The Tadpole Galaxy

Arp 188, aka the Tadpole Galaxy, is a disrupted barred spiral galaxy about 420 million light-years from Earth . Its most noticeable feature is a massive tail of stars about 280,000 light-years long. Astronomers believe that the tail was formed about 100 million years ago by a merger or near merger of two galaxies.

A more compact galaxy crossed in front of a larger one and was partially strung out behind the resulting Tadpole by the gravitational interactions.

Image Credit: NASA / ESA

The Rotation of Neptune

This video is a full-globe map of Neptune created from Hubble Space Telescope data taken in January, 2020. The planet completes a rotation every 16 hours.

Neptune has dynamic weather. White clouds of methane ice crystals swirl around the planet, and two giant dark spots, giant storms, circle around the northern hemisphere. Around the southern pole, banding is concentrated where the winds are blowing west to east, in the same direction as the planet’s rotation. but near the equator, the winds blow east to west, in the opposite direction as the planet’s rotation.

The giant vortex near the equator is 4,600 miles across, wider than the Atlantic Ocean. Its slightly smaller companion is 3,900 miles across.

Video Credit: STScI

A Lonely Galaxy

0105-4x5color.aiMost galaxies are clumped together in groups or clusters, but NGC 6503 is in a lonely position at the edge of a strangely empty patch of space called the Local Void. The Local Void is a region of space over 150 million light-years across that is essentially empty of stars or galaxies. NGC 6503 is 18 million light-years away from us in the constellation Draco. It’s about 30,000 light-years or a third of the size of the Milky Way.

Image Credit: NASA / ESA

WR 124

WR 124 is a Wolf–Rayet star in the constellation of Sagitta surrounded by a ring nebula of expelled material known as M1-67. It is one of the fastest runaway stars in the Milky Way moving away from the center of the galaxy with a radial velocity around 200 km/s.

Wolf–Rayet stars are a rare set of stars with unusual spectra showing prominent broad emission lines of ionized helium and highly ionized nitrogen or carbon. WR 124 is about 15% hydrogen with most of the remaining mass being helium.

WR 124 is surrounded by an intensely hot nebula formed from the star’s extreme stellar wind. It is expanding at a over 150,000 km/h and is about 6 light-years across.

Image Credit: NASA / ESA

NGC 4394

Hubble spies NGC 4394NGC 4394 is a barred spiral galaxy about 55 million light-years away. It’s a member of the Virgo Cluster and an archetypal barred spiral galaxy Its bright spiral arms emerge from the ends of a bar that runs across the galaxy’s central bulge. The arms are filled with young blue stars, trails of dark cosmic dust, and regions of active star formation.

Image Credit: ESA / NASA

AG Caraine

This is a 3D animation of the star AG Caraine, a star that is in a balancing act between gravity and radiation to avoid self-destruction. It’s surrounded by an expanding shell of gas and dust—a nebula about five light-years wide, That’s roughly the distance from the Sun to our nearest star Alpha Centauri.

Video Credit: NASA / ESA / STScI

The Tadpole Nebula

The_TadpoleWhen I was a kid, one of the pleasures of spring was going to the creek and catching tadpoles. Even though I was interested in astronomy, I never thought of looking for one in the night sky. This bright blue tadpole seems to swim through the inky blackness of space. Catalogued as IRAS 20324+4057, “The Tadpole” is a clump of gas and dust giving birth to a bright protostar, one of the earliest steps in building a star.

There are multiple protostars in the tadpole’s head; the glowing yellow one in this image is the most luminous and massive. When this protostar has gathered together enough mass from its surroundings, it will become a fully-fledged young star.

The intense blue glow is caused by intense ultraviolet radiation from nearby stars. Pressure from that UV sculpts the tail into a long, wiggly shape. The Tadpole spans roughly a light-year from head to tail-tip, and contains gas with about four times the mass of the Sun.

Image Credit: NASA / ESA

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