Tag: astronomy

Once again, the first known binary of two supermassive black holes flares as predicted

9:37 am

The predicted orbit of OJ287

Using a variety of space telescopes astronomers have successfully predicted and then observed a major flare that occurred on November 12, 2021 from OJ287, the first known binary of two supermassive black holes located 3.5 billion light years away at the center of a very active galaxy dubbed a blazar.

On Nov. 12, 2021, TESS detected OJ 287 brightening by about two magnitudes for about 12 hours, as it released as much energy in that short burst as 100 average galaxies would release in the same time. This flare was attributed to a jet from the second black hole; observations from the other telescopes supported that result as well, with Fermi in particular detecting a significant outburst of gamma rays.

The figure to the right comes from the published paper [pdf], and shows the orbit of the smaller supermassive black hole — weighing 150 million solar masses — as it circled the larger central supermassive black hole — weighing 18 billion solar masses — from 2000 to 2021.

This was not the first time such a flare from OJ287 had been predicted and observed. Astronomers also did it in 2019. These observations now strongly confirm the predicted orbit of the small black hole, as shown in the figure.

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Webb produces false color infrared image of the Crab Nebula

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The Crab Nebula as in infrared by Webb
Click for original image.

The false-color infrared picture to the right, reduced and sharpened to post here, was taken by the Webb Space Telescope of the Crab Nebula, located 6,500 light years away and created when a star went supernova in 1054 AD, in order to better understand its make-up and origins. From the caption:

The supernova remnant is comprised of several different components, including doubly ionized sulfur (represented in green), warm dust (magenta), and synchrotron emission (blue). Yellow-white mottled filaments within the Crab’s interior represent areas where dust and doubly ionized sulfur coincide.

The spectroscopic data from this infrared observation has in fact increased the puzzle of the Crab’s origin. Previously the data suggested the supernova that caused it was one type of supernova. This data now suggests it could have been a different type, without precluding the possibility of the first.

“Now the Webb data widen the possible interpretations,” said Tea Temim, lead author of the study at Princeton University in New Jersey. “The composition of the gas no longer requires an electron-capture explosion, but could also be explained by a weak iron core-collapse supernova.”

You can read the published science paper here [pdf].

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Evidence of giant asteroid collision in debris disk surrounding the star Beta Pictoris

9:48 am

Data difference between Spitzer and Webb
Click for original figure.

Scientists comparing infrared data collected twenty years apart — first by the Spitzer Space Telescope and then by the Webb Space Telescope — think they have detected evidence of a gigantic asteroid collision in the debris disk that surrounds the very young star Beta Pictoris, located 63 light years away.

The graph to the right shows the change found between the observations. From the caption:

Scientists theorize that the massive amount of dust seen in the 2004–05 image from the Spitzer Space Telescope indicates a collision of asteroids that had largely cleared by the time the James Webb Space Telescope captured its images in 2023.

…When Spitzer collected the earlier data, scientists assumed something like small bodies grinding down would stir and replenish the dust steadily over time. But Webb’s new observations show the dust disappeared and was not replaced. The amount of dust kicked up is about 100,000 times the size of the asteroid that killed the dinosaurs, Chen said.

It is believed by scientists that the debris disk that surrounds Beta Pictoris is comparable to the early solar system when the planets first started to form. This collision could be similar to the kind of collision that is thought to have formed the Moon, when a large Mars-sized object smashed into the early Earth.

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Webb detects carbon in early galaxy, far earlier than expected

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The uncertainty of science: Astronomers using the Webb Space Telescope have detected evidence of carbon in a galaxy estimated to exist only 350 million years after the Big Bang, much sooner than any theory had predicted such an element could have developed.

“We were surprised to see carbon so early in the universe, since it was thought that the earliest stars produced much more oxygen than carbon,” said Maiolino. “We had thought that carbon was enriched much later, through entirely different processes, but the fact that it appears so early tells us that the very first stars may have operated very differently.”

According to some models, when the earliest stars exploded as supernovas, they may have released less energy than initially expected. In this case, carbon, which was in the stars’ outer shell and less gravitationally bound than oxygen, could have escaped more easily and spread throughout the galaxy, while a large amount of oxygen fell back and collapsed into a black hole.

The paper is available here.

