Tag: astronomy

NASA signs deal to launch Israel’s first space telescope mission

9:50 am

NASA today announced that it has agreed to provide the launch opportunity for Israel’s first space telescope, dubbed the Ultraviolet Transient Astronomy Satellite (ULTRASAT), designed to make wide-field ultraviolet observations from geosynchronous orbit.

Led by the Israel Space Agency and Weizmann Institute of Science, ULTRASAT is planned for launch into geostationary orbit around Earth in early 2026. In addition to providing the launch service, NASA will also participate in the mission’s science program.

The press release, both from NASA and from Weizmann, was remarkably vague about how NASA will provide that launch capability. The only orbital rocket NASA has is SLS. Will ULTRASAT launch as a secondary payload on a future Artemis launch? Or will NASA buy launch services from another rocket company? The press releases did not say.

Regardless, this deal means that American taxpayers have agreed to foot the launch cost of this Israeli space telescope, in exchange for obtaining telescope time for American astronomers. Interestingly, the press releases also provided no information about how much that launch cost would be.

There has long been a need for a dedicated new ultraviolet space telescope, so this deal could be a good one for American astronomers and a worthwhile use of some of NASA’s budget. It just seems inappropriate for NASA to keep the details so secret.

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VLT takes picture of exoplanet

9:20 am

VLT's picture of exoplanet
Click for original image.

The ground-based Very Large Telescope (VLT) in Chile has successfully taken a picture of an exoplanet four to six times larger than Jupiter that is circling its star at about the same distance as Saturn.

That picture, cropped to post here, is to the right. Other data from other observatories had suggested the star AF Leporis, 87.5 light years away, might have an exoplanet, so astronomers decided to focus VLT on it to see if it could spot it.

AF Leporis is about as massive and as hot as the sun, ESO wrote in the statement, and in addition to its one known planet the star also has a disk of debris similar to the solar system’s Kuiper Belt. AF Leporis is, however, much younger than the sun. At 24 million years old, it is about 200 times younger than our star. This young age makes AF Leporis and its planetary system especially intriguing for astronomers as it can provide important insights into the evolution of our own solar system.

To snap this picture, the VLT had to use adaptive optics to smooth out the fuzziness produced by the Earth’s atmosphere, while also blocking out the star’s own light (as shown by the black disk in the image).

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A galaxy’s structure of gas and dust, as seen in the infrared by Webb

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NGC 1433 as seen in the infrared
NGC 1433 as seen in the infrared. Click for original image.

Scientists have now released 21 papers on the gas and dust structures in nearby galaxies, based on infrared images from the Webb Space Telescope, used in collaboration with other telescopes looking in other wavelengths.

The largest survey of nearby galaxies in Webb’s first year of science operations is being carried out by the Physics at High Angular resolution in Nearby Galaxies (PHANGS) collaboration, involving more than 100 researchers from around the globe. The Webb observations are led by Janice Lee, Gemini Observatory chief scientist at the National Science Foundation’s NOIRLab and affiliate astronomer at the University of Arizona in Tucson.

The team is studying a diverse sample of 19 spiral galaxies, and in Webb’s first few months of science operations, observations of five of those targets – M74, NGC 7496, IC 5332, NGC 1365, and NGC 1433 – have taken place.

The image to the right is Webb’s infrared image of NGC 1433, estimated to be 46 million light years away. The bright areas extending outward in the spiral arms are believed to be star-forming regions. From the caption:

At the center of the galaxy, a tight, bright core featuring a unique double ring structure shines in exquisite detail with Webb’s extreme resolution. In this case, that ‘double ring’ is actually tightly wrapped spiral arms that wind into an oval shape along the galaxy’s bar.

NGC 1433 is a Seyfert galaxy, which are typically relatively close to Earth and has a supermassive black hole at the center eating material at a high rate. The brightness and lack of dust in the MIRI image of NGC 1433 could hint at a recent collision with another galaxy.

When comparing Webb’s infrared view with Hubble’s optical view, taken in 2014 and found here, the differences are definitely striking. Webb sees the gas and dust that is dark in Hubble’s images, while Hubble sees things at much higher resolution and thus sees more fine detail.

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For only 7th time, searchers find meteorite immediately after fall

8:57 am

For only 7th time, searchers on February 15th found a fragment of a meteorite that had only fallen to Earth three days before, and was furthermore only discovered mere hours before it entered the Earth’s atmosphere.

