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On February 15th, Intuitive Machines (IM) launched its first Nova-C class spacecraft from Kennedy Space Center in Florida atop a SpaceX Falcon 9 rocket. On February 22nd, the spacecraft – codenamed Odysseus (or “Odie”) – became the first American-built vehicle to soft-land on the lunar surface since the Apollo 17 mission in 1972. While the landing was a bit bumpy (Odysseus fell on its side), the IM-1 mission successfully demonstrated technologies and systems that will assist NASA in establishing a “sustained program of lunar exploration and development.”

After seven days of operation on the lunar surface, Intuitive Machines announced on February 29th that the mission had ended with the onset of lunar night. While the lander was not intended to remain operational during the lunar night, flight controllers at Houston set Odysseus into a configuration that would “call home” if it made it through the two weeks of darkness. As of March 23rd, the company announced that their flight controllers’ predictions were correct and that Odie would not be making any more calls home.

The company started listening for a wake-up signal from Odysseus on March 20th, when they projected that there was enough sunlight in the lander’s vicinity. At the time, it was thought that this could potentially charge Odysseus‘ power system, allowing it to activate its radio and reestablish contact with Houston. However, three days later, at 10:30 AM Central Standard Time (08:30 AM PST; 11:30 AM EST), flight controllers determined that the lander was not charging up after it completed its mission.

Image from the IM-1 Odysseus lander after it soft landed on the lunar surface. Credit: Intuitive Machines

This consisted of the Nova-C spacecraft making its inaugural soft landing on the Moon, the first time an American spacecraft has done so in over 50 years. The IM-1 mission was also the first time a spacecraft used methalox – the combination of liquid methane and liquid oxygen (LOX) – to navigate between the Earth and the Moon. While the IM-1 was not expected (or intended) to survive the lunar night, the data acquired by this mission could prove useful as the company continues to improve the lunar landing systems to deliver payloads to the Moon.

One of the company’s main objectives is to develop heat and power sources that can “keep systems from freezing during the lunar night.” This technology will greatly extend the life of lunar surface missions and facilitate the buildup of infrastructure on the Moon’s surface. A second Nova-C lander with the IM-2 mission will launch aboard a Falcon 9 no earlier than December 2024. This mission will land a drill and the Polar Resources Ice Mining Experiment-1 (PRIME-1) mass spectrometer near the south pole of the Moon.

This NASA payload will demonstrate the feasibility of In-Situ Resource Utilization (ISRU) and measure the volatile content of subsurface samples. ISRU and the presence of water are vital to the creation of a lunar base and the ability to send crews to the lunar surface well into the foreseeable future. A third mission (IM-3) is scheduled for early 2025, which will carry four NASA payloads to the Reiner Gamma region of the Moon, a rover, a data relay satellite, and secondary payloads to be determined. All three launches were contracted as part of NASA’s Commercial Lunar Payload Services (CLPS) program.

In addition, the IM-1 mission controllers and company managed to have a final farewell with the Odysseus mission before nightfall and the depletion of its battery power. On February 22nd, the lander transmitted a final image (shown below), which mission controllers in Houston received by February 29th. The image, Intuitive Machines said in a statement, “showcases the lunar vista with the crescent Earth in the backdrop, a subtle reminder of humanity’s presence in the universe. Goodnight, Odie. We hope to hear from you again.”

The last image sent by the IM-1 Odysseus mission on Feb. 22nd, 2024. Credit: Intuitive Machines

Further Reading: Intuitive Machines

The post Lunar Night Permanently Ends the Odysseus Mission appeared first on Universe Today.

We can’t understand what we can’t clearly see. That fact plagues scientists who study how planets form. Planet formation happens inside a thick, obscuring disk of gas and dust. But when it comes to seeing through that dust to where nascent planets begin to take shape, astronomers have a powerful new tool: the James Webb Space Telescope.

In the past few years, we’ve been getting tantalizing looks at the protoplanetary disks around young stars. ALMA, the Atacama Large Millimetre/submillimetre Array, is responsible for that. It’s imaged many of these disks around young stars, including the telltale gaps where planets are likely forming.

ALMA’s high-resolution images of nearby protoplanetary disks are the results of the Disk Substructures at High Angular Resolution Project (DSHARP). Credit: ALMA (ESO/NAOJ/NRAO), S. Andrews et al.; NRAO/AUI/NSF, S. Dagnello

Imaging the disks is now becoming a regular occurrence, but astronomers have only spotted two forming planets.

