A long-armed galaxy

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.

NASA requesting proposals for raising Hubble’s orbit

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.

Blobs in space

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.

A barred spiral galaxy with distorted galaxy

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.

A wall of smoke, as seen by Hubble

A wall of smoke, as seen by Hubble
Click for full image.

Using the Hubble Space Telescope, astronomers have produced a magnificent image of an interstellar cloud, cropped and reduced to post here. From the caption:

A portion of the open cluster NGC 6530 appears as a roiling wall of smoke studded with stars in this image from the NASA/ESA Hubble Space Telescope. NGC 6530 is a collection of several thousand stars lying around 4350 light-years from Earth in the constellation Sagittarius. The cluster is set within the larger Lagoon Nebula, a gigantic interstellar cloud of gas and dust. It is the nebula that gives this image its distinctly smokey appearance; clouds of interstellar gas and dust stretch from one side of this image to the other.

Astronomers investigated NGC 6530 using Hubble’s Advanced Camera for Surveys and Wide Field Planetary Camera 2. They scoured the region in the hope of finding new examples of proplyds, a particular class of illuminated protoplanetary discs surrounding newborn stars. The vast majority of proplyds have been found in only one region, the nearby Orion Nebula. This makes understanding their origin and lifetimes in other astronomical environments challenging.

The first proplyds were seen in the very first images taken by Hubble after it was fixed and could finally take sharp pictures. That so few have been seen since is thus somewhat surprising.

A ghost goddess in space

Ghost goddess in space
Click for original image.

Cool image time! The image to the right, cropped, rotated, reduced, and enhanced to post here, is without doubt one of my favorite objects that the Hubble Space Telescope has photographed over the decades. This new image combines imagery obtained by earlier Hubble cameras and the newer cameras installed in 2009.

The delicate sheets and intricate filaments are debris from the cataclysmic death of a massive star that once lived in the Large Magellanic Cloud, a small satellite galaxy of the Milky Way. DEM L 190 — also known as LMC N49 — is the brightest supernova remnant in the Large Magellanic Cloud and lies approximately 160 000 light-years away from Earth in the constellation Dorado.

What makes this supernova remnant so visually appealing to my eye is its ghostly resemblance to a woman’s face, her hair blowing freely to the right. The original 2003 Hubble picture, shown below, has been the desktop image of my computer for almost two decades.
» Read more

Smeared colliding galaxies

Smeared colliding galaxies
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 as part of its continuing program to collect images of unusual galaxies that had previously not been observed at high resolution.

The Arp-Madore catalogue is a collection of particularly peculiar galaxies spread throughout the southern sky, and includes a collection of subtly interacting galaxies as well as more spectacular colliding galaxies. Arp-Madore 417-391, which lies around 670 million light-years away in the constellation Eridanus in the southern celestial hemisphere, is one such galactic collision. The two galaxies have been distorted by gravity and twisted into a colossal ring, leaving the cores of the two galaxies nestled side by side.

It is likely that this collision has been going on for many millions of years, and will not be over for many millions of years to come. In the end the two galaxies will likely merge into one whose final shape cannot be predicted.

Hubble takes a long exposure of spiral galaxy

A Hubble long exposure of a spiral galaxy
Click for original image.

This morning’s cool image on the right, reduced and sharpened to post here, comes courtesy of the Hubble Space Telescope.

NGC 7038 lies around 220 million light-years from Earth in the southern constellation Indus. This image portrays an especially rich and detailed view of a spiral galaxy, and exposes a huge number of distant stars and galaxies around it. That’s because it’s made from a combined 15 hours worth of Hubble time focused on NGC 7038 and collecting light. So much data indicates that this is a valuable target, and indeed, NGC 7038 has been particularly helpful to astronomers measuring distances at vast cosmic scales.

The press release focuses on how astronomers will use this data to refine the techniques they use to estimate distances to astronomical objects. However, a deep field image of this galaxy offers a wealth of other data. Note the reddish streams of dust along and between the spiral arms. This dust, as well as the bright patches in those arms likely signal star-forming regions. And I expect the details in the full resolution image, too large to make available on a webpage, would tell astronomers a lot about what is going on in the galaxy’s central regions.

