Thursday, March 19, 2015

Earth During a Total Eclipse of the Sun

Earth During a Total Eclipse of the Sun: APOD: 2015 March 18 - Earth During a Total Eclipse of the Sun


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.

2015 March 18


See Explanation. Clicking on the picture will download the highest resolution version available.
Explanation: What does the Earth look like during a total solar eclipse? It appears dark in the region where people see the eclipse, because that's where the shadow of the Moon falls. The shadow spot actually shoots across the Earth at nearly 2,000 kilometers per hour, darkening locations in its path for only a few minutes before moving on. The featured image shows the Earth during the total solar eclipse of 2006 March, as seen from the International Space Station. On Friday the Moon will move in front of the Sun once again, casting another distorted circular shadow that, this time, will zip over part of the north Atlantic Ocean.

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Surprise – Mars Has Auroras Too!

Surprise – Mars Has Auroras Too!:



Artist’s conception of MAVEN’s Imaging UltraViolet Spectrograph observing the “Christmas Lights Aurora" on Mars. (University of Colorado)


Artist’s conception of MAVEN observing the “Christmas Lights Aurora” on Mars. (University of Colorado)
Just a day after skywatchers at mid- to upper-latitudes around the world were treated to a particularly energetic display of auroras on the night of March 17 as a result of an intense geomagnetic storm, researchers announced findings from NASA’s MAVEN mission of auroral action observed on Mars – although in energetic ultraviolet wavelengths rather than visible light.

Detected by MAVEN’s Imaging Ultraviolet Spectrograph (IUVS) instrument over five days before Dec. 25, 2014, the ultraviolet auroras have been nicknamed Mars’ “Christmas lights.” They were observed across the planet’s mid-northern latitudes and are the result of Mars’ atmosphere interacting directly with the solar wind.



Map of the UV aurora detected on Mars in Dec. 2014 (University of Colorado)


Map of the UV aurora detected on Mars in Dec. 2014 (University of Colorado)
While auroras on Earth typically occur at altitudes of 80 to 300 kilometers (50 to 200 miles) and occasionally even higher, Mars’ atmospheric displays were found to be much lower, indicating higher levels of energy.

“What’s especially surprising about the aurora we saw is how deep in the atmosphere it occurs – much deeper than at Earth or elsewhere on Mars,” said Arnaud Stiepen, IUVS team member at the University of Colorado. “The electrons producing it must be really energetic.”

To a human observer on Mars the light show probably wouldn’t be very dramatic, though. Without abundant amounts of oxygen and nitrogen in its thin atmosphere a Martian aurora would be a dim blue glow at best, if not out of the visible spectrum entirely.

This isn’t the first time auroras have been spotted on Mars; observations with ESA’s Mars Express in 2004 were actually the first detections of the phenomenon on the Red Planet. Made with the spacecraft’s SPICAM ultraviolet spectrometer, the observations showed that Mars’ auroras are unlike those found anywhere else in the Solar System in that they are generated by particle interactions with very localized magnetic field emissions, rather than a globally-generated one (like Earth’s).

(So no, it’s not a total surprise… but it’s still very cool!)

In addition to auroras MAVEN also detected diffuse but widespread dust clouds located surprisingly high in the Martian atmosphere. It’s not yet understood what process is delivering dust so high – 150-300 kilometers up (93-186 miles) – or if it is a permanent or temporary feature.

Read more in the MAVEN news release here.

Source: NASA and Nature



About 

A graphic designer in Rhode Island, Jason writes about space exploration on his blog Lights In The Dark, Discovery News, and, of course, here on Universe Today. Ad astra!

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Wednesday, March 18, 2015

Slender Moonspotting, Occultations, Daytime Planets and More

Slender Moonspotting, Occultations, Daytime Planets and More:



Credit and copyright:


The waxing crescent Moon approaching Venus and Mars on February 20th. Credit and copyright: David Blanchflower.
One of nature’s grandest ‘occultations’ of all is coming right up this Friday, as the Moon passes in front of the Sun for viewers in the high Arctic for a total solar eclipse. And although 99.999+% percent of humanity will miss totality, everyone can trace the fascinating path of the Moon as it moves back into the evening sky this weekend.

As of this writing, it looks like the fickle March weather is going to keep us guessing right up to eclipse day. Fear not, as the good folks over at the Virtual Telescope Project promise to bring us views of the eclipse live.  Not only does this eclipse fall on the same day as the start of astronomical spring in the northern hemisphere known as the vernal (northward) equinox, but it also marks the start of lunation 1141.

Ever try hunting for the slender crescent Moon in the dawn or dusk sky? The sport of thin Moon-spotting on the days surrounding the New Moon can push visual skills to the very limit. Binoculars are your friend in this endeavor, as you sweep back and forth attempting to see the slim fingernail of a Moon against the low contrast background sky.  Thursday morning March 19th provides a great chance for North American observers to spy an extremely thin Moon about 24 hours prior to Friday’s eclipse.



