016, they seem to have come close,with a star called AR Scorpii. Locked in a binary system with a red dwarf star, AR Scorpii flashes on a timescale of minutes.

However, as Katz notes, its binary orbit is closer than those of neutron star pulsars in binary systems, and the periodic signal lacks coherence. This means that the physical processes that produces the signal might be very different from traditional radio pulsars.

This brings us back to GLEAM-X J162759.5523504.3, located roughly 4,000 light-years away from Earth. From January to March of 2018, data collected by the Murchison Widefield Array in the Australian desert showed it pulsing brightly for roughly 30 to 60 seconds, every 18.18 minutes one of the most luminous objects in the low-frequency radio sky.

It matched the profile of no known astronomical object, but the research team that discovered it thought it might be a hypothetical object known as an ultra-long-period magnetar. That's a neutron star with an extraordinarily powerful magnetic field, but the explanation still didn't quite fit.

"Nobody expected to directly detect one like this because we didn't expect them to be so bright," astrophysicist Natasha Hurley-Walker of the Curtin University node of the International Centre for Radio Astronomy Research (ICRAR) in Australia explained at the time. "Somehow it's converting magnetic energy to radio waves much more effectively than anything we've seen before."

A pulsar was considered as a possibility, but there are two major problems: the first is that long rotation period, and the second is that the pulses were too bright for a neutron star pulsar. Both these problems, Katz lays out, are resolved if the object is a white dwarf.

If this is the case, it would be the first white dwarf discovered that shares the physics and radiation mechanism of traditional radio pulsars. This means that GLEAM-X J162759.5523504.3 could be a promising target for optical observations; although white dwarfs are very dim, and we might not be able to pick up any visible light at its distance. Nevertheless, given the possibility, it's worth a shot.

And astronomers could also examine other white dwarfs, to see if they match any of the properties of GLEAM-X J162759.5523504.3.

"If it were bright enough, optical observations could also determine its magnetic field, spectroscopically or polarimetrically," Katz explained.

"The fast-rotating, strongly magnetized, white dwarves would be promising targets for low frequency radio observations to determine if any of them are white dwarf pulsars."

The paper has been uploaded to preprint server arXiv.

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Mysterious Signal Coming From Our Galaxy Could Be One of The Rarest Known Objects - ScienceAlert

The Emirates Astronomical Society said on Friday that Ramadan is set to begin on April 2.

Eid Al Fitr and the first of Shawwal will be on May 2.

Ibrahim Al Jarwan, chairman of the board of directors of the society, said that the holy month is expected to last 30 days, according to state news agency Wam.

Residents of Khorfakkan will be the first to start fasting due to the city's location. Abu Dhabi residents will begin eight minutes later.

At the start of Ramadan, the dawn call to prayer in Khorfakkan will be at 4:48am. In the capital it is 4:56am, and in Sila and Ghuwaifat it is 5:08am.

Mr Al Jarwan said each day will call for around 13 hours and 46 minutes of fasting.

The precise start of Ramadan will be confirmed closer to the time through the moon-sighting committee.

First day of Ramadan at the Sheikh Zayed Grand Mosque. A canon is fired to mark the beginning of iftar. Victor Besa/The National

Updated: March 18, 2022, 12:27 PM

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Ramadan 2022 set to begin on April 2, UAE astronomy society says - The National

COLUMBIA, Md., March 18, 2022 /PRNewswire/ --The Stratospheric Observatory for Infrared Astronomy, SOFIA, landed at the Santiago International Airport on March 18, 2022. Like other deployments to the Southern Hemisphere, SOFIA is a partnership between NASA and German Aerospace Agency (DLR) and temporarily changing its base of operations from Palmdale, California, to Santiago, Chile, to observe celestial objects that can only be seen from Southern Hemisphere latitudes.

