Terry's Astronomy Thread.

[Bluearrowll]

Re: Terry's Astronomy Thread.

Daily Suspicious0bserver's Weather Post:
September 29, 2014

What's in the sky tonight?
September 29, 2014

-There are now four sunspot groups on the solar disk with unstable magnetic fields, which means an eruption today is likely. NOAA forecasters have raised the daily odds of an M-class solar flare to 75% and an X-flare to 15%.

-While much attention is being paid to the fact that September's equinox kicked off aurora season in the Northern Hemisphere, we should not forget that the Southern Hemisphere has just experienced the exact same equinox. It is aurora season there, too. Petr Horálek sends this example of Southern Lights over Lauder, New Zealand, on Sept 25th. "The auroras burned very low above the southern horizon here at the NIWA atmospheric research station," Horálek says. "The opened dome is the BOOTES telescope, which is used to detect the optical afterglow of distant gamma-ray bursts. A green lidar behind me reflected from the dome, giving it a green hue."

For reasons researchers do not fully understand, at this time of year even gentle gusts of solar wind can ignite beautiful auroras. Right now Earth is passing through a minor stream of solar wind that has both poles aglow.

Astro Picture of the Day:
September 29, 2014

Source:
How did these Martian rocks form? As the robotic Curiosity rover has approached Pahrump Hills on Mars, it has seen an interesting and textured landscape dotted by some unusual rocks. The featured image shows a curiously round rock spanning about two centimeters across. Seemingly a larger version of numerous spherules dubbed blueberries found by the Opportunity rover on Mars in 2004, what caused this roundness remains unknown. Possibilities include frequent tumbling in flowing water, sprayed molten rock in a volcanic eruption, or a concretion mechanism. The inset image, taken a few days later, shows another small but unusually shaped rock structure. As Curiosity rolls around and up Mount Sharp, different layers of the landscape will be imaged and studied to better understand the ancient history of the region and to investigate whether Mars could once have harbored life.

[Zageron]

Re: Terry's Astronomy Thread.

Still continues to be the most interesting thread on the internet.

[Bluearrowll]

Re: Terry's Astronomy Thread.

Daily Suspicious0bserver's Weather Post:
September 30, 2014

What's in the sky tonight?
September 30, 2014

-Arcturus is the bright star due west at nightfall. It's an orange giant 37 light-years away. Off to its right in the northwest is the Big Dipper, most of whose stars are about 80 light-years away. They're both sinking lower every week now.

-Saturn (magnitude +0.6, in Libra) is sinking away into the afterglow of sunset. Look for it well to the right of the Mars-Antares pair, and probably a little lower depending on your latitude.

Astro Picture of the Day:
September 30, 2014

Source:
Have you ever seen an entire rainbow? From the ground, typically, only the top portion of a rainbow is visible because directions toward the ground have fewer raindrops. From the air, though, the entire 360 degree circle of a rainbow is more commonly visible. Pictured here, a full circle rainbow was captured over Cottesloe Beach near Perth, Australia last year by a helicopter flying between a setting sun and a downpour. An observer-dependent phenomenon primarily caused by the internal reflection of sunlight by raindrops, the 84-degree diameter rainbow followed the helicopter, intact, for about 5 kilometers. As a bonus, a second rainbow that was more faint and color-reversed was visible outside the first.

[Bluearrowll]

Re: Terry's Astronomy Thread.

Daily Suspicious0bserver's Weather Post:
October 1, 2014

What's in the sky tonight?
October 1, 2014

-So far this week, solar activity has been low. However, there are five sunspots on the solar disk poised to break the quiet. All of them have 'beta-gamma' magnetic fields that harbor energy for moderately strong eruptions. NOAA forecasters estimate a 65% chance of M-class solar flares and a 15% chance of X-flares.

-For the 5th day in a row, observers around the Arctic Circle are reporting dynamic auroras. Pilot Brian Whittaker photographed this outburst on Sept. 30th while he was flying 35,000 feet over Hudson Bay, Canada. "For many hours we watched the sky come alive, often with rapid pulses," Whittaker says. "It was mostly cloudy below, but a fantastic show at 35,000 ft."