But now researchers have brought the JWST to bear on the problem. Three new studies in The Astronomical Journal present the results of that effort. They are:

• JWST/NIRCam Imaging of Young Stellar Objects. I. Constraints on Planets Exterior to the Spiral Disk Around MWC 758
• JWST/NIRCam Imaging of Young Stellar Objects. II. Deep Constraints on Giant Planets and a Planet Candidate Outside of the Spiral Disk Around SAO 206462
• JWST/NIRCam Imaging of Young Stellar Objects. III. Detailed Imaging of the Nebular Environment around the HL Tau Disk

The research combines new JWST observations with previous observations by the Hubble and ALMA. The astronomers behind each of the studies used the JWST to uncover new, early clues about the planet formation process, including how the process shapes the disk they’re born from. If they can identify features unique to planet formation, they can then look for these features around other disks.

HL Tau, SAO 206462 and MWC 758 are all protoplanetary disks that have been observed by other telescopes. The JWST’s powerful infrared capabilities should provide new insights into these disks and their planets. That’s because as planets gather more material to them, they release infrared radiation.

“When material falls onto the planet, it shocks at the surface and gives off an emission line at specific wavelengths,” said astronomer Gabriel Cugno, who was involved with all three papers. “We use a set of narrow-band filters to try to detect this accretion. This has been done before from the ground at optical wavelengths, but this is the first time it’s been done in the infrared with JWST.”

MWC 758 is a young star that hosts a spiral protoplanetary disk.

This JWST/NIRCam image of MWC 758 shows the star’s unusual spiral disk. Wagner et al. 2024.

Using mathematical simulations, the researchers showed that a giant planet called MWS 758c outside the spirals can produce the spirals. They also showed that the symmetry of the arms can constrain the planet’s mass. In this case, they can determine a lower range for the planet’s mass: between about 4 to 8 Jupiter masses. But they didn’t find it. There may also be an even more massive companion further out, according to the simulations, but none was detected.

SAO 206462 is another young star surrounded by a disk. It also has clearly defined spiral arms, signifying the presence of a massive planet. The astronomers studying this star and disk did find a planet, but not the one they expected.

This is a JWST image of the star SAO 296462 and its spiral disk. Image Credit: Cugno et al. 2024.

“Several simulations suggest that the planet should be within the disk, massive, large, hot, and bright. But we didn’t find it. This means that either the planet is much colder than we think, or it may be obscured by some material that prevents us from seeing it,” said lead author Gabriele Cugno, also a co-author on the other paper papers. “What we have found is a different planet candidate, but we cannot tell with 100% certainty whether it’s a planet or a faint background star or galaxy contaminating our image. Future observations will help us understand exactly what we are looking at.”

Massive gas giants are expected to be responsible for the spiral shapes. But even the JWST struggles to find them. “The problem is, whatever we’re trying to detect is hundreds of thousands, if not millions of times fainter than the star,” Cugno said. “That’s like trying to detect a little light bulb next to a lighthouse.”

HL Tau is the third star and disk that the JWST examined and the youngest, at less than 100,000 years old. HL Tau is well-known in astronomy for the telltale gaps and rings in its disk, as well as some other features. For example, astronomers found water vapour in its disk right in the location where a suspected planet is forming.

In this image of HL Tau, observations from the Atacama Large Millimeter/submillimeter Array (ALMA) show water vapour in shades of blue in the same location where astronomers thought a planet may be forming. Image Credit: ALMA (ESO/NAOJ/NRAO)/S. Facchini et al.

The JWST found the known stellar envelope, outflow cavity, and other features. But, unfortunately, no planet.

This image from the paper shows an ALMA image of HL Tau and a JWST image of HL Tau. The JWST is able to see details that the ALMA image doesn’t show, including a feature called the hook-shaped clump. Image Credit: Mullin et al. 2024

“HL Tau is the youngest system in our survey and still surrounded by a dense inflow of dust and gas falling onto the disk,” said Mullin, a co-author of all three studies. “We were amazed by the level of detail with which we could see this surrounding material with JWST, but unfortunately, it obscures any signals from potential planets.”

One of the difficulties with HL Tau is its youth. The younger a star is, the more gas and dust is in the disk. It eventually gets taken up by planets, and the rest is dissipated by disk wind. But HL Tau is so young that the disk is very thick.

