Terry's Astronomy Thread.

[Bluearrowll]

Re: Terry's Astronomy Thread.

Daily Suspicious0bserver's Weather Post:
May 9, 2014

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

-The waxing gibbous Moon forms a curving line tonight with Mars to its left and Spica to Mars's lower left.

-An interplanetary shock wave, origin unknown, hit Earth's magnetic field during the late hours of May 7th. Although the weak impact did not spark a geomagnetic storm, solar wind conditions in the wake of the shock have been favorable for auroras. Nancy Dean took this picture last night on Mount Spur, Alaska. "The sunset was still showing strong on May 8th when the Northern Lights came out to dance across the Alaskan sky," says Dean.

As northern spring unfolds, persistent twilight is spreading into the night skies of Alaska. It takes a bright display of auroras to be seen against such a backdrop. Dean's photo is evidence that a weak shock does not necessarily produce weak auroras.

More lights are possible tonight. NOAA forecasters estimate a 30% chance of polar geomagnetic storms as Earth exits the wake of the shock.

Astro Picture of the Day:
May 9, 2014

Source:
The early morning hours of May 6 were moonless when grains of cosmic dust streaked through dark skies. Swept up as planet Earth plows through dusty debris streams left behind periodic Comet Halley, the annual meteor shower is known as the Eta Aquarids. This inspired exposure captures a meteor streak moving left right through the frame. Its trail points back across the arc of the Milky Way to the shower's radiant above the local horizon in the constellation Aquarius. Known for speed Eta Aquarid meteors move fast, entering the atmosphere at about 66 kilometers per second. Still waters of the small pond near Albion, Maine, USA reflect the starry scene and the orange glow of nearby artificial lights scattered by a low cloud bank. Of course, northern hemisphere skygazers are expecting a new meteor shower on May 24, the Camelopardalids, caused by dust from periodic comet 209P/LINEAR.

[Bluearrowll]

Re: Terry's Astronomy Thread.

Daily Suspicious0bserver's Weather Post:
May 10, 2014

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

-Bright Mars shines left of the Moon. Although they look rather close together, Mars is 260 times farther away — and twice as big in diameter.

-Imagine what it would be like if, from time to time, a hole opened up in Earth's atmosphere and air went blowing out into space. On the sun, this happens all the time. The openings are called "coronal holes." NASA's Solar Dynamics Obervatory is monitoring one right now; it is the dark wedge-shaped region in this extreme ultraviolet image of the sun's southern hemisphere. Coronal holes are places in the sun's atmosphere where the magnetic field bends back and allows gas to escape. From such openings, solar wind blows out into space. A stream of solar wind flowing from this particular coronal hole could reach Earth on May 11-12, sparking auroras when it arrives. On the other hand, the stream might sail south of our planet, delivering only a glancing blow. Stay tuned for updates.

Astro Picture of the Day:
May 10, 2014

Source:
The Flame Nebula stands out in this optical image of the dusty, crowded star forming regions toward Orion's belt, a mere 1,400 light-years away. X-ray data from the Chandra Observatory and infrared images from the Spitzer Space Telescope can take you inside the glowing gas and obscuring dust clouds though. The second image will reveal many stars of the recently formed, embedded cluster NGC 2024, ranging in age from 200,000 years to 1.5 million years young. The X-ray/infrared composite image overlay spans about 15 light-years across the Flame's center. The X-ray/infrared data also indicate that the youngest stars are concentrated near the middle of the cluster. That's the opposite of the simplest models of star formation for the stellar nursery. They predict star formation to begin first in the denser center and progressively move outward toward the edges leaving the older stars, not the younger ones, in the center of the Flame Nebula.

[Bluearrowll]

Re: Terry's Astronomy Thread.

Daily Suspicious0bserver's Weather Post:
May 11, 2014

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

-Now the Moon is positioned between Mars and Spica (for the Americas in the evening).

-Jupiter shines within the western Arch of Spring as twilight fades. The top of the Arch is formed by Pollux and Castor, roughly horizontal. To their lower left is Procyon, the left end of the Arch. The right end is formed by Menkalinen and then Capella. Jupiter is gradually moving toward the Arch's upper left side.

