Showing posts with label Galaxy. Show all posts
Showing posts with label Galaxy. Show all posts

Thursday, April 16, 2015

N11: Star Clouds of the LMC

N11: Star Clouds of the LMC:

Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

2013 February 11


See Explanation. Clicking on the picture will download the highest resolution version available.
Explanation: Massive stars, abrasive winds, mountains of dust, and energetic light sculpt one of the largest and most picturesque regions of star formation in the Local Group of Galaxies. Known as N11, the region is visible on the upper right of many images of its home galaxy, the Milky Way neighbor known as the Large Magellanic Clouds (LMC). The above image was taken for scientific purposes by the Hubble Space Telescope and reprocessed for artistry by an amateur to win the Hubble's Hidden Treasures competition. Although the section imaged above is known as NGC 1763, the entire N11 emission nebula is second in LMC size only to 30 Doradus. Studying the stars in N11 has shown that it actually houses three successive generations of star formation. Compact globules of dark dust housing emerging young stars are also visible around the image.

Posted by Nelio Inacio at 12:01 PM 0 comments
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Shadows Across Jupiter

Shadows Across Jupiter: APOD: 2013 February 15 - Shadows Across Jupiter


Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

2013 February 15


See Explanation. Clicking on the picture will download the highest resolution version available.
Explanation: Two dark shadows loom across the banded and mottled cloud tops of Jupiter in this sharp telescopic view. In fact, captured on January 3rd, about a month after the ruling gas giant appeared at opposition in planet Earth's sky, the scene includes the shadow casters. Visible in remarkable detail at the left are the large Galilean moons Ganymede (top) and Io. With the two moon shadows still in transit, Jupiter's rapid rotation has almost carried its famous Great Red Spot (GRS) around the planet's limb from the right. The pale GRS was preceded by the smaller but similar hued Oval BA, dubbed Red Spot Jr., near top center. North is down in the inverted image.

Posted by Nelio Inacio at 12:00 PM 0 comments
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M51: The Whirlpool Galaxy in Dust and Stars

M51: The Whirlpool Galaxy in Dust and Stars: APOD: 2013 February 24 - M51: The Whirlpool Galaxy in Dust and Stars





Discover the cosmos!
Each day a different image or photograph of our fascinating universe is
featured, along with a brief explanation written by a professional astronomer.


2013 February 24


See Explanation. Clicking on the picture will download the highest resolution version available.

M51: The Whirlpool Galaxy in Dust and Stars
Image Credit: N. Scoville
(Caltech), T. Rector
(U. Alaska, NOAO)
et al., Hubble Heritage Team,
NASA
Explanation:
The Whirlpool Galaxy is a classic spiral galaxy.

At only 30 million
light years distant and fully 60 thousand light years across,
M51, also known as

NGC 5194, is one of the brightest and most
picturesque galaxies on the sky.

The above
image
is a digital combination of a ground-based image from the
0.9-meter telescope at
Kitt Peak National Observatory
and a space-based image from the
Hubble Space Telescope highlighting sharp features normally too red to be seen.

Anyone with a good pair of
binoculars, however, can see this
Whirlpool toward the constellation of the Hunting Dogs
(Canes Venatici.

M51 is a
spiral galaxy of type Sc
and is the dominant member of a
whole group of galaxies.

Astronomers speculate that M51's
spiral structure is primarily due to its
gravitational interaction with a
smaller galaxy just off the top of the image.





Ask Me Anything:
APOD Editor to
answer questions on reddit at 11 am EST this Thursday
Posted by Nelio Inacio at 11:58 AM 0 comments
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Fly Me to the Moons

Fly Me to the Moons: APOD: 2013 February 25 - Fly Me to the Moons


Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

2013 February 25


See Explanation. Clicking on the picture will download the highest resolution version available.
Explanation: Sometimes the Moon is a busy direction. Last week, for example, our very Moon passed in front of the planet Jupiter. While capturing this unusual spectacle from New South Wales, Australia, a quick-thinking astrophotographer realized that a nearby plane might itself pass in front of the Moon, and so quickly reset his camera to take a continuous series of short duration shots. As hoped, for a brief instant, that airplane, the Moon, and Jupiter were all visible in a single exposure, which is shown above. But the project was not complete -- a longer exposure was then taken to bring up three of the Jupiter's own moons: Io, Calisto, and Europa (from left to right). Unfortunately, this triple spectacle soon disappeared. Less than a second later, the plane flew away from the Moon. A few seconds after that, the Moon moved to cover all of Jupiter. A few minutes after that, Jupiter reappeared on the other side of the Moon, and even a few minutes after that the Moon moved completely away from Jupiter. Although hard to catch, planes cross in front of the Moon quite frequently, but the Moon won't eclipse Jupiter again for another three years.

