Saturday, November 7, 2015

Comet Tails and Star Trails

Comet Tails and Star Trails: APOD: 2015 July 21 - Comet Tails and Star Trails



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2015 July 21


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Comet Tails and Star Trails
Image Credit & Copyright: Kevin Parker
Explanation: After grazing the western horizon on northern summer evenings Comet PanSTARRS (also known as C/2014 Q1) climbed higher in southern winter skies. A visitor to the inner Solar System discovered in August 2014 by the prolific panSTARRS survey, the comet was captured here on July 17. Comet and colorful tails were imaged from Home Observatory in Mackay, Queensland, Australia. The field of view spans just over 1 degree. Sweeping quickly across a the sky this comet PanSTARRS was closest to planet Earth about 2 days later. Still, the faint stars of the constellation Cancer left short trails in the telescopic image aligned to track the comet's rapid motion. PanSTARRS' bluish ion tails stream away from the Sun, buffetted by the solar wind. Driven by the pressure of sunlight, its more diffuse yellowish dust tail is pushed outward and lags behind the comet's orbit. A good target for binoculars from southern latitudes, in the next few days the comet will sweep through skies near Venus, Jupiter, and bright star Regulus.

Tomorrow's picture: gamma-ray rain
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Posted by Nelio Inacio at 12:05 PM 0 comments

Unraveling NGC 3169

Unraveling NGC 3169: APOD: 2015 November 6 - Unraveling NGC 3169



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2015 November 6


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Unraveling NGC 3169
Image Credit & Copyright: Warren Keller, Steve Mazlin, Jack Harvey, Steve Menaker (SSRO/ UNC/PROMPT/ CTIO)
Explanation: 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 (top) 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 bottom 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.

Tomorrow's picture: light-weekend
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Posted by Nelio Inacio at 12:03 PM 0 comments

The Great Orion Nebula M42

The Great Orion Nebula M42:

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2015 November 4


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Explanation: The Great Nebula in Orion, also known as M42, is one of the most famous nebulas in the sky. The star forming region's glowing gas clouds and hot young stars are on the right in this sharp and colorful image that includes the bluish reflection nebulae NGC 1977 and friends on the left. Located at the edge of an otherwise invisible giant molecular cloud complex, these eye-catching nebulas represent only a small fraction of this galactic neighborhood's wealth of interstellar material. Within the well-studied stellar nursery, astronomers have also identified what appear to be numerous infant planetary systems. The gorgeous skyscape spans nearly two degrees or about 45 light-years at the Orion Nebula's estimated distance of 1,500 light-years.

Posted by Nelio Inacio at 12:01 PM 0 comments

NGC 1333: Stellar Nursery in Perseus

NGC 1333: Stellar Nursery in Perseus:

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2015 November 5



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Explanation: NGC 1333 is seen in visible light as a reflection nebula, dominated by bluish hues characteristic of starlight reflected by interstellar dust. A mere 1,000 light-years distant toward the heroic constellation Perseus, it lies at the edge of a large, star-forming molecular cloud. This striking close-up spans about two full moons on the sky or just over 15 light-years at the estimated distance of NGC 1333. It shows details of the dusty region along with hints of contrasting red emission from Herbig-Haro objects, jets and shocked glowing gas emanating from recently formed stars. In fact, NGC 1333 contains hundreds of stars less than a million years old, most still hidden from optical telescopes by the pervasive stardust. The chaotic environment may be similar to one in which our own Sun formed over 4.5 billion years ago.