The scientists are struggling to explain this result in the context of the Big Bang theory itself, and have come up with scenarios where it will work. However, the fact that Webb has found another data point suggesting the early universe was more complicated than any model predicted increases the difficulty in producing Big Bang models that will work.

All in all, there remains great uncertainty here. This particular observation required 65 hours of observation time. Pulling real data from these very distant points of light remains quite challenging.

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Telescope removed from Mauna Kea on Big Island as local Hawaiian council rejects new telescopes on Haleakala on Maui

8:09 am

Even as a local Hawaiian authority on the Big Island has completed the removal of the first of three telescopes on the top of Mauna Kea, a local council on the island of Maui have voted 9-0 to oppose an Air Force project to build new telescopes on top of Haleakala.

The proposed new facility is called AMOS STAR, which is an acronym for Air Force Maui Optical and Supercomputing Site Small Telescope Advanced Research. It would feature six telescopes enclosed in ground-mounted domes and one rooftop-mounted domed telescope.

The county’s resolution urged the military to heed community calls to cease their development efforts. It urged the National Park Service, Federal Aviation Administration and the Hawaii Department of Land and Natural Resources to deny the project permits.

At this time it appears that Hawaiians desended from the original indigenous population are opposed to all western technology, even as they rely on it. These new telescopes are proposed by the Air Force because it needs better capilities to track the tens of thousands of new satellites being launched by numerous companies and governments. This information will help prevent collisions in space.

As for their claims that these peaks are “considered wao akua, or ‘realm of the gods,’ and [places] of deep spirituality for Native Hawaiians to engage in some of these traditional practices,” as stated in the council’s resolution, I have some doubts. For almost three-quarters of a century such religious concerns and objections were never mentioned by anyone. If they existed indigenous Hawaiians appeared to have no problem “engaging in traditional practices” right next to telescopes. Only when some activists appeared in the past decade, looking to insert themselves in the process (thus obtaining positions of power and money) did the peaks become so important religiously.

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Hubble goes to one-gyro mode, limiting the telescope’s observational capabilities; NASA rejects private repair mission

9:59 am

Story Musgrave on the shuttle robot arm during the last spacewalk of the 1993 Hubble repair mission
Story Musgrave on the shuttle robot arm during
the last spacewalk of the 1993 Hubble repair mission

After the third safe mode event in six months, all caused by issues with the same gyroscope, engineers have decided to shift the Hubble Space Telescope to what they call one-gyro mode, whereby the telescope is pointed using only one gyroscope, and the remaining working gyro is kept in reserve.

The spacecraft had six new gyros installed during the fifth and final space shuttle servicing mission in 2009. To date, three of those gyros remain operational, including the gyro currently experiencing problems, which the team will continue to monitor. Hubble uses three gyros to maximize efficiency but can continue to make science observations with only one gyro. NASA first developed this plan more than 20 years ago, as the best operational mode to prolong Hubble’s life and allow it to successfully provide consistent science with fewer than three working gyros. Hubble previously operated in two-gyro mode, which is negligibly different from one-gyro mode, from 2005-2009. One-gyro operations were demonstrated in 2008 for a short time with no impact to science observation quality.

While continuing to make science observations in one-gyro mode, there are some expected minor limitations. The observatory will need more time to slew and lock onto a science target and won’t have as much flexibility as to where it can observe at any given time. It also will not be able to track moving objects closer than Mars, though these are rare targets for Hubble.

This NASA press release is carefully spun to hide the simple fact that in one-gyro mode, the telescope will simply not be able to take sharp pictures. » Read more

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Hubble once again in safe mode due to gyro problem

10:23 am

On May 24, 2024 the Hubble Space Telescope once again paused its science operations and entered in safe mode, apparently due to gyroscope problem.

The telescope automatically entered safe mode when one of its three gyroscopes gave faulty telemetry readings. Hubble’s gyros measure the telescope’s slew rates and are part of the system that determines and controls precisely the direction the telescope is pointed. NASA will provide more information early the first week of June.

It is not clear if this is the same gyroscope that caused the last two safe mode events.

With each such event the telescope gets closer and closer to having only two gyroscopes. At that point it will shift to one-gyro mode, using only one and holding the second in reserve. From then on it will no longer be able to take perfectly sharp pictures. Science will still be possible, but not like before.