Distant interacting galaxies

Interacting galaxies
Click for original image.

Cool image time! The picture to the right, cropped and reduced to post here, was taken by the Hubble Space Telescope as part of a survey of known “weird and wonderful galaxies.” This particular pair is dubbed Arp 248, and is estimated to be about 200 million light years away.

Two spiral galaxies are viewed almost face-on; they are a mix of pale blue and yellow in colour, crossed by strands of dark red dust. They lie in the upper-left and lower-right corners. A long, faint streak of pale blue joins them, extending from an arm of one galaxy and crossing the field diagonally. A small spiral galaxy, orange in colour, is visible edge-on, left of the lower galaxy.

The connecting stream indicates that these galaxies are interacting with each other, gravity drawing stars and gas from the upper galaxy towards the lower.

A hole in space

A hole 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 was released today as its picture of the week. From the caption:

This peculiar portrait from the NASA/ESA Hubble Space Telescope showcases NGC 1999, a reflection nebula in the constellation Orion. NGC 1999 is around 1350 light-years from Earth and lies near to the Orion Nebula, the closest region of massive star formation to Earth. NGC 1999 itself is a relic of recent star formation — it is composed of detritus left over from the formation of a newborn star.

Just like fog curling around a street lamp, reflection nebulae like NGC 1999 only shine because of the light from an embedded source. In the case of NGC 1999, this source is the aforementioned newborn star V380 Orionis which is visible at the centre of this image. The most notable aspect of NGC 1999’s appearance, however, is the conspicuous hole in its centre, which resembles an inky-black keyhole of cosmic proportions.

Once astronomers thought the black area was caused by dust, blocking the light. Now, based on a lot of new data from multiple ground- and space-based telescopes, they know that it actually is a black empty void. Why it exists however is not yet understood.

Webb takes infrared image of Hubble’s Pillars of Creation

The Pillars of Creation, as seen by Hubble and Webb
Click for original image.

Not unexpectedly, astronomers have quickly begun aiming the Webb Space Telescope’s infrared eye at some of the most famous targets previously imaged in optical wavelengths by the Hubble Space Telescope.

The newest example is shown to the right and reduced and labeled to post here. It shows what NASA officials dubbed “The Pillars of Creation” when Hubble first photographed this nebula in 1995, with a later 2014 Hubble optical image at the top and the new 2022 Webb infrared image on the bottom. From this image’s caption:

A new, near-infrared-light view from NASA’s James Webb Space Telescope, at [bottom], helps us peer through more of the dust in this star-forming region. The thick, dusty brown pillars are no longer as opaque and many more red stars that are still forming come into view.

While the pillars of gas and dust seem darker and less penetrable in Hubble’s view [top], they appear more diaphanous in Webb’s. The background of this Hubble image is like a sunrise, beginning in yellows at the bottom, before transitioning to light green and deeper blues at the top. These colors highlight the thickness of the dust all around the pillars, which obscures many more stars in the overall region.

In contrast, the background light in Webb’s image appears in blue hues, which highlights the hydrogen atoms, and reveals an abundance of stars spread across the scene. By penetrating the dusty pillars, Webb also allows us to identify stars that have recently – or are about to – burst free. Near-infrared light can penetrate thick dust clouds, allowing us to learn so much more about this incredible scene.

While the Hubble colors attempt to mimic the colors seen by the human eye, the colors in the Webb image are all false colors, chosen by the scientists to distinguish the different infrared wavelengths produced by different features in the picture.

Jets from baby stars

Jets from baby stars
Click for full image.

Cool image time! The picture to the right, rotated and reduced to post here, was taken across multiple wavelengths by the Hubble Space Telescope and shows two different Herbig–Haro objects (HH 1 at the top and HH 2 on the bottom). Herbig-Haro objects are the bright cloud clumps found near newly formed baby stars. These particular clouds are about 1,250 light years away. The jets flowing away from HH 1 are speeding away at about 250 miles per second.