Astro Picture of the Day:
May 11, 2014

Source:
The largest canyon in the Solar System cuts a wide swath across the face of Mars. Named Valles Marineris, the grand valley extends over 3,000 kilometers long, spans as much as 600 kilometers across, and delves as much as 8 kilometers deep. By comparison, the Earth's Grand Canyon in Arizona, USA is 800 kilometers long, 30 kilometers across, and 1.8 kilometers deep. The origin of the Valles Marineris remains unknown, although a leading hypothesis holds that it started as a crack billions of years ago as the planet cooled. Several geologic processes have been identified in the canyon. The above mosaic was created from over 100 images of Mars taken by Viking Orbiters in the 1970s.

[Bluearrowll]

Re: Terry's Astronomy Thread.

Daily Suspicious0bserver's Weather Post:
May 12, 2014

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

-Three zero-magnitude stars shine after dusk in May: Arcturus high in the southeast, Vega much lower in the northeast, and Capella in the northwest. They appear so bright because each is at least 60 times as luminous as the Sun, and they're all relatively nearby: 37, 25, and 42 light-years from us, respectively.

-NOAA forecasters have boosted the odds of an M-class solar flare today to 50% mainly in response to the rapid growth of a new sunspot in the sun's southern hemisphere. The sunspot, designated AR2060, has a 'beta-gamma' magnetic field that harbors energy for strong eruptions

Astro Picture of the Day:
May 12, 2014

Source:
Over the weekend, the students of Earth to Sky Calculus launched a space weather balloon to the stratosphere carrying four colonies of halobacteria. During the flight, the microbes set a high-altitude ballooning record for their species. Here they are floating 112,000 feet above Earth's surface. In the image, the sky is black not because it is night, but rather because the balloon is floating above 99% of Earth's atmosphere. The payload was on the doorstep of space itself. During the 90 minute ascent, the microbes were exposed to temperatures as low as -58 C and cosmic radiation levels more than 25 times Earth-normal. These conditions are akin to the planet Mars. The students are exposing halobacteria to the Mars-like environment above 100,000 feet in a continuing series of experiments to find out if terrestrial extremophiles could live on other planets. Incubation begins tomorrow in the high school AP Biology Lab.

[Bluearrowll]

Re: Terry's Astronomy Thread.

Daily Suspicious0bserver's Weather Post:
May 13, 2014

What's in the sky tonight?
May 13, 2014

-The bright Moon, practically full, shines near Saturn. The Moon creeps to within 1° to 3° of Saturn before dawn Wednesday morning for the Americas. For New Zealand and most of Australia, the Moon occults (covers and uncovers) Saturn during nighttime; map and timetables. http://www.lunar-occultations.com/io...0514saturn.htm

Astro Picture of the Day:
May 13, 2014

Source:
Can a gas cloud grab a galaxy? It's not even close. The "claw" of this odd looking "creature" in the above photo is a gas cloud known as a cometary globule. This globule, however, has ruptured. Cometary globules are typically characterized by dusty heads and elongated tails. These features cause cometary globules to have visual similarities to comets, but in reality they are very much different. Globules are frequently the birthplaces of stars, and many show very young stars in their heads. The reason for the rupture in the head of this object is not completely known. The galaxy to the left of the globule is huge, very far in the distance, and only placed near CG4 by chance superposition.

[Bluearrowll]

Re: Terry's Astronomy Thread.

Daily Suspicious0bserver's Weather Post:
May 14, 2014

What's in the sky tonight?
May 14, 2014

-Full Moon (exact at 3:16 p.m. Eastern Daylight Time.) Look for Saturn to its upper right. Once the Moon is well up after dark, look for Antares and the other stars of upper Scorpius below it. By dawn they're lying down in the southwest.

-NOAA forecasters estimate a 30% chance of polar geomagnetic storms on May 14th when a co-rotating interaction region (CIR) is expected to hit Earth's magnetic field. CIRs are transition zones between fast and slow solar wind streams. Solar wind plasma piles up in these regions, producing density gradients and shock waves that do a good job of sparking auroras.

-Today, the sun's atmosphere is split down the middle by a canyon-shaped coronal hole. NASA's Solar Dynamics Observatory photographed the chasm, which is almost directly facing Earth.

