Tag: astronomy

Viewing Comet Tsuchinshan-ATLAS when it enters the evening sky

9:20 am

Link here. For those living in the northern hemisphere, Comet Tsuchinshan-ATLAS will be bright and visible to the naked eye just after sunset beginning tomorrow.

“As soon as October 11th, ambitious comet spotters may pick up the comet during twilight just above the western horizon,” says Sky & Telescope Contributing Editor Bob King. “Binoculars will help you see the comet throughout its appearance.”

About 40 minutes after sunset on Friday, find a spot with a good view down to the western horizon. The first thing that will catch your eye will be the bright planet Venus, the Evening Star — that’s your starting point. Hold your fist out at arm’s length; the comet is about 2½ fists to Venus’s right. The comet will still look tiny in Friday’s twilight — like a hazy star with a small tail — and will set while twilight is still in progress.

Comet Tsuchinshan-ATLAS (pronounced choo-cheen-SHAHN) will remain visible for the next ten days, with the best viewing likely from October 13th to October 16th.

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Jupiter’s Great Red Spot appears to jiggle like Jello on a 90-day cycle

9:07 am

Jupiter as seen by Hubble over time
Click for original image.

Using the Hubble Space Telescope to photograph Jupiter’s Great Red Spot repeatedly over a four month period from December 2023 to March 2024 scientists have detected a 90-day cycle in which the spot oscillated in shape, shaking like Jello.

“While we knew its motion varies slightly in its longitude, we didn’t expect to see the size oscillate. As far as we know, it’s not been identified before,” said Amy Simon of NASA’s Goddard Space Flight Center in Greenbelt, Maryland, lead author of the science paper published in The Planetary Science Journal. “This is really the first time we’ve had the proper imaging cadence of the GRS. With Hubble’s high resolution we can say that the GRS is definitively squeezing in and out at the same time as it moves faster and slower. That was very unexpected, and at present there are no hydrodynamic explanations.”

The four images to the right are some of those observations. For a full movie showing the changes over ninety days, go here.

The scientists also predict that though the spot has been shrinking for decades, they expect that shrinkage to stop once the spot size no longer extends beyond the jet stream band within which it sits. At that point the different jet streams in the upper and lower bands will hold the spot in place and its size will stabilize.

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Astronomers find another galaxy that shouldn’t be there in the early universe

9:44 am

REBELS-25
Click for original image.

The uncertainty of science: Using ground-based telescopes, astronomers have identified a galaxy only 700 million years after the Big Bang that is far more organized and coherent in shape and structure than thought possibly that soon after the theorized creation of the universe.

The galaxy in question is dubbed REBELS-25. It is at a red shift of z=7.31, which means that it is from a time when the universe was only 700 million years old. The earliest galaxies ever seen are only a few hundred million years older.

REBELS by name rebel by nature. This odd galaxy has stumped astronomers because it shows evidence of an ordered structure and rotation. It may even have a central elongated bar and spiral arms, though further observation is needed to confirm these structures.

This is in contrast to the small, messy, lumpy and chaotic norm for galaxies of a similar age. “According to our understanding of galaxy formation, we expect most early galaxies to be small and messy looking,” says co-author Jacqueline Hodge, an astronomer at Leiden University in the Netherlands.

You can read the published paper here [pdf]. The picture to the right shows this galaxy as seen by the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile.

The consensus view of the early universe said there would not have been enough time for such a structured galaxy to form. And yet as astronomers use the improved astronomical instrumentation of our time to look deeper and deeper at that early universe, they keep finding things — like this galaxy — that defy that consensus view.

The answer to this mystery remains unknown, and is likely not yet answerable with the data we presently have. The data we do have however is beginning to suggest that scientists might have to begin looking at fundamentally different theories as to the inital formation of the universe. The Big Bang might still work, but if so it might require a major rewrite.

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Scientists confirm theory that thunderstorms on Earth also produce gamma ray bursts

11:42 am

Prior to the 1990s, the origin of gamma ray bursts (GRBs) was uttlerly known. First detected by satellites in the early 1970s, astronomers has no idea what caused them because without a parallel detection in optical light they had no way to determine their distance. Theories suggested the bursts could be coming from billions of light years away, from within the Milky Way, from inside the solar system, and from even the Earth’s upper atmosphere.

In the 1990s it was finally proven that GRBs almost all come from very distant cosmic events, billions of light years away, each signaling the formation of a black hole.

Now researchers have confirmed the theory that GRBs are also occuring within the Earth’s atmosphere, though these GRBs have no resemblance to the astronomical ones.

During thunderclouds, two different hard radiation phenomena have so far been known to originate: Terrestrial Gamma-ray Flashes (TGFs) and gamma-ray glows. This third phenomenon, observed and named FGFs by Østgaard et al. [2024] resembles the other two, while at the same time revealing certain characteristics separating FGFs from the others. Most noteworthy may be that FGFs are pulses of gamma-rays not associated with any detectable optical or radio signals.

“We think that FGFs could be the missing link between TGFs and gamma-ray glows, whose absence has been puzzling the atmospheric electricity community for two decades”, says lead author and Professor Nikolai Østgaard at the University of Bergen.