Posted by Nelio Inacio at 11:57 AM 0 comments
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Colors of Mercury

Colors of Mercury: APOD: 2013 March 1 - Colors of Mercury


Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

2013 March 1


See Explanation. Clicking on the picture will download the highest resolution version available.
Explanation: The colors of the solar system's innermost planet are enhanced in this tantalizing view, based on global image data from the Mercury-orbiting MESSENGER spacecraft. Human eyes would not discern the clear color differences but they are real none the less, indicating distinct chemical, mineralogical, and physical regions across the cratered surface. Notable at the upper right, Mercury's large, circular, tan colored feature known as the Caloris basin was created by an impacting comet or asteroid during the solar system's early years. The ancient basin was subsequently flooded with lava from volcanic activity, analogous to the formation of the lunar maria. Color contrasts also make the light blue and white young crater rays, material blasted out by recent impacts, easy to follow as they extend across a darker blue, low reflectance terrain.

Posted by Nelio Inacio at 11:56 AM 0 comments
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IC 1805: The Heart Nebula

IC 1805: The Heart Nebula: APOD: 2013 March 4 - IC 1805: The Heart Nebula


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2013 March 4


See Explanation. Clicking on the picture will download the highest resolution version available.
Explanation: Sprawling across almost 200 light-years, emission nebula IC 1805 is a mix of glowing interstellar gas and dark dust clouds. Derived from its Valentine's-Day-approved shape, its nickname is the Heart Nebula. About 7,500 light-years away in the Perseus spiral arm of our galaxy, stars were born in IC 1805. In fact, near the cosmic heart's center are the massive hot stars of a newborn star cluster also known as Melotte 15, about 1.5 million years young. A little ironically, the Heart Nebula is located in the constellation of the mythical Queen of Aethiopia (Cassiopeia). This deep view of the region around the Heart Nebula spans about two degrees on the sky or about four times the diameter of the Full Moon.

Posted by Nelio Inacio at 11:56 AM 0 comments
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Thor's Helmet

Thor's Helmet: APOD: 2013 March 7 - Thor's Helmet


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2013 March 7


See Explanation. Clicking on the picture will download the highest resolution version available.
Explanation: This helmet-shaped cosmic cloud with wing-like appendages is popularly called Thor's Helmet. Heroically sized even for a Norse god, Thor's Helmet is about 30 light-years across. In fact, the helmet is actually more like an interstellar bubble, blown as a fast wind from the bright, massive star near the bubble's center sweeps through a surrounding molecular cloud. Known as a Wolf-Rayet star, the central star is an extremely hot giant thought to be in a brief, pre-supernova stage of evolution. Cataloged as NGC 2359, the nebula is located about 15,000 light-years away in the constellation Canis Major. The sharp image, made using broadband and narrowband filters, captures striking details of the nebula's filamentary structures. It shows off a blue-green color from strong emission due to oxygen atoms in the glowing gas.

Posted by Nelio Inacio at 11:55 AM 0 comments
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Spin up of a Supermassive Black Hole

Spin up of a Supermassive Black Hole:

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2013 March 12


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Explanation: How fast can a black hole spin? If any object made of regular matter spins too fast -- it breaks apart. But a black hole might not be able to break apart -- and its maximum spin rate is really unknown. Theorists usually model rapidly rotating black holes with the Kerr solution to Einstein's General Theory of Relativity, which predicts several amazing and unusual things. Perhaps its most easily testable prediction, though, is that matter entering a maximally rotating black hole should be last seen orbiting at near the speed of light, as seen from far away. This prediction was tested recently by NASA's NuSTAR and ESA's XMM satellites by observing the supermassive black hole at the center of spiral galaxy NGC 1365. The near light-speed limit was confirmed by measuring the heating and spectral line broadening of nuclear emissions at the inner edge of the surrounding accretion disk. Pictured above is an artist's illustration depicting an accretion disk of normal matter swirling around a black hole, with a jet emanating from the top. Since matter randomly falling into the black hole should not spin up a black hole this much, the NuSTAR and XMM measurements also validate the existence of the surrounding accretion disk.