Note that the baby stars themselves are not visible, buried in the dust that surrounds them. The bright star in the upper right is an unrelated foreground star.

In the case of HH 1/2, two groups of astronomers requested Hubble observations for two different studies. The first delved into the structure and motion of the Herbig–Haro objects visible in this image, giving astronomers a better understanding of the physical processes occurring when outflows from young stars collide with surrounding gas and dust. The second study instead investigated the outflows themselves to lay the groundwork for future observations with the NASA/ESA/CSA James Webb Space Telescope. Webb, with its ability to peer past the clouds of dust enveloping young stars, will revolutionise the study of outflows from young stars.

There is a lot of complexity here that this image only hints at. Note for example the smaller cloud objects near HH1, the shape of which suggest a shaping by some interstellar wind.

Chandra takes an X-ray look at early Webb infrared observations

Chandra's X-ray vision of the Cartwheel Galaxy
Chandra’s X-ray view of the Cartwheel Galaxy

Webb's view of the Cartwheel Galaxy
Webb’s infrared view of the Cartwheel Galaxy
Click for full image.

Hubble's optical view of the Cartwheel Galaxy
Hubble’s optical view of the Cartwheel Galaxy. Click for original image.

Astronomers have now taken X-ray images using the orbital Chandra X-ray Observatory of four of the first Webb Space Telescope observations. The four targets were the Cartwheel Galaxy, Stephan’s Quintet, galaxy cluster SMACS 0723.3–7327, and the Carina Nebula.

The three images to the right illustrate the importance of studying astronomy across the entire electromagnetic spectrum. Each shows the Cartwheel Galaxy as seen by three of the world’s most important space-based telescopes, each looking at the galaxy in a different wavelength.

The top picture is Chandra’s new X-ray observations. As the press release notes,

Chandra data generally show higher-energy phenomena (like superheated gas and the remnants of exploded stars) than Webb’s infrared view. … X-rays seen by Chandra (blue and purple) come from superheated gas, individual exploded stars, and neutron stars and black holes pulling material from companion stars.

The middle picture was produced by Webb, shortly after the start of its science operations. It looks at the galaxy in the infrared.

In this near- and mid-infrared composite image, MIRI data are colored red while NIRCam data are colored blue, orange, and yellow. Amidst the red swirls of dust, there are many individual blue dots, which represent individual stars or pockets of star formation. NIRCam also defines the difference between the older star populations and dense dust in the core and the younger star populations outside of it.

The bottom picture was taken by the Hubble Space Telescope in 1995. I have rotated the image to match the others. It looks at the galaxy in optical wavelengths, the wavelengths that our eyes perceive.

Note how bright the central galactic region is in the infrared and optical, but is invisible in X-rays. Chandra is telling us that all the most active regions in the Cartwheel are located in that outer ring, not in its center.

Interacting galaxies

Interacting galaxies
Click for full image.

The news is light this morning, so this cool image will be the first of three. The picture to the right, cropped and reduced to post here, was taken by the Hubble Space Telescope and released today. From the caption:

The two interacting galaxies making up the pair known as Arp-Madore 608-333 seem to float side by side in this image from the NASA/ESA Hubble Space Telescope. Though they appear serene and unperturbed, the two are subtly warping one another through a mutual gravitational interaction that is disrupting and distorting both galaxies.

I did a search for any research of this galaxy pair, and found that its identification was only part of a larger survey, with only a little research done on its spectroscopy. Thus, I can’t tell you the size or distance, or how far apart from each other these galaxies lie.

SpaceX and Jared Isaacman offer private mission to NASA to raise Hubble’s orbit

Capitalism in space: In a press release issued yesterday, NASA revealed that it has signed an unfunded agreement with SpaceX and Jared Isaacman’s Polaris program (which has purchased a series of manned missions on Dragon) to study the possibility of sending one of those private manned missions to the Hubble Space Telescope to raise its orbit.

SpaceX – in partnership with the Polaris Program – proposed this study to better understand the technical challenges associated with servicing missions. This study is non-exclusive, and other companies may propose similar studies with different rockets or spacecraft as their model.