From the tweet of the discoverers:

FRIPON/Vigie-Ciel finds a fragment of asteroid 2023CX1 in Seine Maritime!!! The discovery was made by Loïs Leblanc, an 18-year-old student, part of the field research team.

Vigie-Ciel (“Sky Watchers”) and FRIPON are a volunteer project that searches for meteorites. The asteroid itself was discovered by Hungarian astronomer Krisztián Sárneczky while doing routine survey scan for near Earth asteroids.

The find was the second time Sárneczky has spotted an asteroid just hours before it broke apart in Earth’s atmosphere as a fireball, following an incredible find in March 2022.

By finding meteorites this quickly after arrival scientists get a more pristine sample, since the asteroid has not been exposed to the Earth’s environment for any extended length of time.

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Trio of colliding galaxies

9:32 am

Trio of colliding galaxies
Click for original image.

Cool image time! The picture above, cropped and reduced to post here, was taken by the Hubble Space Telescope and released today. From the caption:

Three galaxies stand together just right of centre. They are close enough that they appear to be merging into one. Their shapes are distorted, with strands of gas and dust running between them. Each is emitting a lot of light. Further to the left is an unconnected, dimmer spiral galaxy. The background is dark, with a few smaller, dim and faint galaxies and a couple of stars.

Astronomers estimate the colliding galaxies are about 50,000 light years from each other, which for galaxies is quite close. Eventually gravity will cause all three to merge into a single very large galaxy, its shape distorted by the merger. What that shape will be is one of the things astronomers are trying to figure out. At present their theories for galaxy evolution states that as galaxies grow by absorbing smaller nearby neighbors, they evolve from spirals to ellipticals, giant blobs lacking a distinct obvious structure.

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Space Force to do major cleanup of diesel fuel spill on Hawaiian mountaintop

9:36 am

Space Force officials yesterday announced that it will to do major cleanup of the diesel fuel spill that occurred on the top of the mountain Haleakala on the Hawaiian island of Maui last week.

The plan is to remove about 200 cubic yards of fuel-tainted soil, test the base of the dig, and then determine if more soil has to be removed.

The official making this announcement apologized repeatedly for the spill, so much so it was almost as if he was on his face on the ground, kow-towing. It of course made no difference. The leftist race-baiters in Hawaii made it clear where they stood on the matter.

On Friday, the Hawaiian rights group Kākoʻo Haleakalā called for the removal of all telescopes from the peak of Haleakala. The military “showcased their incompetence and lack of human decency when they allowed more than 700 gallons of diesel fuel to be spilled atop Haleakalā,” the group said in a statement.

“This is just the most recent example of how U.S. imperialism and military hegemony is protected in the Pacific while Hawaiians are ignored and our ʻāina is violated,” the statement said, using the Hawaiian term for land.

Let me translate: “We hate whites and America, and we want you out of Hawaii, now. And if you don’t go, we want you to cede all control to us, so that we treat you as the inferior beings we consider you to be.”

Note too that this group’s agenda is identical to the agenda of the race-baiters on the Big Island who are blocking construction of the Thirty Meter Telescope and are forcing the removal of telescopes there.

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Galaxies without end

9:57 am

Webb infrared image of galaxies without end
Click for original image.

Cool image time! The mid-infrared picture to the right, cropped, reduced, and sharpened to post here, was taken by the Webb Space Telescope during its commissioning process last year shortly after launch, and was used to calibrate the Near-InfraRed Imager and Slitless Spectrograph (NIRISS) instrument, the very same instrument that for the past two weeks was not in operation because a cosmic ray had scrambled its software, requiring a reboot to fix it. From the caption:

The large spiral galaxy at the base of this image is accompanied by a profusion of smaller, more distant galaxies which range from fully-fledged spirals to mere bright smudges. Named LEDA 2046648, it is situated a little over a billion light-years from Earth, in the constellation Hercules.

While the large spiral is majestic, the tiny galaxy smudges are actually more important. Astronomers are right now scrambling to determine their distance and age in order to better understand what the universe was like, thirteen-plus billion years ago. So far the Webb data of these very early galaxies suggests that in this early universe there were many more fully formed galaxies, similar to ones we see in our time, than any theory of the Big Bang had predicted.

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Astronomers discover twelve more Jupiter moons

9:21 am

In reviewing ground-based data from 2021 and 2022, astronomers have discovered another twelve Jupiter moons, bringing that planet’s total moon population to 92.