Posted by Nelio Inacio at 12:00 PM 0 comments

Sunday, November 1, 2015

Ultraviolet Rings of M31

Ultraviolet Rings of M31: APOD: 2015 July 24 - Ultraviolet Rings of M31



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2015 July 24


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Ultraviolet Rings of M31
Image Credit: GALEX, JPL-Caltech, NASA
Explanation: A mere 2.5 million light-years away the Andromeda Galaxy, also known as M31, really is just next door as large galaxies go. So close and spanning some 260,000 light-years, it took 11 different image fields from the Galaxy Evolution Explorer (GALEX) satellite's telescope to produce this gorgeous portrait of the spiral galaxy in ultraviolet light. While its spiral arms stand out in visible light images of Andromeda, the arms look more like rings in the GALEX ultraviolet view, a view dominated by the energetic light from hot, young, massive stars. As sites of intense star formation, the rings have been interpreted as evidence Andromeda collided with its smaller neighboring elliptical galaxy M32 more than 200 million years ago. The large Andromeda galaxy and our own Milky Way are the most massive members of the local galaxy group.

Tomorrow's picture: infrared trifid
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Posted by Nelio Inacio at 5:11 PM 0 comments

Infrared Trifid

Infrared Trifid: APOD: 2015 July 25 - Infrared Trifid



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2015 July 25


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Infrared Trifid
Image Credit: J. Rho (SSC/Caltech), JPL-Caltech, NASA
Explanation: The Trifid Nebula, also known as Messier 20, is easy to find with a small telescope, a well known stop in the nebula rich constellation Sagittarius. But where visible light pictures show the nebula divided into three parts by dark, obscuring dust lanes, this penetrating infrared image reveals filaments of glowing dust clouds and newborn stars. The spectacular false-color view is courtesy of the Spitzer Space Telescope. Astronomers have used the Spitzer infrared image data to count newborn and embryonic stars which otherwise can lie hidden in the natal dust and gas clouds of this intriguing stellar nursery. As seen here, the Trifid is about 30 light-years across and lies only 5,500 light-years away.

Tomorrow's picture: Sombrero Sunday
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Posted by Nelio Inacio at 5:11 PM 0 comments

The Sombrero Galaxy from Hubble

The Sombrero Galaxy from Hubble:

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2015 July 26


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Explanation: Why does the Sombrero Galaxy look like a hat? Reasons include the Sombrero's unusually large and extended central bulge of stars, and dark prominent dust lanes that appear in a disk that we see nearly edge-on. Billions of old stars cause the diffuse glow of the extended central bulge. Close inspection of the bulge in the above photograph shows many points of light that are actually globular clusters. M104's spectacular dust rings harbor many younger and brighter stars, and show intricate details astronomers don't yet fully understand. The very center of the Sombrero glows across the electromagnetic spectrum, and is thought to house a large black hole. Fifty million-year-old light from the Sombrero Galaxy can be seen with a small telescope towards the constellation of Virgo.

Posted by Nelio Inacio at 5:10 PM 0 comments

Milky Way and Aurora over Antarctica

Milky Way and Aurora over Antarctica: APOD: 2015 July 27 - Milky Way and Aurora over Antarctica



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2015 July 27


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Milky Way and Aurora over Antarctica
Image Credit & Copyright: LI Hang
Explanation: It has been one of the better skies of this long night. In parts of Antarctica, not only is it winter, but the Sun can spend weeks below the horizon. At China's Zhongshan Station, people sometimes venture out into the cold to photograph a spectacular night sky. The featured image from one such outing was taken in mid-July, just before the end of this polar night. Pointing up, the wide angle lens captured not only the ground at the bottom, but at the top as well. In the foreground is a colleague also taking pictures. In the distance, a spherical satellite receiver and several windmills are visible. Numerous stars dot the night sky, including Sirius and Canopus. Far in the background, stretching overhead from horizon to horizon, is the central band of our Milky Way Galaxy. Even further in the distance, visible as extended smudges near the top, are the Large and Small Magellanic Clouds, satellite galaxies near our huge Milky Way Galaxy.