Teams expect the study to take up to six months, collecting technical data from both Hubble and the SpaceX Dragon spacecraft. This data will help determine whether it would be possible to safely rendezvous, dock, and move the telescope into a more stable orbit.

In my book describing the history of the people who created Hubble, The Universe in a Mirror, I repeatedly noted how throughout its history people have tried to kill it, first in the design phase, then in the budget, then during construction, then after it was launched and the mirror was found to be ground incorrectly, and then after the Columbia accident when NASA management tried to cancel its last shuttle servicing mission.

Every attempt failed. As I have noted in that book and many times since its publication, Hubble is a telescope that will not die. NASA has for years intended to launch a mission to de-orbit it when its orbit had decayed enough that it was unstable. I’ve always said that when that time came, someone would propose and push for a mission to instead raise that orbit.

That prediction is now coming true. Though no robot arm exists yet for Dragon to use to grab Hubble in any rendezvous attempt, creating one is hardly difficult. At that point raising the telescope’s orbit becomes relatively trivial.

Whether such a mission could do more, such as replace Hubble’s ailing gyroscopes, is unknown. It would be foolish however not to review that possibility as well.

Hubble & Webb make first coordinated observations, tracking DART impact of Dimorphus

Webb and Hubble together look at DART impact of Dimorphus
Click for full image.

For the first time scientists have used both the Hubble Space Telescope and the James Webb Space Telescope to observe the same astronomical event, in this case the impact of the DART spacecraft on the asteroid Dimorphus on September 26, 2022.

The two images to the right show the asteroid several hours after impact. Both telescopes also captured images before the impact as well. From the press release:

Observations from Webb and Hubble together will allow scientists to gain knowledge about the nature of the surface of Dimorphos, how much material was ejected by the collision, and how fast it was ejected. Additionally, Webb and Hubble captured the impact in different wavelengths of light – Webb in infrared and Hubble in visible. Observing the impact across a wide array of wavelengths will reveal the distribution of particle sizes in the expanding dust cloud, helping to determine whether it threw off lots of big chunks or mostly fine dust. Combining this information, along with ground-based telescope observations, will help scientists to understand how effectively a kinetic impact can modify an asteroid’s orbit.

When Webb was first conceived in the late 1990s, it was exactly for this reason, to combine Hubble’s optical vision with Webb’s infrared view. Though more than a decade late, it has finally happened.

It will be months before scientists begin to decipher the data produced by all the telescopes and spacecraft used to observe the DART impact. What we are seeing now are merely hints at what has been learned.

A galaxy slowly being eaten by its black hole

Spiral galaxy
Click for full image.

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

NGC 5495, which lies around 300 million light-years from Earth in the constellation Hydra, is a Seyfert galaxy, a type of galaxy with a particularly bright central region. These luminous cores — known to astronomers as active galactic nuclei — are dominated by the light emitted by dust and gas falling into a supermassive black hole. This image is drawn from a series of observations captured by astronomers studying supermassive black holes lurking in the hearts of other galaxies.

Essentially Seyfert galaxies are galaxies whose central supermassive black hole has become dominant, large enough that its gravity is slowly eating up the rest of the galaxy. As it increasingly swallows stars and gas, the black hole emits more and more energy, thus becoming an active galactic nuclei.

Two stars from our own galaxy also dominate this picture, one inside and to the right of the galaxy’s center, and the other the bright star at the bottom of the picture, both identified by the diffraction spikes.

Interstellar clouds backlit by nearby massive star

Interstellar clouds backlit by nearby massive star
Click for full image.

Cool image time! The photo to the right, cropped and reduce to post here, was taken by the Hubble Space Telescope of what astronomers believe is a newly formed massive star about 9,000 light years away that has periodically spewed out material during eruptions.

The scientists hope to use Hubble to determine the speed in which this material is flying away from the star by taking pictures at intervals and then measuring the amount of change from image to image. This data will also allow the scientists to better gauge the distance to this star, as well as its actual mass, information that will help them better understand what is happening.

I highlight this picture however simply because of its beauty. The interstellar clouds on the left are all apparently backlit by the brightest star on the right, and thus their shape is easy to perceive.