More information on this research can be found here. The research not only confirms the early theories as well as later detections, it adds significant nuance to the data. As noted at this second link:

“The dynamics of gamma-glowing thunderclouds starkly contradicts the former quasi-stationary picture of glows, and rather resembles that of a huge gamma-glowing boiling pot both in pattern and behavior,” said Martino Marisaldi, professor of physics and technology at the University of Bergen.

Given the size of a typical thunderstorm in the tropics, which get much larger than storms at other latitudes, this suggests that more than half of all thunderstorms in the tropics are radioactive. The researchers postulate that this low-level production of gamma radiation acts like steam boiling off a pot of water and limits how much energy can be built up inside.

This data will help refined the computer models that attempt to predict weather patterns, as it appears the phenomenon impacts the formation of thunderstorms.

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Viewing Comet Tsuchinshan-ATLAS

9:02 am

While the newly discovered Comet Tsuchinshan-ATLAS in the past week reached naked eye visibility in the dawn sky, in the next few weeks it will shift into the evening sky on October 11, 2024 while brightening to peak levels.

Although Comet Tsuchinshan-ATLAS will be visible in both hemispheres, the northern one is favored because the comet tracks north. Also, sunsets are getting earlier and twilights shorter, while the opposite is happening in southern latitudes.

Observers should be aware that the Moon will interfere for several nights, from about Oct. 15-20 (full Moon is on Oct. 17th), around the same time the comet climbs out of twilight.

As it begins to fade, the comet will be visible at an increasing height above the horizon each night through the end of October. At its brightest it is expected to be one of the brightest objects in the sky.

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Astronomers detect exoplanet half as massive as the Earth around second closest star system

11:28 am

Using the Very Large Telescope (VLT) in Chile, astronomers have detected evidence of an exoplanet about half as massive as the Earth orbiting Barnard’s Star, only six light years away and the second closest star system.

Barnard’s Star is a prime target in the search for exoplanets due to its proximity and its status as a red dwarf, a common type of star where low-mass planets are often found. Despite a promising signal detected in 2018, no planet had been definitively confirmed around it until now. The ESPRESSO spectrograph [on VLT] … enabled the astronomers to detect Barnard b, a subterrestrial planet that orbits the star in 3.15 days. The team also identified signals indicating the possible presence of three other candidate exoplanets, which have yet to be confirmed.

Back in the 1960s using the less precise instruments of the time, astronomers thought they had detected an exoplanet orbiting Barnard’s Star. That detection however proved false. The detection is real, however, and adds weight to the growing evidence that planets can form around red dwarf stars, the most common stars in the universe with the longest lifespan, predicted to be many tens of billions of years. Having planets around such stars significantly increases the chances of habitable planets, even if those planets do not harbor life of its own.

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Data from two different studies suggest Betelgeuse has a Sun-sized companion star

9:46 am

Betelqeuse
An optical image of Betelgeuse taken in 2017 by a ground-based
telescope, showing its not unusual aspherical shape.
Click for original image.

Two different independent studies have uncovered evidence that the red giant star Betalgeuse likely has an unseen companion star about the mass of the Sun and orbiting it every six years.

MacLeod and colleagues linked a six-year cycle of Betelgeuse brightening and dimming to a companion star tweaking its orbit, in a paper submitted to arXiv.org September 17. MacLeod examined global, historical measurements dating back to 1896.

Separately, Jared Goldberg of the Flatiron Institute in New York and colleagues used the last 20-odd years of measurements of Betelgeuse’s motion on the sky, which have the highest precision. That team also found evidence of a companion nudging the bigger star, submitted to arXiv.org August 17.

Previous observers noticed Betelgeuse’s light varying on a roughly six-year cycle. In 1908, English astronomer Henry Cozier Plummer suggested the cycle could be from the gravity of a companion star tugging Betelgeuse back and forth.

You can download the two papers here and here. This quote from the first paper’s abstract not only explains why the star has not been detected previously, but suggests its doomed future:

The companion star would be nearly twenty times less massive and a million times fainter than Betelgeuse, with similar effective temperature, effectively hiding it in plain sight near one of the best-studied stars in the night sky. The astrometric data favor an edge-on binary with orbital plane aligned with Betelgeuse’s measured spin axis. Tidal spin-orbit interaction drains angular momentum from the orbit and spins up Betelgeuse, explaining the spin–orbit alignment and Betelgeuse’s anomalously rapid spin. In the future, the orbit will decay until the companion is swallowed by Betelgeuse in the next 10,000 years. [emphasis mine]

The presence and future capture of this small companion star will help astronomers better calculate future fluctuations of Betelgesue itself. That capture is also going to occur relatively soon, on astronomical time scales.

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The jet 3,000 light years long that causes nearby stars to explode

10:48 am

The jet from M87
Click for original image.

Cool image time! The picture to the left, cropped, reduced, and sharpened to post here, was taken by the Hubble Space Telescope of the giant eliptical galaxy M87, known for more than a century by astronomers for the jet of gas that points outward from its center. Astronomers now know that this jet is produced by a supermassive black hole in the center of M87, weighing 6.5 billion times the mass of our Sun.