Coronal holes are places where the sun's magnetic field opens up and allows solar wind to escape. This hole is straddling the sun's equator so the solar wind stream emerging from it will intersect Earth's orbit. ETA: May 16-17. High-latitude sky watchers should be alert for auroras on those dates.

Astro Picture of the Day:
May 14, 2014

http://www.ustream.tv/channel/17074538

Source:
If you were floating above the Earth right now, this is what you might see. Two weeks ago, the robotic SpaceX Dragon capsule that delivered supplies to the Earth-orbiting International Space Station (ISS) also delivered High Definition Earth Viewing (HDEV) cameras that take and transmit live views of Earth. Pictured above, when working, is the live video feed that switches between four cameras, each pointed differently. Watch white clouds, tan land, and blue oceans drift by. The above video will appear black when it is nighttime on the Earth below, but the space station's rapid 90-minute orbit compresses this dark time into only 45 minutes. The present location of the ISS above the Earth can be found on the web. If the video appears gray, this indicates that the view is either being switched between cameras, or communications with the ISS is temporarily unavailable. As the HDEV project continues, video quality will be monitored to assess the effects of high energy radiation, which types of cameras work best, and which Earth views are the most popular. Although this feed will eventually be terminated, lessons learned will enable better cameras to be deployed to the ISS in the future, likely returning even more interesting live feeds.

[Bluearrowll]

Re: Terry's Astronomy Thread.

Is anyone else experiencing performance issues on the main page of this thread? It seems to be getting progressively slower for me each passing day, and will probably have to make some changes.

Also, tomorrow is the beginning of my annual Victoria Day Weekend camping trip - the target this year is Killarney Provincial Park. Weather looks good so I'll be up many nights as well as the day doing some astrophotography. The trip spans from Friday until Monday night. This picture from the internet will be a common sight that I see during the day:



Daily Suspicious0bserver's Weather Post:
May 15, 2014

What's in the sky tonight?
May 15, 2014

-Jupiter's moon Io crosses the face of the planet from 9:41 to 11:57 p.m. Eastern Daylight Time. Io's tiny but more visible shadow follows it across from 10:42 p.m. to 12:59 a.m. EDT.

-Last night, May 14th, a Japanese spy satellite passed over Brazil. Leonardo Caldas of Brasilia saw it backlit by the full Moon. Click to view the split-second transit:

"Looking at Calsky, I noticed a possible transit of a satellite called IGS 7A," says Caldas. "I set my Canon SX50 HS digital camera to film at the predicted time--and there it was!" The dark silhouette of the satellite zipped across the Moon in only 0.48 seconds. "IGS 7A is a Japanese reconnaissance satellite, launched from Tanegashima on Dec. 12, 2011," explains Caldas. "It is a member of Japan's Information Gathering Satellite (IGS) system whose primary mission is to provide early warning of impending hostile launches."

According to folklore, this month's full Moon is the "Flower Moon," named after the abundant flowers of northern spring.

Astro Picture of the Day:
May 15, 2014

Source:
Cruising through the outer solar system, the Voyager 2 spacecraft made its closest approach to Neptune on August 25, 1989, the only spacecraft to visit the most distant gas giant. Based on the images recorded during its close encounter and in the following days, this inspired composited scene covers the dim outer planet, largest moon Triton, and faint system of rings. From just beyond Neptune's orbit, the interplanetary perspective looks back toward the Sun, capturing the planet and Triton as thin sunlit crescents. Cirrus clouds and a dark band circle Neptune's south polar region, with a cloudy vortex above the pole itself. Parts of the very faint ring system along with the three bright ring arcs were first imaged by Voyager during the fly-by, though the faintest segments are modeled in this composited picture. Spanning 7.5 degrees, the background starfield is composed from sky survey data centered on the constellation Camelopardalis, corresponding to the outbound Voyager's view of the magnificent Neptunian system.

[Bluearrowll]

Re: Terry's Astronomy Thread.

Heading off to Killarney now - will be back monday night or tuesday morning.