Credit:


Projected locales for the first sightings of the slim crescent Moon on the evening of March 20th. Credit: Created by author.
Unfortunately, most of North America misses the eclipse, though folks on the extreme east coast of Newfoundland might see a partially eclipsed sunrise if the day dawns clear.

The Moon will first be picked up in the evening sky post-eclipse this weekend. On Friday evening, folks in the southern United States might just be able to spy a 15 hour old Moon with optical assistance if skies are clear.

As the Moon fattens, expect to see it at its most photogenic as Ashen light or Earthshine illuminates its nighttime side. What you’re seeing is sunlight from the Earth being reflected back in a reverse (waning gibbous) phase as seen from the earthward side of the Moon. The prominence of Earthshine can vary depending on the amount of cloud and snow cover currently turned moonward, though of course, if it’s cloudy from your location, you won’t see a thing…



Credit


The universe smiles back: A skewed emoticon grouping of Venus, Mars and the Moon plus Earthshine on February 20th. Photo by author.
Watch that Moon over the coming weeks, as it has a date with destiny.

The Moon occults (passes in front of) two planets and one bright star in the coming week. First up is an occultation of Uranus on March 21st at around 11:00 UT/7:00 AM EDT. Sure, this one is for the most part purely academic and unobservable, as it occurs over central Africa in the daytime and is only 15 degrees east of the Sun. Still, if you can pick up the Moon on the evenings of March 20th or March 21st, you might just be able to spy nearby Uranus shining at +6th magnitude nearby before it heads towards solar conjunction on April 6th.



Credit:


The visibility footprint of the March 21st occultation of Mars by the Moon. Credit: Occult 4.1.
Next, the Moon occults Mars on March 21st at 22:00 UT/6:00 PM EDT for the southern Pacific coast of South America. North America will see an extremely close photogenic pairing of Luna and the Red Planet. This is one of seven occultations of a naked eye planet by the Moon for 2015, and the first of two for Mars for the year, the next falling on December 6th.



Credit


The Moon pairs with Venus on the evening of March 22nd. Credit: Stellarium.
Next up, the Moon has a tryst with brilliant Venus, passing 2.8 degrees from the Cytherean world on March 22nd. Can you spy -4th magnitude Venus near the two day old Moon before sunset? This is the stuff that has inspired astronomically-themed flags and skewed emoticon ‘smiley face conjunctions’ of yore, including the close pairing of Mars, Venus and the Moon seen worldwide last month.



Credit:


The occultation of Aldebaran by the Moon on March 25th. Credit: Occult 4.1.
Next up, the 30% illuminated Moon occults the bright star Aldebaran for Alaskan viewers at dusk on March 25th. This is the third occultation of the star by the Moon in the ongoing cycle, and to date, no one has, to our knowledge, successfully caught an occultation of Aldebaran in 2015… could this streak be broken next week?



Credit:


The daytime Moon paired with Jupiter on March 30th. Credit: Starry Night Education software.
And speaking of daytime planet-spotting, Jupiter will sit only five degrees south of the waxing gibbous Moon on the evening of March 30th. Can you spy the giant planet near the daytime Moon in the afternoon sky using binocs? And finally, watch that Moon, as it heads for the third total lunar eclipse of the last 12 months visible from the Americas and the Pacific region on the morning of April 4th…

More to come!



About 

David Dickinson is an Earth science teacher, freelance science writer, retired USAF veteran & backyard astronomer. He currently writes and ponders the universe from Tampa Bay, Florida.

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Astrophoto: Hi-Res Stereo Pair of Jupiter and the GRS

Astrophoto: Hi-Res Stereo Pair of Jupiter and the GRS:



A high resolution stereo pair of Jupiter and its Great Red Spot, captured on February 26, 2015. The two images were taken roughly five minutes apart. Credit and copyright: Damian Peach.


A high resolution stereo pair of Jupiter and its Great Red Spot, captured on February 26, 2015. The two images were taken roughly five minutes apart. Credit and copyright: Damian Peach.
Cross your eyes and take a look at this image. If you’re lucky, you will be treated to a wonderfully clear 3-D view of Jupiter and its Great Red Spot, without the aid of a stereoscope. Or — if you haven’t quite mastered the art of viewing stereo pairs — you might end up with eyestrain.

Prolific astrophotographer Damian Peach took these two shots roughly five minutes apart — which makes them a great candidate for creating a stereo pair.

“Inspired by a suggestion from Dr. Brian May,” Peach told Universe Today via email, “this is the first time I’ve had two excellent quality sets of data so close in time with the GRS right in the centre to attempt this. I completely reprocessed the data for both images to keep a soft natural appearance and to closely match the colour between them as possible.”

Peach also said he measured the size of the GRS at 15,500km in width.