The ongoing display is a result of our planet's response to the interplanetary magnetic field (IMF). For days the IMF has been tipping south, slightly, just enough to open a crack in Earth's magnetosphere. Solar wind leaks in to fuel the auroras.

Conditions favor more auroras tonight. NOAA forecasters estimate a 35% chance of polar geomagnetic storms on Oct. 1st. However, a full-fledged storm is not required for Northern Lights at this time of year. The odds of Arctic auroras are, therefore, quite a bit higher than 35%.

Astro Picture of the Day:
October 1, 2014

Source:
The bright clusters and nebulae of planet Earth's night sky are often named for flowers or insects. Though its wingspan covers over 3 light-years, NGC 6302 is no exception. With an estimated surface temperature of about 250,000 degrees C, the dying central star of this particular planetary nebula has become exceptionally hot, shining brightly in ultraviolet light but hidden from direct view by a dense torus of dust. This sharp close-up of the dying star's nebula was recorded in 2009 by the Hubble Space Telescope's Wide Field Camera 3, and is presented here in reprocessed colors. Cutting across a bright cavity of ionized gas, the dust torus surrounding the central star is near the center of this view, almost edge-on to the line-of-sight. Molecular hydrogen has been detected in the hot star's dusty cosmic shroud. NGC 6302 lies about 4,000 light-years away in the arachnologically correct constellation of the Scorpion (Scorpius).

[Bluearrowll]

Re: Terry's Astronomy Thread.

Daily Suspicious0bserver's Weather Post:
October 2, 2014

What's in the sky tonight?
October 2, 2014

-If you thought an X1-class solar flare was bad, how about an X100,000? NASA's Swift spacecraft has detected such a explosion. Fortunately for life on Earth, it did not come from the sun. The source of the super-flare was another star almost 60 light-years away.

-It only looks like a lunchbox. Pictured below is a Space Weather Buoy--an insulated capsule containing a cosmic ray detector, video cameras, GPS trackers, and other sensors. On Sept. 28th, it flew 115,000 feet above Earth's surface to check radiation levels in the stratosphere. This picture was taken at the apex of the flight.

In collaboration with Spaceweather.com, the students of Earth to Sky Calculus have been launching these buoys on a regular basis to study the effect of solar activity on Earth's upper atmosphere. Their latest flight has a sharply defined purpose: to find out if stratospheric radiation is rebounding from a "Forbush Decrease" earlier this month.

The story begins on Sept. 12th when a CME hit Earth head-on, sparking the strongest geomagnetic storm of the year. The students launched a Space Weather Buoy into the storm, expecting to measure an increase in energetic particles. Instead of more, however, they measured less. The CME swept away many of the cosmic rays around Earth and, as a result, radiation levels in the stratosphere dropped. This counterintuitive effect is called a "Forbush Decrease" after the 20th century physicist Scott Forbush who first described it.

Now that the CME is long gone, cosmic radiation levels around Earth should be returning to normal. But are they? The answer lies inside the payload, which a team recovered yesterday from a remote landing site in Death Valley National Park. Stay tuned.

Note: The students wish to thank Sander Geophysics for sponsoring this flight. (Note their logo in the upper right corner of the payload.) Their generous contribution of $500 paid for the helium and other supplies necessary to get this research off the ground.

Astro Picture of the Day:
October 2, 2014

Source:
Blown by the wind from a massive star, this interstellar apparition has a surprisingly familiar shape. Cataloged as NGC 7635, it is also known simply as The Bubble Nebula. Although it looks delicate, the 10 light-year diameter bubble offers evidence of violent processes at work. Below and left of the Bubble's center is a hot, O star, several hundred thousand times more luminous and around 45 times more massive than the Sun. A fierce stellar wind and intense radiation from that star has blasted out the structure of glowing gas against denser material in a surrounding molecular cloud. The intriguing Bubble Nebula and associated cloud complex lie a mere 11,000 light-years away toward the boastful constellation Cassiopeia. This tantalizing view of the cosmic bubble is composed from narrowband image data, recording emission from the region's ionized hydrogen and oxygen atoms. To create the three color image, hydrogen and oxygen emission were used for red and blue and combined to create the green channel.

