Tag: astronomy

Galaxies without end

8:55 am

Galaxies without end
Click for original.

Cool image time! The picture to the right, reduced and enhanced to post here, was taken by the Hubble Space Telescope as part of a monitoring program studying the two supernovae that have occurred in this galaxy previously.

Hubble has turned its attention toward NGC 1309 several times; previous Hubble images of this galaxy were released in 2006 and 2014. Much of NGC 1309’s scientific interest derives from two supernovae, SN 2002fk in 2002 and SN 2012Z in 2012. SN 2002fk was a perfect example of a Type Ia supernova, which happens when the core of a dead star (a white dwarf) explodes.

SN 2012Z, on the other hand, was a bit of a renegade. It was classified as a Type Iax supernova: while its spectrum resembled that of a Type Ia supernova, the explosion wasn’t as bright as expected. Hubble observations showed that in this case, the supernova did not destroy the white dwarf completely, leaving behind a ‘zombie star’ that shone even brighter than it did before the explosion. Hubble observations of NGC 1309 taken across several years also made this the first time the white dwarf progenitor of a supernova has been identified in images taken before the explosion.

The image however carries a far more philosophic component. Except for the star near the top (identified by the four diffraction spikes), every single dot and smudge you see in this picture is a galaxy. NGC 1309 is about 100 million light years away, but behind it along its line of sight and at much greater distances are innumerable other galaxies, so many it is impossible to count them. And each is roughly comparable in size to our own Milky Way galaxy, containing billions of stars.

The scale of the universe is simply impossible to grasp, no matter how hard we might try.

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Spain offers $470 million to move Thirty Meter Telescope to Canary Islands

8:52 am

The Spanish government this week announced it is willing to commit $470 million to fund the long delayed and no longer funded Thirty Meter Telescope (TMT) and move it from Hawaii to the Canary Islands.

Last month, the administration of US president Donald Trump announced plans to abandon further support for the telescope, as part of its proposals to slash by half funding for the US National Science Foundation (NSF), which has until now supported the telescope’s design.

Now the Spanish government has pitched to bring the giant facility to La Palma, in Spain’s Canary Islands — and backed up the effort with a pledge to contribute €400 million (US$470 million). “Spain reinforces its commitment as a refuge for science, betting on excellent research and technological innovation,” wrote the Spanish minister for science and innovation, Diana Morant, on X, as she announced the funding on 23 July. According to a statement from her ministry, Morant has already submitted a formal proposal to host the telescope to the TMT board, which would have to back such a move for it to go ahead.

The quote incorrectly spins the Trump cuts. The NSF never had the funds to build both the Giant Magellan Telescope in Chile and TMT. For years it has been lobbying to get that additional money, and failed. Even now, Congress is not interested in funding both even as it restores much of the funding cuts proposed by Trump.

The idea of moving TMT to the Canary Islands was first put forth in 2016, but in 2021 a Spanish judge blocked the tentative deal. The move also caused Japan to cut its funding to the project, leaving it without the cash to continue.

This new financing commitment by Spain might actually revive the telescope.

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Study identifies range of interference produced by Starlink satellites

8:58 am

In analyzing about 76 million radio images produced by the new Square Kilometer Array (SKA) in Australia scientists have found within them signals produced by SpaceX’s Starlink satellites.

PhD candidate and study lead Dylan Grigg said the team detected more than 112,000 radio emissions from 1806 Starlink satellites, making it the most comprehensive catalogue of satellite radio emissions at low frequencies to date. “Starlink is the most immediate and frequent source of potential interference for radio astronomy: it launched 477 satellites during this study’s four-month data collection period alone,” Mr Grigg said. “In some datasets, we found up to 30 per cent of our images showed interference from a Starlink satellite.”

Mr Grigg said the issue wasn’t just the number of satellites, but the strength of the signals and the frequencies they were visible at. “Some satellites were detected emitting in bands where no signals are supposed to be present at all, such as the 703 satellites we identified at 150.8 MHz, which is meant to be protected for radio astronomy,” Mr Grigg said. “Because they may come from components like onboard electronics and they’re not part of an intentional signal, astronomers can’t easily predict them or filter them out.”

The researchers were careful to note that SpaceX has been following all international regulations, and that these signals are not a violation of any law or regulation. Further, they emphasized that “Discussions we have had with SpaceX on the topic have been constructive.”

Because many other such constellations are now being launched — with several from China that normally does not negotiate these issues like SpaceX — the scientists want new international regulations imposed to protect their work.

