An M80 with No Kaboom

M80This one’s a star cluster not a firecracker.

M80 is in the constellation Scorpius between the stars α Scorpii (Antares) and β Scorpii in a part of the Milky Way rich in nebulae. When viewed with a modest amateur telescope (like mine), it appears as a mottled ball of light. This Hubble image shows more detail. M80 is roughly 95 light-years in diameter. It contains several hundred thousand stars, making it one of the more densely populated globular clusters in the galaxy.

M80 contains a fair number of blue stragglers, stars that appear to be much younger than the cluster itself. Astronomers believe that these stars lost part of their outer layers during close encounters with other cluster members or as the result of collisions between stars in the tightly packed cluster. Images from Hubble show regions with very high blue straggler densities which suggests that the center of the cluster probably has a very high capture and collision rate.

Image Credit: NASA

The Veil Nebula

The Veil Nebula is about 2,100 light-years from Earth in the constellation of Cygnus (the Swan), making it a relatively close neighbor in astronomical terms. It’s the visible portion of a supernova remnant formed around 10,000 years ago known as the Cygnus Loop.

This image which only shows a portion of the nebula. It was assembled from data taken using five different filters with the Wide Field Camera 3 on the Hubble Space Telescope. Post-processing of the data brings out enhanced details of emissions from doubly ionized oxygen (blues) and ionized hydrogen and ionized nitrogen (reds).

Image Credit: NASA / ESA / Z. Levay

VY Canis Majoris

VY Canis Majoris is a red hypergiant and pulsating variable star which is extremely rich in oxygen. It’s about 3,900 light-years from Earth in the slightly southern constellation of Canis Major. It is one of the largest known stars and one of the most luminous and massive red supergiants. It’s also one of the most luminous stars in the Milky Way. This Hubble Space Telescope image shows the huge nebula of material cast off by VY Canis Majoris. This nebula is approximately a trillion miles across.

Image Credit: STScI

A Young Stellar Object

A young star takes centre stageThe reflection nebula spiraling out of this star looks a bit like a snail’s shell.The star V1331 Cyg is located in a dark cloud and is classified as a Young Stellar Object, but it is starting to contract to become a main sequence star similar to the Sun.

From our point of view V1331Cyg is special because we look almost exactly at one of its poles. Usually, the view of a young star is obscured by the dust from its circumstellar disc. In the case of V1331Cyg we are looking straight into the polar jet driven by the star that is clearing the dust. This point of view give us an almost undisturbed view of the star and its immediate surroundings, allowing astronomers to study it in greater detail and look for features that might suggest the formation of a very low-mass object (a planet) in the outer circumstellar disk.

Image Credit: ESA / NASA

An Irregular Dwarf Galaxy

ngc-4214This is dwarf galaxy NGC 4214 which is forming clusters of new stars from its interstellar gas and dust. The young clusters of new stars are within glowing gas clouds. The gas glows because it is excited by the strong ultraviolet light emitted from the young stars forming in the gravitational collapse of the gas. These hot stars eject stellar winds moving at thousands of km/s which blow bubbles in the gas. Near the center of the galaxy, there is a cluster of hundreds of massive blue stars, each more than 10,000 X brighter than our Sun, and a huge bubble inflated by stellar winds and radiation pressure surrounds the cluster.

Image Credit: NASA / ESA

Warp Factor

How did spiral galaxy ESO 510-13 get bent out of shape? The disks of many spiral galaxies are thin and flat, but with the gaps between star they are not solid. Spiral disks are loose conglomerations of billions of stars and diffuse gas all gravitationally orbiting a galaxy center. The common flat disk shape  is thought to be created by sticky collisions of large gas clouds early in the galaxy’s formation. Warped disks are not uncommon, though, and even our own Milky Way Galaxy is thought to have a bit of warp. The causes of spiral warps are still being investigated, but some warps are thought to result from interactions or even collisions between galaxies. ESO 510-13, shown in the digitally sharpened Hubble image above, is about 150 million light years away and about 100,000 light years across.

Image Credit: NASA

An Eye in Space?

Sauron in SpaceEven though it looks like it belongs atop the Dark Tower of Barad-dûr, this fiery swirl is actually a planetary nebula known as ESO 456-67. It lies in the constellation of Sagittarius (The Archer) in the southern sky.

It is possible to see in this image of the nebula the various layers of material expelled by the central star. Each appears in a different color—red, orange, yellow, and green-tinted bands of gas are visible, with clear patches of at the center. Astronomers don’t fully understood how planetary nebulae form such a wide variety of shapes and structures. Some are spherical, some elliptical, others shoot material in waves from their polar regions, some look like hourglasses or figures of eight, and others resemble large, messy stellar explosions.