The blowtorch-like jet seems to cause stars to erupt along its trajectory. These novae are not caught inside the jet, but are apparently in a dangerous neighbourhood nearby. During a recent 9-month survey, astronomers using Hubble found twice as many of these novae going off near the jet as elsewhere in the galaxy. The galaxy is the home of several trillion stars and thousands of star-like globular star clusters.

M87 is considered an old galaxy, but its entire formation process remains uncertain.

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Webb takes an infrared look at a galaxy looked at by Hubble

12:21 pm

Comparing Hubble with Webb
For original images go here and here.

Cool image time! The bottom picture on the right, cropped to post here, is a just released false color infrared image of the galaxy Arp 107, taken by the Webb Space Telescope. The picture at the top is a previously released optical image taken by the Hubble Space Telescope and featured as a cool image back in September 2023. The Hubble image was taken as part of a survey project to photograph the entire Arp catalog of 338 “peculiar galaxies,” put together by astronomer Halton Arp in 1966. In this case Arp 107 is peculiar because it is actually two galaxies in the process of merging. It is also peculiar because the galaxy on the left has an active galactic nuclei (AGN), where a supermassive black hole is sucking up material and thus emitting a lot of energy.

The Webb infrared image was taken to supplement that optical image. The blue spiral arms indicate dust and star-forming regions. The bright orange object in the center of the galaxy is that AGN, clearly defined by Webb’s infrared camera.

When I posted the Hubble image in 2023, I noted that “if you ignore the blue whorls of the left galaxy, the two bright cores of these merging galaxies are about the same size.” In the Webb image the two cores still appear about the same size, but in the infrared they produce emissions in decidedly different wavelengths, as shown by the different false colors of orange and blue. The core of the galaxy on the right is dust filled and forming stars, while the core of the left galaxy appears to have less dust with all of its emissions resulting from the energy produced by the material being pulled into the supermassive black hole.

The universe is very active and changing, but to understand that process we humans have to look at everything across the entire electromagnetic spectrum, not just in the optical wavelengths our eyes see.

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Newly discovered potentially dangerous asteroid found to be a contact binary

11:38 am

Radar images of asteroid 2024ON
Click for original image.

Radar images taken during the close fly of a newly discovered potentially dangerous asteroid has revealed that it is a contact binary, formed by two objects stuck together to produce a single asteroid with a peanutlike shape.

Discovered by the NASA-funded Asteroid Terrestrial-impact Last Alert System (ATLAS) on Mauna Loa in Hawaii on July 27, the near-Earth asteroid’s shape resembles that of a peanut. Like the asteroid 2024 JV33 that made close approach with Earth a month earlier, 2024 ON is likely a contact binary, with two rounded lobes separated by a pronounced neck, one lobe about 50% larger than the other. The radar images determined that it is about 755 feet (350 meters) long. Features larger than 12.3 feet (3.75 meters) across can be seen on the surface. Bright radar spots on the asteroid’s surface likely indicate large boulders. The images show about 90% of one rotation over the course of about six hours.

The radar images were taken one day before that close approach of 620,000 miles on September 17, 2024, and once again show that a large number of near-Earth asteroids, as much as 14%, are contact binaries. The data also helped better refine 2024ON’s orbit around the Sun, which show that though the asteroid has the potential to hit the Earth, its path will not do so for the foreseeable future.

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What the Milky Way would look like if it was presently a star forming powerhouse

9:15 am

A galaxy as seen by Hubble and Webb
For the original images go here and here.

Cool image time! The two pictures to the right, taken respectively by the Hubble and Webb space telescopes of the same galaxy, shows us many different features of a barred galaxy, located about 35 million light years away. From the caption for the Hubble image:

This picture is composed of a whopping ten different images taken by the Hubble Space Telescope, each filtered to collect light from a specific wavelength or range of wavelengths. It spans Hubble’s sensitivity to light, from ultraviolet around 275 nanometres through blue, green and red to near-infrared at 1600 nanometres. This allows information about many different astrophysical processes in the galaxy to be recorded: a notable example is the red 656-nanometre filter used here. Hydrogen atoms which get ionised can emit light at this particular wavelength, called H-alpha emission. New stars forming in a molecular cloud, made mostly of hydrogen gas, emit copious amounts of ultraviolet light which is absorbed by the cloud, but which ionises it and causes it to glow with this H-alpha light.

Therefore, filtering to detect only this light provides a reliable means to detect areas of star formation (called H II regions), shown in this image by the bright red and pink colours of the blossoming patches filling NGC 1559’s spiral arms.

The Z-shaped blue indicates the stars and its most distinct spiral arms. Astronomers presently believe that the Milky Way is also a barred spiral like this, though its star-forming regions are thought to be far less extensive and distinct.

The Webb infrared image matches the Hubble data, with the false color blue indicating the near-infrared and the false color red the mid-infrared. As with the Hubble picture, the red indicates the galaxy’s extensive star forming regions.