More and more it seems astronomers should simply move their operations into space or the Moon, where such issues will not exist. Getting above the atmosphere and away from our modern technological society provides so many benefits for research the move should be a no-brainer. That it is now also much cheaper to do it (thanks to SpaceX) makes the move even more practical.

For some reason however the idea seems too difficult for many astronomers to fathom.

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First Hubble images of interstellar comet 3I/Atlas released

5:03 pm

Comet 3I/Atlas, taken by Hubble
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An undergraduate student has just released the first pictures taken by the Hubble Space Telescope of the interstellar object 3I/Atlas, confirming that it is a comet as indicated by the earlier image taken by the Gemini North telescope.

One of those images, taken only hours ago, is the inset on the map showing the comet’s route through the solar system to the right. The streaks on the image are either stars or cosmic rays. Though this image is of significantly lower quality than the Gemini North picture, it once again shows both the comet’s nucleus and developing coma.

A preprint [pdf] of a new research paper based on data from both telescopes further confirms this conclusion:

[T]hese results suggest that 3I/ATLAS hosts a coma containing large water ice grains, and that its dust continuum is stable over at least week-long timescales. The spectral characteristics further distinguish 3I from known ultrared trans-Neptunian objects and align it more closely with active Jupiter-family comets.

The last conclusion is very significant. Though the path and speed of this interstellar object says it must come from beyond the solar system, its cometary make-up more resembles comets that reside in the inner solar system. These facts strongly imply that there is at least one other solar systems not very different from our own.

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Astronomers detect exoplanet shaping the protoplanetary disk surrounding a baby star

9:41 am

Star with disk
Click for original image.

Astronomers using two different instruments on the Very Large Telescope (VLT) in Chile have now directly detected what they think is an exoplanet as it shapes the spiral arms of a baby star’s protoplanetary disk.

In the case of HD 135344B’s disc, swirling spiral arms had previously been detected by another team of astronomers using SPHERE (Spectro-Polarimetric High-contrast Exoplanet REsearch), an instrument on ESO’s VLT. However, none of the previous observations of this system found proof of a planet forming within the disc.

Now, with observations from the new VLT’s Enhanced Resolution Imager and Spectrograph (ERIS) instrument, the researchers say they may have found their prime suspect. The team spotted the planet candidate right at the base of one of the disc’s spiral arms, exactly where theory had predicted they might find the planet responsible for carving such a pattern.

The newly detected object however might be a brown dwarf and not an exoplanet. More observations are required to reduce the uncertainty.

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Have astronomers observed a black hole twice gobble from the same star?

9:23 am

Astronomers have now observed identical flares 700 days apart and coming from the same supermassive black hole, suggesting that a star was partially disrupted both times as it orbited the black hole.

Both flares produced less energy than predicted, based on calculations that assumed the complete destruction of a star. From the paper’s [pdf] abstract:

Here we present the optical-ultraviolet tidal disruption event AT 2022dbl, which showed a nearly identical repetition 700 days after the first flare. Ruling out gravitational lensing and two chance unrelated disruptions, we conclude that at least the first flare represents the partial disruption of a star.

…Since both flares are typical of the optical-ultraviolet class of tidal disruptions in terms of their radiated energy, temperature, luminosity, and spectral features, it follows that either the entire class are partial rather than full stellar disruptions, contrary to the prevalent assumption, or some members of the class are partial disruptions, having nearly the same observational characteristics as full disruptions. Whichever option is true, these findings could require revised models for the emission mechanisms of optical-ultraviolet tidal disruption flares and a reassessment of their expected rates.

Assuming the star wasn’t completely destroyed during the second flare, a third flare should occur about two years from now, as the star swings around and makes its next close approach. If so it will confirm this theory. If not, we will be left with the simple uncertainty of science.

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A galaxy surrounded by galaxies

11:12 am

A galaxy surrounded by galaxies
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 where Type 1a supernovae have occurred, in order to better refine the precise brightness of these explosions.

What makes this galaxy most interesting are the hundreds of other galaxies that appear to surround it. And that ain’t an illusion.

NGC 3285B is a member of the Hydra I cluster, one of the largest galaxy clusters in the nearby Universe. Galaxy clusters are collections of hundreds to thousands of galaxies that are bound to one another by gravity. The Hydra I cluster is anchored by two giant elliptical galaxies at its centre. Each of these galaxies is about 150,000 light-years across, making them about 50% larger than our home galaxy, the Milky Way. NGC 3285B sits on the outskirts of its home cluster, far from the massive galaxies at the centre.