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Astronomers find another record-setting most distant galaxy

9:42 am

The uncertainty of science: Using the Webb Space Telescope, astonomers have identified another record-setting most distant galaxy, believed to exist only 300 million years after the Big Bang and once again far more massive and developed than expected that early in the universe.

The galaxy was actually one of two very early galaxies identified that lie close to each other on the sky but are not linked in any way.

The two record-breaking galaxies are called JADES-GS-z14-0 and JADES-GS-z14-1, the former being the more distant of the two. In addition to being the new distance record holder, JADES-GS-z14-0 is remarkable for how big and bright it is. “The size of the galaxy clearly proves that most of the light is being produced by large numbers of young stars,” said Eisenstein, a Harvard professor and chair of the astronomy department, “rather than material falling onto a supermassive black hole in the galaxy’s center, which would appear much smaller.”

The combination of the extreme brightness and the fact that young stars are fueling this high luminosity makes JADES-GS-z14-0 the most striking evidence yet found for the rapid formation of large, massive galaxies in the early Universe.

All the early galaxies that Webb has found so far have been far more massive and developed than cosmologists had predicted. The expectation had been that there wouldn’t have been enough time after the Big Bang for such galaxies to develop. Yet they have, suggesting something is not right with our theories about the beginning of the universe.

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The “Vulcan” exoplanet discovered in 2018 now refuted

9:52 am

In 2018 astronomers had thought they had detected an exoplanet orbiting the star 40 Eridani A — which is where in Star Trek the home world Mr. Spock was supposed to be located.

That discovery has now been refuted by much more precise observations.

[T]he planet signal is really the flickering of something on the star’s surface that coincides with a 42-day rotation – perhaps the roiling of hotter and cooler layers beneath the star’s surface, called convection, combined with stellar surface features such as spots and “plages,” which are bright, active regions.

In other words, this exoplanet does not exist. For once at least life did not imitate art.

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Dry ice and carbon monoxide detected on asteroids beyond Neptune

9:31 am

Based on new infrared observations by the Webb Space Telescope, scientists have detected for the first time carbon dioxide and carbon monoxide on asteroids beyond Neptune. From the abstract of their paper:

Out of 59 [trans-Neptunian objects] and centaur [asteriods] observed by the James Webb Space Telescope and the NIRSpec Integral Field Unit as part of the DiSCo-TNOs project, we report the widespread detection of CO2 ice in 95% of the sample and CO ice in 47% of the sample.

It appears dry ice is ubiquitous in the outer solar system. Since it is believed these asteroids are very primitive, this data suggests there was a lot of it in the early solar system when the planets were forming.

The discovery of so much carbon monoxide is however more puzzling, as it is expected to sublimate away even in the very cold environment so far from the Sun and is therefore likely not from the early solar system. The scientists posit that it might have been produced when radiation transformed the other carbon-bearing ices.

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Visiting a galactic bar

9:27 am

Visiting a galactic bar
Click for original image.

Cool image time! The picture to the right, reduced and sharpened to post here, was taken by the Hubble Space Telescope as part of a research project studying the flow of gases inside barred galaxies. It shows a spiral galaxy, NGC 4731, edge on, located about 43 million light years away. From the caption:

Barred spiral galaxies outnumber both regular spirals and elliptical galaxies put together, numbering around 60% of all galaxies. The visible bar structure is a result of orbits of stars and gas in the galaxy lining up, forming a dense region that individual stars move in and out of over time. This is the same process that maintains a galaxy’s spiral arms, but it is somewhat more mysterious for bars: spiral galaxies seem to form bars in their centres as they mature, accounting for the large number of bars we see today, but can also lose them later on as the accumulated mass along the bar grows unstable. The orbital patterns and the gravitational interactions within a galaxy that sustain the bar also transport matter and energy into it, fuelling star formation.

Astronomers don’t really understand why these barred structures develop, since you would expect the overall gravity of the galaxy would promote a spiral or spherical shape. There must are factors not yet understood or completely identified (such as the magnetic fields of such galaxies).

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Astronomers discover nearby Earth-sized exoplanet only slightly hotter than Earth

10:49 am

Using the TESS space telescope as well as a number of ground-based telescopes astronomers have discovered an Earth-sized exoplanet only 40 light years away that has a surface temperature estimated to be about 107 degrees Fahrenheit, assuming it has no atmosphere.