Overlapping galaxies

Overlapping galaxies, as seen by Hubble
Click for full image.

Cool image time! The picture to the right, cropped and reduced to post here, was taken by astronomers using the Hubble Space Telescope, and captures two galaxies that happen to overlap in their line of sight to Earth.

The two galaxies, which have the uninspiring names SDSS J115331 and LEDA 2073461, lie more than a billion light-years from Earth. Despite appearing to collide in this image, the alignment of the two galaxies is likely just by chance — the two are not actually interacting.

This image was taken as part of the citizen-scientist project dubbed Galaxy Zoo, whereby volunteers review lower resolution images of strange-looking galaxies and propose the best for Hubble higher resolution imaging.

A galaxy with swirling arms

A galaxy with swirling arms
Click for full image.

Cool image time! The picture to the right, cropped and reduced to post here, was released yesterday by the science team that operates the Hubble Space Telescope. It captures a galaxy about 520 million light years away that appears to have been reshaped due to a galaxy merger.

That merger somehow distorted the disk of the inner galaxy, the brightest area, while also producing two sweeping spiral streams in the surrounding periphery.

Despite its unusual shape, astronomers did not choose to study this galaxy. From the caption:

This observation is a gem from the Galaxy Zoo project, a citizen science project involving hundreds of thousands of volunteers from around the world who classified galaxies to help scientists solve a problem of astronomical proportions: how to sort through the vast amounts of data generated by telescopes. A public vote selected the most astronomically intriguing objects for follow-up observations with Hubble. CGCG 396-2 is one such object, imaged here by Hubble’s Advanced Camera for Surveys.

Another grand galaxy imaged by Hubble

NGC 3631
Click for full image.

Cool image time! The photo to the right, reduced to post here, was released today and is one in what has become a steady string of recent and quite spectacular galaxy images produced by scientists using the Hubble Space Telescope. From the caption:

This image from NASA’s Hubble Space Telescope features the Grand Design Spiral, NGC 3631, located some 53 million light-years away in the direction of the constellation Ursa Major. The “arms” of grand design spirals appear to wind around and into the galaxy’s nucleus.

Close inspection of NGC 3631’s grand spiral arms reveals dark dust lanes and bright star-forming regions along the inner part of the spiral arms. Star formation in spirals is similar to a traffic jam on the interstate. Like cars on the highway, slower moving matter in the spiral’s disk creates a bottleneck, concentrating star-forming gas and dust along the inner part of their spiral arms. This traffic jam of matter can get so dense that it gravitationally collapses, creating new stars (here seen in bright blue-white).

This spiral follows the classic shape of these whirlpool galaxies. The Milky Way, though also a spiral, is now thought to be a barred spiral, whereby the galaxy’s whirlpool shape is distorted by a large straight bar of stars crossing its center.

Scientists also released today a second photo from Hubble of a different spiral galaxy, which you can check out here.

A pair of spiral galaxies

IC 4271, or AP 40, a pair of active galaxies
Click for full image.

Another cool image to herald in the weekend! The photo to the right, cropped and reduced to post here, was taken by the Hubble Space Telescope and shows a pair of spiral galaxies about 800 million light years away.

The smaller galaxy is superimposed on the larger one, which is a type of active galaxy called a Seyfert galaxy.

Seyfert galaxies are named for astronomer Carl K. Seyfert who, in 1943, published a paper about spiral galaxies with very bright emission lines. Today we know that about 10% of all galaxies may be Seyfert galaxies. They belong to the class of “active galaxies” – galaxies that have supermassive black holes at their centers accreting material, which releases vast amounts of radiation. The active cores of Seyfert galaxies are at their brightest when observed in light outside the visible spectrum. The larger galaxy in this pair is a Type II Seyfert galaxy, which means it is a very bright source of infrared and visible light.

In other words, both of these galaxies emit a lot of radiation in the infrared, radio, and X-rays due to activity taking place at the supermassive black holes believed to be at their cores.

A giant elliptical galaxy

A giant elliptical galaxy
Click for full image.

