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

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

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

Approaching Venus

Global_dynamics_of_Venus_northern_hemisphere_node_full_imageYes, tomorrow’s the day for Perseverance to be landing on Mars, but that shouldn’t stop up us from taking a look at our closer neighbor Venus. This false-colour movie was put together using ultraviolet images taken by the Venus Monitoring Camera on board ESA’s Venus Express spacecraft on 22 May, 2006. The spacecraft was flying over the northern hemisphere at distances ranging between about 39,100 and 22,600 km from the surface.

Video Credit: 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

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

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

NGC 2481

ngc-2841NGC 2841 lies 46 million light-years away in the constellation of Ursa Major. It currently has a relatively low star formation rate compared to other spirals that are ablaze with emission nebulae. Notably missing are pinkish emission nebulae that accompany new star birth. It is likely that the radiation and supersonic winds from fiery, super-hot, young blue stars cleared out the remaining gas, and  shut down further nearby star formation. MGC 2481 is prime example of a flocculent spiral galaxy, one whose arms are patchy and discontinuous. It has no grand design structure apparent when seen in visible light as in this Hubble image, although some inner spiral arms can be seen in the near infrared.

Image Credit: NASA / ESA

Cosmic Leftovers

galex-view-m81_m82The Hubble Space Telescope has resolved some strange objects nicknamed “blue blobs” and found them to be brilliant blue clusters of stars born in the swirls and eddies of a galactic smashup 200 million years ago. These “blue blobs” exist along a wispy bridge of gas strung among three colliding galaxies, M81, M82, and NGC 3077 about 12 million light-years away from Earth. This is not a place astronomers expect to find star clusters because the gas filaments should be too thin to allow enough material to accumulate and actually build so many stars. The star clusters in this diffuse structure might have formed from gas collisions and subsequent turbulence which locally enhanced the density of the gas streams.

Image Credit: NASA, ESA

A Galaxy Seen Head On

NGC1309_HLANGC 1309 lies on the banks of the constellation Eridanus (The River) about 100 million light-years away. It about 30,000 light-years across or about one third the size of our Milky Way galaxy. Bluish clusters of young stars and dust lanes trace out NGC 1309’s spiral arms, winding around an older yellowish star population at the galaxy’s core.

NGC 1309’s recent supernova and Cepheid variable stars are used to derive calibration data for the expansion of the Universe.

Image Credit: NASA / ESA

Watching a Supernova Remnant Grow

This time-lapse video shows the movement of a supernova remnant that erupted approximately 1,700 years ago. The gaseous remains of an exploded star named 1E 0102.2-7219, is in the Small Magellanic Cloud, a satellite galaxy of our Milky Way. The opening frame shows ribbons of glowing gaseous clumps that make up the remnant. The video then toggles between a pair of black-and-white images taken 10 years apart, showing subtle shifts in the strands of gas over the decade. 

Video Credit: NASA / ESA / A. Pagan (STScI) / J. Banovetz and D. Milisavljevic (Purdue University)

M9

Hubble image of Messier 9M9 is one of the globular clusters closest to the center of the Milky Way Galaxy, only around 5,500 light-years from the galactic core. It’s about 25,800 light-years from Earth.

M9 has an apparent magnitude of 7.9, an angular size of 9.3′, and can be viewed with a small telescope. It is one of the nearer globular clusters to the center of the galaxy as is around 5,500 light-years from the Galactic Core. Its distance from Earth is 25,800 light-years.

The total luminosity of this cluster is around 120,000 times that of the Sun. It has an apparent magnitude of 7.9, so it can be viewed with a small telescope.

Image Credit: NASA