All of the newly discovered moons are small and far out, taking more than 340 days to orbit Jupiter. Nine of the 12 are among the 71 outermost Jovian moons, whose orbits are more than 550 days. Jupiter probably captured these moons, as evidenced by their retrograde orbits, opposite in direction to the inner moons. Only five of all the retrograde moons are larger than 8 kilometers (5 miles); Sheppard says the smaller moons probably formed when collisions fragmented larger objects.

One newly discovered moon, dubbed Valetudo, is about 3,000 feet across and orbits in a retrograde orbit that crosses the orbits of several other moons that orbit in the opposite direction. As the article notes, “This highly unstable situation is likely to lead to head-on collisions that would shatter one or both objects.”

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Webb instrument back in operation

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Engineers have returned NIRISS, the near infrared spectrograph instrument on the Webb Space Telescope, to full operation after rebooting its software and determining the cause of the problem.

On Jan. 15, NASA’s James Webb Space Telescope’s Near Infrared Imager and Slitless Spectrograph (NIRISS) experienced a communications delay within the science instrument, causing its flight software to time out. Following a full investigation by NASA and Canadian Space Agency (CSA) teams, the cause was determined to likely be a galactic cosmic ray, a form of high-energy radiation from outside our solar system that can sometimes disrupt electrical systems. Encountering cosmic rays is a normal and expected part of operating any spacecraft. This cosmic ray event affected logic in the solid-state circuitry of NIRISS electronics known as the Field Programmable Gate Array. Webb engineers determined that rebooting the instrument would bring it back to full functionality.

After completing the reboot, NIRISS telemetry data demonstrated normal timing, and to fully confirm, the team scheduled a test observation. On Jan. 28, the Webb team sent commands to the instrument to perform the observation, and the results confirmed on Jan. 30 NIRISS is back to full scientific operations.

Engineers actually have a name for such cosmic ray incidents that effect software. They call it a bitflip.

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Viewing the Green Comet

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Link here. Though there has been much hype about this comet, which has a 50,000 year orbit as well as an unusual color, it really doesn’t deserve that hype because it will barely become bright enough to be visible to the naked eye.

Nonetheless, in the northern hemisphere it will be in the sky all night during the month of February, so if you are in a good dark sky location, you should try to spot it. On February 1st it will be closest to Earth.

According to In-the-Sky, from New York City C/2022 E3 (ZTF) is circumpolar, meaning it is permanently above the horizon, and should therefore be visible for most of the night. It will be visible in the Camelopardalis constellation while at perigee, a large but faint area of sky devoid of bright stars and located close to the north celestial pole.

The comet will become visible at around 6:49 p.m. EST (2349 GMT) on Wednesday (Feb. 1) when it will be 49 degrees over the northern horizon. C/2022 E3 (ZTF) will climb to its highest point in the sky, 58 degrees over the northern horizon, at around 9:46 p.m. EST (0246 GMT). Following this it will disappear in the dawn light at around 5:57 a.m. EST (1057 GMT) on Feb. 2 while at around 30 degrees over the horizon to the north.

The link provides more information for finding it, which will likely be seen best with binoculars.

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The twin asteroid Janus probes, stranded by Psyche delay, might go to Apophis

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Apophis' path past the Earth in 2029
A cartoon showing Apophis’s path in 2029

The science team that built the twin Janus spacecraft, designed to fly past an asteroid but stranded when its launch got canceled, are now considering the potentially dangerous asteroid Apophis as a new target.

If the Janus spacecraft can find a ride by early 2028, scientists could use one or both of the spacecraft to scout out the large asteroid Apophis before its super-close approach to Earth in April 2029. (If only one spacecraft visits Apophis, scientists would see only about half of the asteroid but could send the second spacecraft elsewhere; if both spacecraft fly past the same object they can be arranged to reveal the whole surface.)

Initially the entire Janus mission had been designed on the assumption it would launch as a secondary payload when the Psyche mission to the asteroid Psyche launched last fall. When that launch had to be canceled because Psyche was not ready, Janus lost its mission. The science team has since been struggling to find a replacement, handicapped by the fact that it must go as a secondary payload.

There is a serious issue however with arriving ahead of Apophis’s close approach in 2029. The science community has discouraged such missions, because they fear a spacecraft arriving then could shift Apophis’s trajectory and actually increase the chance it will hit the Earth during a later close approach. Instead, all planetary probes presently going to Apophis in 2029 are planning to arrive after the flyby.

The risk is extremely small, but it must be considered before sending Janus to Apophis.

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Communications issue shuts down one of Webb’s instruments

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The near infrared instrument on the Webb Space Telescope, NIRISS, has been unavailable for science observations for more than a week due to a communications issue.