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Mars loses hydrogen at very different rates, depending on the planet’s distance from the Sun

11:37 am

Hubble uv images of Mars atmosphere
Click for original image.

Scientists using data from both the MAVEN Mars Orbiter and the Hubble Space Telescope have determined that the rate in which Mars loses hydrogen and deuterium varies considerably during the Martian year, with the rate going up rapidly when the red planet reaches its closest point to the Sun. The picture to the right, reduced to post here, shows the data from Hubble.

These are far-ultraviolet Hubble images of Mars near its farthest point from the Sun, called aphelion, on December 31, 2017 (top), and near its closest approach to the Sun, called perihelion, on December 19, 2016 (bottom). The atmosphere is clearly brighter and more extended when Mars is close to the Sun.

Reflected sunlight from Mars at these wavelengths shows scattering by atmospheric molecules and haze, while the polar ice caps and some surface features are also visible. Hubble and NASA’s MAVEN showed that Martian atmospheric conditions change very quickly. When Mars is close to the Sun, water molecules rise very rapidly through the atmosphere, breaking apart and releasing atoms at high altitudes.

From this data scientists will be better able to map out the overall loss rate of water on Mars over many billions of years.

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Two-lobed asteroid imaged by radar

10:04 am

Two-lobed asteroid
Click for original image.

During the August 18, 2024 first close fly-by of a potentially-dangerous asteroid only discovered back in May, astronomers used the Goldstone dish in California to produce the high resolution radar images shown in the picture to the right, reduced and sharpened to post here.

The images were captured when the asteroid was at a distance of 2.8 million miles (4.6 million kilometers), about 12 times the distance between the Moon and Earth.

Discovered by the NASA-funded Catalina Sky Survey in Tucson, Arizona, on May 4, the near-Earth asteroid’s shape resembles that of a peanut – with two rounded lobes, one lobe larger than the other. Scientists used the radar images to determine that it is about 980 feet (300 meters) long and that its length is about double its width. Asteroid 2024 JV33 rotates once every seven hours.

Asteroids formed as contact binaries, once considered the stuff of science fiction, have now been found to be relatively common, comprising about 14% of the near Earth asteroids larger than 700 feet across that have been radar-imaged. The refined orbital data suggests this asteroid might be a dead comet, though that conclusion is unconfirmed. That orbital data also tells us that though this object has the potential of hitting the Earth, it will not do so “for the foreseeable future.”

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Scientists find oldest known reference to a solar eclipse dated approximately 6,000 years ago

9:36 am

In studying an ancient Hindu text called the Rig Veda that was compiled around 1,500 BC, scientists have found what they think is the oldest known reference to a solar eclipse, dated approximately 6,000 years ago.

You can read the peer-reviewed paper here [pdf]. From the paper’s conclusion:

We propose that the eclipse recorded in the Rig Veda refers to observations made of an eclipse around 4000 BC. By analyzing the description, we propose that the eclipse was the one that occurred in 4202 BC or else in 3811 BC. We propose that it was observed in Central Asia. To our knowledge, this is one of the oldest known references to a specific total solar eclipse mentioned in the historical literature.

The scientists came to this conclusion based on information contained and not contained in the Hindu text. The text noted the event occurred three days before the autmnal equinox, and that it occurred when that equinox occurred in the constellation Orion, when today the equinox occurs in the constellation Pisces. This reduced the number of possible eclipses to a small number during the time period around 4,000 BC. The text also lacked any mention of various Hindo myths explaining eclipses that appeared more recently, thus confirming this ancient date and telling the researchers that the nomadic people who compiled the Rig Veda were likely living in central Asia at that time.

The only two eclipses that fit the bill occurred on either October 22, 4202 BC or October 9, 3811 BC. This makes it the earliest known reference to an eclipse, far earlier than the possible eclipses that occurred in around 3340 BC and around 1300 BC.

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A galaxy with a halo and a stupendous central black hole

9:22 am

A galaxy with a halo and a stupendous black hole
Click for original image.

Cool image time! The picture to the right, cropped, reduced, and sharpened to post here, was taken by the Hubble Space Telescope as part of a survey of galaxies that have what astronomers call active galactic nuclei (AGNs). This galaxy, dubbed IC 4709, is about 240 million light years away.

If IC 4709’s core were just filled with stars, it would not be nearly so bright. Instead it hosts a gargantuan black hole, 65 million times the mass of our Sun. A disc of gas spirals around and eventually into this black hole, with the gas crashing together and heating up as it spins. It reaches such high temperatures that it emits vast quantities of electromagnetic radiation, from infrared to visible to ultraviolet light and beyond — in this case including X-rays. The AGN in IC 4709 is obscured by a lane of dark dust, just visible at the centre of the galaxy in this image, which blocks any optical emission from the nucleus itself.

To get a very vague sense of scale, this supermassive black hole is more than sixteen times more massive than the relatively inactive supermassive black hole in the center of the Milky Way. This imagery and data from Hubble will help astronomers better understand the interaction between the black hole and its surrounding galaxy.