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Tomorrow's picture: rays and rainbows
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Posted by Nelio Inacio at 5:09 PM 0 comments

Rainbows and Rays over Bryce Canyon

Rainbows and Rays over Bryce Canyon: APOD: 2015 July 28 - Rainbows and Rays over Bryce Canyon



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2015 July 28


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Rainbows and Rays over Bryce Canyon
Image Credit & Copyright: John Rummel
Explanation: What's happening over Bryce Canyon? Two different optical effects that were captured in one image taken earlier this month. Both effects needed to have the Sun situated directly behind the photographer. The nearest apparition was the common rainbow, created by sunlight streaming from the setting sun over the head of the photographer, and scattering from raindrops in front of the canyon. If you look closely, even a second rainbow appears above the first. More rare, and perhaps more striking, are the rays of light that emanate out from the horizon above the canyon. These are known as anticrepuscular rays and result from sunlight streaming though breaks in the clouds, around the sky, and converging at the point 180 degrees around from the Sun. Geometrically, this antisolar point must coincide with the exact center of the rainbows. Located in Utah, USA, Bryce Canyon itself contains a picturesque array of ancient sedimentary rock spires known as hoodoos.

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Tomorrow's picture: pink lagoon
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Posted by Nelio Inacio at 5:08 PM 0 comments

The Deep Lagoon

The Deep Lagoon: APOD: 2015 July 29 - The Deep Lagoon



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2015 July 29


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The Deep Lagoon
Image Credit & Copyright: Adam Block, Mt. Lemmon SkyCenter, Univ. Arizona
Explanation: Ridges of glowing interstellar gas and dark dust clouds inhabit the turbulent, cosmic depths of the Lagoon Nebula. Also known as M8, The bright star forming region is about 5,000 light-years distant. But it still makes for a popular stop on telescopic tours of the constellation Sagittarius, toward the center of our Milky Way Galaxy. Dominated by the telltale red emission of ionized hydrogen atoms recombining with stripped electrons, this stunning, deep view of the Lagoon's central reaches is about 40 light-years across. Near the center of the frame, the bright hourglass shape is gas ionized and sculpted by energetic radiation and extreme stellar winds from a massive young star.

Tomorrow's picture: the rocky milky way
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Posted by Nelio Inacio at 5:07 PM 0 comments

Milky Way over Uluru

Milky Way over Uluru:

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2015 July 30


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Explanation: The central regions of our Milky Way Galaxy rise above Uluru/Ayers Rock in this striking night skyscape. Recorded on July 13, a faint airglow along the horizon shows off central Australia's most recognizable landform in silhouette. Of course the Milky Way's own cosmic dust clouds appear in silhouette too, dark rifts along the galaxy's faint congeries of stars. Above the central bulge, rivers of cosmic dust converge on a bright yellowish supergiant star Antares. Left of Antares, wandering Saturn shines in the night.

Posted by Nelio Inacio at 5:07 PM 0 comments

The ISS and a Colorful Moon

The ISS and a Colorful Moon: APOD: 2015 July 31 - The ISS and a Colorful Moon



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2015 July 31


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The ISS and a Colorful Moon
Image Credit & Copyright: Dylan O'Donnell
Explanation: Tonight's Full Moon, the second Full Moon in July, could be called a blue moon according to modern folklore. But this sharp and detailed mosaic, recorded with telescope and digital camera just before July's first Full Moon, actually does show a colorful lunar surface. The colors have been enhanced in the processed image but are real nonetheless, corresponding to real differences in the chemical makeup of the lunar surface. Also easy to see especially when the Moon is near full phase, bright rays from 85 kilometer wide Tycho crater at the upper right extend far across the lunar surface. Against the southern lunar highlands above and right of Tycho is an amazingly detailed silhouette of the International Space Station. Seen from Byron Bay, NSW Australia on June 30, the ISS lunar transit lasted about 1/3 of a second, captured with a fast shutter speed in burst mode.

