Category Archives: Hubble

Hand Prints on Hubble

Kind of a fun video from Science@NASA.

Tiangong Update: The remains of the Space Station ended up in the Pacific Ocean, reentry occurred on 2018/04/02 00:16 UTC.

I also want to mention there is a Space X launch of a cargo-spaceship heading to the International Space Station tomorrow with coverage beginning at about 19:00 UTC / 15:00 ET.

Hubble Watches A Storm on Neptune

Hubble watches Neptune’s Dark Storm Die, the title of the video says it all.

Credit: NASA’s Goddard Space Flight Center/Katrina Jackson

Music credit: “Struggling in the City” by Emre Ramazanoglu [PRS], Jamie Michael Bradley Reddington [PRS], and Patrick Green [PRS]; Atmosphere Music Ltd [PRS]; BLOCK; Killer Tracks Production Music

A Baby Solar System Found by Hubble?

Credits: NASA/ESA/G. Schneider (Univ. of Arizona)

Hubble Et al. (see below): Astronomers have used NASA’s Hubble Space Telescope to uncover a vast, complex dust structure, about 150 billion miles across, enveloping the young star HR 4796A. A bright, narrow, inner ring of dust is already known to encircle the star and may have been +69corralled by the gravitational pull of an unseen giant planet. This newly discovered huge structure around the system may have implications for what this yet-unseen planetary system looks like around the 8-million-year-old star, which is in its formative years of planet construction.

The debris field of very fine dust was likely created from collisions among developing infant planets near the star, evidenced by a bright ring of dusty debris seen 7 billion miles from the star. The pressure of starlight from the star, which is 23 times more luminous than the Sun, then expelled the dust far into space.

But the dynamics don’t stop there. The puffy outer dust structure is like a donut-shaped inner tube that got hit by a truck. It is much more extended in one direction than in the other and so looks squashed on one side even after accounting for its inclined projection on the sky. This may be due to the motion of the host star plowing through the interstellar medium, like the bow wave from a boat crossing a lake. Or it may be influenced by a tidal tug from the star’s red dwarf binary companion (HR 4796B), located at least 54 billion miles from the primary star.

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Hubble’s View: PLCK G004.5-19.5

The name of this galaxy cluster is PLCK G004.5-19.5.  You may not think the name is very creative, but it did remind me of a paper:  Strong Lensing Analysis of PLCK G004.5-19.5, a Planck-Discovered Cluster Hosting a Radio Relic at z=0.52.  Thanks Hubble it was very useful.

Heh, I remember the paper because of a happy coincidence.  About a week ago I happened to be doing some housekeeping on this computer and that was one of the files – and I didn’t delete it.

ESA — This image from the NASA/ESA Hubble Space Telescope shows the galaxy cluster PLCK G004.5-19.5. It was discovered by the ESA Planck satellite through the Sunyaev-Zel’dovich effect — the distortion of the cosmic microwave background radiation in the direction of the galaxy cluster by high-energy electrons in the intracluster gas. The large galaxy at the center is the brightest galaxy in the cluster, and above it a thin, curved gravitational lens arc is visible. This arc is caused by the gravitational forces of the cluster bending the path of light from stars and galaxies behind it, in a similar way to how a glass lens bends light.

Several stars are visible in front of the cluster — recognizable by their diffraction spikes — but aside from these, all other visible objects are distant galaxies. Their light has become redshifted by the expansion of space, making them appear redder than they actually are. By measuring the amount of redshift, we know that it took more than 5 billion years for the light from this galaxy cluster to reach us. The light of the galaxies in the background had to travel even longer than that, making this image an extremely old window into the far reaches of the universe.

This image was taken by Hubble’s Advanced Camera for Surveys (ACS) and Wide Field Camera 3 (WFC3) as part of an observing program called RELICS (Reionization Lensing Cluster Survey). RELICS imaged 41 massive galaxy clusters with the aim of finding the brightest distant galaxies for the forthcoming NASA James Webb Space Telescope to study.