[Calwyn]

Re: Terry's Astronomy Thread.

I'm insanely thankful for this thread as it's the one time I've gone through 54 pages and not been bored at all. Great work putting this all together, Bluearrowll!

[Bluearrowll]

Re: Terry's Astronomy Thread.

Thanks for the kind words Calwyn!

Daily Suspicious0bserver's Weather Post:
October 3, 2014

What's in the sky tonight?
October 3, 2014

-Departing sunspot complex AR2172-AR2173 erupted on Oct. 2nd around 1915 UT, producing an M7-class solar flare. NASA Solar Dynamics Observatory photographed a massive plume of debris flying away from the blast site.

A flash of UV radiation from the flare ionized the top of Earth's atmosphere, briefly disturbing the normal propagation of shortwave and VLF radio signals on the dayside of Earth. Otherwise there should be few Earth-effects from this eruption. Perched on the sun's western limb, the instigating sunspot group is not facing our planet and most of the explosion's debris should sail wide of Earth.

There is a slim chance that a CME emerging from the blast site could deliver a glancing blow to Earth's magnetic field in a few days. To evaluate this possibility, NOAA analysts are looking carefully at coronagraph data from SOHO and STEREO.

Astro Picture of the Day:
October 3, 2014

Source:
Stepping stones seem to lead to the Milky Way as it stretches across this little sky. Of course, the scene is really the northern hemisphere's autumnal equinox night. Water and sky are inverted by a top to bottom, around the horizon stereographic projection centered on the zenith above Lake Storsjön in Jämtland, Sweden. In the north the Milky Way arcs from east to west overhead as fall begins, but the season is also a good time for viewing aurora. Geomagnetic storms increase in frequency near the equinox and produce remarkable displays of northern lights at high latitudes, like the eerie greenish glow reflected in this watery cosmos.e green channel.

[Bluearrowll]

Re: Terry's Astronomy Thread.

Daily Suspicious0bserver's Weather Post:
October 4, 2014

What's in the sky tonight?
October 4, 2014

-The W pattern of Cassiopeia stands vertically (on its dimmer end) high in the northeast around 10 or 11 p.m., depending on your location. By then the Big Dipper is lying level just above the north-northwest horizon — if you live in the mid-northern latitudes. As far south as San Diego and Jacksonville, the Dipper will lie partly below the horizon.

-Mark your calendar. On Wednesday morning, Oct. 8th, observers across the Pacific side of Earth will see the Moon turn a beautiful shade of red as it passes through the sunset-colored shadow of our planet. Totality begins at 10:25 UT (3:25 a.m. PDT) and lasts for nearly an hour. Don't miss it! Details: http://eclipse.gsfc.nasa.gov/LEplot/...2014Oct08T.pdf

-The Moon is waxing full. That means now is a good time to look for lunar coronas. Lauri Kangas photographed this specimen over Fort Frances, Ontario, on October 2nd. Lunar coronas are made of moonlight diffracted by tiny droplets of water in the air. Sometimes the droplets are supplied by passing clouds. This time, however, they came in the form of fog.

"Late in that evening the temperature dropped rapidly and a ground fog developed," says Kangas. "I could see the tiny water droplets with my flashlight. These water droplets formed a beautiful corona around the Moon. To the naked eye the blue colored ring was awesome."

Rings around the Moon also form when ice crystals drift by, but those are ice halos, and they have a different appearance.

Astro Picture of the Day:
October 4, 2014

Source:
Mars, Antares, Moon, and Saturn are the brightest celestial beacons in this serene sky. The Sun's golden light is still scattered along the southwestern horizon though, captured after sunset on September 28. The evening gathering of wandering planets and Moon along with the bright star viewed as an equal to Mars and the Scorpion's Heart was enjoyed around planet Earth. But from the photographer's perspective looking across the calm waters of Lake Balaton, Hungary, they were joined by a more terrestrial sailboat mast light. Mast light, bright star, planets and Moon are all posing near the plane of the ecliptic.

[Bluearrowll]

Re: Terry's Astronomy Thread.