“While there is a ton of evidence for ongoing planet formation, HL Tau is too young with too much intervening dust to see the planets directly,” said Jarron Leisenring, the principal investigator of the observing campaign searching for forming planets and astronomer at the University of Arizona Steward Observatory. “We have already begun looking at other young systems with known planets to help form a more complete picture.”

But astronomy is full of surprises, especially when working with a powerful tool like the JWST. Astronomers often set out to find one thing and find something else they didn’t expect. That’s what happened with HL Tau.

This image of HL Tau from 2016 shows an inner gap and an outer gap where planets may be forming. Unfortunately, the JWST wasn’t able to detect them. But it did find other features. Image Credit: Yen et al. 2016.

In this case, the JWST detected HL Tau’s stellar envelope, where in-falling material gathers around the still coalescing young star. This material eventually becomes part of the star, disk, and planets.

While the astronomers behind all three papers hoped to find planets, that proved difficult. But the JWST’s sensitivity still helped them make progress.

“The lack of planets detected in all three systems tells us that the planets causing the gaps and spiral arms either are too close to their host stars or too faint to be seen with JWST,” said Wagner, a co-author of all three studies. “If the latter is true, it tells us that they’re of relatively low mass, low temperature, enshrouded in dust, or some combination of the three—as is likely the case in MWC 758.”

Planet formation could be the key to understanding how some planets end up with water and how other chemical elements are distributed in a solar system. Astronomers think that massive gas giants like Jupiter end up regulating the movement and flow of elements. But not all stars host planets so massive.

“Only about 15 percent of stars like the sun have planets like Jupiter. It’s really important to understand how they form and evolve and to refine our theories,” said U-M Michael Meyer, University of Michigan astronomer and coauthor of all three studies. “Some astronomers think that these gas giant planets regulate the delivery of water to rocky planets forming in the inner parts of the disks.”

Image of Jupiter taken by NASA’s Juno spacecraft. Massive gas giants like Jupiter might govern the movement of water in a young solar system, affecting which planets get it. That’s just one of the reasons why astronomers want to find them around young stars. (Credit: NASA/JPL-Caltech/SwRI/MSSS/Kevin M. Gill)

In every disk that astronomers can get a good look at, they find gaps, rings, and sometimes spirals and other structures that can be explained by the formation of giant planets. But they also can’t rule out other explanations. And this is where the issue stands, for now.

“Basically, in every disk we have observed with high enough resolution and sensitivity, we have seen large structures like gaps, rings and, in the case of SAO 206462, spirals,” Cugno said. “Most if not all of these structures can be explained by forming planets interacting with the disk material, but other explanations that do not involve the presence of giant planets exist.”

Finding these massive planets forming around young stars is the next step. Even though the JWST didn’t find them, it still made progress on the issue. That’s how science works. Because if astronomers can eventually see some of these planets, they can then untangle the relationships between all the other features the JWST has observed with the planets themselves.

“If we manage to finally see these planets, we can connect some of the structures with forming companions and relate formation processes to the properties of other systems at much later stages,” Cugno said. “We can finally connect the dots and understand how planets and planetary systems evolve as a whole.”

Upcoming telescopes can make even more progress. The ESO’s Extremely Large Telescope will probe the earliest stages of planetary formation and will also detect water and organic chemicals in protoplanetary disks. Its first light is scheduled for 2028.

The Giant Magellan Telescope will also study the formation of planetary systems with its Near-Infrared Spectrograph. The GMT will see its first light in the 2030s.

The post Webb Joins the Hunt for Protoplanets appeared first on Universe Today.

Scientists have shown that Barkhausen noise can be produced not only through traditional, or classical means, but through quantum mechanical effects. The research represents an advance in fundamental physics and could one day have applications in creating quantum sensors and other electronic devices.

Analysing the diversity of organic compounds dissolved in freshwater provides a reliable measure of ecosystem health, say scientists.

Solar scientists have been preparing for years for a 4-minute window, during the total solar eclipse on 8 April, in which they will study the sun's corona

Historical astronomical records from China and Japan recorded a supernova explosion in the year 1181. It was in the constellation Cassiopeia and it shone as bright as the star Vega for 185 days. Modern astronomers took their cue from their long-gone counterparts and have been searching for its remnant.

But it took them time to find it because they were looking for the wrong thing.