Posted by Nelio Inacio at 11:54 AM 0 comments
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NGC 6751: The Glowing Eye Nebula

NGC 6751: The Glowing Eye Nebula: APOD: 2013 March 13 - NGC 6751: The Glowing Eye Nebula


Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

2013 March 13


See Explanation. Clicking on the picture will download the highest resolution version available.
Explanation: Planetary nebulae can look simple, round, and planet-like in small telescopes. But images from the orbiting Hubble Space Telescope have become well known for showing these fluorescent gas shrouds of dying Sun-like stars to possess a staggering variety of detailed symmetries and shapes. This composite color Hubble image of NGC 6751, the Glowing Eye Nebula, is a beautiful example of a classic planetary nebula with complex features. It was selected in April of 2000 to commemorate the tenth anniversary of Hubble in orbit, but was reprocessed recently by an amateur as part of the Hubble Legacy program. Winds and radiation from the intensely hot central star (140,000 degrees Celsius) have apparently created the nebula's streamer-like features. The nebula's actual diameter is approximately 0.8 light-years or about 600 times the size of our Solar System. NGC 6751 is 6,500 light-years distant in the high-flying constellation of the Eagle (Aquila).

Posted by Nelio Inacio at 11:53 AM 0 comments
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GRAIL Maps the Moons Gravity

GRAIL Maps the Moons Gravity: APOD: 2013 March 19 - GRAIL Maps the Moons Gravity


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2013 March 19


See Explanation. Clicking on the picture will download the highest resolution version available.
Explanation: How did the Moon form? To help find out, NASA launched the twin Gravity Recovery and Interior Laboratory (GRAIL) satellites in 2011 to orbit and map the Moon's surface gravity in unprecedented detail. Pictured above is a resulting GRAIL gravity map, with regions of slightly lighter gravity shown in blue and regions of slightly stronger gravity shown in red. Analysis of GRAIL data indicates that the moon has an unexpectedly shallow crust than runs about 40 kilometers deep, and an overall composition similar to the Earth. Although other surprising structures have been discovered that will continue to be investigated, the results generally bolster the hypothesis that the Moon formed mostly from Earth material following a tremendous collision in the early years of our Solar System, about 4.5 billion years ago. After completing their mission and running low on fuel, the two GRAIL satellites, Ebb and Flow, were crashed into a lunar mountain at about 6,000 kilometer per hour.

Posted by Nelio Inacio at 11:52 AM 0 comments
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M42: Inside the Orion Nebula

M42: Inside the Orion Nebula: APOD: 2013 March 20 - M42: Inside the Orion Nebula


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2013 March 20


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Explanation: The Great Nebula in Orion, an immense, nearby starbirth region, is probably the most famous of all astronomical nebulas. Here, glowing gas surrounds hot young stars at the edge of an immense interstellar molecular cloud only 1500 light-years away. In the above deep image in assigned colors highlighted by emission in oxygen and hydrogen, wisps and sheets of dust and gas are particularly evident. The Great Nebula in Orion can be found with the unaided eye near the easily identifiable belt of three stars in the popular constellation Orion. In addition to housing a bright open cluster of stars known as the Trapezium, the Orion Nebula contains many stellar nurseries. These nurseries contain much hydrogen gas, hot young stars, proplyds, and stellar jets spewing material at high speeds. Also known as M42, the Orion Nebula spans about 40 light years and is located in the same spiral arm of our Galaxy as the Sun.

Posted by Nelio Inacio at 11:51 AM 0 comments
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NGC 2736: The Pencil Nebula

NGC 2736: The Pencil Nebula: APOD: 2013 March 21 - NGC 2736: The Pencil Nebula


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2013 March 21


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Explanation: Moving left to right near the center of this beautifully detailed color composite, the thin, bright, braided filaments are actually long ripples in a sheet of glowing gas seen almost edge on. The interstellar shock wave plows through space at over 500,000 kilometers per hour. Cataloged as NGC 2736, its elongated appearance suggests its popular name, the Pencil Nebula. The Pencil Nebula is about 5 light-years long and 800 light-years away, but represents only a small part of the Vela supernova remnant. The Vela remnant itself is around 100 light-years in diameter, the expanding debris cloud of a star that was seen to explode about 11,000 years ago. Initially, the shock wave was moving at millions of kilometers per hour but has slowed considerably, sweeping up surrounding interstellar material. In the narrowband, wide field image, red and blue-green colors track the characteristic glow of ionized hydrogen and oxygen atoms.