Daily Suspicious0bserver's Weather Post:
October 5, 2014

What's in the sky tonight?
October 5, 2014

-The sun is peppered with spots, but not one of the eight numbered sunspot groups on the solar disk has the type of unstable magnetic field that poses a threat for strong flares. Solar activity is low. NOAA forecasters estimate a 15% chance of M-flares today, decreasing to only 5% tomorrow.

Astro Picture of the Day:
October 5, 2014

http://vimeo.com/25808333

Source:
If the full Moon suddenly faded, what would you see? The answer during the total lunar eclipse of 2011 June was recorded in a dramatic time lapse video from Tajikistan. During a total lunar eclipse, the Earth moves between the Moon and the Sun, causing the moon to fade dramatically. The Moon never gets completely dark, though, since the Earth's atmosphere refracts some light. As the above video begins, the scene may appear to be daytime and sunlit, but actually it is a nighttime and lit by the glow of the full Moon. As the moon becomes eclipsed and fades, the wind dies down and background stars can be seen reflected in foreground lake. Most spectacularly, the sky surrounding the eclipsed moon suddenly appears to be full of stars and highlighted by the busy plane of our Milky Way Galaxy. The sequence repeats with a closer view, and the final image shows the placement of the eclipsed Moon near the Eagle, Swan, Trifid, and Lagoon nebulas. Nearly two hours after the eclipse started, the moon emerged from the Earth's shadow and its bright full glare again dominated the sky. The next total lunar eclipse will occur this Wednesday.

[Bluearrowll]

Re: Terry's Astronomy Thread.

Daily Suspicious0bserver's Weather Post:
October 6, 2014

What's in the sky tonight?
October 6, 2014

-As twilight fades, look for Arcturus, the Spring Star, twinkling in the west to west-northwest. It's still pretty easy to see. But how much later into the fall, as it sinks away, will you be able to keep it in view?

-Jupiter (magnitude –1.9, at the Cancer-Leo border) rises in the east-northeast around 2 or 3 a.m. It shines brightly high in the east before and during dawn. It forms a big triangle with Pollux above it (by about two fists at arm's length) and Procyon to their right. Look below Jupiter and a bit left for Regulus.

Astro Picture of the Day:
October 6, 2014

Source:
Where did all these high energy positrons come from? The Alpha Magnetic Spectrometer (AMS-02) onboard the International Space Station (ISS) has been meticulously recording how often it is struck by both high energy electrons and positrons since 2011. After accumulating years of data, it has now become clear that there are significantly more positrons than electrons at the highest energies detected. The excess may have a very exciting and profound origin -- the annihilation of distant but previously undetected dark matter particles. However, it is also possible that astronomical sources such as pulsars are creating the unexplained discrepancy. The topic remains a very active area of research. Pictured here, the AMS is visible on the ISS just after being installed, with a US Space Shuttle docked on the far right, a Russian Soyuz capsule docked on the far left, and the blue Earth that houses all nations visible across the background.

[Bluearrowll]

Re: Terry's Astronomy Thread.

Daily Suspicious0bserver's Weather Post:
October 7, 2014

What's in the sky tonight?
October 7, 2014

-On Wednesday morning, Oct. 8th, there will be a total lunar eclipse. Observers across the Pacific side of Earth can see the normally-pale full Moon turn a beautiful shade of red as it passes through the sunset-colored shadow of our planet. The Moon first dips into Earth's shadow at approximately 9:15 UT (2:15 a.m. PDT), kicking off the partial phase of the eclipse. Totality, when the Moon is fully immersed, begins at 10:25 UT (3:25 a.m. PDT) and lasts for nearly an hour. Details: http://eclipse.gsfc.nasa.gov/OH/OHfi...2014-Fig03.pdf

Astro Picture of the Day:
October 7, 2014

Source:
What connects the Sun to the Moon? Many answers have been given throughout history, but in the case of today's featured image, it appears to be the plane of our Milky Way Galaxy. The 16-image panorama was taken in Capitol Reef National Park, Utah, USA where two sandstone monoliths -- the Temple of the Moon on the left and the Temple of the Sun on the right -- rise dramatically from the desert. Each natural monument stands about 100 meters tall and survives from the Jurassic period 160 million years ago. Even older are many of the stars and nebula that dot the celestial background, including the Andromeda Galaxy. Tomorrow the Earth will connect the Sun to the Moon by way of its shadow: a total lunar eclipse will be visible from many locations around the globe.