On Sunday, Jan. 15, the James Webb Space Telescope’s Near Infrared Imager and Slitless Spectrograph (NIRISS) experienced a communications delay within the instrument, causing its flight software to time out. The instrument is currently unavailable for science observations while NASA and the Canadian Space Agency (CSA) work together to determine and correct the root cause of the delay.

According to the update, the instrument’s hardware, as well as the rest of the telescope, has been unaffected and remains in good condition.

In November the telescope’s mid-infrared instrument MIRI experienced its own problems with one of its “grating wheels” that allows it to some spectroscopy. Since then the instrument has been in use, but it is unclear if the issue was resolved or observations have had to be adjusted to avoid the problem.

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Construction of the Thirty Meter Telescope in Hawaii remains in limbo

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Despite the successful power grab by protesters that stopped construction and took management of the telescopes on Mauna Kea in Hawaii away from the University of Hawaii and gave it to a newly created board made up of “observatory representatives, Native Hawaiian cultural practitioners, local business and education officials, and experts in land management,” construction of the Thirty Meter Telescope (TMT) in Hawaii remains in limbo.

But there is another actor in this drama: the National Science Foundation (NSF). TMT has accrued substantial financial backing from its university backers and the governments of China, Japan, India, and Canada, but it is still far from fully funded and has asked NSF to fill the gap. TMT’s request has come in partnership with the Giant Magellan Telescope (GMT), another U.S.-led effort to build a massive new telescope. GMT’s site is already being prepared in Chile but it is also in financial straits.

Together, the two projects are seeking $3 billion from NSF in exchange for the wider U.S. astronomical community gaining access to a large slice of both scopes’ observing time. That proposal was judged by U.S. astronomers as their top priority for ground-based astronomy in the community’s decadal survey published in November 2021. NSF is now assessing whether this is a good investment for U.S. taxpayers.

Considering that Congress now believes that money grows on trees, and there is no reason not to fund anything anyone wants no matter how much debt it produces, I expect that the NSF will eventually fund both telescopes. There is however the slim possibility that the NSF will look at the new and very complex managerial make-up now running things in Hawaii and decide it is impractical and guaranteed to produce problems. The goals of the different members of this board are so contradictory that any construction on Mauna Kea will likely have to be renegotiated over and over again, causing further delays.

Of course, endless funding and delays could be considered a feature, not a bug, by our present corrupt federal government. In that case the NSF will celebrate these delays.

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First exoplanet confirmed by Webb

10:23 am

Astronomers have used for the first time the Webb Space Telescope to confirm the existence of an exoplanet, previous noted in data from the orbiting TESS telescope.

Formally classified as LHS 475 b, the planet is almost exactly the same size as our own, clocking in at 99% of Earth’s diameter. The research team is led by Kevin Stevenson and Jacob Lustig-Yaeger, both of the Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland.

The team chose to observe this target with Webb after carefully reviewing targets of interest from NASA’s Transiting Exoplanet Survey Satellite (TESS), which hinted at the planet’s existence. Webb’s Near-Infrared Spectrograph (NIRSpec) captured the planet easily and clearly with only two transit observations.

The data is still preliminary, so more analysis is necessary to provide some information about the planet’s atmosphere.

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Astronomers discover more than 800 new supermassive black holes

3:54 pm

Using archival data from both the orbiting Chandra X-Ray telescope and the ground-based Sloan Digital Sky Survey telescope (SDSS), astronomers have discovered more than 800 new supermassive black holes hidden in the center of galaxies.

By systematically combing through the deep Chandra Source Catalog and comparing to SDSS optical data, the researchers identified 817 XBONG candidates, more than ten times the number known before Chandra was in operation. Chandra’s sharp images, matching the quality of those from SDSS, and the large amount of data in the Chandra Source Catalog made it possible to detect this many XBONG candidates. Further study revealed that about half of these XBONGs represent a population of previously hidden black holes.

The key to this discovery is the use of telescopes observing in different wavelengths, X-rays with Chandra and optical with SDSS. Combined the data showed evidence of the hidden supermassive black holes.

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January 11, 2023 Quick space links

3:29 pm

Courtesy of BtB’s stringer Jay.

 

 

 

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TESS finds a second Earthsize planet orbiting in the habitable zone of a star

9:37 am

TESS solar system

The orbiting survey telescope TESS has discovered a second Earthsize planet in a solar system of four exoplanets.

