Celestial Fireworks – Astronomy Picture of the Day

 

Credit: NASA/ESA and The Hubble Heritage Team (STScI/AURA)

Click to Enlarge image

Resembling the puffs of smoke and sparks from a summer fireworksdisplay in this image from NASA/ESA Hubble Space Telescope, these delicate filaments are actually sheets of debris from a stellar explosion in a neighboring galaxy. Hubble’s target was a supernova remnant within the Large Magellanic Cloud (LMC), a nearby, small companion galaxy to the Milky Way visible from the southern hemisphere.

Denoted N 49, or DEM L 190, this remnant is from a massive star that died in a supernova blast whose light would have reached Earth thousands of years ago. This filamentary material will eventually be recycled into building new generations of stars in the LMC. Our own Sun and planets are constructed from similar debris of supernovae that exploded in the Milky Way billions of years ago.

 

Credit: NASA/ESA and The Hubble Heritage Team (STScI/AURA)

Astronomy Picture of The Day – The Red Spider Nebula: Surfing in Sagittarius

Credit: ESA & Garrelt Mellema (Leiden University, the Netherlands)

Huge waves are sculpted in this two-lobed nebula some 3000 light-years away in the constellation of Sagittarius. This warm planetary nebula harbors one of the hottest stars known and its powerful stellar winds generate waves 100 billion kilometres high. The waves are caused by supersonic shocks, formed when the local gas is compressed and heated in front of the rapidly expanding lobes. The atoms caught in the shock emit the spectacular radiation seen in this image.

Astronomy Picture of The Day – Galaxy NGC 4214

Credit: NASA, ESA and the Hubble Heritage Team (STScI/AURA)-ESA/Hubble Collaboration. Acknowledgment: R. O’Connell (University of Virginia) and the WFC3 Scientific Oversight Committee

Hubble’s newest camera has taken an image of galaxy NGC 4214. This galaxy glows brightly with young stars and gas clouds, and is an ideal laboratory to research star formation and evolution.

Size isn’t everything… in astronomy, at least. Dwarf galaxy NGC 4214 may be small, but what it lacks in size it makes up for in content. It is packed with everything an astronomer could ask for, from hot, young star-forming regions to old clusters with red supergiants.

The intricate patterns of glowing ionised hydrogen gas, cavities blown clear of gas by stellar wind, and bright stellar clusters of NGC 4214 can be seen in this optical and near-infrared image, taken using the Wide Field Camera 3 (WFC3) instrument on the NASA/ESA Hubble Space Telescope.

A huge heart-shaped cavity — possibly the galaxy’s most eye-catching feature — can be seen at the centre of the image. Inside this hole lies a large cluster of massive, young stars ranging in temperature from 10 000 to 50 000 degrees Celsius. Their strong stellar winds are responsible for the creation of this hollow area. The resulting lack of gas prevents any further star formation from occurring in this region.

Located around 10 million light-years away in the constellation of Canes Venatici (The Hunting Dogs), the galaxy’s relative close proximity to us, combined with the wide variety of evolutionary stages among the stars, makes it an ideal laboratory to research what triggers star formation and evolution. By chance, there is relatively little interstellar dust between us and NGC 4214, making our measurements of it more accurate.

NGC 4214 contains a large amount of gas, some of which can be seen glowing red in the image, providing abundant material for star formation. The area with the most hydrogen gas, and consequently, the youngest clusters of stars (around two million years old), lies in the upper part of this Hubble image. Like most of the features in the image, this area is visible due to ionisation of the surrounding gas by the ultraviolet light of a young cluster of stars within.

Observations of this dwarf galaxy have also revealed clusters of much older red supergiant stars that we see at a late stage in their evolution. Additional older stars can be seen dotted all across the galaxy. While these are dominant in infrared emission they can only be seen shining faintly in this visible-light image. The variety of stars at different stages in their evolution, indicate that the recent and ongoing starburst periods are by no means the first, and the galaxy’s numerous ionised hydrogen regions suggest they will not be the last.

via spacetelescope.org

Astronomy Picture of The Day – Aurora Australis From Space

Image Credit: NASA

This image is of Atlantis and its Orbital Boom Sensor System robot arm extension backdropped against Earth’s horizon and a greenish phenomenon associated with Aurora Australis. One of the station’s solar array panels appears at upper left. Because of the exposure time needed for this type of photography, some of the stars in the background are blurred.

