Lens-shaped galaxies have characteristics astronomers see in elliptical and spiral galaxies
Space news (lenticular galaxies) – 50 million light-years from Earth, in the constellation of Canes Venatici (The Hunting Dogs) –
This Hubble Space Telescope image of lenticular galaxy NGC 4111 shows an island universe with a more chaotic past than first thought. Lenticular or lens-shaped galaxies are labelled S0 on the Hubble Tuning Fork and are classified as a transitional type between spiral and elliptical galaxies.
Lenticular galaxies host older stars as observed in elliptical galaxies and include a disc as seenin spiral galaxies. However, they have a bulge and thin disc, which hasn’t been observed in elliptical galaxies. They also don’t have arms and the gas and dust detected in spiral galaxies.
NGC 4111 appears as a thin sliver of lights in this image because Hubble’s viewing the edge of the galaxy. At first glance, this island universe looks relatively quiet, but there are regions suggesting a more chaotic past. Pillars of dark filaments silhouetted against the bright core of the galaxy and running through the centre at right angles to the thin disc. Dark filaments of dust and gas astronomers associate with a ring of materialorbiting its core.
This ring of orbiting material isn’t aligned with the main disc of NGC 4111, which has astrophysicists thinking it could be the remains of a smaller galaxy it collided with long ago. Considering the possible mass and volume of this past meal, indigestion probably isn’t unexpected.
To celebrate 26th solar orbit of Hubble Space Telescope
Space news (Interaction of young, massive stars with the environment) – 7,100 light-years from Earth in the constellation Cassiopeia –
To celebrate the 26th year of the Hubble Space Telescope’s journey to the beginning of space and time NASA released this image of the Bubble Nebula (NGC 7635). The outeredge of the bubbleis a stellar wind of hot gas moving at over 4 million miles per hour. A stellar wind that slams into and heats dense regions of cold gas on the outer edge of the bubble to varying temperatures. Heated gases that emit different colours, with oxygen near the star emitting blue light while light emitted by hydrogen and nitrogen combines to produce yellow, cooler pillars in the upper left of the image. Cooler pillars illuminated by strong ultraviolet radiation from the hot, massive star producing the bubble, which is similar to the iconic “Pillars of Creation” in the Eagle Nebula.
“As Hubble makes its 26th revolution around our home star, the sun, we celebrate the event with a spectacular image of a dynamic and exciting interaction of a young star with its environment. The view of the Bubble Nebula, crafted from WFC-3 images, reminds us that Hubble gives us a front row seat to the awe-inspiring universe we live in,” said John Grunsfeld, Hubble astronaut and associate administrator for NASA’s Science Mission Directorate at NASA Headquarters, in Washington, D.C.
The outer edgeof the Bubble Nebula’saround seven light years across, which is about the same distance as travelling to our nearest stellar neighbour Alpha Centauri one and a half times. The super-hot, massive star producing the hot stellar winds at the outer edge is about 45 times the mass of Sol. It appears in the ten o’clock position in this image, off-centre from the outer edge due tovarying stellar winds.
The Bubble Nebula. Image: NASA, Donald Walter (South Carolina State University), Paul Scowen and Brian Moore (Arizona State University)
Imagine the reaction of the discoverer of the Bubble Nebula, William Herschel, who in 1787 first observed this colourful celestial object, to this Hubble Space Telescope image. How would he react to discovering it’s created by an extremely bright, super-massive star turning hydrogen into helium at a furious rate? A star about four million years old that within the next 20 million years will detonate as a supernova. The possibilities would expand his mind much like the O-type star that created the Bubble Nebula.
Imagine the expression on his face as he views the thousands of startling images taken by the Hubble Space Telescope of stellar objects across billions of light-years of space. The opening of his mind could probably be witnessed in his eyes and the expanding of his consciousness. He would fly about the universe on the edge of a bubble of hot gas and become one with the cosmos.
No better way to celebrate the 26th year of the space journeyof one of the greatest and grandest telescopes ever conceived and constructed by humankind.
Watch this YouTube video about the 26th anniversary of the space journey of the Hubble Space Telescope.
Nearly 90 percent of its stars were formed only 8 billion years ago, which is young in comparison to the majority of stars surveyed in the cosmos, so far
Space news (new star formation in dwarf galaxy Leo A, 2.54 million light-years from Earth) – It appears star formation in this smaller galaxy didn’t start until it was good and ready, which for astronomers poses a fewpuzzling questions –
Astronomers studying planetary formation in smaller dwarf galaxies sprinkled around the nearby cosmoshave found something different about the process of star formation in a member of the Local Group of galaxies. This nearby group contains two large spiral galaxies, the Milky Way and Andromeda galaxy (M31), and about 30 galaxies in total.
Dwarf galaxies are both more numerous in the cosmos and simpler in structure than larger spiral galaxies, but harder to study in most cases due to the extreme distances involved.In the case of closer dwarf galaxies, like Leo A, they’re easier to study in detail, but still hard to studydue to their smaller size of around 10,000 light-years.