Still trying to view this as a 3-D image? Try this suggestion from Oxford University:

Hold a finger a short distance in front of your eyes and stare at it. In the background you should see two copies of the stereo pair, giving four views altogether. Move your finger away from you until you see the middle two of the four images come together. You should now see just three images in the background. Try to direct your attention slowly toward the middle image without moving your eyes, and it should gradually come into focus.
See more of Peach’s great astrophotography at his website.



About 

Nancy Atkinson is currently Universe Today's Contributing Editor. Previously she served as UT's Senior Editor and lead writer, and has worked with Astronomy Cast and 365 Days of Astronomy. Nancy is also a NASA/JPL Solar System Ambassador.

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Green and Red Auroras Light Up St. Patrick’s Day Dawn

Green and Red Auroras Light Up St. Patrick’s Day Dawn:



Just in time for St. Patrick's Day - a spectacular green and red aurora photographed early this morning March 17 from Donnelly Creek, Alaska. Credit: Sebastian Saarloos


Just in time for St. Patrick’s Day – a spectacular green and red aurora photographed early this morning March 17 from Donnelly Creek, Alaska. Credit: Sebastian Saarloos
A strong G3 geomagetic storm surged across the planet this morning producing a spectacular display of the northern lights. Some of you may who may have risen to see the new nova were no doubt as surprised as the NOAA space weather folks, whose overnight forecast did not include an alert for even a minor storm.

So what happened? Let’s just say the Sun isn’t always as predictable as we’d like. An interplanetary shock wave in the form of a sudden increase in the solar wind speed from 250 miles per second to 375 mph (400-600 km/sec) began blasting Earth shortly before midnight. It appears the combined effects of earlier coronal mass ejections (CMEs) and an outpouring of high-speed solar particles from a gaping hole in the Sun’s magnetic canopy crashed through Earth’s magnetic defenses.

Particle-wise, all hell broke loose. You can start looking for more as soon as it gets dark tonight.



A powerful X2.2-class flare from sunspot region 2297 glows fiery yellow in this photo taken by NASA’s Solar Dynamics Observatory on March 11, 2015. Credit: NASA


A powerful X2.2-class flare from sunspot region 2297 glows intensely in this photo taken in short wavelength ultraviolet light by NASA’s Solar Dynamics Observatory on March 11, 2015. Credit: NASA Goddard SDO
We know that recent flares from sunspot group 2297 have sent more than a few billows of solar particles our way called CMEs or coronal mass ejections. Weekend forecasts called for minor storms but little materialized. Only when we thought it was safe to go back to bed did the aurora pounce. Reading the magnetospheric tea leaves, better known as the Kp index, a measure of magnetic activity high overhead in Earth’s ionosphere, quiet conditions gave way to auroral abandon starting around 1 a.m (CDT) today.

A wall of colorful red and green aurora met the eye and camera of Jim Schaff of Duluth this morning around 3 a.m. CDT. Credit: Jim Schaff
A wall of colorful red and green aurora met the eye and camera of Jim Schaff of Duluth this morning around 3 a.m. CDT. Credit: Jim Schaff
Like a spring grassfire the northern lights took off from there and burned till dawn, peaking between 2 and 4 a.m. Most of us are usually asleep during those deep hours of the night, but I’m hoping those who arose to see the nova or catch the lunar crescent at dawn may have been as surprised and delighted as I was to see auroras.

Like paw prints made by a cat, pale green auroral rays mark the northern sky around 5:45 a.m this morning March 17. Credit: Bob King
Like paw prints made by a cat, pale green auroral rays mark the northern sky around 5:45 a.m this morning March 17. Credit: Bob King
More are in the offing. The latest space weather forecast calls for continued severe storms (G3 or higher) to continue through tonight. G1 or minor storms are normally only visible as arcs or low rays across the north from the northern tier of states, but if tonight’s forecast holds, a fair portion of the U.S. should see auroras. Keep an eye peeled for bright, moving glow and arcs across the northern sky.



The awesome 30-minute aurora forecast map updates the shrinking and expanding of Earth's northern auroral oval due to changes in the solar wind from CMEs, flares and the like. This view is from this morning around 4:55 a.m. Red indicates intense aurora. Credit: NOAA


The awesome 30-minute aurora forecast map updates the shrinking and expanding of Earth’s northern auroral oval due to changes in the solar wind from CMEs, flares and the like. This view is from this morning around 4:55 a.m. Red indicates intense aurora. Credit: NOAA
There are lots of tools available you can use yourself to know if auroras are lurking about. First, check the NOAA 3-day space weather forecast. There you’ll see a list of times along with a Kp index number indicating magnetic activity. Number “1-4″ means no storm and little likelihood you’ll see an aurora. “5”  indicates a minor storm; the higher the number the more severe the storm and more widespread the northern lights will be.