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Webb finds six exoplanets, all flying in interstellar space without a star

11:11 am

Astronomers using the Webb Space Telescope have discovered six different planets ranging in mass 5 to 10 times that of Jupiter, all unattached to any star or solar system.

The most intriguing of the starless objects is also the lightest, having an estimated mass of five Jupiters (about 1,600 Earths). The presence of a dusty disk means the object almost certainly formed like a star, as space dust generally spins around a central object in the early stages of star formation, said Langeveld, a postdoctoral researcher in Jayawardhana’s group.

All of these starless planets likely formed like this one, coalescing like a star does but unlike a star never having enough mass to ignite.

The astronomers are next going to attempt to detect the atmosphere’s of these rogue exoplanets, though it is not clear exactly how they will do this unless one of the exoplanets just happened to transit across a more distant star, something that simply does not happen very often.

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A real whirlpool in space

9:52 am

A real whirlpool in space
Click for original image.
Cool image time! The picture above, cropped to post here, was taken by the Hubble Space Telescope as part of a survey of nearby galaxies that have what astronomers call an Active Galactic Nuclei (AGN), because the supermassive black hole at the center is devouring nearby material at a great rate and thus producing high energy emissions as it does so.

Many active galaxies are known to astronomers at vast distances from Earth, thanks to the great brightness of their nuclei highlighting them next to other, dimmer galaxies. At 128 million light-years from Earth, UGC 3478 is positively neighbourly to us. The data used to make this image comes from a Hubble survey of nearby powerful AGNs found in relatively high-energy X-rays, like this one, which it is hoped can help astronomers to understand how the galaxies interact with the supermassive black holes at their hearts.

The bottom line is that this spiral galaxy literally is a whirlpool, the entire galaxy spiralling down into that massive black hole in its center. One cannot help wondering why such galaxies don’t end up eventually getting completely swallowed by that black hole.

Or maybe they do, and we don’t see such things because all that is left is a supermassive black hole that emits no light or energy at all, a dark silent ghost traveling between the galaxies unseen and undetectable.

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The North Star has spots!

9:38 am

The spoted surface of Polaris
Click for original image.

Astronomers using an array of six ground-based telescopes have obtained best new data of Polaris, the North Star, including the first rough image of its surface, and discovered sunspots on its surface.

You can read the paper here [pdf]. The image to the right, taken from figure 4 of the paper, shows the surface as seen by the telescopes over two nights in April 2021. Polaris is what astronomers call a Cepheid variable star, which changes brightness on a very precise schedule as its diameter grows and shrinks. In the case of Polaris, that variation is four days long. The star’s brightness itself varies only slightly, and over the decades has even at times appeared to cease its variations.

As the true brightness of Cepheids is very predictable based on their pulse rate, these stars are one of the main tools astronomers use to determine distances to other galaxies. Knowing more about them thus has great importance to cosmological research.

The orbital motion showed that Polaris has a mass five times larger than that of the Sun. The images of Polaris showed that it has a diameter 46 times the size of the Sun.

The biggest surprise was the appearance of Polaris in close-up images. The CHARA observations provided the first glimpse of what the surface of a Cepheid variable looks like. “The CHARA images revealed large bright and dark spots on the surface of Polaris that changed over time,” said Gail Schaefer, director of the CHARA Array. The presence of spots and the rotation of the star might be linked to a 120-day variation in measured velocity.

The researchers plan to take regular images again of Polaris to better track the changes to its surface.

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New data continues to refine the margin of error for the Hubble constant

9:45 am

The uncertainty of science: New data using the Webb Space Telescope’s spectroscopic capabilities has provided a more refined measure of the expansion rate of the universe, dubbed the Hubble constant.

According to previous research, that rate could be anywhere from 67.4 to 73.2 kilometers per second per megaparsecs, depending on whether you rely on data from the Planck orbiter or that of the Hubble Space Telescope. Though this difference appears reasonable considering the uncertainties and assumptions that go into research that determines both numbers, astronomers have been unhappy with the difference. The numbers should match and they don’t.

Now new data from Webb suggests this difference really is nothing more than the margin of error caused by the many uncertainties and assumptions involved. That new Webb data measured the Hubble constant using three different methods, all similar to that used by Hubble, and came up with 67.85, 67.96, and 72.04, all in the middle of the previous two numbers from Hubble and Planck.

In other words, all the data is beginning to fall within this margin of error.

Astronomers are without doubt still going to argue about this, but it does appear that the research is beginning to coalesce around an approximate number. More important, in terms of cosmology these results confirm the theory that the expansion of the universe is accelerating (dubbed “dark energy” simply because it needs a name), since they confirm the method used to measure that expansion rate in the very distant universe.

Keep your minds open however. There remain many questions and uncertainties with all these conclusions. Nothing is settled, nor will it be likely for decades if not centuries.

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Astronomers discover a nearby star moving so fast it could even escape the Milky Way

10:20 am

Astronomers, both professional and amateur, have discovered a nearby star only 400 light years away that is moving so fast, 1.3 million miles per hour (almost three times faster than the Sun), it might very well escape the Milky Way and fly into intergalactic space in the far future.