Source nasa.gov

Astronomy Picture of the Day | A rose made of galaxies

Credit: NASA, ESA and the Hubble Heritage Team (STScI/AURA)

This image of a pair of interacting galaxies called Arp 273 was released to celebrate the 21st anniversary of the launch of the NASA/ESA Hubble Space Telescope.

The distorted shape of the larger of the two galaxies shows signs of tidal interactions with the smaller of the two. It is thought that the smaller galaxy has actually passed through the larger one.

via spacetelescope.org

Astronomy Picture of the Day – A Lunar Eclipse on Solstice Day

A Lunar Eclipse on Solstice Day
Credit & Copyright: Jerry Lodriguss
(Catching the Light)

Astronomy Picture of the Day | Mirach's Ghost


Mirach’s Ghost

Credit & Copyright: Anthony Ayiomamitis (TWAN)

Explanation: As far as ghosts go, Mirach’s Ghost isn’t really that scary. In fact, Mirach’s Ghost is just a faint, fuzzy galaxy, well known to astronomers, that happens to be seen nearly along the line-of-sight to Mirach, a bright star. Centered in this star field, Mirach is also called Beta Andromedae. About 200 light-years distant, Mirach is a red giant star, cooler than the Sun but much larger and so intrinsically much brighter than our parent star. In most telescopic views, glare and diffraction spikes tend to hide things that lie near Mirach and make the faint, fuzzy galaxy look like a ghostly internal reflection of the almost overwhelming starlight. Still, appearing in this sharp image just above and to the right of Mirach, Mirach’s Ghost is cataloged as galaxy NGC 404 and is estimated to be some 10 million light-years away.

Credit: Mac Hunter

Mirach’s ghost is, in itself, not a very interesting galaxy. A small plain looking E-S0 type galaxy. However, its postion about 7 arc minutes from the 2nd magnitude M0 star beta And – known as Mirach – makes it into an interesting photographic target.

Astronomy Picture Of The Day | NGC 2683: Spiral Edge-On

NGC 2683: Spiral Edge-On

Credit: Data: Hubble Legacy Archive, ESA, NASA; Processing: Nikolaus Sulzenauer

Explanation: Does spiral galaxy NGC 2683 have a bar across its center? Being so nearly like our own barred Milky Way Galaxy, one might guess it has. Being so nearly edge-on, however, it is hard to tell. Either way, this gorgeous island universe, cataloged as NGC 2683, lies a mere 20 million light-years distant in the northern constellation of the Cat (Lynx). NGC 2683 is seen nearly edge-on in this cosmic vista, with more distant galaxies scattered in the background. Blended light from a large population of old yellowish stars forms the remarkably bright galactic core. Starlight silhouettes the dust lanes along winding spiral arms, dotted with the telltale blue glow of young star clusters in this galaxy‘s star forming regions.

NGC 2683 was discovered by William Herschel on February 5, 1788.

This spiral galaxy is viewed nearly edge-on from our perspective. Because of its appearance, it was nicknamed the “UFO Galaxy” by the Astronaut Memorial Planetarium and Observatory site. Note the small yellowish core in the center of the galaxy, consisting of older stars. Also note the fine details of the spiral structure, traced by dark dust in the brighter part of the disk (particularly well visible in the larger image.

The UFO is receding from us at 410 km/s, and from the Galactic Center at 375 km/s. This indicates that it is probably one of the nearby galaxies, perhaps at about 16 million light years.