Curtains of aurora still pushed through the growing light of dawn. Credit: Bob King
Curtains of aurora still pushed through the growing light of dawn (blue sky at top). Credit: Bob King
There’s also a nice visual representation of the numbers on the Planetary K-index site, where magnetic activity is updated every 3 hours.  The dashed line on the bar chart represents 0 UT or 7 p.m. CDT. One of my favorites and the ultimate visual feast of an aurora indicator is NOAA’s Aurora 30-minute Forecast. Here you get a birds-eye representation of the current aurora based on satellite data. When the permanent auroral oval expands southward and intensifies, put on your coat and head out for a look. For education and entertainment, click on the gray arrow below the graphic and you’ll see a whole day’s worth of activity play out before your eyes. Totes cool.



ACE plot from a June 2013 aurora. Note the steep drop in the Bz. Credit: NOAA


ACE plot from a June 2013 aurora. Note the steep drop in the Bz. ACE  orbits around the L1 Lagrange point about a million miles ahead of Earth in the direction of the Sun. There it studies the incoming particle streams from the Sun hours before they reach Earth. Credit: NOAA
I’m also in big believer in the the Advanced Composition Explorer (ACE) Bz plot. Bz is the direction of the embedded solar magnetic field that gift-wraps the streams of high-speed particles sent our way by the Sun. Like a magnet, it has a south pole and a north pole. When the south pole of the field sweeps by – what scientists call a negative Bz – the blast is more likely to link up with Earth’s magnetic field and spark auroras. When you see the Bz “head south” to -5 or lower, there’s a chance for auroras.

Now that you’re armed with information, cross your fingers all the indicators will point in the right direction for the aurora to continue tonight. And yes, Happy St. Patrick’s Day!



Skiing stop to take in the northern lights near Fairbanks Monday night. Credit: John Chumack


Skywatchers stop to take in the northern lights near Fairbanks Monday night. Credit: John Chumack
UPDATE: The storm continues and is now rated G4 or severe as of 10 a.m. CDT. Lucky for you if you live somewhere where it’s dark right now.



About 

I'm a long-time amateur astronomer and member of the American Association of Variable Star Observers (AAVSO). My observing passions include everything from auroras to Z Cam stars. Every day the universe offers up something both beautiful and thought-provoking. I also write a daily astronomy blog called Astro Bob.

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Powerful Magnetic Storm Produces Beautiful Aurora Around the World

Powerful Magnetic Storm Produces Beautiful Aurora Around the World:

The strong geomagetic storm surprised early risers yesterday on St. Patrick’s Day with a spectacular display of the northern lights, ended up with staying power. According to Spaceweather.com, a fast-moving CME hit Earth’s magnetic field that at first had little effect. But as Earth moved into the CME’s strongly-magnetized wake, the storm intensified until it became a G4-class event. “For more than 9 hours, it was the strongest geomagnetic storm of the current solar cycle,” and the glow of aurora was seen around the world — in the northern hemisphere, anyway — farther south than usual, such as in Kanasa and Virginia in the US and in Oxfordshire, Wiltshire and Hampshire in the UK.

Speaking of ‘around the world,’ astronaut Terry Virts took the Vine video above, from the International Space Station.

Below are more aurora images from Universe Today readers:




St Patrick's Day Aurora. This is a 5 image panorama of the Northern Lights display around 10PM in central Maine. Credit and copyright: Mike Taylor/Mike Taylor Photography.


St Patrick’s Day Aurora. This is a 5 image panorama of the Northern Lights display around 10PM in central Maine. Credit and copyright: Mike Taylor/Mike Taylor Photography.


Powerful Aurora Borealis from March 18, 2015.Photographed in Saaremaa, Estonia. Credit and copyright: Marko Palm.


Powerful Aurora Borealis from March 18, 2015.Photographed in Saaremaa, Estonia. Credit and copyright: Marko Palm.


Aurora on St. Patrick's Day night, seen west of Keene, Ontario, Canada at about 10:00 p.m. EDST. Credit and copyright: Rick Stankiewicz


Aurora on St. Patrick’s Day night, seen west of Keene, Ontario, Canada at about 10:00 p.m. EDST. Credit and copyright: Rick Stankiewicz


Aurora borealis as seen from Leek in Staffordshire, England on March 17, 2015. Credit and copyright: Gareth Harding.


Aurora borealis as seen from Leek in Staffordshire, England on March 17, 2015. Credit and copyright: Gareth Harding.


90 Minute Aurora Star Trails as seen from the UK on March 17, 2015. Credit and copyright: Mary Spicer.


90 Minute Aurora Star Trails as seen from the UK on March 17, 2015. Credit and copyright: Mary Spicer.
The team from the Slooh telescope had a special broadcast last night from Iceland to showcase the aurora, and the skies were alive with brilliant, green aurora. Here is a highlight, showcasing some of the incredible moments:





About 

Nancy Atkinson is currently Universe Today's Contributing Editor. Previously she served as UT's Senior Editor and lead writer, and has worked with Astronomy Cast and 365 Days of Astronomy. Nancy is also a NASA/JPL Solar System Ambassador.