Cool image time! The image to the right, reduced to post here, was taken by the Hubble Space Telescope of the giant elliptical galaxy NGC 474.

Located some 100 million light-years from Earth, NGC 474 spans about 250,000 light-years across – that’s 2.5 times larger than our own Milky Way galaxy! Along with its enormous size, NGC 474 has a series of complex layered shells that surround its spherical-shaped core. The cause of these shells is unknown, but astronomers theorize that they may be the aftereffects of the giant galaxy absorbing one or more smaller galaxies. In the same way a pebble creates ripples on a pond when dropped into the water, the absorbed galaxy creates waves that form the shells.

About 10% of elliptical galaxies have shell structures, but unlike the majority of elliptical galaxies, which are associated with galaxy clusters, shelled ellipticals usually lie in relatively empty space. It may be that they’ve cannibalized their neighbors.

NGC 474 is no exception, also located in a relatively empty region of space.

Colliding galaxies

Merging galaxies

The string of amazing galaxy images coming from the Hubble Space Telescope continues. The photo to the right, cropped and reduced to post here, was released today and shows an object dubbed VV-689 that is believed to be two galaxies in the process of colliding and merging.

The angelic image comes from a set of Hubble observations that took a closer look at “Zoo Gems,” interesting galaxies from the Galaxy Zoo citizen science project. This crowdsourced program relies on hundreds of thousands of volunteers to classify galaxies and help astronomers wade through a deluge of data from robotic telescopes. In the process, volunteers discovered a gallery of weird and wonderful galaxy types, some not previously studied.

This image will lay the groundwork for more detailed research. Right now it appears no one has even estimated its distance.

Hubble looks at a tight cluster of five galaxies

Hickson Compact Group 40
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 to celebrate the telescope’s 32nd year in orbit. This cluster of five galaxies is dubbed Hickson Compact Group 40.

This menagerie includes three spiral-shaped galaxies, an elliptical galaxy, and a lenticular (lens-like) galaxy. Somehow, these different galaxies crossed paths in their evolution to create an exceptionally crowded and eclectic galaxy sampler.

Caught in a leisurely gravitational dance, the whole group is so crowded that it could fit within a region of space that is less than twice the diameter of our Milky Way’s stellar disk.

Though such cozy galaxy groupings can be found in the heart of huge galaxy clusters, these galaxies are notably isolated in their own small patch of the universe, in the direction of the constellation Hydra.

The red streaks in three galaxies is thought to be dust, suggesting that stars are still forming in these galaxies. The vertical galaxy on the right is seen edge on. Note too the tilted ring that appears to surround the galaxy on the left.

As for Hubble’s anniversary, the press release notes that since launch in 1990 the space telescope has made 1.5 million observations covering 50,000 heavenly objects, an archive of data available to anyone to access.

The spiral galaxy M91

spiral galaxy M91
Click for full release image.

Cool image time! The image to the right, reduced to post here, was released today by the Space Telescope Science Institute as part of a regular program using the Hubble Space Telescope to photograph galaxies.

This observation is part of an effort to build a treasure trove of astronomical data exploring the connections between young stars and the clouds of cold gas in which they form. To do this, astronomers used Hubble to obtain ultraviolet and visible observations of galaxies already seen at radio wavelengths by the ground-based Atacama Large Millimeter/submillimeter Array.

The galaxy is estimated to be about 55 million light years away, and is thought to have a supermassive black hole at its center with a mass somewhere between 9 and 38 million times the mass of the Sun.

Astronomers think they have detected the most distant star ever

The most distant star ever detected?
Click for full image.

The uncertainty of science: Using the Hubble Space Telescope astronomers now think they have detected the most distant single star ever located, the light of which is estimated to have come from a time only less than a billion years after the Big Bang itself.

The star, nicknamed Earendel by astronomers, emitted its light within the universe’s first billion years. It’s a significant leap beyond Hubble’s previous distance record, in 2018, when it detected a star at around 4 billion years after the big bang. Hubble got a boost by looking through space warped by the mass of the huge galaxy cluster WHL0137-08, an effect called gravitational lensing. Earendel was aligned on or very near a ripple in the fabric of space created by the cluster’s mass, which magnified its light enough to be detected by Hubble.