When a massive star runs out of fuel, it collapses in on itself and then explodes. It leaves behind a dense core where the protons and electrons are crushed into neutrons. It’s called a neutron star, and they’re the smallest and densest stellar objects in the Universe other than black holes.

It took a concerted effort from astronomers over the years to understand SN 1181’s remnant. At first, they couldn’t even find it.

For a time, researchers thought that the pulsar 3C 58 was the remnant. The ancient Chinese and Japanese records were not accurate enough to pinpoint SN 1181’s exact location, and the pulsar was the only known supernova remnant in the area. However, as astronomers studied 3C 58, they determined that it was much too old to be the remnant.

This X-ray image of pulsar 3C58 is from NASA’s Chandra X-ray Observatory. At 3500 years old, it’s too old to be the remnant of SN 1181. Image Credit: By NASA – http://apod.nasa.gov/apod/ap041223.htmlhttp://chandra.harvard.edu/photo/2004/3c58/, Public Domain, https://commons.wikimedia.org/w/index.php?curid=4074985

In 2013, an American amateur astronomer discovered a nebula, now named Pa 30, near the region where the Japanese and Chinese saw it. It has an extremely blue central star, and now the name Pa 30 refers to both the star and the nebula.

The cyan region in this image is where modern astronomers think SN 1181’s remnant should be, according to ancient Japanese and Chinese documents. Astronomers were guided by the ancient names and locations of constellations, like Wangliang and Ziwei. (Modern constellations are shown in grey.) The pulsar 3C58 is outside the region, while the white dwarf Pa 30 is inside it. Image Credit: By Bradley E. Schaefer – https://arxiv.org/abs/2301.04807, CC BY 4.0, https://commons.wikimedia.org/w/index.php?curid=140937093

Eventually, in 2018, French amateur astronomers working with an 8-inch telescope spotted a very hot blue star in the remnant’s center. It had a very odd spectrum, unlike stars in the centers of other remnants. Then, in 2019, astronomers published a paper showing that the nebula had a fierce stellar wind with a high velocity. This was strong evidence that what they were seeing was a supernova remnant.

But where was the neutron star? There was none, and in its place was a white dwarf. That means that astronomers were wrong about what type of supernova SN 1181 was.

SN 1181 wasn’t a core-collapse supernova, the type caused by a massive star that collapses in on itself and then explodes as it runs out of fuel. It was a Type Iax, a supernova created when two white dwarfs merge and explode. Those explosions typically leave no remnants, but in this case, it did. The Type Iax explosion was incomplete, and it’s responsible for the SN remnant’s unusual shape and the fact that the remnant isn’t a neutron star but a zombie star.

The leading image is a composite image of the Pa 30, the name given to the remnant and the star. The data for the image comes from multiple telescopes that capture different parts of the electromagnetic spectrum.

A composite image of the remnant of supernova 1181, called Pa 30. G. Ferrand and J. English (U. of Manitoba), NASA/Chandra/WISE, ESA/XMM, MDM/R.Fessen (Dartmouth College), Pan-STARRS

X-rays captured by the ESA’s XMM-Newton spacecraft are shown in blue, tracing the nebula’s full extent. NASA’s Chandra X-ray Observatory pinpointed the central source in the middle, the star named WD J005311. With a temperature greater than 220,000 Kelvin, it’s the hottest star known.

The remnant is almost invisible in optical light but is bright in infrared. NASA’s Wide-field Infrared Space Explorer (WISE) captured the infrared, shown in red and pink in the image. The nebula’s radial structure is interesting and has an unusual cause. The lines are heated sulphur glowing in visible light, captured by the ground-based Hiltner 2.4 m telescope at the MDM Observatory. The background stars were imaged with Pan-STARRS.

The ancient Japanese and Chinese who recorded the event had no real idea what they were seeing. They were more like court bureaucrats than astronomers, and they were steeped in astrology, not science. A member of the Japanese imperial court wrote that the supernova was “a sign of abnormality.” Another chronicler wrote that it was an “occasion for making auspicious offerings for a good harvest.”

But modern science shows us that it’s none of those things. Instead, it’s a wondrous object in the distant heavens, the result of forces and energies that the ancients had no idea existed. As a supernova, it forged heavy elements—especially the ones needed for life to appear—and spread them out into space. Its shock waves could’ve even triggered the birth of more stars as it slammed into the interstellar medium.

They couldn’t have known any of this, but from their perspective, they were right about one thing. As a Type Iax supernova that left behind a zombie star, SN 1181 was definitely a sign of abnormality.