The graphic to the right, a screen capture from a short video provided by the press release, shows these four exoplanets. Planet D had previously been discovered. Planet E is the new discovery, and is thought to be 95% Earth’s mass and likely terrestrial in make-up. Both are near the inner edge of the habitable zone.

TOI 700 is a small, cool M dwarf star located around 100 light-years away in the southern constellation Dorado. In 2020, Gilbert and others announced the discovery of the Earth-size, habitable-zone planet d, which is on a 37-day orbit, along with two other worlds.

The innermost planet, TOI 700 b, is about 90% Earth’s size and orbits the star every 10 days. TOI 700 c is over 2.5 times bigger than Earth and completes an orbit every 16 days. The planets are probably tidally locked, which means they spin only once per orbit such that one side always faces the star, just as one side of the Moon is always turned toward Earth.

This discovery only underlines the infinite possibilities and variables that exist for life on other worlds. These planets might be similar in mass to the Earth and get about the same heat/light energy from their sun, but the star is very different, their orbits are very different, and their environment is very different.

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Starlink and National Science Foundation sign deal coordinating spectrum use

9:10 pm

SpaceX and the National Science Foundation (NSF) today signed an agreement coordinating the use of radio spectrum so that Starlink satellites will not interfere with radio astronomy.

The National Science Foundation (NSF) and SpaceX have finalized a radio spectrum coordination agreement to limit interference from the company’s Starlink satellites to radio astronomy assets operating between 10.6 and 10.7 GHz. The agreement, detailed in a statement released by NSF today, ensures that Starlink satellite network plans will meet international radio astronomy protection standards, and protect NSF-funded radio astronomy facilities, including the National Radio Astronomy Observatory (NRAO) and the Green Bank Observatory (GBO).

This deal was part of a larger negotiation with the entire astronomy community to limit the problems caused to astronomy by the 3,000-plus Starlink satellites presently in orbit. These other actions include

…continuing to work to reduce the optical brightness of their satellites to 7th visual magnitude or fainter by physical design changes, attitude maneuvering, or other ideas to be developed; maintaining orbital elevations at ~700 km or lower; and providing orbital information publicly that astronomers can use for scheduling observations around satellite locations.

This agreement demonstrates again that SpaceX has tried hard to be a good citizen in this matter. It also illustrates once again that ground-based astronomical observations is becoming increasingly impractical. Astronomers have to go to space, and if Starship flies as SpaceX desires, the company will provide them a way to do it.

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Webb finds “wide diversity of galaxies in the early universe”

12:35 pm

Webb galaxies in the early universe
Click for full image.

New data from the Webb Space Telescope and presented this week at an astronomy conference has found that galaxies in the early universe exhibit much of the same range of shapes and morphologies seen in the recent universe, a result that was not expected.

The image to the right comes from the press release. You can read the research paper here [pdf].

The study examined 850 galaxies at redshifts of z three through nine, or as they were roughly 11-13 billion years ago. Associate Professor Jeyhan Kartaltepe from Rochester Institute of Technology’s School of Physics and Astronomy said that JWST’s ability to see faint high redshift galaxies in sharper detail than Hubble allowed the team of researchers to resolve more features and see a wide mix of galaxies, including many with mature features such as disks and spheroidal components.

“There have been previous studies emphasizing that we see a lot of galaxies with disks at high redshift, which is true, but in this study we also see a lot of galaxies with other structures, such as spheroids and irregular shapes, as we do at lower redshifts,” said Kartaltepe, lead author on the paper and CEERS co-investigator. “This means that even at these high redshifts, galaxies were already fairly evolved and had a wide range of structures.”

The results of the study, which have been posted to ArXiv and accepted for publication in The Astrophysical Journal, demonstrate JWST’s advances in depth, resolution, and wavelength coverage compared to Hubble. Out of the 850 galaxies used in the study that were previously identified by Hubble, 488 were reclassified with different morphologies after being shown in more detail with JWST. Kartaltepe said scientists are just beginning to reap the benefits of JWST’s impressive capabilities and are excited by what forthcoming data will reveal.

“This tells us that we don’t yet know when the earliest galaxy structures formed,” said Kartaltepe. “We’re not yet seeing the very first galaxies with disks. We’ll have to examine a lot more galaxies at even higher redshifts to really quantify at what point in time features like disks were able to form.”

In other words, it appears galaxies of all shapes, as we see them today, already existed 11-13 billion years ago, shortly after the universe was born. This defies most theories about the formation of the universe, which predict that these early galaxies would be different than today’s.