The star, named CWISE J124909+362116.0 (or “J1249+36” for short), was first spotted by some of the over 80,000 citizen science volunteers participating in the Backyard Worlds: Planet 9 project, who comb through enormous reams of data collected over the past 14 years by NASA’s Wide-field Infrared Survey Explorer (WISE) mission. This project capitalizes on the keen ability of humans, who are evolutionarily programmed to look for patterns and spot anomalies in a way that is unmatched by computer technology. Volunteers tag moving objects in data files and when enough volunteers tag the same object, astronomers investigate.

J1249+36 immediately stood out because it was moving at about .1 percent the speed of light.

The star itself is either a very low mass red dwarf, or possibly a brown dwarf that never quite had enough mass to ignite as a star.

You can read the research paper here [pdf]. The researchers posit two possible explanations for the star’s speed. Either it was once part of a binary and thrown out when its white dwarf companion exploded as a supernova, or was once located in a densely packed globular cluster, where the interaction with other stars or even black holes could have flung it away.

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A galaxy with a ring

9:34 am

A galaxy with a ring
Click for full image.

Cool image time! The photo to the right, cropped, reduced, and sharpened to post here, was taken by the Hubble Space Telescope, and appears part of a long term survey of nearby ringed galaxies. From the caption:

MCG+07-07-072 has quite an unusual shape, for a spiral galaxy, with thin arms emerging from the ends of its barred core to draw a near-circle around its disc. It is classified, using a common extension of the basic Hubble scheme, as an SBc(r) galaxy: the c denotes that its two spiral arms are loosely wound, each only performing a half-turn around the galaxy, and the (r) is for the ring-like structure they create. Rings in galaxies come in quite a few forms, from merely uncommon, to rare and astrophysically important!

Lenticular galaxies are a type that sit between elliptical and spiral galaxies. They feature a large disc, unlike an elliptical galaxy, but lack any spiral arms. Lenticular means lens-shaped, and these galaxies often feature ring-like shapes in their discs. Meanwhile, the classification of “ring galaxy” is reserved for peculiar galaxies with a round ring of gas and star formation, much like spiral arms look, but completely disconnected from the galactic nucleus – or even without any visible nucleus! They’re thought to be formed in galactic collisions.

This galaxy is about 320 million light years away, and is also known as Abell 426. Though astronomers think that these various shapes of galaxies, from barred to lenticular to ringed, are formed from a variety of galactic collusions and interactions with each galaxy’s nucleus, that remains nothing more than an educated guess. The complexity of galaxy evolution, involving billions of years and millions of stars, is barely in its infancy, and requires a lot of assumptions because our observations only involves a mere nanosecond in that grand history.

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WISE/NEOWISE space telescope mission ends after fourteen years

9:11 pm

Comet NEOWISE, photographed by the Hubble Space Telescope
Click for full image.

Launched in 2009, the Wide-field Infrared Survey Explorer (WISE) was shut down today after almost fourteen years of successful observations, with its first years dedicated to creating an infrared survey of the sky. In 2013, after two years of hibernation, it was reactivated and renamed NEOWISE (for reasons that I have always found absurd), with the goal over the next thirteen years of mapping the sky for near Earth objects.

By repeatedly observing the sky from low Earth orbit, NEOWISE created all-sky maps featuring 1.45 million infrared measurements of more than 44,000 solar system objects. Of the 3,000-plus near-Earth objects it detected, 215 were first spotted by NEOWISE. The mission also discovered 25 new comets, including the famed comet C/2020 F3 NEOWISE that streaked across the night sky in the summer of 2020.

A Hubble image of that comet is to the right.

The mission was ended because the telescope’s orbit is now too low to provide good data. It is expected to re-enter the atmosphere and burn up before the end of the year.

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Gaia space telescope identifies more than 350 asteroids with candidate moons

9:24 am

Using the Gaia space telescope, astronomers have identified 352 asteroids that the data suggests have smaller satellite asteroids in orbit around them.

In its data release 3, Gaia precisely pinpointed the positions and motions of 150 000+ asteroids — so precisely that scientists could dig deeper and hunt for asteroids displaying the characteristic ‘wobble’ caused by the tug of an orbiting companion (the same mechanism as displayed here for a binary star). Gaia also gathered data on asteroid chemistry, compiling the largest ever collection of asteroid ‘reflectance spectra’ (light curves that reveal an object’s colour and composition).

These results need to be confirmed by direct observation, as this method does involve some assumptions and uncertainties. If these numbers are confirmed however it will give planetary scientists a better census on the percentage of asteroids with moons, which in turn can be used to create better models of the formation of the solar system as well as the evolution of asteroids over time. At the moment scientists predict about one out of every six asteroids will have a moon. This data suggests that number might be high.

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A supernova overpowers a spiral galaxy

9:34 am

A supernova overwhelms a small galaxy

Cool image time! The picture to the right, cropped, reduced, and sharpened to post here, was taken in early 2023 by the Hubble Space Telescope because a ground-based automated sky survey had detected a new supernovae in late 2022 in this galaxy. The spiral galaxy is dubbed LEDA 857074, and is interesting because of its bright central bar and dim and broken spiral arms.