The host star, called Gliese 12, is a cool red dwarf located almost 40 light-years away in the constellation Pisces. The star is only about 27% of the Sun’s size, with about 60% of the Sun’s surface temperature. The newly discovered world, named Gliese 12 b, orbits every 12.8 days and is Earth’s size or slightly smaller — comparable to Venus. Assuming it has no atmosphere, the planet has a surface temperature estimated at around 107 degrees Fahrenheit (42 degrees Celsius).

At the moment however scientists do not yet know if the exoplanet has an atmosphere or not. Follow-up observations using the Webb Space Telescope are planned to find this out. Based on the data presently available, the exoplanet could either be like Venus, too hot to sustain life, or like Earth, cooler with water and an atmosphere and thus very habitable.

Gliese 12 b could therefore become one of the primary targets for the first interstellar missions once humanity begins such exploration.

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Euclid releases new images and first science results

10:37 am

Euclid image
Click for original image.

The Euclid science team today released five early science images in connection of the publication of ten papers.

The picture to the right is one of those images, cropped, reduced, and sharpened to post here. From the caption:

In this image Euclid showcases NGC 6744, an archetype of the kind of galaxy currently forming most of the stars in the local Universe. Euclid’s large field-of-view covers the entire galaxy, capturing not only spiral structure on larger scales but also exquisite detail on small spatial scales. This includes feather-like lanes of dust emerging as ‘spurs’ from the spiral arms, shown here with incredible clarity.

Scientists are using this dataset to understand how dust and gas are linked to star formation; map how different star populations are distributed throughout galaxies and where stars are currently forming; and unravel the physics behind the structure of spiral galaxies, something that is still not fully understood after decades of study.

Euclid is a wide-field space telescope that has instruments that observe in both visible and near-infrared wavelengths. Its primary mirror at 1.2 meters is half the width of Hubble’s. More details about these early images and links to the new science results can be found here.

Unlike Hubble, it appears Euclid will not be used as a general observatory, at least initially. Its primary goal is to do a survey of one third of the sky, focusing on extragalactic sources outside the Milky Way. Once this is complete however it is possible the space telescope will be made available for other observations.

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Earth-sized exoplanet discovered orbiting dwarf star 55 light years away

10:49 am

Using a number of ground-based telescopes worldwide, astronomers have discovered an Earth-sized exoplanet orbiting what the scientists label an “ultra-cool” dwarf star only about 55 light years away.

You can read the paper here.

Though Earth-sized, this exoplanet is not habitable. It orbits the star every 17 hours and is believed to be tidally locked, with one side always facing the star. More important, though this red dwarf star has likely existed for many tens of billions of years and will continue for many tens of billions of years into the future, the star is too dim and lacking in the kind of resources needed for life. It also drenches the planet with bursts of radiation, which is also believed to have stripped the planet of an atmosphere.

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The aurora as seen looking down from space

9:12 am

The aurora over the U.S. on May 11, 2024
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NOAA on May 13, 2024 released a set of eight images taken by its fleet of JPSS weather satellites, showing the strong Aurora Borealis or Northern Lights that were activated over the May 11th weekend due to several very strong solar flares on the Sun and sent a geomagnetic storm at the Earth.

One of those images, reduced to post here, is to the right. You can see the eastern coast of the United States, outlined by city lights, with a band of aurora cutting across the northern half and reaching south below the Great Lakes. The other seven images are available at the link above.

The geomagnetic storm was the strongest produced by the Sun in more than two decades, since 2003. That storm occurred during solar maximum, as did the May 11th this past weekend. However, the Sun experienced another solar maximum in-between, in 2014, which produced few such storms, and none as strong.

I want to add that despite the screams of panic prior to the arrival of this storm, its arrival produced only minor disturbances in the world’s electrical grid, and in fact was proof positive that the many decades of work that electrical companies have devoted to protecting the grid from such storms has paid off. It is very unlikely any major storm from the Sun can harm that grid in the future, unless of course we get lazy and stop maintaining it.

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A planet with the density of cotton candy?

10:32 am

The uncertainty of science: According to data obtained from ground-based telescopes of a newly discovered transiting exoplanet, that planet has the density of cotton candy.