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WOW - The Clouds of Orion the Hunter

The Clouds of Orion the Hunter: APOD: 2015 March 16 - The Clouds of Orion the Hunter


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.

2015 March 16



See Explanation. Moving the cursor over the image will bring up an annotated version. Clicking on the image will bring up the highest resolution version available.
Explanation: Cradled in cosmic dust and glowing hydrogen, stellar nurseries in Orion the Hunter lie at the edge of giant molecular clouds some 1,500 light-years away. Spanning about 30 degrees, this breath-taking vista stretches across the well-known constellation from head to toe (left to right) and beyond. At 1,500 light years away, the Great Orion Nebula is the closest large star forming region, here visible just right and below center. To its left are the Horsehead Nebula, M78, and Orion's belt stars. Sliding your cursor over the picture will also find red giant Betelgeuse at the hunter's shoulder, bright blue Rigel at his foot, the Witch Head Nebula above -- and illuminated by -- Rigel, and the glowing Lambda Orionis (Meissa) nebula on the left, near Orion's head. Of course, the Orion Nebula and bright stars are easy to see with the unaided eye, but dust clouds and emission from the extensive interstellar gas in this nebula-rich complex, are too faint and much harder to record. In this mosaic of broadband telescopic images, additional image data acquired with a narrow hydrogen alpha filter was used to bring out the pervasive tendrils of energized atomic hydrogen gas like in the arc of the giant Barnard's Loop.

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Monday, March 16, 2015

"Mini Supernova" Explosion Could Have Big Impact

"Mini Supernova" Explosion Could Have Big Impact:



GK Persei*


In Hollywood blockbusters, explosions are often among the stars of the show. In space, explosions of actual stars are a focus for scientists who hope to better understand their births, lives, and deaths and how they interact with their surroundings.

Using NASA's Chandra X-ray Observatory, astronomers have studied one particular explosion that may provide clues to the dynamics of other, much larger stellar eruptions.

A team of researchers pointed the telescope at GK Persei, an object that became a sensation in the astronomical world in 1901 when it suddenly appeared as one of the brightest stars in the sky for a few days, before gradually fading away in brightness. Today, astronomers cite GK Persei as an example of a "classical nova," an outburst produced by a thermonuclear explosion on the surface of a white dwarf star, the dense remnant of a Sun-like star.

A nova can occur if the strong gravity of a white dwarf pulls material from its orbiting companion star. If enough material, mostly in the form of hydrogen gas, accumulates on the surface of the white dwarf, nuclear fusion reactions can occur and intensify, culminating into a cosmic-sized hydrogen bomb blast. The outer layers of the white dwarf are blown away, producing a nova outburst that can be observed for a period of months to years as the material expands into space.

Classical novas can be considered to be "miniature" versions of supernova explosions. Supernovas signal the destruction of an entire star and can be so bright that they outshine the whole galaxy where they are found. Supernovas are extremely important for cosmic ecology because they inject huge amounts of energy into the interstellar gas, and are responsible for dispersing elements such as iron, calcium and oxygen into space where they may be incorporated into future generations of stars and planets.

Although the remnants of supernovas are much more massive and energetic than classical novas, some of the fundamental physics is the same. Both involve an explosion and creation of a shock wave that travels at supersonic speeds through the surrounding gas.

The more modest energies and masses associated with classical novas means that the remnants evolve more quickly. This, plus the much higher frequency of their occurrence compared to supenovas, makes classical novas important targets for studying cosmic explosions.

More information at http://chandra.harvard.edu/photo/2015/gkper/index.html

-Megan Watzke, CXC
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New Binocular Nova Discovered in Sagittarius

New Binocular Nova Discovered in Sagittarius:



This view shows the sky facing south-southeast just before the start of dawn in mid-March from the central U.S. The nova's located squarely in the Teapot constellation. Source: Stellarium


This view shows the sky facing south-southeast just before the start of dawn in mid-March from the central U.S. The nova’s located squarely in the Teapot constellation. Source: Stellarium
Looks like the Sagittarius Teapot’s got a new whistle. On March 15, John Seach of Chatsworth Island, NSW, Australia discovered a probable nova in the heart of the constellation using a DSLR camera and fast 50mm lens. Checks revealed no bright asteroid or variable star at the location. At the time, the new object glowed at the naked eye limit of magnitude +6, but a more recent observation by Japanese amateur Koichi Itagaki puts the star at magnitude +5.3, indicating it’s still on the rise.

A 5th magnitude nova’s not too difficult to spot with the naked eye from a dark sky, and binoculars will show it with ease. Make a morning of it by setting up your telescope for a look at Saturn and the nearby double star Graffias (Beta Scorpii), one of the prettiest, low-power doubles in the summer sky.