Image Credit: NASA

X Marks the Spot

M51 X in CoreThis Hubble Space Telescope image of the core of the spiral galaxy M51 shows a dark “X” silhouetted across the galaxy’s nucleus. The “X” is caused by absorption of light by dust and marks the position of a black hole which may have a mass about one-million times the mass of the Sun. The darkest bar may be an edge-on view of a dust ring 100 light-years in diameter. It blocks the black hole its accretion disk as seen from Earth. The second bar of the “X” could be a second disk seen edge on, or it might be rotating gas and dust in M51 intersecting with the jets and ionization cones from the black hole.

Image Credit: NASA

NGC 6397

This is a globular cluster called NGC 6397. It’s about 7,800 light-years away, one of the closest globular clusters to Earth.

The cluster’s blue stars are near the end of their lives, having used up their hydrogen fuel. They’re now fusing helium into heavier elements in their cores, a higher temperature process resulting in a blue color. The reddish glow in the cluster is from red giant stars that have consumed most their hydrogen fuel but have expanded in size. The myriad small white objects include stars like our Sun.

Image Credit: NASA / ESA

Einstein Smiles

A smiling lensThis is is the galaxy cluster SDSS J1038+4849, and it seems to be smiling with its two orange eyes and white button nose. The two eyes are very bright galaxies, and the misleading smile lines are arcs caused by an effect known as strong gravitational lensing.

Galaxy clusters are the most massive structures in the Universe and exert such a powerful gravitational pull that they warp the spacetime around them. They act as cosmic lenses which can magnify, distort, and bend the light coming from behind them. In this special case of gravitational lensing, a ring—known as an Einstein Ring—is produced by this bending of light. The gaps in the ring are a consequence of the inexact and not-quite-symmetrical alignment of the source, lens, and observer.

Image Credit: ESA / NASA

Multiwavelength Data Sonification: The Galactic Center

This reimagines combined x-ray, visible light, and infrared data from the Chandra X-Ray Observatory, the Hubble Space Telescope, and the Spitzer Space Telescope as sound rather than an image.

Video Credit: NASA

Another Galaxy On Edge

Dancing on the edgeThis is NGC 7814, also known as the “Little Sombrero.” Its larger namesake, the Sombrero Galaxy, is another stunning example of an edge-on galaxy. Actually, the “Little Sombrero” is about the same size as its bright namesake, about 60,000 light-years across, but as it lies farther away, and so appears smaller in the sky.

Galaxies can take many shapes and be oriented any way relative to us in the sky. This can make it hard to figure out their actual morphology, as a galaxy can look very different from different viewpoints. NGC 7814 is a spiral galaxy that we see on edge. It has a bright central bulge and a bright halo of glowing gas extending outwards. The spiral arms appear as dark streaks because they are made up of dusty material that absorbs and blocks light from the galactic center behind them.

Image Credit: ESA / NASA

We Can’t See This *On* The Earth

aurora uvThis is the first image of Saturn’s aurora that was taken by the Hubble Space Telescope in 1997 when Saturn was 1.3 billion km from Earth. Saturn’s auroral displays are caused by an energetic wind of charged particles from the Sun that sweeps over the planet. Unlike the Earth’s, Saturn’s aurora is only seen in ultraviolet light. Because the UV doesn’t penetrate our atmosphere, Saturn’s aurora can only be observed from space.

Image Credit: NASA

Mergers and Acquisitions

One from manyThis is an odd galaxy known as NGC 1487. It’s not a single galaxy but two or more galaxies in the act of merging. Each of the old galaxies has lost almost all traces of its original appearance as the stars and gas have been thrown about by gravitational interactions. Unless one of the merging galaxies is very much bigger than the other(s), galaxies are always disrupted by the violence of the merging process, so it’s essentially impossible to determine exactly what the original galaxies looked like or how many of them there were. In this case, it may be that this NGC 1487 is the merger of several dwarf galaxies that were previously part of a small group.

Although older yellow and red stars can be seen in the outer regions of the new galaxy, its general appearance is dominated by bright blue stars that probably formed in a burst of star formation triggered by the merger.

Image Credit: ESA / NASA

A Chaotic Nebula

The gas and dust shells of ESO 455-10 would have been initially held tightly together as layers of its central star, but the distinct asymmetrical arc of material over the north side of the nebula is a clear sign of chaotic interactions between it and the interstellar medium. The star at the center of ESO 455-10 allows use to see the interaction with the gas and dust of the nebula, the surrounding interstellar medium, and the intense light from the star itself.

Planetary nebulae like ESO 455-10 are crucial in galactic enrichment because they distribute the heavier metal elements produced inside a star into the interstellar space where they will in time form the stuff of planets.

Image Credit: NASA / ESA

A Visitor From Another Galaxy?

NGC 3201 is an oddball among the 150-or-so globular star clusters in the Milky Way. It is moving very rapidly through the galaxy, and its motion is retrograde, that is, it’s orbiting around the galactic core in the opposite direction of most of the stars in the galaxy. That’s led to speculation that it may have come from outside and have been captured.

Also, it contains a black hole which was revealed by the strange movements of a star being quickly flung around the massive, invisible singularity.

Image Credit: ESA / NASA