The post This Supernova Lit Up the Sky in 1181. Here’s What it Looks Like Now appeared first on Universe Today.

A super-stretchy hydrogel can stretch to 15 times its original length and return to its initial shape, and could be used to make soft inflatable robots

We know how stars form. Clouds of interstellar gas and dust gravitationally collapse to form a burst of star formation we call a stellar nursery. Eventually, the cores of these protostars become dense enough to ignite their nuclear furnace and shine as true stars. But catching stars in that birth-moment act is difficult. Young stars are often hidden deep within their dense progenitor cloud, so we don’t see their light until they’ve already started shining. But new observations from the Hubble Space Telescope have given us our earliest glimpse of a shiny new star.

You can see this image above, which captures the dusty region of the FS Tau system. The bright star just to the right of center is FS Tau A, which is a young star just 2.8 million years old. An infant compared to our Sun’s 4.6 billion years. But the exciting discovery is a bit higher and further right, known as FS Tau B. That line of dust obscuring the protostar is its protoplanetary disk seen edge-on. The light coming from the obscured star isn’t produced by nuclear fusion, but rather the late stages of gravitational collapse.

You can also see that the protostar has begun to produce radiant jets, which are reflected against the dusty nebula as regions of blue light. Because of this reflected light, FS Tau B is classified as a Herbig-Haro (HH) object. HH objects are great for helping astronomers understand the early dynamics of these stars.

FS Tau B is likely in the early stages of becoming a T Tauri star. These are sun-like stars just on the edge of becoming true stars. They can be quite active, with starspots and large flares, but can take 100 million years for one to ignite their cores and settle into a true main-sequence star. As that happens, protoplanets will form within the dusty disk, ready to become full planets in time.

You can find more information about the FS Tau system, as well as high-resolution images and videos, on the ESA Hubble website.

The post Hubble Sees a Star About to Ignite appeared first on Universe Today.

This article in The Atlantic, a very good piece, is written by Theo Baker, who, only a sophomore, is already a skilled journalist. (His reporting also helped bring down Stanford’s President for promulgating bogus research.)  The article is long but engrossing, and describes the intense friction between pro-Palestinian and pro-Israeli (mostly Jewish) students at Stanford, a school that in recent years has been damaged by an infestation of ideology. (Remember the deplatforming of conservative Judge Duncan, which led to the firing of Stanford’s equity dean?)

Baker takes the trouble to interview almost everyone concerned, including Stanford’s President Saller and Provost Martinez, as well as a number of students on both sides, and in the end manages to convey the view that, as it is here in Chicago, most of the trouble is being fomented by aggressive, angry, and loud pro-Palestinian students. (Baker seems to be Jewish.) But the incidents he describes are fascinating and well researched.

You might be able to read the article by clicking below, but if it’s paywalled you can find it archived here. 

I’ll give just one excerpt, but you really should read the whole thing. If I don’t miss my guess, Baker has a good career in front of him.

Zionists, and indeed Jewish students of all political beliefs, have been given good reason to fear for their safety. They’ve been followed, harassed, and called derogatory racial epithets. At least one was told he was a “dirty Jew.” At least twice, mezuzahs have been ripped from students’ doors, and swastikas have been drawn in dorms. Arab and Muslim students also face alarming threats. The computer-science section leader, El Boudali, a pro-Palestine activist, told me he felt “safe personally,” but knew others who did not: “Some people have reported feeling like they’re followed, especially women who wear the hijab.”

In a remarkably short period of time, aggression and abuse have become commonplace, an accepted part of campus activism. In January, Jewish students organized an event dedicated to ameliorating anti-Semitism. It marked one of  [temporary President] Saller’s first public appearances in the new year. Its topic seemed uncontroversial, and I thought it would generate little backlash.

Protests began before the panel discussion even started, with activists lining the stairs leading to the auditorium. During the event they drowned out the panelists, one of whom was Israel’s special envoy for combating anti-Semitism, by demanding a cease-fire. After participants began cycling out into the dark, things got ugly.

Activists, their faces covered by keffiyehs or medical masks, confronted attendees. “Go back to Brooklyn!” a young woman shouted at Jewish students. One protester, who emerged as the leader of the group, said that she and her compatriots would “take all of your places and ensure Israel falls.” She told attendees to get “off our fucking campus” and launched into conspiracy theories about Jews being involved in “child trafficking.” As a rabbi tried to leave the event, protesters pursued him, chanting, “There is only one solution! Intifada revolution!”