Close-in map of Sagittarius showing the nova's location (R.A. 18h36m57s Decl. -28°55'42") and neighboring stars with their magnitudes. For clarity, the decimal points are omitted from the magnitudes, which are from the Tycho catalog. Source: Stellarium


Close-in map of Sagittarius showing the nova’s location (R.A. 18h36m57s Decl. -28°55’42”) and neighboring stars with their magnitudes. For clarity, the decimal points are omitted from the magnitudes, which are from the Tycho catalog. Source: Stellarium
Nova means “new”, but novae aren’t fresh stars coming to life but an explosion occurring on the surface of an otherwise faint star no one’s taken notice of – until the blast causes it to brighten 50,000 to 100,000 times. A nova occurs in a close binary star system, where a small but extremely dense and massive (for its size) white dwarf siphons hydrogen gas from its closely orbiting companion. After swirling about in a disk around the dwarf, it’s funneled down to the star’s 150,000 F° surface where gravity compacts and heats the gas until detonates in a titanic thermonuclear explosion. Suddenly, a faint star that wasn’t on anyone’s radar vaults a dozen magnitudes to become a standout “new star”.



Novae occur in close binary systems where one star is a tiny but extremely compact white dwarf star. The dwarf pulls material into a disk around itself, some of which is funneled to the surface and ignites in a nova explosion. Credit: NASA


Novae occur in close binary systems where one star is a tiny but extremely compact white dwarf star. The dwarf pulls material into a disk around itself, some of which is funneled to the surface and ignites in a nova explosion. Credit: NASA
Regular nova observers may wonder why so many novae are discovered in the Sagittarius-Scorpius Milky Way region. There are so many more stars in the dense star clouds of the Milky Way, compared to say the Big Dipper or Canis Minor, that the odds go up of seeing a relatively rare event like a stellar explosion is likely to happen there than where the stars are scattered thinly. Given this galactic facts of life, that means most of will have to set our alarms to spot this nova. Sagittarius doesn’t rise high enough for a good view until the start of morning twilight. For the central U.S., that’s around 5:45-6 a.m.



A now-you-see-it-now-you-don't animation showing the nova field before and after discovery. Credit: Ernesto Guido and Nick Howes


A now-you-see-it-now-you-don’t animation showing the nova field before and after discovery. Credit: Ernesto Guido and Nick Howes
Find a location with a clear view to the southeast and get oriented at the start of morning twilight or about 100 minutes before sunrise. Using the maps, locate Sagittarius below and to the east (left) of Scorpius. Once you’ve arrived, point your binoculars into the Teapot and star-hop to the nova’s location. I’ve included visual magnitudes of neighboring stars to help you estimate the nova’s brightness and track its changes in the coming days and weeks.

Whether it continues to brighten or soon begins to fade is anyone’s guess at this point. That only makes going out and seeing it yourself that much more enticing.

UPDATE: A spectrum of the object was obtained with the Liverpool Telescope March 16 confirming that the “new star” is indeed a nova. Gas has been clocked moving away from the system at more than 6.2 million mph (10 million kph)!



About 

I'm a long-time amateur astronomer and member of the American Association of Variable Star Observers (AAVSO). My observing passions include everything from auroras to Z Cam stars. Every day the universe offers up something both beautiful and thought-provoking. I also write a daily astronomy blog called Astro Bob.

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A Total Eclipse at the End of the World

A Total Eclipse at the End of the World: APOD: 2015 March 15 - A Total Eclipse at the End of the World


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.

2015 March 15


See Explanation. Clicking on the picture will download the highest resolution version available.
Explanation: Would you go to the end of the world to see a total eclipse of the Sun? If you did, would you be surprised to find someone else there already? In 2003, the Sun, the Moon, Antarctica, and two photographers all lined up in Antarctica during an unusual total solar eclipse. Even given the extreme location, a group of enthusiastic eclipse chasers ventured near the bottom of the world to experience the surreal momentary disappearance of the Sun behind the Moon. One of the treasures collected was the above picture -- a composite of four separate images digitally combined to realistically simulate how the adaptive human eye saw the eclipse. As the image was taken, both the Moon and the Sun peeked together over an Antarctic ridge. In the sudden darkness, the magnificent corona of the Sun became visible around the Moon. Quite by accident, another photographer was caught in one of the images checking his video camera. Visible to his left are an equipment bag and a collapsible chair. A total solar eclipse will occur on Friday and be visible from the north Atlantic Ocean.

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Trifid Nebula Glows in Stunning Photo By Amateur Astronomer

Trifid Nebula Glows in Stunning Photo By Amateur Astronomer:  

by Nina Sen, Space.com Contributor

Date: 12 March 2015 Time: 08:19 AM ET

Trifid Nebula Unnikrishnan
Astrophotographer Navaneeth Unnikrishnan captured the Trifid Nebula from Karnataka, India.