Daily Suspicious0bserver's Weather Post:
May 16, 2014

What's in the sky tonight?
May 16, 2014

-A new study published in the May 15th edition of Environmental Research Letters finds that lightning rates over Europe are modulated by the solar wind. The results contradict some previous studies, and the physical mechanism linking lightning and solar wind is uncertain. Nevertheless, the research appears credible and worthy of follow-up with global studies beyond Europe. Report: http://iopscience.iop.org/1748-9326/9/5/055004/article

-Look for Mercury as twilight darkens. It's low in the west-northwest, far to the lower right of Jupiter and lower left of Capella. Mercury is having its highest showing of 2014 (for skywatchers at mid-northern latitudes).

Astro Picture of the Day:
May 16, 2014

Source:
Staring up into the martian sky, the Opportunity rover captured an image at 11:02 AM local mean time nearly every 3rd sol, or martian day, for 1 martian year. Of course, the result is this martian analemma, a curve tracing the Sun's motion through the sky in the course of a year (668 sols) on the Red Planet. Spanning Earth dates from July, 16, 2006 to June 2, 2008 the images are shown composited in this zenith-centered, fisheye projection. North is at the top surrounded by a panoramic sky and landscape made in late 2007 from inside Victoria crater. The tinted martian sky is blacked out around the analemma images to clearly show the Sun's positions. Unlike Earth's figure-8-shaped analemma, Mars' analemma is pear-shaped, because of its similar axial tilt but more elliptical orbit. When Mars is farther from the Sun, the Sun progresses slowly in the martian sky creating the pointy top of the curve. When close to the Sun and moving quickly, the apparent solar motion is stretched into the rounded bottom. For several sols some of the frames are missing due to rover operations and dust storms.

[Bluearrowll]

Re: Terry's Astronomy Thread.

Previous days will be updated later, still exhausted from the weekend trip. Inside the spoiler is some photos of things I saw.

Daily Suspicious0bserver's Weather Post:
May 20, 2014

What's in the sky tonight?
May 20, 2014

-As the stars come out, Saturn in the southeast, Vega in the northeast, Capella in the northwest, and Procyon in the west-southwest are all at about the same altitude (as seen from about 40° north latitude).

On May 24th, the heavens could put on a display of irony. Forecasters say Earth will cross a stream of debris from Comet 209P/LINEAR, and the encounter could trigger a bright new meteor shower. The ironic thing is, the comet is so faint. Aaron Kingery of NASA's Meteoroid Environment Office took the picture on May 18th using a 0.5 meter telescope at the Marshall Space Flight Center. "209P is not a very photogenic comet," says Kingery. "This is the best I could do with a 60-second exposure."

How could such a dim comet produce a bright meteor shower? In 2014, 209P is producing very little dust. However, the debris Earth is about to encounter didn't come from 2014. It was shed by the comet mainly in the 19th and 20th centuries. In those days, forecasters hope, the comet was more active.

We will find out this weekend. If a magnificent meteor shower erupts on Saturday morning, it will be safe to say that the comet wasn't always so underwhelming.

Astro Picture of the Day:
May 20, 2014

Source:
M61 is a barred spiral galaxy located in the nearby Virgo Cluster of Galaxies. Visible in M61 are a host of features common to spiral galaxies: bright spiral arms, a central bar, dust lanes, and bright knots of stars. M61, also known as NGC 4303, in similar to our own Milky Way Galaxy. M61 was discovered by telescope in 1779 twice on the same day, but one observer initially mistook the galaxy for a comet. Light from M61 takes about 55 million years to reach us. The above image of the central regions of M61 was taken with the Hubble Space Telescope and adapted for release as part of the Hubble's Hidden Treasures image processing competition.

[noname219]

Re: Terry's Astronomy Thread.

Is anyone else experiencing performance issues on the main page of this thread? It seems to be getting progressively slower for me each passing day, and will probably have to make some changes.

Not usually slow, but there is a lot on the first post.

[Bluearrowll]

Re: Terry's Astronomy Thread.

Daily Suspicious0bserver's Weather Post:
May 17, 2014

What's in the sky tonight?
May 17, 2014

-Arcturus shines high in the southeast these nights. Vega shines much lower in the northeast. Look a third of the way from Arcturus to Vega for dim little Corona Borealis, the Northern Crown, with its one modestly bright star, Alphecca or Gemma. Two thirds of the way from Arcturus to Vega glimmers the dim Keystone of Hercules. Continue on down past Vega, and you hit Cygnus.