This is SOFIA's first visit to South America, and its first short-term deployment that will last two weeks. The team will operate from the Santiago International Airport to accomplish eight science flights. SOFIA will primarily observe the Large and Small Magellanic Clouds during the deployment, which are two close neighboring galaxies to our Milky Way. Both are gravitationally bound to each other and are passing by our galaxy for the first time in a hyperbolic orbit.

"Scientific collaboration, particularly in astronomy, has been a cornerstone of the U.S.-Chile relationship dating back to the establishment of the Observatorio de Cerro Santa Lucia in Santiago more than 170 years ago," said Richard Glenn, the U.S. Embassy Chile Charg d'Affaires. "NASA's SOFIA deployment to Chile is the next exciting milestone in that relationship, bringing us closer to the stars than ever before."

This is called a short deployment because of the shorter stay in Chile compared to SOFIA's long deployments, where more than 25 flights are typically planned using multiple instruments. The SOFIA team is taking a single instrument for this deployment, the Far Infrared Field Imaging Line Spectrometer, or FIFI-LS, and will observe several critical Southern Hemisphere celestial targets.

"We are thrilled to deploy to Chile so we can provide more access to the Southern Hemisphere skies for our scientific community," said Naseem Rangwala, SOFIA's project scientist. "We are increasing our deployment tempo with a focus on efficiency and prioritized targets, and we are grateful for the opportunity to do that from Santiago."

Since the Large Magellanic Cloud, or LMC, is so close to our galaxy, SOFIA can observe it in great detail, on relatively small astronomical scales,to help scientists better understand how stars formed in the early universe. Having the context of the physical areas in which stars form is why these LMC observations are so powerful. Scientists cannot see detailed physical structures in distant, ancient galaxies, so, instead, galaxies like the LMC are observed as local stand-ins. The planned observations are to create the first SOFIA map of ionized carbon in the LMC. These observations pair well with NASA's upcoming Galactic/Extragalactic ULDB Spectroscopic Terahertz Observatory, or GUSTO a high altitude balloon-based mission, and they extend the legacy of the Herschel Space Observatory.

In addition to the observations of the Large Magellanic Cloud, SOFIA will observe supernova remnants to investigate how certain types of supernovas might have contributed to the abundance of dust in the early universe. SOFIA will also attempt its first observation to measure the primordial abundance of lithium by looking into the halo of our galaxy where clouds of neutral hydrogen can be found. These clouds have been relatively undisturbed and thus directly probe the properties of pristine gas that existed in the early universe. A successful observation of lithium could have implications for our understanding of fundamental physics and the early universe because there is a significant discrepancy in lithium abundance between the big-bang theory of the evolution of the universe and the observed abundance from astronomical measurements. These observations obtained by SOFIA during this Southern Hemisphere are in line with some of the scientific questions and priorities identified in recently published Astro2020 Decadal Survey.

About SOFIA

SOFIA is a joint project of NASA and the German Space Agency at DLR. DLR provides the telescope, scheduled aircraft maintenance, and other support for the mission. NASA's Ames Research Center in California's Silicon Valley manages the SOFIA program, science, and mission operations in cooperation with the Universities Space Research Association, headquartered in Columbia, Maryland, and the German SOFIA Institute at the University of Stuttgart. The aircraft is maintained and operated by NASA's Armstrong Flight Research Center Building 703, in Palmdale, California.

About USRA

Foundedin 1969, under the auspices of the National Academy of Sciences at the request of the U.S. Government, the Universities Space Research Association (USRA), is a nonprofit corporation chartered to advance space-related science, technology and engineering. USRA operates scientific institutes and facilities, and conducts other major research and educational programs. USRA engages the university community and employs in-house scientific leadership, innovative research and development, and project management expertise.More information about USRA is available at http://www.usra.edu.

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Science in the Southern Hemisphere: SOFIA Deploys to Chile - PR Newswire

I think its fair to say the results exceeded everyones expectations.

Between May and June 2018, the MeerKAT radio telescope observed the center of the Milky Way using 64 antennas located in the Karoo region of South Africa. After more than 200 hours of observations and 3 years of data analysis, the South African Radio Astronomy Observatory (SARAO) released spectacular images of the region near the supermassive black hole in the center of our galaxy, 25,000 light-years from Earth.