The image in this page was obtained by Dick Stone when participating in the Kitt Peak Visitor Center’s Advanced Observing Program. It is a composite of 4 CCD images: Luminance = 42 min, Red = 20 min, Green = 20 min, Blue = 40 min.

via apod.nasa.gov

Astronomy Picture Of The Day | Melotte 15 in the Heart

Melotte 15 in the Heart Image Credit & Copyright: Derek Santiago

Explanation: Cosmic clouds seem to form fantastic shapes in the central regions of emission nebula IC 1805. Of course, the clouds are sculpted by stellar winds and radiation from massive hot stars in the nebula‘s newborn star cluster, Melotte 15. About 1.5 million years young, the cluster stars are near the center in this colorful skyscape, along with dark dust clouds silhouetted against glowing atomic gas. A composite of narrow and broad band telescopic images, the view spans about 40 light-years and includes emission from hydrogen in green, sulfur in red, and oxygen in blue hues. Wider field images reveal that IC 1805’s simpler, overall outline suggests its popular name – The Heart Nebula. IC 1805 is located about 7,500 light years away toward the constellation Cassiopeia.

Astronomy Picture of the Day | NASA's Hubble Harvests Distant Solar System Objects

Beyond the orbit of Neptune reside countless icy rocks known as trans-Neptunian objects (TNOs). One of the biggest, Pluto, is classified as a dwarf planet. The region also supplies us with comets such as famous Comet Halley. Most TNOs are small and receive little sunlight, making them faint and difficult to spot.

This is an artist’s concept of a craggy piece of Solar System debris that belongs to a class of bodies called trans-Neptunian objects (TNOs). Credit: NASA, ESA, and G. Bacon (STScI)

Now, astronomers using clever techniques to cull the data archives of NASA’s Hubble Space Telescope have added 14 new TNOs to the catalog. Their method promises to turn up hundreds more.

“Trans-Neptunian objects interest us because they are building blocks left over from the formation of the solar system,” explained lead author Cesar Fuentes, formerly with the Harvard-Smithsonian Center for Astrophysics and now at Northern Arizona University.

As TNOs slowly orbit the sun, they move against the starry background, appearing as streaks of light in time exposure photographs. The team developed software to analyze hundreds of Hubble images hunting for such streaks. After promising candidates were flagged, the images were visually examined to confirm or refute each discovery.

Most TNOs are located near the ecliptic — a line in the sky marking the plane of the solar system (since the solar system formed from a disk of material). Therefore, the team searched within 5 degrees of the ecliptic to increase their chance of success.

They found 14 objects, including one binary (two TNOs orbiting each other like a miniature Pluto-Charon system). All were very faint, with most measuring magnitude 25-27 (more than 100 million times fainter than objects visible to the unaided eye).

By measuring their motion across the sky, astronomers calculated an orbit and distance for each object. Combining the distance and brightness (plus an assumed albedo or reflectivity), they then estimated the size. The newfound TNOs range from 25 to 60 miles (40-100 km) across.

Unlike planets, which tend to have very flat orbits (known as low inclination), some TNOs have orbits significantly tilted from the ecliptic (high inclination). The team examined the size distribution of TNOs with low- versus high-inclination orbits to gain clues about how the population has evolved over the past 4.5 billion years.

Generally, smaller trans-Neptunian objects are the shattered remains of bigger TNOs. Over billions of years, these objects smack together, grinding each other down. The team found that the size distribution of TNOs with low- versus high-inclination orbits is about the same as objects get fainter and smaller. Therefore, both populations (low and high inclination) have similar collisional histories.

This initial study examined only one-third of a square degree of the sky, meaning that there is much more area to survey. Hundreds of additional TNOs may lurk in the Hubble archives at higher ecliptic latitudes. Fuentes and his colleagues intend to continue their search.

“We have proven our ability to detect and characterize TNOs even with data intended for completely different purposes,” Fuentes said.

The Hubble Space Telescope is a project of international cooperation between NASA and the European Space Agency. NASA’s Goddard Space Flight Center manages the telescope. The Space Telescope Science Institute (STScI) conducts Hubble science operations.

Headquartered in Cambridge, Mass., the Harvard-Smithsonian Center for Astrophysics (CfA) is a joint collaboration between the Smithsonian Astrophysical Observatory and the Harvard College Observatory. CfA scientists, organized into six research divisions, study the origin, evolution and ultimate fate of the universe.