Credit: ESA/Hubble & NASA, RELICS; Acknowledgement: D. Coe et al.
Text: European Space Agency

Hubble’s Pegasus Spiral

This is a wonderful telescope target, at a magnitude 9.5 it shows up nicely, however it is much too dim to be seen by binoculars in most places thanks to light pollution.

This was discovered by the famous Charles Messier, but oddly enough this galaxy was NOT included in his most excellent catalog.

NASA/ESA Hubble — This NASA/ESA Hubble Space Telescope image shows a spiral galaxy known as NGC 7331. First spotted by the prolific galaxy hunter William Herschel in 1784, NGC 7331 is located about 45 million light-years away in the constellation of Pegasus (the Winged Horse). Facing us partially edge-on, the galaxy showcases its beautiful arms, which swirl like a whirlpool around its bright central region.

Astronomers took this image using Hubble’s Wide Field Camera 3 (WFC3), as they were observing an extraordinary exploding star — a supernova — near the galaxy’s central yellow core. Named SN 2014C, it rapidly evolved from a supernova containing very little hydrogen to one that is hydrogen-rich — in just one year. This rarely observed metamorphosis was luminous at high energies and provides unique insight into the poorly understood final phases of massive stars.

NGC 7331 is similar in size, shape and mass to the Milky Way. It also has a comparable star formation rate, hosts a similar number of stars, has a central supermassive black hole and comparable spiral arms. The primary difference between this galaxy and our own is that NGC 7331 is an unbarred spiral galaxy — it lacks a “bar” of stars, gas and dust cutting through its nucleus, as we see in the Milky Way. Its central bulge also displays a quirky and unusual rotation pattern, spinning in the opposite direction to the galactic disk itself.

By studying similar galaxies we hold a scientific mirror up to our own, allowing us to build a better understanding of our galactic environment, which we cannot always observe, and of galactic behavior and evolution as a whole.

Credit: ESA/Hubble & NASA/D. Milisavljevic (Purdue University)
Text: European Space Agency

Hubble’s Cartwheels – Just Wow

Spectacular image, thanks Hubble.
ESA – This is an image of the Cartwheel Galaxy taken with the NASA/ESA (European Space Agency) Hubble Space Telescope.

The object was first spotted on wide-field images from the U.K. Schmidt telescope and then studied in detail using the Anglo-Australian Telescope.

Lying about 500 million light-years away in the constellation of Sculptor, the cartwheel shape of this galaxy is the result of a violent galactic collision. A smaller galaxy has passed right through a large disk galaxy and produced shock waves that swept up gas and dust — much like the ripples produced when a stone is dropped into a lake — and sparked regions of intense star formation (appearing blue). The outermost ring of the galaxy, which is 1.5 times the size of our Milky Way, marks the shock wave’s leading edge. This object is one of the most dramatic examples of the small class of ring galaxies.

This image is based on earlier Hubble data of the Cartwheel Galaxy that was reprocessed in 2010, bringing out more detail in the image than seen before.

Image credit: ESA/Hubble & NASA
Text credit: ESA

Hubble’s Look at M 79

I usually don’t think about Globular clusters in the northern winter except for possibly Messier 79 and just look at this Hubble image

Hubblesite — It’s beginning to look a lot like the holiday season in this NASA Hubble Space Telescope image of a blizzard of stars, which resembles a swirling snowstorm in a snow globe.

The stars are residents of the globular star cluster Messier 79, or M79, located 41,000 light-years from Earth, in the constellation Lepus. The cluster is also known as NGC 1904.

Globular clusters are gravitationally bound groupings of as many as 1 million stars. M79 contains about 150,000 stars packed into an area measuring only 118 light-years across. These giant “star-globes” contain some of the oldest stars in our galaxy, estimated to be 11.7 billion years old.