Posted by Nelio Inacio at 11:51 AM 0 comments
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Comet Castle

Comet Castle: APOD: 2013 March 22 - Comet Castle


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2013 March 22


See Explanation. Clicking on the picture will download the highest resolution version available.
Explanation: The broad dust tail of Comet PanSTARRS (C/2011 L4) has become a familiar sight for many northern hemisphere comet watchers, as the comet fades but rises higher above the western horizon after sunset. This view of the popular comet may seem a little fantastic, though. Sweeping away from the Sun and trailing behind the comet's orbit, the curving dust tail also seems to stream away from a shining mountaintop castle. Comet Castle might be an appropriate name in this scene, but its traditional name is Castle Hohenzollern. Taken on March 15 with an extreme telephoto lens, the Comet Castle image was captured in exceptionally clear skies about 80 kilometers away from Stuttgart, Germany.

Posted by Nelio Inacio at 11:50 AM 0 comments
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Planck Maps the Microwave Background

Planck Maps the Microwave Background: APOD: 2013 March 25 - Planck Maps the Microwave Background


Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

2013 March 25


See Explanation. Clicking on the picture will download the highest resolution version available.
Explanation: What is our universe made of? To help find out, ESA launched the Planck satellite to map, in unprecedented detail, slight temperature differences on the oldest surface known -- the background sky left billions of years ago when our universe first became transparent to light. Visible in all directions, this cosmic microwave background is a complex tapestry that could only show the hot and cold patterns observed were the universe to be composed of specific types of energy that evolved in specific ways. The results, reported last week, confirm again that most of our universe is mostly composed of mysterious and unfamiliar dark energy, and that even most of the remaining matter energy is strangely dark. Additionally, Planck data impressively peg the age of the universe at about 13.81 billion years, slightly older than that estimated by various other means including NASA's WMAP satellite, and the expansion rate at 67.3 (+/- 1.2) km/sec/Mpc, slightly lower than previous estimates. Some features of the above sky map remain unknown, such as why the temperature fluctuations seem to be slightly greater on one half of the sky than the other.

Posted by Nelio Inacio at 11:50 AM 0 comments
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Unraveling NGC 3169

Unraveling NGC 3169: APOD: 2013 March 28 - Unraveling NGC 3169


Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

2013 March 28


See Explanation. Clicking on the picture will download the highest resolution version available.
Explanation: Bright spiral galaxy NGC 3169 appears to be unraveling in this cosmic scene, played out some 70 million light-years away just below bright star Regulus toward the faint constellation Sextans. Its beautiful spiral arms are distorted into sweeping tidal tails as NGC 3169 (left) and neighboring NGC 3166 interact gravitationally, a common fate even for bright galaxies in the local universe. In fact, drawn out stellar arcs and plumes, indications of gravitational interactions, seem rampant in the deep and colorful galaxy group photo. The picture spans 20 arc minutes, or about 400,000 light-years at the group's estimated distance, and includes smaller, dimmer NGC 3165 at the right. NGC 3169 is also known to shine across the spectrum from radio to X-rays, harboring an active galactic nucleus that is likely the site of a supermassive black hole.

Posted by Nelio Inacio at 11:49 AM 0 comments
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Ringside with Rhea

Ringside with Rhea: APOD: 2013 March 29 - Ringside with Rhea


Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

2013 March 29


See Explanation. Clicking on the picture will download the highest resolution version available.
Explanation: Orbiting in the plane of Saturn's rings, Saturnian moons have a perpetual ringside view of the gas giant planet. Of course, while passing near the ring plane the Cassini spacecraft also shares their stunning perspective. The thin rings themselves slice across the middle of this Cassini snapshot from April 2011. The scene looks toward the dark night side of Saturn, in the frame at the left, and the still sunlit side of the rings from just above the ringplane. Centered, over 1,500 kilometers across, Rhea is Saturn's second largest moon and is closest to the spacecraft, around 2.2 million kilometers away. To Rhea's right, shiny, 500 kilometer diameter Enceladus is about 3 million kilometers distant. Dione, 1,100 kilometers wide, is 3.1 million kilometers from Cassini's camera on the left, partly blocked by Saturn's night side.