That supernova is the bright spot inside the galaxy’s central bar. It is so bright that it almost looks like someone accidently pasted a white dot there using a graphics program. From the caption:

Astronomers have catalogued millions of galaxies, so while today tens of thousands of supernovae are detected annually, the chance that one is spotted in any particular galaxy is slim. We also do not know how actively LEDA 857074 is forming stars, and therefore how often it might host a supernova. This galaxy is therefore an unlikely and lucky target of Hubble, thanks to this supernova shining a spotlight on it! It now joins the ranks of many more famous celestial objects, with its own Hubble image.

The galaxy itself had been studied by almost no one until this supernova was discovered in it.

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Inspector General: Roman Space Telescope is meeting the budget overruns and schedule delays NASA predicted

4:57 pm

According to the twisted language in a new NASA inspector general report [pdf] describing the present status of the Roman Space Telescope, the project is on schedule and on budget because NASA decided to predict ahead of time how much it would behind schedule and over budget at this moment. From its executive summary:

[A]s of March 2024, Roman was meeting its cost obligations and schedule to launch by May 2027. Roman was on track to launch despite encountering contractor performance issues and cost overruns related to hardware anomalies, under scoping of work, and inadequate oversight of subcontractors. Roman remains on schedule because Science Mission Directorate officials conducted a replan in May 2021 to mitigate the expected cost and schedule growth caused by COVID-19, increasing the life-cycle cost estimate from $3.9 billion to $4.3 billion. This replan also included delaying the launch readiness date from October 2026 to May 2027. As of March 2024, Roman was tracking its project reserves and potential delays with L3Harris as its top risks. Roman has been using its project reserves to mitigate cost growth related to L3Harris’s performance challenges. Despite these contract value increases, Roman is still within its life-cycle cost estimate because the project’s reserves cover these extra costs.

The insulting nature of this inspector general report is astonishing. The administrative state really does think the American public is too stupid to notice this. I wonder if they are right.

The report further notes issues with the telescope’s two subcontractors, BAE Systems and L3Harris, as well as warning of insufficient ground-based antenna capacity for downloading the data that Roman will produce.

[A]s of April 2024, the NSN [Near Space Network] did not have adequate capacity to support Roman’s mission requirements without planned upgrades to the White Sands antenna and lacked the funding to implement the necessary upgrades by the mission’s launch readiness date.

In other words, more money will be needed to build more ground antennas, something that NASA conveniently forgot to mention when it first proposed Roman to Congress. How interesting, but completely par for the course.

Hat tip stringer Jay.

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Do Kepler’s sunspot drawings tell us the length of the solar cycle in the 17th century?

9:19 am

Kepler's first sunspot drawing
Click for original image.

The uncertainty of science: Scientists have done a new analysis of Johannes Kepler’s three drawings of sunspots on the Sun in 1607, and have concluded that the solar cycle at that time — just before the start of the Maunder grand minimum of no sunspots for decades — was about the same length, 11 years, that has been measured since the 1700s onward.

You can read the peer-reviewed paper here. The drawing to the right is figure 1 in that paper, and shows Kepler’s first drawing of the Sun’s surface showing sunspots. From the paper’s conclusion:

In combination with sunspot drawings in the 1610s–1620s, it is reasonable to suppose that the duration of the Solar Cycle −13 was between 11 and 14 yr. This does not support Miyahara et al.’s claim of anomalously long/short durations for Solar Cycle −13 (16 yr) and Solar Cycle −14 (5 yr) but supports Usoskin et al.’s reconstruction of regular durations of Solar Cycle −13 (11 yr) and Solar Cycle −14 (14 yr).

In other words, the solar cycle prior to the sixty-plus yearlong Maunder Minimum, when few to none sunpots occurred, was about eleven years long, like now, and not five years or sixteen years long, as some scientists have theorized. Knowing the length and nature of the cycle before the Maunder grand minimum would help scientists predict when the next minimum might occur. It would also help them better document the Sun’s long term behavior.

There is however great uncertainty in this result, since there really is so little data about sunspots prior to the Maunder Minimum. Before Galileo’s first use of the telescope in astronomy in 1609, such observations like Kepler’s were rare and very difficult. The conclusions here are intriguing, but hardly convincing.

In fact, it is really impossible to get a defiinitive answer from this data. We really won’t know how the Sun behaves just prior to a grand minimum until it happens again and scientists can use modern technology to observe it.

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Webb: Carbon monoxide detected on surface of Uranus’s moon Ariel suggests an underground ocean

12:04 pm

The best image of Ariel, as seen by Voyager-2, January 24, 1986
Voyager-2’s best image of Ariel during the
January 24, 1986 fly-by. Click for original.

By doing infrared spectroscopy using the Webb Space Telescope, scientists have detected carbon monoxide (CO) and confirmed extensive carbon dioxide (CO2) deposits on the surface of Uranus’s moon Ariel, with the carbon monoxide suggesting the moon has an underground ocean.

