Lopsided M96

A galactic maelstromThis is Messier 96, a spiral galaxy a bit more than 35 million light-years away in the constellation of Leo (The Lion). It is roughly the same mass and size as the Milky Way, but unlike our more or less symmetrical galaxy, M96 is lopsided. Its dust and gas are unevenly spread throughout its weak spiral arms, and its core is not exactly at the apparent galactic center. Its arms are also asymmetrical, perhaps because of the gravitational pull of other galaxies within the same group as Messier 96.

Image Credit: ESA / NASA

The Evolving Universe

Astronomers have assembled one of the most comprehensive portraits yet of the universe’s evolutionary history. It’s based on a broad spectrum of observations by the Hubble Space Telescope and other space and ground-based telescopes. In particular, Hubble’s ultraviolet vision has been used to track the birth of stars over the last 11 billion years, going all the way back to the cosmos’ busiest star-forming period about 3 billion years after the big bang. This composite image encompasses a sea of around 15,000 galaxies widely distributed in time and space. About 12,000 of them are undergoing star formation. This mosaic is 14 times the area of the Hubble Ultra Violet Ultra Deep Field released in 2014. Right click on the image to embiggen it.

Image Credits: NASA / ESA / P. Oesch (University of Geneva) / M. Montes (University of New South Wales)

A Horsehead of a Different Color

horseheadofadifferentcolorhorsehead_cThe Hubble Space Telescope took the data used to make the photograph above of the iconic Horsehead Nebula. The nebula has been a staple image in astronomy books for a century or so. While it’s shadowy in visible light (at left), it appears transparent and ethereal when photographed at infrared wavelengths, popping out against a backdrop of stars and distant galaxies visible in infrared light.

Image Credit: NASA

Eskimo Nebula

In 1787, English astronomer William Herschel discovered the Eskimo Nebula (aka, NGC 2392). From the ground, the nebula resembles someone’s head in a parka hood; hence, the name. The picture above was made by Hubble in 2000. Seen from orbit, the nebula’s gas clouds are complex, so complex they are not fully understood. The Eskimo Nebula is a planetary nebula, and it’s gas cloud came from the outer layers of a Sun-like star only about 10,000 years ago. The inner filaments seen in the picture are being ejected by a strong wind of particles from that central star. The Eskimo Nebula spans about 1/3 of a light year and is about 3,000 light years distant in the constellation Gemini.

Image Credit: NASA

NGC 6153

A nitrogen-rich nebula This is NGC 6153. The faint blue haze is what remains of a star like the sun after it had depleted most of its fuel. When that happened, the outer layers of the star were ejected and then ionized by the ultraviolet light from hot core of the star, forming the nebula.

NGC 6153 is a planetary nebula which contains large amounts of neon, argon, oxygen, carbon and chlorine—up to three times more than can be found in our solar system. It contains five times more nitrogen than our sun! It could be that the star developed higher levels of these elements as it grew and evolved, but it is more likely that the star originally formed from a cloud of material that already contained an abundance of those elements.

Image Credit: ESA / NASA

A Big Sibling for the Milky Way

NGC 6744 is similar to our home galaxy, but it’s about 200,000 light-years in diameter, about twice the size of our galaxy. Like the Milky Way, NGC 6744 has a prominent central core packed with old yellow stars. Its dusty spiral arms glow in shades of pink and blue; while the blue sites are full of young star clusters, the pink ones are regions of active star formation, indicating that the galaxy is still very lively.

Image Credit: ESA / NASA