Tomorrow's picture: ram pressure
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Posted by Nelio Inacio at 5:06 PM 0 comments

Stripping ESO 137-001

Stripping ESO 137-001: APOD: 2015 August 1 - Stripping ESO 137-001



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2015 August 1


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Stripping ESO 137-001
NASA, ESA, CXC
Explanation: Spiral galaxy ESO 137-001 hurtles through massive galaxy cluster Abell 3627 some 220 million light years away. The distant galaxy is seen in this colorful Hubble/Chandra composite image through a foreground of the Milky Way's stars toward the southern constellation Triangulum Australe. As the spiral speeds along at nearly 7 million kilometers per hour, its gas and dust are stripped away when ram pressure with the cluster's own hot, tenuous intracluster medium overcomes the galaxy's gravity. Evident in Hubble's near visible light data, bright star clusters have formed in the stripped material along the short, trailing blue streaks. Chandra's X-ray data shows off the enormous extent of the heated, stripped gas as diffuse, darker blue trails stretching over 400,000 light-years toward the bottom right. The significant loss of dust and gas will make new star formation difficult for this galaxy. A yellowish elliptical galaxy, lacking in star forming dust and gas, is just to the right of ESO 137-001 in the frame.

Tomorrow's picture: where you parked
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Posted by Nelio Inacio at 5:06 PM 0 comments

A Proton Arc Over Lake Superior

A Proton Arc Over Lake Superior: APOD: 2015 August 3 - A Proton Arc Over Lake Superior



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2015 August 3
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A Proton Arc Over Lake Superior
Image Credit & Copyright: Ken Williams
Explanation: The setting had been picked out -- all that was needed was an aurora. And late last August, forecasts predicted that an otherwise beautiful night sky would be lit up with auroral green. Jumping into his truck, the astrophotographer approached his secret site -- but only after a five hour drive across the rural Upper Peninsula of Michigan. What he didn't know was that his luck was just beginning. While setting up for the image, a proton arc -- a rare type of aurora -- appeared. The red arc lasted only about 15 minutes, but that was long enough to capture in a 30-second exposure. As the name indicates, proton arcs are caused not by electrons but by more massive protons that bombard the Earth's atmosphere following an energetic event on the Sun. In the featured image, the yellow lights on the horizon are the city lights of Marquette, Michigan, USA. The blue and yellow rocks in the Lake Superior foreground are lit by a LED flashlight. Also captured, to the left of the red proton arc, was the band of our Milky Way Galaxy.

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Tomorrow's picture: galaxies cluster
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Posted by Nelio Inacio at 5:05 PM 0 comments

X ray Echoes from Circinus X 1

X ray Echoes from Circinus X 1: APOD: 2015 August 5 - X ray Echoes from Circinus X 1



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2015 August 5


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X-ray Echoes from Circinus X-1
Image Credit: X-ray - NASA/CXC/Univ. Wisconsin-Madison/S.Heinz et al, Optical - DSS
Explanation: Circinus X-1 is an X-ray binary star known for its erratic variability. In the bizarre Circinus X-1 system, a dense neutron star, the collapsed remnant of a supernova explosion, orbits with a more ordinary stellar companion. Observations of the X-ray binary in months following an intense X-ray flare from the source in 2013 progressively revealed striking concentric rings - bright X-ray light echoes from four intervening clouds of interstellar dust. In this X-ray/optical composite, the swaths of Chandra Observatory X-ray image data showing partial outlines of the rings are in false colors. Remarkably, timing the X-ray echoes, along with known distances to the interstellar dust clouds, determines the formerly highly uncertain distance to Circinus X-1 itself to be 30,700 light-years.

Tomorrow's picture: pixels in space
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Full Earth, Full Moon