As for the survey program, Type 1a supernovae are the measure cosmologists have used to discover the unexpected acceleration of the universe’s expansion rate at the largest scales, something they dub “dark energy” because they really don’t understand what they have discovered. That discovery however hinges entirely on the assumed intrinsic brightness of Type 1a supernovae. Astronomers have assumed these supernovae all have the same approximate brightness, and extrapolate their distance by that brightness.

The problem are the assumptions. We really don’t know if all Type 1a supernovae are approximately the same brightness. And even if they are equally bright, we also do not have a firm grasp of what that brightness should be.

This survey is an attempt to narrow or eliminate these uncertainties.

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Astronomers detect first evidence of gas condensing to molecular solids in baby solar system

11:39 am

Baby star with jets of new material
Click for original image.

Using a combination of ground- and space-based telescopes, astronomers have detected the first evidence of the gas and dust surrounding a young star condensing to molecular solids, thus beginning the initial stages of planet formation.

This newborn planetary system is emerging around HOPS-315, a ‘proto’ or baby star that sits some 1300 light-years away from us and is an analogue of the nascent Sun. Around such baby stars, astronomers often see discs of gas and dust known as ‘protoplanetary discs’, which are the birthplaces of new planets. … Their results show that SiO [silicon monoxide] is present around the baby star in its gaseous state, as well as within these crystalline minerals, suggesting it is only just beginning to solidify. “This process has never been seen before in a protoplanetary disc — or anywhere outside our Solar System,” says co-author Edwin Bergin, a professor at the University of Michigan, USA.

…With these data, the team determined that the chemical signals were coming from a small region of the disc around the star equivalent to the orbit of the asteroid belt around the Sun.

The false-color picture to the right, cropped, reduced, and sharpened to post here, was taken by the Atacama Large Millimeter/submillimeter Array (ALMA) telescope in Chile. It shows jets blowing out from the central baby star. Orange indicates carbon monoxide, while blue is the silicon monoxide. Initially the astronomers detected these molecules using spectroscopy from the Webb Space Telescope. This ALMA image was then used to identify where these molecules were located in the system.

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First good image released of interstellar object 3I/Atlas as it plunges through the solar system

3:25 pm

First good image of instellator object 3I/Atlas
Click for original image of 3I/Atlas.

Astronomers using the Gemini North Telescope in Hawaii have obtained the first good image of the interstellar object 3I/Atlas, as it plunges within the orbit of Jupiter on its way through the solar system.

That picture is to the right, cropped to post here and overlaid on top of a map showing the interstellar object’s calculated path through the solar system.

The picture clearly shows this is a comet, with central nucleus surrounded by a cloud of dust and gas. The data also suggests its nucleus has a diameter of about twelve miles. That it resembles a comet also suggests it is a dirty snowball, made up of ice and rocky material mixed together.

Because it will never get closer to the Sun then just inside the orbit of Mars, it is not likely it will ever get bright enough for naked eye observations. At the same time, it is large enough and will be close enough to make possible some excellent observations as it zips by and leaves the solar system sometime in the fall. The previous two identified interstellar objects, Oumuamua and Comet 21/Borisov, were either too small or too far away as they flew past to get this kind of good data.

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Webb spots aftermath of collision of two galaxies

10:06 am

colliding galaxies
Click for source.

Using the Webb Space Telescope, astronomers have discovered the collision of two spiral galaxies that appears to have caused a supermassive black hole to collapse in its wake.

The Webb false-color infrared image to the right shows the two galaxies as the red dots, both surrounded by a ring, with the supermassive black hole the bluish spot in between but offset somewhat to the left. Follow-up radio observations suggested that this bluish spot was a supermassive black hole, having a mass of a million suns and sucking up matter from the giant gas cloud that surrounds it.

The team proposes that the black hole formed there via the direct collapse of a gas cloud – a process that may explain some of the incredibly massive black holes Webb has found in the early universe.

This hypothesis however has enormous uncertainties, and requires a lot more observations to confirm. The black hole could simply exist unrelated to the galaxy collision, having come there from elsewhere. Or it could be from a third galaxy in this group that these initial observations have not yet detected.

The image however is quite cool.

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A distant globular cluster

10:03 am

A distant globular cluster
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 research project to study globular clusters in galaxies other than the Milky Way.