This new planet, located 1,200 light-years from Earth, is 50% larger than Jupiter but seven times less massive, giving it an extremely low density comparable to that of cotton candy. “WASP-193b is the second least dense planet discovered to date, after Kepler-51d, which is much smaller,” explains Khalid Barkaoui, a Postdcotral Researcher at ULiège’s EXOTIC Laboratory and first author of the article published in Nature Astronomy. Its extremely low density makes it a real anomaly among the more than five thousand exoplanets discovered to date. This extremely-low-density cannot be reproduced by standard models of irradiated gas giants, even under the unrealistic assumption of a coreless structure.”

Such a gas giant is not impossible. For example, Saturn’s density is so low that if you could find an ocean large enough it would float. The scientists theorize that this exoplanet is likly comprised mostly of hydrogen and helium.

Nonetheless, there are phenomenon here that we certainly do not understand.

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XRISM X-ray space telescope functioning despite closed “aperture door”

9:50 am

XRISM, a joint X-ray space telescope built by NASA and Japan’s space agency JAXA, is collecting data despite the failure on one instrument of an aperture door to open.

In January, project scientists said that XRISM was working well except for an aperture door, also called a gate valve, for the Dewar on its imaging instrument, Resolve, which failed to open. The instrument can still operate with the door closed, although the door, made of beryllium, does attenuate some X-rays at lower energies.

At the time, efforts were underway to try and open the gate valve. However, speaking at a May 7 meeting of the National Academies’ Board on Physics and Astronomy, Mark Clampin, director of NASA’s astrophysics division, said those efforts were on hold for the next year and a half.

Instead, the science team decided to proceed with science operations, since the telescope has two other working instruments, and can get data even from this hindered third.

XRISM is a replacement of a previous JAXA X-ray telescope that launched in 2016 but failed immediately.

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A galaxy’s net of dust

10:02 am

A galaxy's net of dust
Click for full image.

Cool image time! The picture to the right, cropped, reduced, and sharpened to post here, was taken by the Hubble Space Telescope of the central part of galaxy NGC 4753, 60 million light years away and known as a lenticular galaxy because of its elongated elliptical shape and ill-defined spiral arms. It is believed we looking at this galaxy edge-on.

You can see a wider image of NGC 4753 here, released in January and taken by the Gemini South telescope in Chile. According to that press release, the brown dust lanes that seem to form a wavy net in the foreground are created by a process called differential precession:

Precession occurs when a rotating object’s axis of rotation changes orientation, like a spinning top that wobbles as it loses momentum. And differential means that the rate of precession varies depending on the radius. In the case of a dusty accretion disk orbiting a galactic nucleus, the rate of precession is faster toward the center and slower near the edges. This varying, wobble-like motion results from the angle at which NGC 4753 and its former dwarf companion collided and is the cause of the strongly twisted dust lanes we see wrapped around the galaxy’s luminous nucleus today.

Once again, the limitation of only observing this object from one angle makes it very difficult to untangle what it really looks like. Therefore, these conclusions carry a great deal of uncertainty.

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The spiral dust streams within the Andromeda galaxy

10:15 am

Andromeda in infrared
Click for original image.

Cool image time! The picture above, cropped and reduced to post here, was released yesterday and uses archival infrared data from the now retired Spitzer Space telescope to highlight the dust found within the Andromeda galaxy, about two million light years away.

Spitzer’s infrared view was similar to Webb’s but at a far lower resolution. In the picture above the red indicates cool dust.

By separating these wavelengths and looking at the dust alone, astronomers can see the galaxy’s “skeleton” — places where gas has coalesced and cooled, sometimes forming dust, creating conditions for stars to form. This view of Andromeda revealed a few surprises. For instance, although it is a spiral galaxy like the Milky Way, Andromeda is dominated by a large dust ring rather than distinct arms circling its center. The images also revealed a secondary hole in one portion of the ring where a dwarf galaxy passed through.

The data also suggested that the dust is flowing at a very steady rate into Andromeda’s central black hole. According to computer simulations, this steady rate would explain why the supermassive black holes at the center of both Andromeda and the Milky Way are relative inactive. If the dust fell in clumps rather than a steady flow, both black holes would exhibit bursts of high activity, similar to active galactic centers.