CREDIT: Navaneeth Unnikrishnan


This stunning image of the Trifid Nebula was taken from Karnataka, India.

Astrophotographer Navaneeth Unnikrishnan captured the star factory using a DSLR camera and tracking mounted telescopes.

The Trifid Nebula (Messier 20 or NGC 6514) is a combination of emission nebula (the red area) and reflection nebula (the blue area) and dark nebula.  [What Do You See? Strange Nebula Shapes (Photos)]

The Trifid Nebula is located about 5,200 light-years from Earth. A light-year is the distance light travels in one year, or about 6 trillion miles (10 trillion kilometers). The Trifid takes its name from the dark dust bands that trisect its glowing heart. Astronomer Charles Messier first observed the Trifid Nebula in June 1764. Observations made about 60 years later revealed the dividing bands.

Unnikrishnan used a 11'' Schmidt Cassegrain Telescope, Canon 20D (Modified) with ISO 400 to combine 15 darks, 15 offset images.

To see more amazing night sky photos submitted by Space.com readers, visit our astrophotography archive.

Editor's note: If you have an amazing night sky photo you'd like to share for a possible story or image gallery, please contact managing editor Tariq Malik at spacephotos@space.com.



Posted by Nelio Inacio at 4:57 AM 0 comments
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AWESOME Space Stories of the Week

Best Space Stories of the Week – March 15, 2015:


By Mike Wall, Senior Writer

Date: 15 March 2015 Time: 11:29 AM ET

Enceladus Cross-Section
Saturn's icy moon Enceladus is home to giant water geysers in the moon's south polar region. Scientists say interactions between hot water and rock on the floor of a subsurface ocean powers the hydrothermal reaction pushing gas and ice through Enceladus' 50-kilometer-thick (31 miles) ice crust.

CREDIT: NASA/JPL-Caltech


NASA launched a new space-weather mission, scientists found evidence of a hydrothermal system on Saturn's ocean-bearing moon Enceladus and three astronauts returned safely to Earth after nearly six months aboard the International Space Station. Here's a look at Space.com's top stories of the week:

NASA space weather mission takes flight

NASA launched its Magnetospheric Multiscale (MMS) mission, which consists of four satellites that will study energy eruptions in Earth’s magnetic field caused by space weather. MMS blasted off Thursday night (March 12) from Cape Canaveral, Florida, aboard a United Launch Alliance Atlas V rocket. [Full Story: Spectacular Night Launch Sends NASA Satellites on Hunt for Magnetic Collisions]

A hydrothermal system on Enceladus

Scientists have found evidence of active hydrothermal vents on Saturn's ice-covered moon Enceladus. Conditions deep in Enceladus' subsurface ocean may therefore be similar to those that gave rise to the first life on Earth. [Full Story: Hot Springs on Saturn's Moon Enceladus Powered by Hydrothermal Vents]

Spaceflyers come home

A Russian Soyuz spacecraft touched down on the steppes of Kazakhstan Wednesday night (March 11), wrapping up a nearly six-month stint aboard the International Space Station for NASA astronaut Barry "Butch" Wilmore and cosmonauts Alexander Samokutyaev and Elena Serova. [Full Story: US-Russian Space Crew Returns to Earth After 167 Days in Orbit]

Happy birthday, Kepler!

NASA's prolific Kepler space telescope, which has discovered more than half of all known planets beyond our solar system, just celebrated six years in space. The prolific planet hunter blasted off on March 6, 2009. [Full Story: Happy Birthday, Kepler! NASA Planet Hunter Marks 6 Years in Space]

NASA test-fires booster for Space Launch System megarocket

A giant rocket booster designed to help NASA’s next megarocket, the Space Launch System, soar into space roared to life in the Utah proving grounds of aerospace firm Orbital ATK on Wednesday (March 11). [Full Story: World's Largest Solid Rocket Booster Fired in Ground Test for NASA]

The first X-flare of 2015

The sun unleashed its first superpowerful flare of the year on Wednesday (March 11), and the intense eruption was aimed directly at Earth. The monster X-class solar flare, the strongest category of sun storms, caused an hour-long blackout in high-frequency radio communications over wide areas. [Full Story: Sun Unleashes 1st Monster Solar Flare of 2015 (Photos, Video)]

Pluto probe performs most-distant engine burn ever

NASA's New Horizons spacecraft, which will zoom through the Pluto system on July 14, fired its engines for 93 seconds on Tuesday (March 10), when it was about 3 billion miles (4.83 billion kilometers) from Earth. No spacecraft had ever conducted an engine burn at so great a distance from its handlers, mission officials said. [Full Story: NASA Probe Makes Record-Setting Engine Burn on Path to Pluto]