At one point, some members of the group turned on a few Stanford employees, including another rabbi, an imam, and a chaplain, telling them, “We know your names and we know where you work.” The ringleader added: “And we’ll soon find out where you live.” The religious leaders formed a protective barrier in front of the Jewish students. The rabbi and the imam appeared to be crying.

Saller avoided the protest by leaving through another door. Early that morning, his private residence had been vandalized. Protesters frequently tell him he “can’t hide” and shout him down. “We charge you with genocide!” they chant, demanding that Stanford divest from Israel. (When asked whether Stanford actually invested in Israel, a spokesperson replied that, beyond small exposures from passive funds that track indexes such as the S&P 500, the university’s endowment “has no direct holdings in Israeli companies, or direct holdings in defense contractors.”)

The image of a rabbi and imam, weeping as they’re trying together to protect the Jewish students, is unforgettable. It reminds me a bit of the Four Chaplains during World War II who went down with their ship.

h/t: Susan

Anyone can be an underachiever, even if you’re an astronomical singularity weighing over four billion times the mass of the Sun. At least the quasar H1821+643 doesn’t have parents to be disappointed in it. But its underachievement could shed light on how quasars, a potent type of black hole, can come to influence entire clusters of galaxies, as described in a new paper from researchers at the University of Nottingham and Harvard.

Using X-ray data from the Chandra observatory, the researchers looked closely at H1821+643 and decided it influenced its local environment much less than expected. Granted, a lot was expected of it – quasars are super powerful black holes that rapidly pull in new material rapidly and eject radiation as well as sometimes emitting powerful streams of particles. In particular, H1821+643 is a quasar located about 3.4 billion light-years away from Earth at the center of a cluster of galaxies. 

Both the quasar and its surrounding galaxy are shrouded in a field of hot gas that showed up as a fuzzy haze in Chandra’s X-ray dataset. That fuzzy haze, which would let astronomers understand what was happening to the gas in the galaxy at large, was massively overwhelmed by the brightness of the X-rays emitted from the quasar itself.

Fraser describes what quasars are.

To study the effects of the quasar on the location gas population, the researchers had to remove the effects of its own X-rays, leaving only the light emitted from the gas itself. They found that the gas is significantly less hot than might be expected given its proximity to such a forceful quasar, showing that the quasar itself isn’t outputting as much energy as might otherwise be expected.

Counterintuitively, the Chandra data shows that the density of gas around the quasar is higher. At the same time, the temperature is cooler than areas of the galaxy that are further away from the center. If the quasar were emitting the typical series of outbursts, they would have expected there to be not as much gas close to the quasar itself, as the outbursts would have blown it away and that what gas there was close in would be heated to extraordinarily high temperature by those same outbursts.

Without those outbursts, though, the local environment appears to be rife for star formation. The authors estimate that gas equivalent to about 3,000 times the mass of our Sun cools below the point where it emits X-rays every year. Some of that cooling gas is formed into about 120 solar masses worth of new stars yearly, while the black hole itself swallows up another 40 solar masses. What happens with the thousands of solar masses of gas left over after those two processes is anyone’s guess.

Here’s a fund, speculative video from Fraser about whether our own supermassive black hole could become a quasar.

However, the quasar itself isn’t cooling the gas surrounding it. At least not much. This process can happen when photons emitted from the black hole run into the electrons of the surrounding gas, resulting in an energy transfer that increases the energy of the photon but decreases the energy of the electron – hence causing the gas to cool down. While that process might be ongoing near H1821-643, the authors calculate that it would only explain a small percentage of the cooling of the gas they observed.

In short, much is still unknown about this seemingly unique quasar system. Studying it further can help scientists understand the influence these massive singularities can have on their immediate surroundings and physical properties more generally. At least, no matter what H1821-643’s physical properties might be, it won’t be getting chewed out by its parents.

Learn More:
NASA / CXC – NASA’s Chandra Identifies an Underachieving Black Hole
Russell et al. – A cooling flow around the low-redshift quasar H1821+643
UT – What Is A Quasar?
UT – This New Map of 1.3 Million Quasars Is A Powerful Tool

Lead Image:
Image of the H1821-643 quasar.
Credit: X-ray: NASA/CXC/Univ. of Nottingham/H. Russell et al.
Radio: NSF/NRAO/VLA
Image Processing: NASA/CXC/SAO/N. Wolk

The post This Black Hole is a Total Underachiever appeared first on Universe Today.