A side note for anyone wishing to star-gaze: Andromeda is actually the largest visible galaxy in the night sky, about six times with width of the full Moon. If you can get to a very dark-sky location, get your eyes very dark-adapted, and you know where to look, you can actually see it with the naked eye. I did this once at a star party, helped by a bunch of amateur astronomers. The galaxy is very faint, and it helps to use binoculars to help locate it, but once identified its size in the sky truly is breath-taking.

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TESS resumes science operations

9:26 am

Engineers have corrected the issue that put the space telescope TESS into safe mode on April 8, 2024 and have resumed science operations.

The operations team determined this latest safe mode was triggered by a failure to properly unload momentum from the spacecraft’s reaction wheels, a routine activity needed to keep the satellite properly oriented when making observations. The propulsion system, which enables this momentum transfer, had not been successfully repressurized following a prior safe mode event April 8. The team has corrected this, allowing the mission to return to normal science operations. The cause of the April 8 safe mode event remains under investigation.

As for that April 8th safe mode, though engineers were able to return the spacecraft to normal operations after about a week, that they still do not know what caused it remains a concern.

TESS takes high resolution survey images of 93% of the sky about once per month. By comparing the data from each scan, scientists have discovered so far more than 300 transiting exoplanets as well as many supernovae and other phenomenon related to variable stars.

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A supernova factory

9:44 am

A supernova factory

Cool image time! The picture to the right, cropped, reduced, and sharpened to post here, was taken by the Hubble Space Telescope in 2023 as part of a survey of galaxies where recent supernovae have occurred. One occurred in 2020 in this galaxy, which is about 240 million light years away and dubbed UGC 9684.

Remarkably, the 2020 supernova in this galaxy isn’t the only one that’s been seen there — four supernova-like events have been spotted in UGC 9684 since 2006, putting it up there with the most active supernova-producing galaxies. It turns out that UGC 9684 is a quite active star-forming galaxy, calculated as producing one solar mass worth of stars every few years! This level of stellar formation makes UGC 9684 a veritable supernova factory, and a galaxy to watch for astronomers hoping to examine these exceptional events.

This image provides scientists a high resolution baseline should another supernova occur. It will not only make it easier to spot a future supernova, it also increases the chances that the progenitor star that went boom could be identified.

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Hubble out of safe mode and resumed science observations

8:43 am

According to the Hubble website, engineers have corrected the gyro issue that put the Hubble Space Telescope into safe mode on April 23, 2024.

On April 30, 2024, NASA announced it restored the agency’s Hubble Space Telescope to science operations April 29. The spacecraft is in good health and once again operating using all three of its gyros. All of Hubble’s instruments are online, and the spacecraft has resumed taking science observations.

No other information was released. The safe mode was initiated by faulty readings from one of those gyros. Was the problem in the gyro itself, or were the readings merely incorrect? This matters because when one of those gyros finally fails, the telescope will go to one-gyro mode, saving its second gyro in reserve. At that point Hubble will no longer be able to take sharp images, though it will still be able to some science.

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Webb maps the global temperature and water vapor of a hot exoplanet

10:37 am

The uncertainty of science: Using detailed infrared data from the Webb Space Telescope, scientists have mapped the temperature swings and atmospheric water vapor across the entire global of a tidally locked “hot Jupiter” exoplanet about 284 light years away that orbits its star every 19.5 hours.

The team used Webb’s MIRI (Mid-Infrared Instrument) to measure light from the WASP-43 system every 10 seconds for more than 24 hours. “By observing over an entire orbit, we were able to calculate the temperature of different sides of the planet as they rotate into view,” explained Bell. “From that, we could construct a rough map of temperature across the planet.”

The measurements show that the dayside has an average temperature of nearly 2,300 degrees Fahrenheit (1,250 degrees Celsius) – hot enough to forge iron. Meanwhile, the nightside is significantly cooler at 1,100 degrees Fahrenheit (600 degrees Celsius). The data also helps locate the hottest spot on the planet (the “hotspot”), which is shifted slightly eastward from the point that receives the most stellar radiation, where the star is highest in the planet’s sky. This shift occurs because of supersonic winds, which move heated air eastward.

…To interpret the map, the team used complex 3D atmospheric models like those used to understand weather and climate on Earth. The analysis shows that the nightside is probably covered in a thick, high layer of clouds that prevent some of the infrared light from escaping to space. As a result, the nightside – while very hot – looks dimmer and cooler than it would if there were no clouds.