The data however at this point is sparse. Webb has only begun this work, and as Kartaltepe notes, they need to look a lot more galaxies.

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Two nearby galactic neighbors

11:46 am

Two nearby galactic neighbors
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 of two nearby galaxy neighbors to the Milky way.

This image from the NASA/ESA Hubble Space Telescope features the galaxy LEDA 48062 in the constellation Perseus. LEDA 48062 is the faint, sparse, amorphous galaxy on the right side of this image, and it is accompanied by a more sharply defined neighbour on the left, the large, disc-like lenticular galaxy UGC 8603. A smattering of more distant galaxies also litter the background, and a handful of foreground stars are also visible throughout the image.

LEDA 48062 is estimated to be approximately 30 million light years away. This image was part of a recent Hubble campaign to study every known galaxy within 33 million light years.

Assuming that UGC 8603 is about the same approximate distance, the utter dissimilarity between these two galaxies is quite mystifying. It is also possible that UGC 8603 is larger and much farther away.

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China to build giant ground-based optical telescope

9:45 am

China has announced its plan to build ground-based multi-segmented optical telescope, similar in design to the 10-meter Keck Telescope in Hawaii.

Peking University wants to build the largest optical telescope in Asia and close the gap in astronomy capabilities with the rest of the world.

The project aims to create an initial telescope with an aperture of 19.7 feet (6 meters) by 2024; the mirror will be expanded to 26.2 feet (8 m) by 2030. The project, which in English is called the Expanding Aperture Segmented Telescope (EAST), is being led by Peking University.

Like Keck, the primary mirror would be made of smaller segments, fitted together to create the larger mirror. While not as large as Keck, EAST would be among the largest in the world.

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Royal Astronomical Society ends blacklisting of James Webb

9:30 am

That’s nice of them: The Royal Astronomical Society in Britain last week announced that it has ended its blacklisting of James Webb, the man who headed NASA during the 1960s space race, by once again permitting writers of science papers for its Monthly Notices journal to use the full name of the James Webb Space Telescope.

The Royal Astronomical Society (RAS) previously criticized NASA for not immediately addressing concerns that Webb persecuted queer employees; the NASA-led James Webb Space Telescope (JWST or Webb) that launched in December 2021 is named after him. But with new information to hand suggesting Webb played no direct role in these issues, Webb’s name can now reappear in scientific papers, the RAS stated Dec. 22.

“The RAS will now allow authors submitting scientific papers to its journals to use either ‘James Webb Space Telescope’ or the acronym ‘JWST’ to refer to the observatory,” RAS officials wrote. The major journals of the RAS include the Monthly Notices of the Royal Astronomical Society (MNRAS), one of the top astronomical journals worldwide.

The society backed off from its position after NASA published a long detailed report documenting the utter falsehood of the claim. Too bad this so-called science organization didn’t consider the evidence itself before issuing its blacklist order. One would think scientists above all would consider evidence, not undocumented slanders, as essential before condemning a person.

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A long-armed galaxy

8:51 am

Galaxy with long and faint tidal streams
Click for full image.

Cool image time! The photo to the right, cropped, enhanced, and reduced to post here, was taken by the Hubble Space Telescope as part of a survey of peculiar looking galaxies.

The peculiar spiral galaxy ESO 415-19, which lies around 450 million light-years away, stretches lazily across this image from the NASA/ESA Hubble Space Telescope. While the centre of this object resembles a regular spiral galaxy, long streams of stars stretch out from the galactic core like bizarrely elongated spiral arms. These are tidal streams caused by some chance interaction in the galaxy’s past, and give ESO 415-19 a distinctly peculiar appearance.

ESO 415-19’s peculiarity made it a great target for Hubble. This observation comes from an ongoing campaign to explore the Arp Atlas of Peculiar Galaxies, a menagerie of some of the weirdest and most wonderful galaxies that the Universe has to offer. These galaxies range from bizarre lonesome galaxies to spectacularly interacting galaxy pairs, triplets, and even quintets. These space oddities are spread throughout the night sky, which means that Hubble can spare a moment to observe them as it moves between other observational targets.

I have intentionally brightened the galaxy to make the two faint two tidal streams more obvious. That they are so faint compared to the galaxy itself is in itself a mystery.

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NASA requesting proposals for raising Hubble’s orbit

9:23 am

NASA has published a request for proposals from the private commercial space industry for a possible future mission to raise Hubble’s orbit.

NASA published a request for information (RFI) Dec. 22 asking industry how they would demonstrate commercial satellite servicing capabilities by raising the orbit of Hubble. The agency said it is looking for technical information about how a company would carry out the mission, the risks involved and the likelihood of success.