Astro Picture of the Day:
May 17, 2014

Source:
Gas giant Jupiter is the solar system's largest world with about 320 times the mass of planet Earth. It's also known for a giant swirling storm system, the Great Red Spot, featured in this sharp Hubble image from April 21. Nestled between Jupiter-girdling cloud bands, the Great Red Spot itself could still easily swallow Earth, but lately it has been shrinking. The most recent Hubble observations measure the spot to be about 10,250 miles (16,500 kilometers) across. That's the smallest ever measured by Hubble and particularly dramatic when compared to 14,500 miles measured by the Voyager 1 and 2 flybys in 1979, and historic telescopic observations from the 1800s indicating a width of about 25,500 miles on its long axis. Current indications are that the rate of shrinking is increasing for the long-lived Great Red Spot.



Daily Suspicious0bserver's Weather Post:
May 18, 2014

What's in the sky tonight?
May 18, 2014

-Look south after dark for Mars at its highest. Straight below Mars, by more than a fist at arm's length, is the distinctive springtime constellation Corvus the Crow. Its four brightest stars form a distorted rectangle less than a fist in size.

-Mercury and Saturn are in conjunction in the night sky. Just one problem: You have to be on the far side of the sun to see it. NASA's STEREO-B probe is perfectly positioned to observe the convergence. On Saturday, May 17th, the distance between the two planets was so narrow that they became nearly indistinguishable. If this event were visible from our side of the sun, it would surely be headline news.

NASA's STEREO probes see many things that we cannot. From their orbits high above the farside of the sun, they track hidden sunspots, anti-Earth-directed solar flares, and interplanetary CMEs. STEREO's wide-field Heliospheric Imagers also have a unique view of the planets. See above. This weekend's conjunction of Mercury and Saturn is bracketed by Mars and Earth itself, an arrangement impossible to observe from terra firma.

Astro Picture of the Day:
May 18, 2014

Source:
What will become of Jupiter's Great Red Spot? Recorded as shrinking since the 1930s, the rate of the Great Red Spot's size appears to have accelerated just in the past few years. A hurricane larger than Earth, the Great Red Spot has been raging at least as long as telescopes could see it. Like most astronomical phenomena, the Great Red Spot was neither predicted nor immediately understood after its discovery. Although small eddies that feed into the storm system seem to play a role, a more full understanding of the gigantic storm cloud remains a topic of continued research, and may result in a better understanding of weather here on Earth. The above image is a digital enhancement of an image of Jupiter taken in 1979 by the Voyager 1 spacecraft as it zoomed by the Solar System's largest planet. NASA's Juno spacecraft is currently heading toward Jupiter and will arrive in 2016.



Daily Suspicious0bserver's Weather Post:
May 19, 2014

What's in the sky tonight?
May 19, 2014

-Now that Vega is well up in the northeast in the evening, look to its lower left (by two or three fists) for Deneb. As Deneb rises higher through the night, a dark sky will reveal that it lies inside the Milky Way band looming up all across the eastern sky.

-According to data from the NASA/French Space Agency Jason-2 satellite, something is brewing in the Pacific. Researchers say it could be a significant El Niño with implications for global weather and climate.

-Last month at the Space Weather Workshop in Boulder, Colorado, solar cycle expert Doug Biesecker of NOAA announced that "Solar Maximum is here, finally." According to his analysis, the sunspot number for Solar Cycle 24 is near its peak right now. Spoiler: It's not very impressive. "This solar cycle continues to rank among the weakest on record," says Workshop attendee Ron Turner of Analytic Services, Inc. To illustrate the point, he plotted the smoothed sunspot number of Cycle 24 vs. the previous 23 cycles since 1755. In the composite plot, Cycle 24 is traced in red. Only a few cycles since the 18th century have have had lower sunspot counts. For this reason, many researchers have started calling the ongoing peak a "Mini-Max."