Ian Heywood, a senior researcher at the University of Oxford who led the team that analyzed the data, explained that the galactic center was chosen to demonstrate the possibilities of MeerKAT because the region is a notoriously difficult part of the sky to image at radio wavelengths, because of the very bright emission and complicated structure. I think its fair to say the results exceeded everyones expectations.

Radio astronomy is still emerging from its infancy. Just 90 years before MeerKAT became operational, radio engineer Karl Jansky built a 30-meter antenna while working for Bell Telephone Laboratories in New Jersey. He had been commissioned to find the cause of static in transatlantic telephone callsand found that the radio interference came from outer space. At the time, astronomers did not pay much attention to his work. For Heywood, the first radio astronomer who made an impact was Grote Reber, who illustrated the possibilities of radio astronomy by mapping cosmic radio sources in the galaxy in 1968.

Leaps and bounds is how Emily Rice, an associate professor at Macaulay Honors College at the City University of New York, described current advancements in radio astronomy. The angular resolution is so amazing, the sensitivity is so amazing, she added, that we can turn [radio frequencies] into actual pictures.

With new and more powerful radio telescopes, however, there is a need for more efficient ways to process the huge volumes of data, as well as better calibration and imaging algorithms. Observations from MeerKAT to the galactic center produced about 2 terabytes (2,000 gigabytes) of data per day, and there are other observations at MeerKAT that produce even more data, said Fernando Camilo, chief scientist of SARAO. (In comparison, the Hubble Space Telescope produces about 140 gigabytes of data per week.)

Necessity is the mother of invention[and] many novel developments in this area are being led by South African scientists, said Heywood. One of these scientists is Isabella Rammala, a Ph.D. student at the Rhodes Centre for Radio Astronomy Techniques and Technologies at Rhodes University in Makhanda, South Africa. Rammala is interested in identifying pulsar candidates in the galactic center imaged by MeerKAT. I spent most of my time on my computer writing code, she explained, processing the images or cleaning the dataremoving things like radio interference and correcting for instrumental effects and sky effects.

Radio astronomy offers several technical and practical benefits to scientists. Its observations are not obscured by interstellar gas or dust, sunlight, or anomalies in Earths own atmosphere. This means that unlike optical telescopes, radio telescopes can be built at sea level and observations can be made both night and day. For Rammala, studying the universe in multiple wavelengths such as radio, infrared, and gamma ray gives us somewhat of a complete picture of what is going on.

Jackie Villadsen is a visiting assistant professor at Vassar College in New York and an astrophysicist who uses radio astronomy to study nearby stars and their interactions with planets. She said observing the universe with different types of wavelengths reveals vastly different pictures. Radio waves are good for studying extremes, high-energy processes, and very large objects.

According to Villadsen, new and more powerful radio telescopes with better imaging capabilities will help [astronomers] see analogues to the Sun and Jupiter in exoplanetary systems. For example, coronal mass ejections (CMEs) are fairly easy to detect with radio astronomy. Flares can strip away an atmosphere and bake a planets surface, and red dwarf stars, many of which likely have small, rocky planets, have a higher flare rate than the Sun. Detecting stellar CMEs with radio telescopes will help astronomers determine whether planets around red dwarfs are habitable or friendly to life as we know it, said Villadsen.

In addition, astronomers hope to detect radio bursts produced by the aurorae of exoplanets, similar to those produced by aurorae on Jupiter. Detecting these radio waves will permit scientists to determine the planets magnetic field strength, which would reveal information about a planets interior structure and how well it can hold on to its atmosphere when its blasted by material from the star. This might even become a method for detecting new exoplanets, added Villadsen.

Right now, its something of a golden age for radio astronomy.