Posted by Nelio Inacio at 11:48 AM 0 comments
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PanSTARRS from France

PanSTARRS from France: APOD: 2013 March 16 - PanSTARRS from France


Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

2013 March 16


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Explanation: Still looking for that comet? Comet PanSTARRS (C/2011 L4) naked-eye appearance in the northern hemisphere is described by successful comet spotters as a dim star with a faint tail. If you want to catch it the next few days could be your best bet. Start looking low and almost due west about 45 minutes after sunset. Of course, clear skies and a pair of binoculars should help a lot. Sky photographer Jean-Luc Dauvergne found suitable weather and western horizon for this comet and crescent Moon portrait after a road trip on March 13. Seeing PanSTARRS for the first time, he recorded the beautiful twilight scene with a telephoto lens near historical Alesia in France.

Posted by Nelio Inacio at 11:47 AM 0 comments
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Three Galaxies and a Comet

Three Galaxies and a Comet: Astronomy Picture of the Day


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2015 April 16


See Explanation. Clicking on the picture will download the highest resolution version available.
Explanation: While most spiral galaxies, including our own Milky Way, have two or more spiral arms, NGC 4725 has only one. In this sharp color composite image, the solo spira mirabilis seems to wind from a prominent ring of bluish, newborn star clusters and red tinted star forming regions. The odd galaxy also sports obscuring dust lanes a yellowish central bar structure composed of an older population of stars. NGC 4725 is over 100 thousand light-years across and lies 41 million light-years away in the well-groomed constellation Coma Berenices. Computer simulations of the formation of single spiral arms suggest that they can be either leading or trailing arms with respect to a galaxy's overall rotation. Also included in the frame, sporting a noticably more traditional spiral galaxy look, is a more distant background galaxy.

Posted by Nelio Inacio at 11:46 AM 0 comments
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A Raging Storm System on Saturn

A Raging Storm System on Saturn: APOD: 2013 April 28 - A Raging Storm System on Saturn


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2013 April 28


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Explanation: It was one of the largest and longest lived storms ever recorded in our Solar System.   First seen in late 2010, the above cloud formation in the northern hemisphere of Saturn started larger than the Earth and soon spread completely around the planet. The storm was tracked not only from Earth but from up close by the robotic Cassini spacecraft currently orbiting Saturn. Pictured above in false colored infrared in February, orange colors indicate clouds deep in the atmosphere, while light colors highlight clouds higher up. The rings of Saturn are seen nearly edge-on as the thin blue horizontal line. The warped dark bands are the shadows of the rings cast onto the cloud tops by the Sun to the upper left. A source of radio noise from lightning, the intense storm was thought to relate to seasonal changes when spring emerges in the north of Saturn. After raging for over six months, the iconic storm circled the entire planet and then tried to absorb its own tail -- which surprisingly caused it to fade away.

Posted by Nelio Inacio at 11:46 AM 0 comments
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WOW - A Year on the Sun

A Year on the Sun: APOD: 2013 April 26 - A Year on the Sun


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2013 April 26
See Explanation. Clicking on the picture will download the highest resolution version available.
Explanation: Our solar system's miasma of incandescent plasma, the Sun may look a little scary here. The picture is a composite of 25 images recorded in extreme ultraviolet light by the orbiting Solar Dynamics Observatory between April 16, 2012 and April 15, 2013. The particular wavelength of light, 171 angstroms, shows emission from highly ionized iron atoms in the solar corona at a characteristic temperatures of about 600,000 kelvins (about 1 million degrees F). Girdling both sides of the equator during approach to maximum in the 11-year solar cycle, the solar active regions are laced with bright loops and arcs along magnetic field lines. Of course, a more familiar visible light view would show the bright active regions as groups of dark sunspots. Three years of Solar Dynamics Observatory images are compressed into this short video.

Posted by Nelio Inacio at 11:45 AM 0 comments
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