The data for this image comes from an observing programme comparing old globular clusters in nearby dwarf galaxies — the LMC [Large Magellanic Cloud], the Small Magellanic Cloud and the Fornax dwarf spheroidal galaxy — to the globular clusters in the Milky Way galaxy. Our galaxy contains over 150 of these old, spherical collections of tightly-bound stars, which have been studied in depth — especially with Hubble Space Telescope images like this one, which show them in previously-unattainable detail. Being very stable and long-lived, they act as galactic time capsules, preserving stars from the earliest stages of a galaxy’s formation.

Astronomers once thought that the stars in a globular cluster all formed together at about the same time, but study of the old globular clusters in our galaxy has uncovered multiple populations of stars with different ages. In order to use globular clusters as historical markers, we must understand how they form and where these stars of varying ages come from. This observing programme examined old globular clusters like NGC 1786 [pictured] in these external galaxies to see if they, too, contain multiple populations of stars. This research can tell us more not only about how the LMC was originally formed, but the Milky Way Galaxy, too.

This cluster, discovered in 1835 by John Herschel, is about 160,000 light years away.

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LIGO detects gravitational waves of largest black hole merger yet

9:22 am

The LIGO gravitational wave detector, spread across several continents, successfully detected the largest black hole merger yet on November 23, 2023.

The two black holes that merged were approximately 100 and 140 times the mass of the Sun. In addition to their high masses they are also rapidly spinning, making this a uniquely challenging signal to interpret and suggesting the possibility of a complex formation history. “This is the most massive black hole binary we’ve observed through gravitational waves, and it presents a real challenge to our understanding of black hole formation,” says Professor Mark Hannam, from Cardiff University and a member of the LIGO Scientific Collaboration. “Black holes this massive are forbidden through standard stellar evolution models. One possibility is that the two black holes in this binary formed through earlier mergers of smaller black holes.”

To date, approximately 300 black-hole mergers have been observed through gravitational waves, including candidates identified in the ongoing O4 run. Until now the most massive confirmed black-hole binary was the source of GW190521, with a much smaller total mass of “only” 140 times that of the sun.

As noted by the press release as well as this news article, present theories of stellar evolution say that these black holes could not have come from single stars, which are predicted to never be this massive. It is posited that each black hole might have formed from earlier mergers, but there is also a lot of uncertainty in the data. To quote the release again: “Extracting accurate information from the signal required the use of theoretical models that account for the complex dynamics of highly spinning black holes.”

That this detection was almost two years ago and only announced now makes me wonder if the timing of the announcement has more to do with lobbying and less to do with science. Trump’s proposed budget eliminates the U.S. funding portion for this project, and it is standard operating procedure for such projects to suddenly announce big discoveries timed to correspond to when Congress is considering the budget.

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Astronomers link fast X-ray bursts with gamma ray bursts and supernovae

1:17 pm

Using observations of a fast X-ray burst (FXT) 2.8 billion light years away by a plethora of space- and ground-based telescopes, astronomers now think the burst was caused by a massive star’s supernova explosion that would normally result in a gamma ray burst (GRB), but does not because the star’s outer layers trap the gamma rays from escaping.

Through analysis of EP 250108a’s rapidly evolving signal over the first six days following initial detection, the team found that this FXT is likely a ‘failed’ variation of a gamma-ray burst (GRB). GRBs are the most powerful explosions in the Universe and have been observed preceding supernovae. During these events, violent geysers of high-energy particles burst through a star’s outer layers as it collapses in on itself. These jets flow at nearly the speed of light and are detectable by their gamma-ray emission.

EP 250108a appears similar to a jet-driven explosion, but one in which the jets do not break through the outer layers of the dying star and instead remain trapped inside. As the stifled jets interact with the star’s outer layers, they decelerate and their kinetic energy is converted to the X-rays detected by Einstein Probe.

As always, there are many uncertainties with this conclusion.

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Another interstellar object identified entering the solar system

11:44 am

A11pl3Z's path through the solar system

Astronomers think they have identified another interstellar object that is now entering the solar system.

The dim space rock is currently at about magnitude 18.8. Our new visitor, A11pl3Z, will get its closest to the sun – at about 2 astronomical units (AU), or twice as far as Earth is from the sun – in October. As it reaches perihelion – its closest point to the sun – it should be moving at about 68 km/s relative to the sun, or at about 152,000 miles per hour.

The object’s calculated path through the solar system, shown by the blue line in the graphic to the right, as well as the object’s high speed, are why the astronomers think it is interstellar in origin. Both facts suggest it is coming from beyond the Oort cloud.

This is the third such object discovered, after Oumuamua (whose nature remains somewhat unknown), followed by Comet 21/Borisov.