The Solar and Heliospheric Observatory (SOHO) was designed to examine the Sun, but as a side benefit, it has been the most successful comet hunter ever built. Since early in the mission, citizen scientists have been scanning through the telescope’s data, searching for icy objects passing close to the Sun. An astronomy student in Czechia has identified 200 comets in SOHO data since he started in 2009 at the age of 13. He recently spotted the observatory’s 5,000th comet.

“Prior to the launch of the SOHO mission and the Sungrazer Project, there were only a couple dozen sungrazing comets on record – that’s all we knew existed,” said Karl Battams, who is the principal investigator for the Sungrazer Project, the citizen science project that was launched after so many comets started showing up in the data. “The fact that we’ve finally reached this milestone – 5000 comets – is just unbelievable to me.”

SOHO moves around the Sun on the sunward side of Earth, where it enjoys a clear, uninterrupted view of the Sun, by slowly orbiting around Lagrange point L1.  That means it has been observing the Sun 24 hours a day, 365 days a year without interruptions since shortly after it launched in 1995. With this view, SOHO can easily spot the kind of comet that’s known as a sungrazer – so named because of their close approach to the Sun. Many of these comets don’t survive their close pass to the Sun.

Many congratulations to Hanjie Tan (@HonkitTan) for making that 5,000th discovery! Hanjie has been discovering comets with the Sungrazer Project since he was 13yrs old, and is now pursuing for his PhD studying asteroids! pic.twitter.com/wa51ZlVnjm

— Karl Battams (@SungrazerComets) March 27, 2024

Hanjie Tan is the student who discovered the 5,000th comet. Inspired by his many years of searching for comets, Tan is now an astronomy PhD student in Prague, Czechia, studying comets and asteroids. The small comet that he spotted is part of the ‘Marsden group’ of comets, named after the British astronomer Brian Marsden, who first recognized the group based on SOHO observations. Marsden group comets are thought to be pieces shed by the much bigger Comet 96P/Machholz, which SOHO observes as it passes close to the Sun every 5.3 years.

“The Marsden group comets represent only about 1.5% of all SOHO comet discoveries,” said Tan in an ESA press release, “so finding this one as the 5000th SOHO comet felt incredibly fortunate. It’s really exciting to be the first to see comets get bright near the Sun after they’ve been travelling through space for thousands of years.”

Artist’s impression of the SOHO spacecraft studying the Sun. Credit: NASA/ESA.

The SOHO mission has now been operational for almost 30 years. It’s almost been lost twice and is now flying without the use of its gyroscopes, which help it point precisely. Engineers have figured out a way to work around the issue. It’s longevity has not only provided an incredible treasure trove of data about the Sun, but it also has allowed the spacecraft to become the most prolific discoverer of comets in astronomical history.

Related: 22 years of the Sun from SOHO

Launched in 1995, SOHO studies the Sun from its interior to its outer atmosphere, providing unique views and investigating the cause of the solar wind. During the last three decades, SOHO has become the most prolific discoverer of comets in astronomical history.

“A huge congratulations to EVERYONE who has ever contributed to Sungrazer,” Battams said on Twitter. “Hanjie may have found #5000, but it took 24-years of combined volunteer ‘amateur’ scientist efforts to find the other 4,999. This was a team effort, and I’m so thankful to all who have helped!”

The post Someone Just Found SOHO's 5,000th Comet appeared first on Universe Today.

Measuring the distance to far away objects in space can be tricky. We don’t even know the precise distance to even our closest neighbors in the Universe – the Small and Large Magellanic Clouds. But, we’re starting to get to the tools to measure it. One type of tool is a Cepheid Variable – a type of star that varies its luminosity in a well-defined pattern. However, we don’t know much about their physical properties, making utilizing them as distance markers harder. Finding their physical properties would be easier if there were any Cepheid binaries that we could study, but astronomers have only found one pair so far. Until a recent paper from researchers from Europe, the US, and Chile shows measurements of 9 additional binary Cepheid systems – enough that we can start understanding the statistics of these useful distance markers.

Like traditional stars, binary Cepheid systems result when two stars orbit around each other. In this case, both of those stars must be Cepheids – meaning they are massive compared to our Sun and much brighter. In addition, their luminosity must vary in a repeatable pattern so that we can track it consistently.