Full Earth, Full Moon: APOD: 2015 August 7 - Full Earth, Full Moon



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2015 August 7


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Full Moon, Full Earth
Image Credit: NASA, NOAA/DSCOVR
Explanation: The Moon was new on July 16. Its familiar nearside facing the surface of planet Earth was in shadow. But on that date a million miles away, the Deep Space Climate Observatory (DSCOVR) spacecraft's Earth Polychromatic Imaging Camera (EPIC) captured this view of an apparently Full Moon crossing in front of a Full Earth. In fact, seen from the spacecraft's position beyond the Moon's orbit and between Earth and Sun, the fully illuminated lunar hemisphere is the less familiar farside. Only known since the dawn of the space age, the farside is mostly devoid of dark lunar maria that sprawl across the Moon's perpetual Earth-facing hemisphere. Only the small dark spot of the farside's Mare Moscoviense (Sea of Moscow) is clear, at the upper left. Planet Earth's north pole is near 11 o'clock, with the North America visited by Hurricane Dolores near center. Slight color shifts are visible around the lunar edge, an artifact of the Moon's motion through the field caused by combining the camera's separate exposures taken in quick succession through different color filters. While monitoring the Earth and solar wind for space weather forcasts, about twice a year DSCOVR can capture similar images of Moon and Earth together as it crosses the orbital plane of the Moon.

Tomorrow's picture: light-weekend
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Posted by Nelio Inacio at 5:03 PM 0 comments

HCG 87: A Small Group of Galaxies

HCG 87: A Small Group of Galaxies: APOD: 2015 August 9 - HCG 87: A Small Group of Galaxies



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2015 August 9


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HCG 87: A Small Group of Galaxies
Image Credit: GMOS-S Commissioning Team, Gemini Observatory
Explanation: Sometimes galaxies form groups. For example, our own Milky Way Galaxy is part of the Local Group of Galaxies. Small, compact groups, like Hickson Compact Group 87 (HCG 87) shown above, are interesting partly because they slowly self-destruct. Indeed, the galaxies of HCG 87 are gravitationally stretching each other during their 100-million year orbits around a common center. The pulling creates colliding gas that causes bright bursts of star formation and feeds matter into their active galaxy centers. HCG 87 is composed of a large edge-on spiral galaxy visible near the image center, an elliptical galaxy visible to its right, and a spiral galaxy visible near the top. The small spiral near the center might be far in the distance. Several stars from our Galaxy are also visible in the foreground. Studying groups like HCG 87 allows insight into how all galaxies form and evolve.

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Tomorrow's picture: arching through space
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Posted by Nelio Inacio at 5:03 PM 0 comments

A Sagittarius Triplet

A Sagittarius Triplet: APOD: 2015 August 10 - A Sagittarius Triplet



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2015 August 10


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A Sagittarius Triplet
Image Credit & Copyright: Christian vd Berge (DSLR Astrophotograhy)
Explanation: These three bright nebulae are often featured in telescopic tours of the constellation Sagittarius and the crowded starfields of the central Milky Way. In fact, 18th century cosmic tourist Charles Messier cataloged two of them; M8, the large nebula left of center, and colorful M20 on the right. The third, NGC 6559, is above M8, separated from the larger nebula by a dark dust lane. All three are stellar nurseries about five thousand light-years or so distant. The expansive M8, over a hundred light-years across, is also known as the Lagoon Nebula. M20's popular moniker is the Trifid. Glowing hydrogen gas creates the dominant red color of the emission nebulae, with contrasting blue hues, most striking in the Trifid, due to dust reflected starlight. The colorful skyscape recorded with telescope and digital camera also includes one of Messier's open star clusters, M21, just above the Trifid.

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Tomorrow's picture: doubly rare
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Posted by Nelio Inacio at 5:02 PM 0 comments

A Blue Moon Halo over Antarctica

A Blue Moon Halo over Antarctica:

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2015 August 11


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Explanation: Have you ever seen a halo around the Moon? Such 22 degree rings around the Moon -- caused by ice crystals falling in the Earth's atmosphere -- are somewhat rare. OK, but have you ever seen a blue moon? Given the modern definition of blue moon -- the second full moon occurring in a calendar month -- these are also rare. What is featured above might therefore be considered doubly rare -- a halo surrounding a blue moon. The featured image was taken late last month near Zhongshan Station in Antarctica. Visible in the foreground are a power generating house and a snowmobile. What might seem to be stars in the background are actually illuminated snowflakes near the camera.

Posted by Nelio Inacio at 5:02 PM 0 comments
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