A Galaxy and a Star

This image taken by the Hubble Space Telescope show a galaxy cataloged as NGC 4907. Its about 270 million light-years away. The bright star in the image below the galaxy is in our galaxy. It appears to outshine the billions of stars in NGC 4907 because it is roughly 100,000 time closer to us.

Image Credit: NASA / ESA

A 3D Model of the Helix Nebula

The Helix Nebula (aka NGC 7293) is a large planetary nebula located in the constellation Aquarius. It’s about 700 light-years away. The Helix Nebula has sometimes been referred to as the “Eye of God.” Tolkien fans have occasionally called it the “Eye of Sauron”

This animation of a 3-D model was created from Hubble Space Telescope and ground-based data of the Helix Nebula.

Credit: NASA, ESA, and G. Bacon (STScI)

The Crab’s Neutron Star

Heart of the CrabThis Hubble image peers deep into the core of the Crab Nebula, revealing its beating heart. At its center are the remnants of a supernova which sends out clock-like pulses of radiation and waves of charged particles. The neutron star at the very center of the Crab Nebula has about the same mass as the Sun, but it’s compressed into an incredibly dense sphere that is only a few miles across. Spinning 30 times a second, the neutron star ticks along, shooting out detectable beams of energy.

Image Credit: NASA / ESA

A Wide Spectrum Look at M101

It’s one of the last entries in Charles Messier’s famous catalog, but M101 is definitely not one of the least. The galaxy is big—roughly 170,000 light-years across, almost twice the size of our own Milky Way Galaxy. This multiwavelength view is a composite of images recorded by space-based telescopes. Color coded from X-rays to infrared wavelengths (high to low energies), the image data was taken from the Chandra X-ray Observatory (x-rays, purple), the Galaxy Evolution Explorer (ultraviolet, blue), the Hubble Space Telescope (visible light, yellow), and the Spitzer Space Telescope (infrared, red). While the X-ray data shows the multimillion degree gas around M101’s exploded stars and neutron star and black hole binary star systems, the lower energy data shows the stars and dust that define M101’s grand spiral arms. Known as the Pinwheel Galaxy, M101 lies within the boundaries of the northern constellation Ursa Major. It’s about 25 million light-years away.

Image Credit: NASA

Blowing a Bubble in Space

U Camelopardalis (aka U Cam) is a star nearing the end of its life. When stars run low on fuel for their normal fusion reactions, they become unstable. Every few thousand years, U Cam coughs out an almost spherical shell of gas as helium from its core begins to fuse. The gas ejected in the star’s latest eruption can be seen in this picture as a faint bubble around the star.

U Cam is an example of a carbon star. That’s a rare type of star with an atmosphere that contains more carbon than oxygen. Because of relatively low surface gravity, as much as half of the total mass of a carbon star may we swept away by powerful stellar winds. U Cam is located in the constellation of Camelopardalis (The Giraffe) which is near the North Celestial Pole, U Cam is much smaller than it appears in this image taken by the Hubble Space Telescope. The star would easily fit within a single pixel in the image. However, it is bright enough to saturate the camera’s photosensors which causes the star look much larger.

The shell of gas, both much larger and much fainter than its parent star, is visible in the picture. Gas clouds from expolsions are often quite irregular and unstable, but the shell of gas ejected from U Cam is almost perfectly spherical.

Image Credit: NASA

A Fluffy Galaxy

NGC 2275 is classified as a flocculent (or fluffy-looking) spiral galaxy. It’s about 67 million light-years away in the direction of the constellation Cancer. It’s fluffy spiral arms are the result of a slowdown in star formation, and virtually no new stars are being formed in center of the galaxy which is unusually large and relatively empty. Essentially all its gas was converted into stars long ago.

Image Credit: NASA / ESA

NGC 7027

NGC 7027 is a very young and dense planetary nebula about 3,000 light-years from Earth in the constellation Cygnus Only a few hundred years old, it’s a tiny infant. Indeed, it’s one of the smallest planetary nebulae, only 0.2 by 0.1 light-year. Most planetary nebulae are around 1 light-year across. NGC 7027 has a very complex structure, consisting of inner elliptical region of ionized gas inside of a large cloud of neutral gas.

The white dwarf at the core of the nebula has a mass about 70 percent of the Sun’s. The expanding halo has roughly three times the mass of the Sun.

Image Credit: NASA / ESA

Life in the Fast and Slow Lanes

Stars in SagittariusThe Hubble Space Telescope took this picture of a group of stars in the constellation of Sagittarius. Blue stars can be seen scattered across the frame, set against a backdrop of red companions. This blue stars are young, most likely formed at the same time from the same collapsing molecular cloud.

Red stars are much cooler than the sun, so they are either at the end of their lives or they are much less massive. These lower-mass stars are called red dwarfs and are thought to be the most common type of star in the Milky Way. The blue stars are hot. They are either young or very massive, many times the mass of the Sun.

A star’s mass decides its lifespan. Massive stars burn brightly over a short lifespan and die after only tens of millions of years. Yellow stars like the Sun typically live longer, burning for approximately ten billion years. Smaller stars, on the other hand, live life in the slow lane and may exist for trillions of years.

Image Credit: NASA

A Pair of Neighborhood Dwarfs

Luhman 16AB is a double star system composed of two brown dwarfs. It’s only about six light-years away, and is the third closest stellar system to Earth—after the triple star system Alpha Centauri and Barnard’s Star. Because the brown dwarfs are so dim, Luhman 16AB was only discovered in 2013.

This series of dots with varying spacings between them in the image above shows the slow waltz of the two brown dwarfs. It’s a composite of 12 images made over the course of three years by the Hubble Space Telescope. Using high-precision astrometry, a team of astronomers tracked the two components of the system as they moved both across the sky and around each other.

The brown dwarfs, Luhman 16A and Luhman 16B, orbit each other at a distance of only about 500,000,000 km, roughly three times the distance between the Earth and the Sun. Observations of the system require high resolution. The astronomers using Hubble to study Luhman 16AB were not only interested in the waltz of the two starss as they orbited each other but also were also searching for a third, invisible partner. Earlier ground-based observation suggested the presence of an exoplanet in the system, but the Hubble data showed that the two dwarfs are indeed dancing alone, unperturbed by a massive planetary companion.

Image Credit: NASA / ESA

A Grand Design Spiral Galaxy

NGC 2608 (also known as Arp 12) is considered a grand design spiral galaxy because the galaxy’s arms wind moderately (neither tightly nor loosely) around its prominent central bar. It is about 93 million light-years away in the constellation Cancer and is 62,000 light-years across, roughly 60% of the width of the Milky Way.

Image Credit: NASA / ESA

Out on the Edge

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 across or a third of the size of the Milky Way.

Image Credit: NASA / ESA