The data also found water vapor on both the day and night sides of the exoplanet, but surprisingly no evidence of methane, suggesting that atmosphere has high winds exceeding 5,000 miles per hour that mixes that atmosphere globally. Any methane that was expected to exist on the night side gets blown to the day side where the heat destroys it.

This data, while excellent, is also very coase and even more uncertain. While Webb can get good infrared spectroscopy from almost 300 light years away, we must take the interpretations of that data with great skepticism.

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Webb takes an infrared look at the mane of the Horsehead Nebula

10:01 am

Context images
Click for original image.

The mane of the Horsehead Nebula, seen in infrared
Click for original image.

The cool infrared image to the right, cropped, reduced, and sharpened to post here, was taken by the Webb Space Telescope and released today. The three pictures above provide the context, with the rectangle inside the rightmost image indicated the area covered by the close-up to the right.

Webb’s new images show part of the sky in the constellation Orion (The Hunter), in the western side of a dense region known as the Orion B molecular cloud. Rising from turbulent waves of dust and gas is the Horsehead Nebula, otherwise known as Barnard 33, which resides roughly 1,300 light-years away.

The nebula formed from a collapsing interstellar cloud of material, and glows because it is illuminated by a nearby hot star. The gas clouds surrounding the Horsehead have already dissipated, but the jutting pillar is made of thick clumps of material and therefore is harder to erode. Astronomers estimate that the Horsehead has about five million years left before it too disintegrates. Webb’s new view focuses on the illuminated edge of the top of the nebula’s distinctive dust and gas structure.

In the close-up, note the many distant tiny galaxies, both above the mane as well as glowing throught it.

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Movies of two supernovae remnants produced from two decades of Chandra X-ray images

9:51 am

Using more than two decades of data from the Chandra X-ray Observatory, scientists have created two movies of the supernovae remnants the Crab nebula and Cassiopeia A.

I have embedded those movies below. From the press release:

Over 22 years, Chandra has taken many observations of the Crab Nebula. With this long runtime, astronomers see clear changes in both the ring and the jets in the new movie. Previous Chandra movies showed images taken from much shorter time periods — a 5-month period between 2000 and 2001 and over 7 months between 2010 and 2011 for another. The longer timeframe highlights mesmerizing fluctuations, including whip-like variations in the X-ray jet that are only seen in this much longer movie. A new set of Chandra observations will be conducted later this year to follow changes in the jet since the last Chandra data was obtained in early 2022.

…Cassiopeia A (Cas A for short) is the remains of a supernova that is estimated to have exploded about 340 years ago in Earth’s sky. While other Chandra movies of Cas A have previously been released, including one with data extending from 2000 to 2013, this new movie is substantially longer featuring data from 2000 through to 2019.

» Read more

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Hubble celebrates 34 years in orbit with a new photo of the Little Dumbbell Nebula

9:53 am

The Little Dumbbell Nebula
Click for original image.

Cool image time! To celebrate the 34th anniversay of its launch in 1990, astronomers have used the Hubble Space Telescope to take a new photo of the Little Dumbbell Nebula (also known as M76), located about 3,400 light years away and one of the most well-known planetary nebulae in the sky.

That picture is to the right, cropped, reduced, and sharpened to post here. From the caption:

M76 is composed of a ring, seen edge-on as the central bar structure, and two lobes on either opening of the ring. Before the star burned out, it ejected the ring of gas and dust. The ring was probably sculpted by the effects of the star that once had a binary companion star. This sloughed off material created a thick disk of dust and gas along the plane of the companion’s orbit. The hypothetical companion star isn’t seen in the Hubble image, and so it could have been later swallowed by the central star. The disk would be forensic evidence for that stellar cannibalism.

The primary star is collapsing to form a white dwarf. It is one of the hottest stellar remnants known at a scorching 250,000 degrees Fahrenheit, 24 times our Sun’s surface temperature. 
The sizzling white dwarf can be seen as a pinpoint in the center of the nebula. A star visible in projection beneath it is not part of the nebula.



Pinched off by the disk, two lobes of hot gas are escaping from the top and bottom of the “belt,” along the star’s rotation axis that is perpendicular to the disk. They are being propelled by the hurricane-like outflow of material from the dying star, tearing across space at two million miles per hour.