[Bluearrowll]

Re: Terry's Astronomy Thread.

Daily Suspicious0bserver's Weather Post:
October 8, 2014

What's in the sky tonight?
October 8, 2014

-Solar activity is low, and the quiet is likely to continue. Not one of the six sunspot groups on the disk of the sun has the type of unstable magnetic field that poses a threat for strong eruptions. NOAA forecasters estimate a scant 5% chance of M-flares on Oct. 8th.

-Altair is the brightest star high in the south at nightfall. Very far to its lower left (about six fist-widths) is Fomalhaut, almost as bright.

-As the total lunar eclipse ends and the moon sets over the North American continent, like almost all other lunar eclipses, there is a solar eclipse that joins it in 2 weeks. The October 23 partial solar eclipse also favours North America, and the further north in latitude you are, the better your chance of seeing it. The further west you are, the more likely you are to see the whole thing. Use this link to find out how much of an eclipse you will have! http://eclipse.gsfc.nasa.gov/SEsearc...p?Ecl=20141023 For those around the Toronto latitude, you are looking at a 50% cover at maximum eclipse. Toronto will see the eclipse as the sun sets.

Astro Picture of the Day:
October 8, 2014

Source:
Star cluster NGC 6823 is slowly turning gas clouds into stars. The center of the open cluster, visible on the upper right, formed only about two million years ago and is dominated in brightness by a host of bright young blue stars. Some outer parts of the cluster, visible in the featured image's center as the stars and pillars of emission nebula NGC 6820, contain even younger stars. The huge pillars of gas and dust likely get their elongated shape by erosion from hot radiation emitted from the brightest cluster stars. Striking dark globules of gas and dust are also visible across the upper left of the featured image. Open star cluster NGC 6823 spans about 50 light years and lies about 6000 light years away toward the constellation of the Fox (Vulpecula).

[Bluearrowll]

Re: Terry's Astronomy Thread.

Daily Suspicious0bserver's Weather Post:
October 9, 2014

What's in the sky tonight?
October 9, 2014

-During a lunar eclipse, the normally-bright full Moon darkens as it passes through the shadow of Earth. Millions of sky watchers witnessed this beautiful dimming on Oct. 8th. David Boatwright of Californiia experienced the eclipse in a different way. His solar array browned out. "My home has a 4.5 kW photovoltaic solar system on its roof," he explains. "During the day it produces a good amount of electricity. It even produces a couple of volts from ambient light at night. A full Moon will increase it to nearly 4 volts DC when overhead."

"Pictured above is a screen shot of the power output from my system. As you can see, it recorded the lunar eclipse. The voltage was cut in half during totality. From 3:30am to 4:30am PDT, the DC voltage dropped from 4 volts to 2 volts and then back up to 3volts at the conclusion of the eclipse. I believe the 1 volt difference, before vs. after the eclipse, is due to the Moon being lower in the sky when the eclipse ended."

"By the way, I was watching the eclipse in my backyard as this voltage drop was occurring," he says.

Astro Picture of the Day:
October 9, 2014

Source:
The Pacific Ocean and Chilean coast lie below this sea of clouds. Seen through the subtle colors of the predawn sky a lunar eclipse is in progress above, the partially eclipsed Moon growing dark. The curved edge of planet Earth's shadow still cuts across the middle of the lunar disk as the Moon sinks lower toward the western horizon. In fact, from this southern hemisphere location as well as much of eastern North America totality, the Moon completely immersed within Earth's shadow, began near the time of moonset and sunrise on October 8. From farther west the total phase could be followed for almost an hour though, the darker reddened Moon still high in the night sky.

[Bluearrowll]

Re: Terry's Astronomy Thread.

Daily Suspicious0bserver's Weather Post:
October 10, 2014

What's in the sky tonight?
October 10, 2014

-NOAA forecasters have raised the odds of an M-class solar flare today to 40%. The likely source is sunspot AR2182, which has tripled in size since yesterday. Because the sunspot is near the sun's western limb, however, its flares may not be geoeffective.