For Rice, theres always going to be technological advancements, but the most important thing is the effects telescopes have in the communities in which theyre located. For example, when MeerKAT made a call for open time observation proposals in 2020, more than a third of the proposals accepted through a dual anonymous review process were from South African researchers.

According to Camilo, around 10% of SARAOs yearly budget goes to scholarships and grants to support human capital and developmentfrom science projects in a high school in a town near the telescope, to Ph.D. fellowships, to more public support for radio astronomy in South Africa.

Right now, its something of a golden age for radio astronomy, added Heywood.

Santiago Flrez (@rflorezsantiago), Science Writer

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With MeerKAT, Astronomers Peer at the Possibilities of Radio Imaging - Eos

An artistic rendition of Oumuamua, which Loeb believes may have been an alien attempt at contact with Earth. Credit: Nagual Design/Wikimedia Commons/CC BY-SA 4.0

Harvard astronomer Dr. Avi Loeb believes that aliens may have tried to contact us in 2017, when an object called Oumuamua flew past Earth.

In a book published in early 2021, Loeb, who was the head of Harvards astronomy department, asserts that the object may have been extraterrestrial in origin.

When the elongated, red-colored object was spotted in space, both scientists and alien enthusiasts took notice. Not shaped like natural space objects like comets and asteroids, Oumuamua was blunt in shape, measuring about a half mile in length.

The name Oumuamua comes from the Hawaiian for scout.

While the majority of scientists who have studied the object believe it is natural in origin, Loeb argues that it wouldnt be wise to rule out the alien hypothesis.

In his book Extraterrestrial: The First Sign of Intelligent Life Beyond Earth, Loeb contends that Oumuamua is unlike any other space object known to man, and may be the product of alien technology.

Loeb stated in an email to Motherboard that The most exciting aspect of the possibility that Oumuamua is weird and unlike any asteroid or comet that we had seen before is that it might be a product of an alien technology.

If so, we might not be the sharpest cookie in the jar or the smartest kid on the block. We should search for additional interstellar objects to find out, he continued.

He rejected the mainstream opinion that, although undoubtedly strange and unique, Oumuamua was likely just a natural space object and not a product of aliens.

Most of the mainstream astronomy community continued with business as usual and ignored Oumuamuas anomaliesSome mainstream astronomers tried to explain the anomalies but needed to invoke objects that were never seen before, like a hydrogen iceberg or a dust bunny, that are not likely to survive the long interstellar journey.

For its part, NASA states that the object likely came from another solar system and did not behave like a comet in space. Astronomers have never seen a natural object with such extreme proportions in the solar system before, according to NASA.

When Oumuamua was first charted in 2017, Loeb argued that the Green Bank Telescope in West Virginia should listen for radio waves coming from the object to help determine if it was an attempt at contact from extraterrestrials, but no radio waves were discovered.

My point is that it is very difficult to explain the weird properties of Oumuamua with conventional natural processes, so studying objects of its type in the future will either educate us about an unusual natural source or about another civilizationLets collect evidence, and not rely on prejudice, he stated.

Loeb is an Israeli-American theoretical physicist and astronomer. He currently serves as the Frank B. Baird Jr. Professor of Science at Harvard, and was the longest serving chair of the Department of Astronomy at the prestigious university.

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Top Harvard Astronomer Believes Aliens Have Tried to Contact Us - Greek Reporter

It's not too often that a new kind of star is seen in the sky, let alone two examples of it. Especially when it comes to dead stars eating other dead star and leaving behind a star that looks like it's still dying but is in fact previously and still dead.

Yeah, let's back up a sec.

A star like the Sun generates energy by fusing hydrogen into helium in its core. Over time the inert helium builds up, and gets heavily compressed and terrifically hot. Eventually the core becomes totally made of helium, and radiates so much energy that the outer layers of the star expand to compensate for the extra heat. The star becomes a red giant.

Gas at the surface of this bloated star feels less gravity holding it on, but a huge amount of energy pushing it upward from below. Because of this the gas starts blowing away from the star, and over time the entire outer part of the star is ejected, exposing the core to space. We call that object a white dwarf. Specifically a helium white dwarf, since it's almost entirely made of helium.