NASA emphasized in the RFI that it had no plans to procure a mission to reboost Hubble. “Partner(s) would be expected to participate and undertake this mission on a no-exchange-of-funds basis,” the document stated, with companies responsible for the cost for the mission.

Apparently, this RFI was issued as a direct result of the agreement between NASA and SpaceX to study a Dragon mission to do exactly this, which in turn was prompted by Jared Isaacman, as part of his private Polaris program of manned Dragon/Starship space flights. I suspect that NASA officials realized that not only were their engineering advantages to getting more proposals, there were probably legal and political reasons for opening the discussion up to the entire commercial space community.

Ideally, a Hubble reboost mission should occur by 2025, though the telescope’s orbit will remain stable into the mid-2030s.

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Webb in safe mode intermittently during the past two weeks

2:49 pm

According to a short update today from the science team, the Webb Space Telescope went into safe mode on December 7, 2022 and was in that state “intermittently” through December 20, 2022 because of a software issue.

The James Webb Space Telescope resumed science operations Dec. 20, after Webb’s instruments intermittently went into safe mode beginning Dec. 7 due to a software fault triggered in the attitude control system, which controls the pointing of the observatory. During a safe mode, the observatory’s nonessential systems are automatically turned off, placing it in a protected state until the problem can be fixed. This event resulted in several pauses to science operations totaling a few days over that time period. Science proceeded otherwise during that time. The Webb team adjusted the commanding system, and science has now fully resumed.

It would be nice to have a more detailed description of that “software fault”, and how it affected the attitude control system. Such things can be very trivial, or they can be disastrous. NASA has a responsibility to tell the public which.

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Kepler’s first discovered exoplanet is spiraling into its aging star

9:33 am

Measurements of the orbit of first exoplanet discovered by the Kepler space telescope have determined that its orbit is very slowly shrinking, and that it will eventually spiral into its aging sun.

In the case of Kepler-1658b, according to the new study, its orbital period is decreasing at the miniscule rate of about 131 milliseconds (thousandths of a second) per year, with a shorter orbit indicating the planet has moved closer to its star.

Detecting this decline required multiple years of careful observation. The watch started with Kepler and then was picked up by the Palomar Observatory’s Hale Telescope in Southern California and finally the Transiting Exoplanet Survey Telescope, or TESS, which launched in 2018. All three instruments captured transits, the term for when an exoplanet crosses the face of its star and causes a very slight dimming of the star’s brightness. Over the past 13 years, the interval between Kepler-1658b’s transits has slightly but steadily decreased.

The scientists think tidal forces are causing the orbit to shrink. The star itself is old and beginning to expand as it evolves towards its own stellar death.

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Astronomers identify what they think are the Milky Way’s first stars

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The concentration of ancient stars in the Milky Way's core region
The concentration of ancient stars in the Milky Way’s core region.
Click for originial image.

The uncertainty of science: Using data produced by the European space telescope Gaia, combined with computer analysis, astronomers think they have identified the Milky Way’s first stars, all located within 30,000 light years of the galaxy’s core region.

The researchers began by locating a sample of two million bright red giant stars with the right spectra, using computer neural network machine learning.

With that sample, it proved comparatively easy to identify the ancient heart of the Milky Way galaxy – a population of stars that Rix has dubbed the “poor old heart”, given their low metallicity, inferred old age, and central location. On a sky map, these stars appear to be concentrated around the galactic center. The distances conveniently supplied by Gaia (via the parallax method) allow for a 3D reconstruction that shows those stars confined within a comparatively small region around the center, approximately 30,000 light-years across

The stars in question neatly complement Xiang’s and Rix’s earlier study of the Milky Way’s teenage years: They have just the right metallicity to have brought forth the metal-poorest of those stars that, later on, formed the Milky Way’s thick disk. Since that earlier study provided a chronology for thick-disk formation, this makes the ancient heart of the Milky Way older than about 12.5 billion years.

While the uncertainties of this scientific result are huge, it still helps identify the beginnings of the Milky Way, its initial size, and the kind of stars that existed here at that time.

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Blobs in space

11:42 am

Blobs in space
Click for full image.