Most globular clusters are grouped around the central hub of our pinwheel-shaped galaxy. However, M79’s home is nearly on the opposite side of the sky from the direction of the galactic center. One idea for the cluster’s unusual location is that its neighborhood may contain a higher-than-average density of stars, which fueled its formation. Another possibility is that M79 may have formed in an unusual dwarf galaxy that is merging with the Milky Way.

In the Hubble image, Sun-like stars appear yellow. The reddish stars are bright giants that represent the final stages of a star’s life. Most of the blue stars sprinkled throughout the cluster are aging “helium-burning” stars. These bright blue stars have exhausted their hydrogen fuel and are now fusing helium in their cores.

A scattering of fainter blue stars are “blue stragglers.” These unusual stars glow in blue light, mimicking the appearance of hot, young stars. Blue stragglers form either by the merger of stars in a binary system or by the collision of two unrelated stars in M79’s crowded core.

The star cluster was discovered by Pierre Méchain in 1780. Méchain reported the finding to Charles Messier, who included it in his catalog of non-cometary objects. About four years later, using a larger telescope than Messier’s, William Herschel resolved the stars in M79, and described it as a “globular star cluster.”

The image is a combination of observations taken in 1995 and 1997 by Hubble’s Wide Field Planetary Camera 2. The red, green, and blue colors used to compose the image represent a natural view of the cluster.

The Hubble Space Telescope is a project of international cooperation between NASA and ESA (European Space Agency). NASA’s Goddard Space Flight Center in Greenbelt, Maryland, manages the telescope. The Space Telescope Science Institute (STScI) in Baltimore, Maryland, conducts Hubble science operations. STScI is operated for NASA by the Association of Universities for Research in Astronomy, Inc., in Washington, D.C.

Image: NASA and ESA Acknowledgment: S. Djorgovski (Caltech) and F. Ferraro (University of Bologna)

Galactic Wobble

Galactic wobble? Crazy dark matter.

HUBBLE – Using the NASA/ESA Hubble Space Telescope, astronomers have discovered that the brightest galaxies within galaxy clusters “wobble” relative to the cluster’s centre of mass. This unexpected result is inconsistent with predictions made by the current standard model of dark matter. With further analysis it may provide insights into the nature of dark matter, perhaps even indicating that new physics is at work.

Dark matter constitutes just over 25 percent of all mass-energy in the Universe but cannot be directly observed, making it one of the biggest mysteries in modern astronomy. Invisible halos of elusive dark matter enclose galaxies and galaxy clusters alike. The latter are massive groupings of up to a thousand galaxies immersed in hot intergalactic gas. Such clusters have very dense cores, each containing a massive galaxy called the “brightest cluster galaxy” (BCG).

The standard model of dark matter (cold dark matter model) predicts that once a galaxy cluster has returned to a “relaxed” state after experiencing the turbulence of a merging event, the BCG does not move from the cluster’s centre. It is held in place by the enormous gravitational influence of dark matter.

But now, a team of Swiss, French, and British astronomers have analysed ten galaxy clusters observed with the NASA/ESA Hubble Space Telescope, and found that their BCGs are not fixed at the centre as expected [1].

The Hubble data indicate that they are “wobbling” around the centre of mass of each cluster long after the galaxy cluster has returned to a relaxed state following a merger. In other words, the centre of the visible parts of each galaxy cluster and the centre of the total mass of the cluster — including its dark matter halo — are offset, by as much as 40 000 light-years.

“We found that the BCGs wobble around centre of the halos,” explains David Harvey, astronomer at EPFL, Switzerland, and lead author of the paper. “This indicates that, rather than a dense region in the centre of the galaxy cluster, as predicted by the cold dark matter model, there is a much shallower central density. This is a striking signal of exotic forms of dark matter right at the heart of galaxy clusters.”

The wobbling of the BCGs could only be analysed as the galaxy clusters studied also act as gravitational lenses. They are so massive that they warp spacetime enough to distort light from more distant objects behind them. This effect, called strong gravitational lensing, can be used to make a map of the dark matter associated with the cluster, enabling astronomers to work out the exact position of the centre of mass and then measure the offset of the BCG from this centre.