Using NASA’s James Webb Space Telescope to collect chemical spectra of the moon and then comparing them with spectra of simulated chemical mixtures in the lab, a research team led by Richard Cartwright from the Johns Hopkins Applied Physics Laboratory (APL) in Laurel, Maryland, found that Ariel has some of the most carbon dioxide-rich deposits in the solar system, adding up to an estimated 10 millimeters (0.4 inches) or more thickness on the moon’s trailing hemisphere. Among those deposits was another puzzling finding: the first clear signals of carbon monoxide.

“It just shouldn’t be there. You’ve got to get down to 30 kelvins [minus 405 degrees Fahrenheit] before carbon monoxide’s stable,” Cartwright said. Ariel’s surface temperature, meanwhile, averages around 65 F warmer. “The carbon monoxide would have to be actively replenished, no question.”

You can read the peer-reviewed paper here [pdf]. Though there are a number of ways in which the carbon monoxide can be replenished, the scientists think it is coming from an underground ocean. From the paper’s abstract:

The evidence for thick CO 2 ice deposits and the possible presence of carbonates on both hemispheres suggests that some carbon oxides could be sourced from Ariel’s interior, with their surface distributions modified by charged particle bombardment, sublimation, and seasonal migration of CO and CO 2 from high to low latitudes.

This theory however has not been confirmed, and the scientists admit it will take a probe making close observations of Ariel to find out for sure.

Hat tip to stringer Jay for this story.

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Webb takes infrared image of exoplanet

10:02 am

A Jupiter-sized exoplanet imaged by Webb
Click for original image.

Cool image time! Using the Webb Space Telescope, scientists have taken an infrared false color image of a multi-Jupiter-sized exoplanet located only twelve light years away and orbiting the K-type star Epsilon Indi A.

That picture, cropped, reduced, and sharpened to post here, is to the right. The light of the star, indicated by the star symbol, has been blocked by Webb’s coronagraph, the size of which is shown by the dashed circle. The exoplanet is the orange blob to the left.

[This exoplanet] is one of the coldest exoplanets to be directly detected, with an estimated temperature of 35 degrees Fahrenheit (2 degrees Celsius) — colder than any other imaged planet beyond our solar system, and colder than all but one free-floating brown dwarf. The planet is only around 180 degrees Fahrenheit (100 degrees Celsius) warmer than gas giants in our solar system. This provides a rare opportunity for astronomers to study the atmospheric composition of true solar system analogs.

The data also revealed that the exoplanet is twice as massive as expected and has a slightly different orbit than expected based on previous less precise data.

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New collection of X-ray false-color Chandra images

9:30 am

Chandra image of galaxy
Click for original image.

Cool image time! As part of a PR campaign by NASA to convince Congress to give it more money to keep the Chandra X-ray Observatory funded, the agency this week released twenty-five new images, supposedly to celebrate the space telescope’s 25th anniversary since launch.

It must be emphasized that these photos are not solely produced by Chandra. They combine its X-ray data wth optical data from Hubble and infrared data from a number of other telescopes.

The picture to the right is of the galaxy NGC 6872 that is interacting with its nearby smaller neighbor. From the caption:

NGC 6872 is 522,000 light-years across, making it more than five times the size of the Milky Way galaxy; in 2013, astronomers from the United States, Chile, and Brazil found it to be the largest-known spiral galaxy, based on archival data from NASA’s Galaxy Evolution Explorer. This record was surpassed by NGC 262, a galaxy that measures 1.3 million light-years in diameter.

Chandra will get its funding to continue operations. NASA is simply playing its old game of bluff with Congress to force it to give the agency a boost in funding. Like a toddler throwing a tantrum, it cancels a successful project, citing funding shortages (even though those shortages are almost always because of mismanagement elsewhere in the agency), and Congress eventually gives in like a weak parent, raising NASA’s budget.

The big image release this week is part of that game. Nonetheless, the images are spectacular, and loaded with new information not otherwise available without Chandra’s X-ray capabilities. If Congress had any spine, it would force NASA to fully fund such successful projects and simply delete the failed ones (such as SLS and Mars Sample Return). It has no spine, however, and thus we have a national debt in the trillions that is bankrupting us.

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A classic spiral galaxy

8:53 am

A classic spiral galaxy
Click for original image.

Monday is always a slow news day in space, so we start the day with a cool image. The picture to the right, reduced and sharpened to post here, was taken by the Hubble Space Telescope of a spiral galaxy about 100 million light years from Earth.

That NGC 3430 is such a fine example of a galactic spiral may be why it ended up as part of the sample that Edwin Hubble used to define his classification of galaxies. Namesake of the Hubble Space Telescope, in 1926 he authored a paper which classified some four hundred galaxies by their appearance — as either spiral, barred spiral, lenticular, elliptical or irregular. This straightforward typology proved immensely influential, and the modern, more detailed schemes that astronomers use today are still based on it. NGC 3430 itself is an SAc galaxy, a spiral lacking a central bar with open, clearly-defined arms.

The bright blue indicates areas of star formation, while the reddish streaks indicates dust. The orange/reddish dots above and below the galaxy are distant background galaxies whose light has been shifted to the red because they appear to be moving away from us due to the expansion rate of the universe.

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