Cool image time! The photo to the right, cropped and reduced to post here, was taken by the Hubble Space Telescope and released today by the science team. From the caption:

This image shows a small region of the well-known nebula Westerhout 5, which lies about 7000 light-years from Earth. Suffused with bright red light, this luminous image hosts a variety of interesting features, including a free-floating Evaporating Gaseous Globule (frEGG). The frEGG in this image is the small tadpole-shaped dark region in the upper left. This buoyant-looking bubble is lumbered with two rather uninspiring names — [KAG2008] globule 13 and J025838.6+604259.

FrEGGs are a particular class of Evaporating Gaseous Globules (EGGs). Both frEGGs and EGGs are regions of gas that are sufficiently dense that they photoevaporate less easily than the less compact gas surrounding them. Photoevaporation occurs when gas is ionised and dispersed away by an intense source of radiation — typically young, hot stars releasing vast amounts of ultraviolet light. EGGs were only identified fairly recently, most notably at the tips of the Pillars of Creation, which were captured by Hubble in iconic images released in 1995. FrEGGs were classified even more recently, and are distinguished from EGGs by being detached and having a distinct ‘head-tail’ shape. FrEGGs and EGGs are of particular interest because their density makes it more difficult for intense UV radiation, found in regions rich in young stars, to penetrate them. Their relative opacity means that the gas within them is protected from ionisation and photoevaporation. This is thought to be important for the formation of protostars, and it is predicted that many FrEGGs and EGGs will play host to the birth of new stars.

The bright red edges of these blobs are places where ionization is occurring, which tells us that the young hot star causing it is to the top, beyond the edge of the picture. Its radiation is also likely causing the blob’s tabpole shape as material is pushed downward away from the star.

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A barred spiral galaxy with distorted galaxy

10:58 am

A barred spiral galaxy
Click for full image.

Cool image time! The photo to the right, reduced and cropped to post here, was taken by the Hubble Space Telescope and shows a barred spiral galaxy about 214 million light years away.

Scientists used NASA’s Hubble Space Telescope to image NGC 6956 to study its Cepheid variable stars, which are stars that brighten and dim at regular periods. Since the period of Cepheid variable stars is a function of their brightness, scientists can measure how bright these stars appear from Earth and compare it to their actual brightness to calculate their distance. As a result, these stars are extremely useful in determining the distance of cosmic objects, which is one of the hardest pieces of information to measure for extragalactic objects.

The press release of course focuses on this magnificent barred spiral. I however want to draw your attention to the smaller galaxy in the white box.

background distorted galaxy

Since we do not know the distance to this distorted galaxy, we do not know if its distortion is caused by the barred spiral. It could be the bigger galaxy’s gravity is pulling material away.

More likely, based on the shape of this smaller galaxy, is that it is many light years farther away — which is why it looks so much smaller — and has been distorted because it is actually a collusion of two galaxies. The two bright nuclei with the red dust between strongly suggests such a collusion.

I highlight this background galaxy because it illustrates the importance when looking at any Hubble image to look at everything. To coin a phrase, there is gold in them thar hills, if you make the effort to look.

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Astronomers determine that two super-Earths are not as rocky as previously believed

10:32 am

Using observations from both the Hubble Space Telescope and the now retired Spitzer infrared space telescope, astronomers now think that two super-Earth-sized explanets are not as rocky as previously believed, and are in fact liquid worlds with as much as half their make-up comprised of water. From the press release:

Water wasn’t directly detected at Kepler-138 c and d, but by comparing the sizes and masses of the planets to models, astronomers conclude that a significant fraction of their volume – up to half of it – should be made of materials that are lighter than rock but heavier than hydrogen or helium (which constitute the bulk of gas giant planets like Jupiter). The most common of these candidate materials is water.

“We previously thought that planets that were a bit larger than Earth were big balls of metal and rock, like scaled-up versions of Earth, and that’s why we called them super-Earths,” explained Björn Benneke, study co-author and professor of astrophysics at the University of Montreal. “However, we have now shown that these two planets, Kepler-138 c and d, are quite different in nature and that a big fraction of their entire volume is likely composed of water. It is the best evidence yet for water worlds, a type of planet that was theorized by astronomers to exist for a long time.”

With volumes more than three times that of Earth and masses twice as big, planets c and d have much lower densities than Earth. This is surprising because most of the planets just slightly bigger than Earth that have been studied in detail so far all seemed to be rocky worlds like ours. The closest comparison, say researchers, would be some of the icy moons in the outer solar system that are also largely composed of water surrounding a rocky core.

This data simply underlines a basic point: The information we have of all exoplanets is sparse, practically nil. Any conclusions about their make-up is an educated guess, at best. Even now the conclusion that these are water worlds should be treated with great skepticism.

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