Since launch Hubble has made 1.6 million observations of over 53,000 astronomical objects, and continues to be in high demand by astronomers, with only one request in six able to get time on the telescope. Not surprisingly, almost all of Hubble’s biggest discoveries were unexpected. Its future right now rests with its last three working gyroscopes used to orient it precisely. When one more fails, it will go to one-gyro mode, which will limit the precision of that orientation significantly. At that point the sharpness of the telescope’s imagery will sadly decline.

The only comparable orbital optical telescope now planned is China’s Xuntian optical telescope, scheduled for launch next year. It will fly in formation with the Tiangong-3 space station, allowing astronauts to periodically do maintenance missions to it. As I noted many times previously, American astronomers better start learning Chinese, assuming China even allows them access. Nor will these American astronomers have a right to complain, as it was their decision to not build a Hubble replacement, in their 2000, 2010, and 2020 decadal reports.

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Patchy arms in a nearby spiral galaxy

9:16 am

Patchy arms in spiral galaxy
Click for original image.

Cool image time! The photo to the right, reduced and sharpened to post here, was taken by the Hubble Space Telescope to study this southern hemisphere galaxy in detail. The galaxy, dubbed ESO 422-41, is located about 34 million light years away, and thus is a relatively close neighbor. From the caption:

A spiral galaxy, with a brightly shining core and two large arms. The arms are broad, faint overall and quite patchy, and feature several small bright spots where stars are forming. A few foreground stars with small diffraction spikes can be seen in front of the galaxy.

The patchy nature of the two arms makes each somewhat indistinct, so that at first glance this galaxy looks more like a elliptical blob, until you look close and notice those arms winding around that bright core. And as patchy as those arms are, the patches of blue are regions where new stars are forming.

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Analysis of Io’s atmosphere suggests it has been volcanically active for its entire 4+ billion year history

9:34 am

By analysizing the isotobes in Io’s atmosphere, scientists now believe that it has been volcanically active since its initial formation at the birth of the solar system 4.5 billion years ago.

de Kleer et al. found that both elements [ sulfer- and chlorine-bearing molecules] are highly enriched in heavy isotopes compared to average Solar System values due to the loss of lighter isotopes from the upper atmosphere as material is continuously recycled between Io’s interior and atmosphere. The findings indicate that Io has lost 94% to 99% of the sulfur that undergoes this outgassing and recycling process. According to the authors, this would require Io to have had its current level of volcanic activity for its entire lifetime.

This data suggests that Io, as well as Jupter’s other three large Galilean moons (Europa, Calisto, and Ganymeded) have been in their present orbits since their formation 4.5 billion years ago. It also means that, while Io’s geological history keeps getting wiped out by its volcanic activity, the other three contain detailed geological records of the solar system’s entire history. Combine that with the geological data we will eventually get from Mars, it appears that we shall someday be able to document that history far beyond anything expected.

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TESS has resumed science operations

9:15 am

Engineers have successfully returned TESS to full science operations, without providing as yet any explanaton as to why on April 8, 2024 it went into safe mode or what they did to fix the issue.

The Aprill 11 press release announcing the safe mode had only mentioned that the shut down had occurred “during scheduled engineering activities.” The lack of information continues to suggest that someone did an “Oops!” during those activities, and NASA is too embarassed to reveal that fact.

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Using Gaia data scientists discover the heaviest stellar black hole ever found

10:30 am

In digging into the precise motion data from the Gaia space telescope scientists have discovered the Milky Way’s heaviest stellar-sized black hole, with a mass thirty-three times the mass of our Sun.

Stellar black holes are formed from the collapse of massive stars and the ones previously identified in the Milky Way are on average about 10 times as massive as the Sun. Even the next most massive stellar black hole known in our galaxy, Cygnus X-1, only reaches 21 solar masses, making this new 33-solar-mass observation exceptional.

Remarkably, this black hole is also extremely close to us — at a mere 2000 light-years away in the constellation Aquila, it is the second-closest known black hole to Earth.

The only known black hole inside the Milky Way that is larger is Sagittarius A* (pronounced A-star), the supermassive central black hole at the galaxy’s center and weighing over four million solar masses. That creature is a very different thing, as it involves the long term evolution of the galaxy itself. Stellar-sized black holes only involve the death of a single star, with possible additions from a handful of others.

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