All of those features can vary a lot if two stars change in luminosity but at different rates and phases around each other. It’s difficult to parse out which star is waxing, which is waning, and which direction they are moving in, both compared to us and each other. Long periods of observation are required to fix some of those variables, and that is precisely what the new paper describes.

The researchers looked at nine sets of Cepheids that were believed to be binary systems but hadn’t yet been confirmed due to the difficulty of separating the two stars from each other. They pulled data from the Optical Gravitational Lensing Experiment (OGLE) database, a variable star observation project run by the University of Warsaw for over 30 years. In so doing, they could confirm, for the first time, that each of these suspected binaries contained two separate stars.

Those nine binary systems were located in the Small and Large Magellanic Cloud and the Milky Way. One located in the Milky Way is by far the closest, at only 11 kiloparsecs (about 3000 light-years) away. The researchers also had good luck because of the length of orbital periods of the binaries they studied – most were over five years, and a shorter observational data set might not have caught them. 

Understanding how these systems exist and where they are is just the first step. Using them for more helpful science is the next. The most obvious way to do so is to increase our understanding of Cepheids. Despite being one of the most commonly used distance markers in the Universe, we know surprisingly little about how they form, what they’re made of, or their life cycle. Closely studying a binary system, where the stars interact, could help shed light (figuratively in this sense) on some of those properties.

Calibrated Period-luminosity Relationship for Cepheids
Credit – NASA

As the authors point out in their paper, this is part of a long-term ongoing project – they were also part of the team that confirmed the original Cepheid binary system back in 2014. OGLE continues to collect more data, as are other sky surveys, and there are likely more Cepheid binaries out there. Every new discovery will help improve our statistical understanding of these critical distance markers – we just need to take the time to find them first.

Learn More:
Pilecki et al. – Cepheids with giant companions II. – Spectroscopic confirmation of nine new double-lined binary systems composed of two Cepheids
UT – What are Cepheid Variables?
UT – Polaris is the Closest, Brightest Cepheid Variable. Very Recently, Something Changed.
UT – Astronomers Rule Out One Explanation for the Hubble Tension

Lead Image:
RS Puppis , one of the brightest known Cepheid variable stars in the Milky Way galaxy
Credit – NASA, ESA, and the Hubble Heritage Team

The post Astronomers Only Knew of a Single Binary Cepheid System. Now They Just Found Nine More appeared first on Universe Today.

Luana and I have been trying to get an accurate figure for the difference in VOLUME between a human sperm and egg, which of course reflects a difference in metabolic investment in making them.  I’m talking now about cytoplasmic volume, not length, as the disparity in length isn’t that relevant (in some flies, the sperm are longer than the fly!).

The figure bandied about is a volume difference of ten million, but I don’t believe that. All these figures trace back to one assertion on a Northwestern University site, but the paper it cites doesn’t give any such figure (or any figure).  Everybody quotes that figure, but it seems way too large for me. However, it might be accurate.

So, I’m crowdsourcing the answer. I have no prize here except for approbation (and I’ll put the winner and correct answer below).

Question: What is the difference in cytoplasmic volume between a human sperm and a human egg?  A reference to a respectable source must be included.

Thank you!

The Smart Lander for Investigating Moon spacecraft has sent back images after surviving its second lunar night – generally these periods are so cold they destroy spacecraft electronics

Generative artificial intelligence (AI) might be best known from text or image-creating applications like ChatGPT or Stable Diffusion. But its usefulness beyond that is being shown in more and more different scientific fields.

Generative artificial intelligence (AI) might be best known from text or image-creating applications like ChatGPT or Stable Diffusion. But its usefulness beyond that is being shown in more and more different scientific fields.

Researchers suggests a groundbreaking strategy to expedite the commercialization of metalens technology.

New research has discovered a rare dust particle trapped in an ancient extra-terrestrial meteorite that was formed by a star other than our sun.

The ALMA radio telescope has detected more than 100 molecular species, including many indicative of different star formation and evolution processes, in a galaxy where stars are forming much more actively than in the Milky Way. This is far more molecules than were found in previous studies. Now the team will try to apply this knowledge to other galaxies.

A breakthrough in sustainable molecular transformations has been announced. Chemists have developed an important way to harness the power of visible light to drive chemical processes with greater efficiencies, offering a greener alternative to traditional methods.