Astronomers studying dwarf galaxy Leo A also called UGC 5364 and LEDA 28868, have found no evidence of recent mergers with any of its neighbours. They have discovered, however, that nearly 90 percent of the stars in this smaller galaxy are younger than 8 billion years. This goes against the current theory that such a result would normally be due toa recent merger with another galaxy. A finding that hasastronomers asking a puzzling question concerning star formation timescales in dwarf galaxies viewed during the human journey to the beginning of space and time.
Why is Leo A dominated by young stars, despite showing no signs of a recent merger with another galaxy?
Other astronomers studying Leo A recently reported the discovery of an old stellar halo and sharp edge, along with a distribution of stars extending just beyond its gaseous envelope. This implies smaller galaxies with less mass and stars also develop complex structures like larger spiral galaxies. This challenges current galaxy evolutiontheory and our understanding of smaller island universes.
Star system HD 44179 pumps out hot gas and other material to create the unusual structure known as the Red Rectangle
Space news (Old, sun-like stars near the end of their days) – 2,300 light-years from Earth in the constellation Monoceros (the Unicorn) –
Tworeasons astronomers study old, sun-like stars near the end of their days is to learn more about Sol, and its final days. Star system HD 44179‘s an older star system that began pumping outhot gas and other material into space starting about 14,000 years ago to create the unusual X-shaped structure seen in the image above. Near the end of its lifespan, astronomers believe this star system is a close binary, with the star at the centre of the image being a sun-like star surrounded by dense dust.
NASA astronomers first observed the unusual shape and colour of HD 44179 using ground-based telescopes. It was these observationsand shots like the Hubble Space Telescope image seen below that first inspired viewers to call it the Red Rectangle. This image revealed a wealth of new features hidden in the nebula that ground-based telescopes can’t see throughEarth’s chaotic atmosphere.
HD 44179 is an unusual example of what astronomers call a proto-planetary nebula. Older, sun-like stars on theirway to becomingplanetary nebulae, once they finish expelling material a smaller, very hot white dwarf star will remain. The ultraviolet radiation they emitwill flood into the nebula and strike the surrounding gas and cause it to glow, creating a planetary nebula.
One of the most common types of island universes viewed during our journey
Space news (The Hubble Tuning Fork: barred spiral galaxies) – 55 million light-years from Earth toward the constellation of Coma Berenices (Berenice’s Hair) –
First documentedin the western world by German-British astronomer William Herschel, barred spiral galaxy NGC 4394 is a member of the most common type of galaxy viewed inthe Galaxy Zoo. Estimated by astronomers to be 55 million light-years from Sol, toward the constellation of Coma Berenices, this island universeis considered a member of the Virgo Cluster.
The prototypical barred spiral galaxy, NGC 4394 has bright spiral arms sprouting from the ends of a bar cutting through its middle bulge. Sprinkled with blue, young stars its spiral arms contain fuzzy regions where stars are being formed and dark filaments of cosmic dust. Near the center of this island universe lies a region of ionized gas known as a low-ionization nuclear emission-line region (LINER). An active region displaying a specific set of emission lines in its spectra, a LINER contains mainly weakly ionized atoms of oxygen, nitrogen, and sulfur.
LINERS have been viewed relatively often during the human journey to the beginning of space and time and they’re starting to piece together their puzzle. Astronomers still need to figure out where the energy comes from to ionize the gas. Presently astronomers believe it could be due to the influence of the supermassive black hole or extreme levels of star formation. In the case of NGC 4394, gas from a nearby galaxy has likely flowed into its central region, providing a new source to fuel the process, either way.
You can learn more about galaxies with a LINER here.
Space news (The search for life beyond Earth) – An artist’s rendition of the Europa spacecraft orbiting Jupiter–
NASA’s Jet Propulsion Laboratory released this artist‘s rendering of the Europa spacecraft, which is set to head to Jupiter sometime in the 2020s. The Europa Mission spacecraftconfiguration in early 2016 is shown in this image. The final spacecraft configuration at launch could easily be different, so stay tuned here for more news. The position of Jupiter in the sky relative to Europa and the spacecraftare also off in this drawing.
Two large solar arrays are shown extending from the sides of the Europa spacecraft to which the ice-penetrating radar antennas are attached in this artist’s rendition. On the side of the craft, a saucer-shaped high gain antenna is depicted next to a magnetometer boom. On the forward section is a remote-sensing palette with the remaining science instruments.
The Europa Mission profile has a very capable, radiation-resistant spacecraft traveling to Jupiter, where it enters into a long, looping orbit of the giant planet in order to perform at least 45 repeated flybys of Europa at altitudes ranging from 1700 miles to 16 miles (2700 kilometers to 25 kilometers above its surface. Planetary scientists want to take a closer look at the evidence for an ocean of liquid water beneath its icy shell. An ocean of liquid water that could be the habitat of alien lifeforms we want to get to know better.