UPDATE: The object has now been renamed 3I/Atlas. The “3I” indicates it is the third interstellar object discovered, and “Atlas” refers to the discovering telescope survey.

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Astronomers discover supernovae that apparently exploded twice

10:55 am

Double detonation supernova
Click for original picture.

Using the ground-based Very Large Telescope (VLT) in Chile, astronomers have discovered evidence suggesting a star apparently exploded twice went it went supernova several hundred years ago.

They detected this possibility by looking at the remnant of that blast, shown to the right. It shows a double halo, indicated by the blue and orange colors. The blue however is seen in both shells. As noted by the VLT’s press notice:

Calcium is shown in blue, and it is arranged in two concentric shells. These two layers indicate that the now-dead star exploded with a double-detonation.

This type of supernova, dubbed type 1a, occurs when a white dwarf sucks matter from its closely orbiting stellar companion. That material piles up on the surface of the star until it reaches critical mass and explodes, causing the supernova.

The two shells, suggesting a double detonation, fits a theory proposed for this process. From the paper’s abstract:

Our analysis reveals that the outer calcium shell originates from the helium detonation at the base of the outer envelope, while the inner shell is associated with the carbon–oxygen core detonation. This morphological distribution of intermediate-mass elements agrees qualitatively with the predicted signature of the double detonation of a sub-Chandrasekhar-mass white dwarf from a hydrodynamical explosion simulation.

In other words, the outer shell resulted from the explosion caused by the helium ripped from the companion star, with the resulting shockwave detonating the second explosion inside the white dwarf’s core.

That’s the theory at least. This data supports it, but it certainly doesn’t prove it.

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Webb detects unexpected “little red dots” in the early universe

11:52 am

The uncertainty of science: Using the Webb Space Telescope astronomers have begun to compile a small catalog of what they call “little red dots” [LRDs], objects in the very early universe that are very small, too small to be galaxies and are thus a mystery.

A team of astronomers recently compiled one of the largest samples of LRDs to date, nearly all of which existed during the first 1.5 billion years after the big bang. They found that a large fraction of the LRDs in their sample showed signs of containing growing supermassive black holes.

“We’re confounded by this new population of objects that Webb has found. We don’t see analogs of them at lower redshifts, which is why we haven’t seen them prior to Webb,” said Dale Kocevski of Colby College in Waterville, Maine, and lead author of the study. “There’s a substantial amount of work being done to try to determine the nature of these little red dots and whether their light is dominated by accreting black holes.”

The present most popular theory to explain the dots, based on the available data, is that the dots are newly formed black holes, their red light caused by material falling into the hole at millions of miles per hour. That theory has of course problems. For example, it doesn’t explain why we don’t see these dots in more recent times. Nor does it explain why the dots are dim in X-rays, a radiation expected from accreting black holes.

As always, the press release claims that this discovery does not “break” the present cosmological theories for the formation of the universe, but at the same time, it does illustrate our overall lack of knowledge about that early universe. We really don’t know very much, which means any theories we have are likely wrong simply due to our present ignorance.

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Baby stars illuminating the dust that surrounds them

10:03 am

Baby stars illuminating dark dust
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 showing the wispy bluish clouds made of dark dust that we can only see because the dust is illuminated by the reflected light from the five red and blue stars nearby. Think of the Moon, lit only by the reflected light of the Sun.

The photo however was not taken to study the clouds, but these baby stars, located in one of the closest star forming regions of the Milky Way.

GN 04.32.8 is a small part of the stellar nursery known as the Taurus Molecular Cloud. At only roughly 480 light-years from Earth in the constellation Taurus, it’s one of the best locations for studying newly forming stars. This reflection nebula is illuminated by the system of three bright stars in the centre of this image, mainly the variable star V1025 Tauri in the very centre. One of those stars overlaps with part of the nebula: this is another variable star that is named HP Tauri, but is classified as a T Tauri star, for its similarity to yet another variable star elsewhere in the Taurus Molecular Complex. T Tauri stars are very active, chaotic stars at an early stage of their evolution, so it’s no surprise that they appear in a prolific stellar nursery like this one! The three stars are also named HP Tau, HP Tau G2 and HP Tau G3; they’re believed to be gravitationally bound to each other, forming a triple system.

Eagle-eyed viewers might notice the small, squashed, orange spot, just left of centre below the clouds of the nebula, that’s crossed by a dark line. This is a newly-formed protostar, hidden in a protoplanetary disc that obstructs some of its light. Because the disc is edge-on to us, it’s an ideal candidate for study. Astronomers are using Hubble here to examine it closely, seeking to learn about the kinds of exoplanets that might be formed in discs like it.