A subsurface ocean on Ganymede

A salty ocean lurks beneath the icy surface of Jupiter's largest moon, Ganymede, scientists using NASA's Hubble Space Telescope have found. Ganymede's ocean could actually harbor more water than all of Earth's surface water combined, according to NASA officials. [Full Story: Jupiter's Moon Ganymede Has a Salty Ocean with More Water than Earth]

Opportunity spies odd rocks near end of marathon trek

NASA's Opportunity Mars rover took a break in the home stretch of its Red Planet marathon to study some rocks the likes of which it's never seen before. As of March 5, the rover's odometer read 26.139 miles (42.067 kilometers), leaving it just 140 yards (128 meters) short of the marathon milestone. [Full Story: On Mars, Opportunity Rover Spots Weird Rocks Near Marathon Finish Line]

Lockheed Martin unveils ambitious new space transportation system

Aerospace firm Lockheed Martin has announced its plans for a new spaceflight system that could ferry cargo to the International Space Station, and also help get people to deep-space destinations such as the moon and Mars. [Full Story: Lockheed's 'Jupiter' Space Tug Could Fly to Space Station, Moon and Beyond]

What will NASA's Dawn probe look for at dwarf planet Ceres?

A Q&A with Chris Russell, principal investigator of NASA's Dawn mission, which recently arrived in orbit around the dwarf planet Ceres. [Full Story: Studying Dwarf Planet Ceres: Q&A with Dawn Scientist Chris Russell]

Follow Mike Wall on Twitter @michaeldwall and Google+. Follow us @Spacedotcom, Facebook or Google+.

Posted by Nelio Inacio at 4:55 AM 0 comments
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Saturday, March 14, 2015

Inside the Eagle Nebula

Inside the Eagle Nebula: APOD: 2014 February 16 - Inside the Eagle 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.

2014 February 16


See Explanation. Clicking on the picture will download the highest resolution version available.
Explanation: From afar, the whole thing looks like an Eagle. A closer look at the Eagle Nebula, however, shows the bright region is actually a window into the center of a larger dark shell of dust. Through this window, a brightly-lit workshop appears where a whole open cluster of stars is being formed. In this cavity tall pillars and round globules of dark dust and cold molecular gas remain where stars are still forming. Already visible are several young bright blue stars whose light and winds are burning away and pushing back the remaining filaments and walls of gas and dust. The Eagle emission nebula, tagged M16, lies about 6500 light years away, spans about 20 light-years, and is visible with binoculars toward the constellation of the Serpent (Serpens). This picture combines three specific emitted colors and was taken with the 0.9-meter telescope on Kitt Peak, Arizona, USA.

Posted by Nelio Inacio at 6:40 PM 0 comments
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The Cosmic Web of the Tarantula Nebula

The Cosmic Web of the Tarantula Nebula: APOD: 2014 February 17 - The Cosmic Web of the Tarantula 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.

2014 February 17


See Explanation. Clicking on the picture will download the highest resolution version available.
Explanation: It is the largest and most complex star forming region in the entire galactic neighborhood. Located in the Large Magellanic Cloud, a small satellite galaxy orbiting our Milky Way galaxy, the region's spidery appearance is responsible for its popular name, the Tarantula nebula. This tarantula, however, is about 1,000 light-years across. Were it placed at the distance of Milky Way's Orion Nebula, only 1,500 light-years distant and the nearest stellar nursery to Earth, it would appear to cover about 30 degrees (60 full moons) on the sky. Intriguing details of the nebula are visible in the above image shown in near true colors. The spindly arms of the Tarantula nebula surround NGC 2070, a star cluster that contains some of the brightest, most massive stars known, visible in blue in the image center. Since massive stars live fast and die young, it is not so surprising that the cosmic Tarantula also lies near the site of a close recent supernova.

Posted by Nelio Inacio at 6:39 PM 0 comments
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Comet Lovejoy over The Great Wall

Comet Lovejoy over The Great Wall: APOD: 2014 February 20 - Comet Lovejoy over The Great Wall


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.

2014 February 20


See Explanation. Clicking on the picture will download the highest resolution version available.
Explanation: Fading now as it returns to the outer solar system Comet Lovejoy (C/2013 R1) still graces planet Earth's sky, a delicate apparition in binoculars or small telescopes. The comet, a relic of the solar system's formative years, is seen here rising in the morning twilight on January 12 among the stars of Ophiuchus, the Serpent Bearer. Posing near the comet is bright star Alpha Ophiuchi, also known as Rasalhague, from Arabic "the head of the serpent collector". Of course, the serpentine shape below is the ancient Great Wall of China, along the Panlongshan section northeast of Beijing. Panlongshan is translated as "a coiled dragon". A moving and fortuitous scene, it was captured with a digital camera and telephoto lens in two consecutive exposures. The exposures were merged to show a natural looking foreground and twilight sky.

Posted by Nelio Inacio at 6:38 PM 0 comments
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