-At this time of year, only a few weeks after the equinox, Northern Lights are almost always visible somewhere around the Arctic Circle. "Last night I was flying to Europe from Calgary and I strategically selected the window seat hoping for a show," reports traveler Christy Turner. This is what she saw.

"Boy did I luck out!" she says. Indeed she did. During her flight, the interplanetary magnetic field (IMF) around Earth tipped south. South-pointing IMFs pry open a crack in Earth's magnetosphere, allowing solar wind to pour through and ignite auroras.

Astro Picture of the Day:
October 10, 2014

Source:
From the early hours of October 8, over the Santa Cruz Mountains near Los Gatos, California, the totally eclipsed Moon shows a range of color across this well-exposed telescopic view of the lunar eclipse. Of course, a lunar eclipse can only occur when the Moon is opposite the Sun in Earth's sky and gliding through the planet's shadow. But also near opposition during this eclipse, and remarkably only half a degree or so from the lunar limb, distant Uranus is faint but easy to spot at the lower right. Fainter still are the ice giant's moons. While even the darkened surface of our eclipsed Moon will be strongly overexposed, Uranus moons Titania, Oberon, and Umbriel can just be distinguished as faint pinpricks of light.

[Bluearrowll]

Re: Terry's Astronomy Thread.

Daily Suspicious0bserver's Weather Post:
October 11, 2014

What's in the sky tonight?
October 11, 2014

-The Moon late this evening shines near Aldebaran amid the Hyades. Take a look with binoculars. This will be a challenging scene to photograph (use a long lens), what with the Moon's brilliance and the Hyades stars' faintness. By dawn they've moved over to high in the southwest.

-A magnetic filament near the sun's southwestern limb collapsed during the late hours of Oct. 10th. Earth-orbiting satellites detected a C3-class Hyder flare when the filament hit the solar surface: movie. The eruption also hurled a CME into space, but the storm cloud appears set to miss Earth.

Astro Picture of the Day:
October 11, 2014

Source:
As the Moon rose and the Sun set on October 8, a lunar eclipse was in progress seen from Chongqing, China. Trailing through this composite time exposure, the rising Moon began as a dark reddened disk in total eclipse near the eastern horizon. Steadily climbing above the populous city's colorful lights along the Yangtze River, the moontrail grows brighter and broader, until a bright Full Moon emerged from the Earth's shadow in evening skies. Although lunar eclipses are not always total ones, this eclipse, along with last April's lunar eclipse, were the first two of four consecutive total lunar eclipses, a series known as a tetrad. The final two eclipses of this tetrad will occur in early April and late September 2015.


Daily Suspicious0bserver's Weather Post:
October 12, 2014

What's in the sky tonight?
October 12, 2014

-There are only two sunspots visible on the solar disk, and both of them appear to be in a state of decay. NOAA forecasters estimate a waning 20% chance of M-flares and only a 1% chance of X-flares this weekend.

-Orion preview: With fall well underway, the "winter" constellation Orion rises in the east by 11 or midnight, depending on how far east or west (respectively) you live in your time zone. It's well to the lower right of the waning Moon. Orion's Belt will be vertical, as it always is when Orion is rising for mid-northern skywatchers. Orion reaches its highest stand in the south well before the first light of dawn, with the Moon now above it (on the morning of the 13th).

Astro Picture of the Day:
October 12, 2014

Source:
How did a star create the Helix nebula? The shapes of planetary nebula like the Helix are important because they likely hold clues to how stars like the Sun end their lives. Observations by the orbiting Hubble Space Telescope and the 4-meter Blanco Telescope in Chile, however, have shown the Helix is not really a simple helix. Rather, it incorporates two nearly perpendicular disks as well as arcs, shocks, and even features not well understood. Even so, many strikingly geometric symmetries remain. How a single Sun-like star created such beautiful yet geometric complexity is a topic of research. The Helix Nebula is the nearest planetary nebula to Earth, lies only about 700 light years away toward the constellation of Aquarius, and spans about 3 light-years.