The arrow in the image, cropped and reduced to post here, points to the theorized star. Note the arc that tiny dot lies along. This arc is the result of the gravitational lensing, and illustrates quite bluntly the large uncertainties of this discovery. We are not seeing the star itself, but the distorted light after it passed through the strong gravitational field of the cluster of galaxies. The scientists conclusion that this dot is thus a single star, must be view with great skepticism.

Nonetheless, the data is intriguing, and will certainly be one of the early targets of the James Webb Space Telescope, which could confirm or disprove this hypothesis.

Have astronomers found an exoplanet with raining metal and gems?

The uncertainty of science: Using data from the Hubble Space Telescope, astronomers think they have detected on a hot Jupiter exoplanet 880 light years away the formation of clouds and rain made up metals and gems.

The exoplanet is tidally locked so that one side always faces its star, which also means the temperature difference between the two hemispheres is gigantic, 5,400 degrees Fahrenheit on the dayside and about 2,600 degrees on the nightside.

Previous Hubble data showed signs of metals including iron, magnesium, chromium and vanadium existing as gasses on the planet’s dayside. But in this study, the researchers have found that on the planet’s nightside, it gets cold enough for these metals to condense into clouds.

And, just as the strong winds pull water vapor and atoms around the planet to break apart and recombine, metal clouds will blow to the planet’s dayside and evaporate, condense back on the nightside and so on.

But metal clouds aren’t the only strange phenomenon these researchers spotted on this hot Jupiter. They also found evidence of possible rain in the form of liquid gems.

While tantalizing and alien, these results have many uncertainties. What the data suggests might not be the reality. To find out more, the astronomers hope to use the James Webb Space Telescope to do more infrared observations, once it becomes operational.

Hugging galaxies

Hugging galaxies
Click for full image.

Cool image time! The Hubble Space Telescope science team today released the photo to the right, cropped and reduced to post here, of the interaction of three galaxies, the larger two of which look like they are hugging each other.

This galaxy triplet is estimated to be about just under 700 million light years away. It was taken as part of a program aimed at producing high quality images of strange looking galaxies.

Using Hubble’s powerful Advanced Camera for Surveys, astronomers took a closer look at some of the more unusual galaxies that volunteers identified. The original Galaxy Zoo project was the largest galaxy census ever carried out and relied on crowdsourcing time from more than 100,000 volunteers to classify 900,000 unexamined galaxies. The project achieved what would have been years of work for a professional astronomer in only 175 days and has led to a steady stream of similar astronomical citizen science projects. Later Galaxy Zoo projects have included the largest ever studies of galaxy mergers and tidal dwarf galaxies, as well as the discovery of entirely new types of compact star-forming galaxies.

If you want to do some real science, you should definitely check out the Galaxy Zoo webpage. Anyone can join in, using images produced by the Victor Blanco 156 inch (4 meter) telescope in Chile to find cool stuff that needs closer examination using better telescopes like Hubble.

A galactic starship Enterprise

A galactic starship Enterprise
Click for full image.

Cool image time! The image to the right, cropped and reduced to post here, was taken by cameras on the Hubble Space Telescope. From the caption:

The subject of this image is a group of three galaxies, collectively known as NGC 7764A. They were imaged by the NASA/ESA Hubble Space Telescope, using both its Advanced Camera for Surveys and Wide Field Camera 3. The two galaxies in the upper right of the image appear to be interacting with one another. The long trails of stars and gas extending from them give the impression that they have both just been struck at great speed, thrown into disarray by the bowling-ball-shaped galaxy to the lower left of the image. In reality, interactions between galaxies happen over very long time periods, and galaxies rarely collide head-on with one another. It is also unclear whether the galaxy to the lower left is interacting with the other two, although they are so relatively close in space that it seems possible that they are.

This galaxy group is estimated to be about 425 million light years away, though that number might be different for the galaxy in the lower left.

1 2 3 4 5 6 8