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)

A Speck in the Corner


Saturn & TethysAt 116,500 km across, Saturn is roughly 10 times the diameter of Earth. The planet is much larger in relation to its moons than our Earth to its Moon. Saturn’s moon Tethys (which is a bit more than 1,000 km in diameter and could be counted as a dwarf planet it orbited the Sun by itself) can be seen as a speck in the lower right of the picture.

Image Credit: NASA

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

A Sunquake


The Sun has quakes—earthquake-like waves tha ripple through it. This is a movie of a sunquake on 30 July, 2011. The left frame shows the active region of a solar flare as seen in visible light (amber) as well as in extreme ultraviolet (red). The right frame shows the ripples on Sun’s outlying surface for up to 42 minutes after the onset of the flare, which is marked by the label “IP” for impulsive flare on the time scale.
Video Credit: NASA

A Star That’s Falling Apart


VY Canis MajorisAstronomers have studied VY Canis Majoris, a red supergiant star that is also classified as a hypergiant because of its very high luminosity, for more than a century. The star is located 5,000 light-years away. It is 500,000 times brighter and about 30 to 40 times more massive than the Sun. If VY Canis Majoris were at the center of our Solar System, its surface could extend to the orbit of Saturn. The star is also in the process of falling apart, and astronomers have learned that its gaseous outflows are more complex than originally thought.

The star has had many outbursts as it nears the end of its life, and the eruptions have formed loops, arcs, and knots of material moving at various speeds and in many different directions. The outermost material was ejected about 1,000 years ago, while a knot near the star may have been ejected as recently as 50 years ago

The typical red supergiant phase of a dying star lasts about 500,000 years as the massive star becomes a red supergiant that has exhausted the hydrogen fuel at its core. As the core contracts under gravity, the outer layers expand, the star’s diameter grows as much as 100 times larger, and it begins to lose mass at a higher rate. VY Canis Majoris has probably already shed about half of its mass, and it will eventually explode as a supernova.

Image Credit: NASA

It’s Raining Mushballs on Jupiter


Here’s NASA’s explanation of this video: This animation takes the viewer high into a large storm high in Jupiter’s atmosphere, where a mushy water-ammonia particle (represented in green) descends through the atmosphere, collecting water ice in the process. The process creates a “mushball” – a special hailstone with a center made partially of liquid water-ammonia mush and a solid water-ice crust exterior. Within about 10 to 60 minutes (depending on their sizes), these mushballs reach Jupiter’s deeper layers, below the water clouds, where they rapidly melt and evaporate. Theoretical models predict these mushballs could grow to about 4 inches (10 centimeters) in diameter, weigh up to 2 pounds (1 kilogram), and reach speeds up to 450 mph (700 kph) during their descent.

Video Credit: NASA / JPL—Caltech / SwRI / MSSS / CNRS

A Cloud of Cosmic Chaos


This composite view of the Orion Nebula was assembled using imaged from the Hubble and Spritzer Space Telescopes. Hubble’s visible light and UV images show hydrogen and sulfur that have been ionized but intense UV radiation from a group of massive stars in this star-forming region. Spitzer’s infrared data reveals carbon-rich molecules in the cloud. And both sets of images are filled with a rainbow of dots of stars.

Image Credit: NASA

Baby Stars


LH_95These swirls of gas and dust and the stars clustered in and around them are know as LH 95. It a region of low-mass, infant stars and their much more massive stellar neighbors found in the Large Magellanic Cloud.

The largest stars in LH 95 (those with at least 3X the mass of the Sun) generate strong stellar winds and high levels of UV radiation that heat the surrounding interstellar gas. The result is a bluish nebula of glowing hydrogen expanding outward into the molecular cloud that originally collapsed to form these massive stars. However, some dense parts of this star-forming region remain intact despite the stellar winds. The appear as dark dusty filaments in the picture. These dust lanes absorb some of the blue light emitted by the stars behind them causing them appear redder. Other parts of the molecular cloud have contracted to form infant stars, the fainter of which have a high tendency to cluster.

Image Credit: NASA

A Dwarf and Its Debris


IDL TIFF fileThis visible-light image of the debris disk around the red dwarf star AU Microscopii hints that planets may be forming or might already exist within it. The disk glows in light reflected by tiny grains of dust resulting from  the collisions of asteroids and comets. This debris disk is more than 40 billion miles across. The star at the center is quite young, about 12 million years old. It is only 32 light-years from Earth which makes its disk the closest yet seen in reflected starlight. It is also the first disk imaged around an M-type red dwarf, the most common type of star in the stellar neighborhood around the Sun.The disk has been cleared of dust within about a billion miles of the star. Images taken by Hubble (including this one) confirm that the disk is warped and has small variations in density that may have been caused by the tugging of an unseen companion, perhaps a large planet. That would be consistent with presence of the inner gap as well.

This debris disk is unusual in that it is the only one known that appears bluer than the star it surrounds. This possibly could it having a greater proportion of very small grains of dust  than other such disks. Smaller grains scatter blue light better than red. The surplus of small grains may be caused by the star not being bright enough to blow away tiny particles. Brighter, hotter stars would produce sufficient radiation to push small dust grains out of the disk and out into interstellar space

Image Credit: NASA