Sometimes, though, there are different steps that happen between the star being a red giant and becoming a white dwarf. For example, if there's enough pressure on the core that the helium can start to fuse too. This makes carbon and oxygen, which usually sink to the center pretty quickly, leaving the helium floating on the surface with just a trace of carbon and oxygen that can be detected. We call these CO white dwarfs, since they're mostly carbon and oxygen, even though we only see small amounts of them on the surface. They can also drive fierce winds of gas away, creating lovely planetary nebulae.

So here's where things start to get weird. There's a kind of star where the core is not a white dwarf quite yet, but is well on its way. The outer layers are mostly blown off and just a thin layer of helium is left, which may still be fusing into carbon and oxygen. These stars have some characteristics that make them look like normal stars what we just call dwarfs, confusingly but they're smaller and fainter, so these are termed subdwarfs. They can be very hot, so they look like what we call O-type normal stars, and these are called sdOs, for subdwarf O stars.

Here's where things recently got even weirder. Astronomers found a pair of unrelated sdOs, both of which had surfaces mostly composed of helium (link to paper). One is called PG1654+322 and is about 9,000 light years away, and the other is PG1528+025 and is 23,000 light years from us.

Now mind you, most hot subdwarfs like these have at most a few percent carbon and oxygen on their surfaces, and even that much is rare. But these two? They have more than just a trace. Way more: While both have surfaces of about 60% helium, they have a whopping 15 and 25% carbon, respectively, and 23 and 17% oxygen.

That's a lot. Like a lot a lot. Where could all that C and O come from?

And here is where the weirdness peaks: They were both probably helium white dwarfs not long ago, and then ate their binary companions. Which were CO dwarfs.

Yeah, I know, what? Let's look at an example of just one pair to avoid more confusion. Basically, things started off long ago with two normal Sun-like stars orbiting each other. Over time, one died, expanding into a red giant, shedding its layers, yadda yadda, and became a CO white dwarf. The other star in the binary did the same thing, but became a helium white dwarf. So now we have two white dwarfs of different types orbiting each other.

Over time they spiraled together, possible by emitting gravitational waves, though the exact mechanism isn't important here. But here's a critical point: The CO dwarf was low mass, and that means it was bigger. White dwarfs are weird that way; they are so unimaginably compressed by gravity that quantum mechanics becomes important, and WM has weird rules. One of them is that matter in these conditions actually shrinks as you add mass, instead of getting bigger. So low-mass white dwarfs are actually larger than high-mass ones.

Why is that important there? Because the surface gravity of the smaller, more massive one the helium one is stronger, and as the two get closer the helium one can strip material off the surface of the other, essentially eating it. Eventually the CO dwarf is gone, consumed by the helium dwarf. The remaining object has a CO white dwarf core mostly covered by helium but will also have a lot more C and O than you'd expect, and looks more like a subdwarf than a white dwarf.

This is a pretty unlikely scenario, as you might expect, because you need pretty exacting conditions to achieve such a weird little object called a CO-sdO in the end. To find one is pretty nifty, but in this case they found two! Which means there are likely more out there waiting to be found.

Why is this important? Stars die in a myriad of ways, and understanding these pathways tells us about how stars live, how they die, and what's left after. Sometimes white dwarfs in binary systems merge and explode, creating extremely powerful supernovae, bright enough to be seen for billions of light years. Sometimes they merge and lack the mass to do this, and we're left with bizarre sdOs that will eventually just become plain old white dwarfs. The vast majority of all stars literally more than 90% will eventually become white dwarfs, so understanding these compact objects is part of understanding stars.

And stars are the building blocks of galaxies, which are the basic components of the Universe itself. And I think that's a pretty good reason to figure all this out. Plus? It's just cool.

Originally posted here:

Bad Astronomy | White dwarfs found that ate their white dwarf companions - Syfy