If this “wobbling” is not an unknown astrophysical phenomenon and in fact the result of the behaviour of dark matter, then it is inconsistent with the standard model of dark matter and can only be explained if dark matter particles can interact with each other — a strong contradiction to the current understanding of dark matter. This may indicate that new fundamental physics is required to solve the mystery of dark matter.

Co-author Frederic Courbin, also at EPFL, concludes: “We’re looking forward to larger surveys — such as the Euclid survey — that will extend our dataset. Then we can determine whether the wobbling of BGCs is the result of a novel astrophysical phenomenon or new fundamental physics. Both of which would be exciting!”


[1] The study was performed using archive data from Hubble. The observations were originally made for the CLASH and LoCuSS surveys.

Image: Hubble (of course)

Galaxy ESO 553-46 – A Busy Place

As far as galaxies are concerned, size can be deceptive. Some of the largest galaxies in the Universe are dormant, while some dwarf galaxies, such as ESO 553-46 imaged here by the NASA/ESA Hubble Space Telescope, can produce stars at a hair-raising rate. In fact, ESO 553-46 has one of the highest rates of star formation of the 1,000 or so galaxies nearest to the Milky Way. No mean feat for such a diminutive galaxy!
Clusters of young, hot stars are speckling the galaxy, burning with a fierce blue glow. The intense radiation they produce also causes surrounding gas to light up, which is bright red in this image. The small mass and distinctive coloring of galaxies of this type prompted astronomers to classify them, appropriately, as blue compact dwarfs (BCD).
Lacking the clear core and structure that many larger galaxies — such as the Milky Way — have, BCDs such as ESO 553-46 are composed of many large clusters of stars bound together by gravity. Their chemical makeup is interesting to astronomers, since they contain relatively little dust and few elements heavier than helium, which are produced in stars and distributed via supernova explosions. Such conditions are strikingly similar to those that existed in the early Universe, when the first galaxies were beginning to form.

Credit: ESA/Hubble & NASA
Text credit: European Space Agency

Hubble and the Coma Cluster

A terrific look at the Coma Cluster, NGC 4874 thanks to Hubble.

ESA/Hubble & NASA — In the center of a rich cluster of galaxies located in the direction of the constellation of Coma Berenices, lies a galaxy surrounded by a swarm of star clusters. NGC 4874 is a giant elliptical galaxy, about ten times larger than the Milky Way, at the center of the Coma Galaxy Cluster. With its strong gravitational pull, it is able to hold onto more than 30,000 globular clusters of stars, more than any other galaxy that we know of, and even has a few dwarf galaxies in its grasp.

In this NASA/ESA Hubble Space Telescope image, NGC 4874 is the brightest object, located to the right of the frame and seen as a bright star-like core surrounded by a hazy halo. A few of the other galaxies of the cluster are also visible, looking like flying saucers dancing around NGC 4874. But the really remarkable feature of this image is the point-like objects around NGC 4874, revealed on a closer look: almost all of them are clusters of stars that belong to the galaxy. Each of these globular star clusters contains many hundreds of thousands of stars.

Recently, astronomers discovered that a few of these point-like objects are not star clusters but ultra-compact dwarf galaxies, also under the gravitational influence of NGC 4874. Being only about 200 light-years across and mostly made up of old stars, these galaxies resemble brighter and larger versions of globular clusters. They are thought to be the cores of small elliptical galaxies that, due to the violent interactions with other galaxies in the cluster, lost their gas and surrounding stars.

This Hubble image also shows many more distant galaxies that do not belong to the cluster, seen as small smudges in the background. While the galaxies in the Coma Cluster are located about 350 million light-years away, these other objects are much farther out. Their light took several hundred million to billions of years to reach us.

This picture was created from optical and near-infrared exposures taken with the Wide Field Channel of Hubble’s Advanced Camera for Surveys. The field of view is 3.3 arcminutes across.