As beautiful as this image is, it is that tiny protostar near the bottom that likely attracts the most interest from astronomers.

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Webb takes infrared image of exoplanet

9:32 am

Webb's image of exoplanet

Using the Webb Space Telescope astronomers have now successfully taken an infrared false-color image of Saturn-sized exoplanet orbiting a young star about half the mass of the Sun and about 111 light years away.

The image is to the right, cropped and reduced to post here. The star, its light blocked out, is indicated by the circle with the star in the middle. The exoplanet is the orange blob to the upper right, sitting inside the blue accretion disk that surrounds the star, photographed in optical light by the Very Large Telescope in Chile.

You can read the paper here. The scientists rejected the possibility that this was a background galaxy after doing computer modeling, based on the data available. From their paper:

Dedicated N-body simulations were conducted for a planet with a mass of 0.34 [mass of Jupiter], located at 52 au [astronomical units] around the 0.46 [solar mass] central star. This value is consistent with the measured projected separation, assuming that the planet and the ≈13°-inclined disk are coplanar. The simulation also included a disk of 200,000 planetesimals, distributed between 20 and 130 au. These parameters were selected to roughly match the boundaries of the observed disk.

Note too that the picture to the right has been significantly enhanced by the press department at JPL, based on the actual data shown in the paper itself. These fact underline the uncertainties involved in this discovery.

Nonetheless, it is a good result, and suggests we are looking at the formation process of a new solar system surrounding a very young baby star.

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Astronomers look at the Andromeda Galaxy in many wavelengths

3:11 pm

Andromeda across many wavelengths
Click for full images.

Astronomers using both old and new and ground- and space-based telescopes have created a full set of observations of the Andromeda Galaxy (also known as M31) across five different wavelengths, producing one of the most complete views of the galaxy so far.

This new composite image contains data of M31 taken by some of the world’s most powerful telescopes in different kinds of light. This image includes X-rays from NASA’s Chandra X-ray Observatory and ESA’s (European Space Agency’s) XMM-Newton (represented in red, green, and blue); ultraviolet data from NASA’s retired GALEX (blue); optical data from astrophotographers using ground based telescopes (Jakob Sahner and Tarun Kottary); infrared data from NASA’s retired Spitzer Space Telescope, the Infrared Astronomy Satellite, COBE, Planck, and Herschel (red, orange, and purple); and radio data from the Westerbork Synthesis Radio Telescope (red-orange).

Each type of light reveals new information about this close galactic relative to the Milky Way. For example, Chandra’s X-rays reveal the high-energy radiation around the supermassive black hole at the center of M31 as well as many other smaller compact and dense objects strewn across the galaxy.

The contrast in emissions between different wavelengths is certainly striking. The radio, infrared, and ultraviolet data clearly delineate the galaxy’s arms where star formation is occurring. The X-ray highlights the galaxy’s central black hole.

This press release is clearly intended to lobby against the cuts at NASA, especially considering that several of these images (Galax, Spitzer) are not new. At the same time, it does demonstrate the need to look at the heavens across the entire electromagnetic spectrum. It seems to me that the astronomical community should begin to consider other methods of funding for this work, other than just the federal government, and in fact they prove this point themselves by the use of images above from some smaller ground-based telescopes not funded by American tax dollars.

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A graceful spiral galaxy

2:35 pm

A graceful spiral galaxy
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 project to study galaxies with very active central supermassive black holes.

What sets UGC 11397 apart from a typical spiral lies at its centre, where a supermassive black hole containing 174 million times the mass of the Sun is growing. As a black hole ensnares gas, dust, and even entire stars from its vicinity, this doomed matter heats up and puts on a fantastic cosmic light show. Material trapped by the black hole emits light from gamma rays to radio waves and can brighten and fade without warning. But in some galaxies, including UGC 11397, thick clouds of dust hide much of this energetic activity from view in optical light. Despite this, UGC 11397’s actively growing black hole was revealed through its bright X-ray emission — high-energy light that can pierce the surrounding dust. This led astronomers to classify it as a Type 2 Seyfert galaxy, a category used for active galaxies whose central regions are hidden from view in visible light by a doughnut-shaped cloud of dust and gas.

To me what sets this galaxy apart is its natural beauty. It also reminds me of the universe’s vastness. Located about 250 million light years away, those hazy spiral arms represent millions of stars, many of which likely harbor planets and maybe even life.

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