"By all Earth-based measures of geomagnetic and geoeffective solar activity, this cycle has been extremely quiet," notes Turner. "However, Doug Biesecker has presented several charts showing that most large events such as strong flares and significant geomagnetic storms occur in the declining phase of the solar cycle."

In other words, there is still a chance for significant solar activity in the months and years ahead.

Astro Picture of the Day:
May 19, 2014

Source:
Sometimes land and sky are both busy and beautiful. The landscape pictured in the foreground encompasses Bryce Canyon in Utah, USA, famous for its many interesting rock structures eroded over millions of years. The skyscape above, photogenic in its own right, encompasses the arching central disk of our Milky Way Galaxy, streaks that include three passing airplanes and at least four Eta Aquariid meteors, and bright stars that include the Summer Triangle. The above image is a digital panorama created from 12 smaller images earlier this month on the night May 6. If you missed the recent Eta Aquariids meteor shower though, don't fret -- you may get an unexpected reprieve. Sky enthusiasts are waiting to see if a new meteor shower develops in the early morning hours of Saturday, May 24, when the Earth moves through a possibly dense cloud of dust and debris ejected by Comet 209P/LINEAR.



Daily Suspicious0bserver's Weather Post:
May 21, 2014

What's in the sky tonight?
May 21, 2014

-The western twilight Arch of Spring is sinking, but you can still catch this big landmark when the stars come out. Jupiter in the west lies within it. Pollux and Castor, above Jupiter, are lined up roughly horizontally; they're the Arch's top. Look far to their lower left for Procyon, and farther to their lower right for Menkalinen and then bright Capella. Jupiter is moving closer to the Arch's upper-left side.

-Anticipation is building as Earth approaches a cloud of debris from Comet 209P/LINEAR. This weekend, meteoroids hitting Earth's atmosphere could produce a never-before-seen shower called the "May Camelopardalids" peaking with as many as 200 meteors per hour. The best time to look is on Saturday, May 24th, between 0600 UT and 0800 UT (2 a.m. and 4 a.m. EDT).

Earth won't be the only body passing through the debris zone. The Moon will be, too. Meteoroids hitting the lunar surface could produce explosions visible through backyard telescopes on Earth. The inset in this picture of an actual lunar meteor shows the region of the crescent Moon on May 24th that could be pelted by May Camelopardalids. According to NASA's Meteoroid Environment Office, the best time for amateur astronomers to scan the Moon for lunar meteors is after 0800 UT (4 a.m. EDT) on May 24th.

There is much uncertainty about the strength of this shower, both on Earth and on the Moon. In recent history, our planet has never passed directly through a debris stream from Comet 209P/LINEAR, so no one knows exactly how much comet dust lies ahead. A magnificent meteor shower could erupt, with streaks of light in terrestrial skies and sparkling explosions on the Moon--or it could be a complete dud.

Astro Picture of the Day:
May 21, 2014

Source:
How do supercell storm clouds form? Pictured above is a time-lapse video taken last Sunday detailing the formation of one such violent supercell in eastern Wyoming, USA. Starting as part of a large and dark thunderstorm complex, the supercell comes together along with a large rotating updraft of air known as a mesocyclone. Mesocyclones form during rapid changes in wind speed and direction with height and can produce torrential rain, damaging hail, swirling winds, and sometimes tornadoes. Storm watchers are seen studying, imaging, and ultimately running from the developing storm cloud during the video. During the middle part of the video, the kilometer-wide supercell can be seen swirling ominously with a nearly flat bottom. Toward the end of the video, another swirling supercell cloud forms but then quickly dissipates.

[Bluearrowll]

Re: Terry's Astronomy Thread.

Daily Suspicious0bserver's Weather Post:
May 22, 2014

What's in the sky tonight?
May 22, 2014

-As twilight fades, spot Mercury low in the west-northwest. It's about 2½ fists to the lower right of bright Jupiter. This evening Mercury is between the horn-tips of Taurus: Beta Tauri (El Nath) to its upper right, and Zeta Tauri to its lower left. Binoculars will help.

-Solar activity is low. Although there are more than half-a-dozen sunspots on the solar disk today, not one has the type of complex magnetic field that harbors energy for strong eruptions. NOAA forecasters estimate a 10% chance of M-flares and a scant 1% chance of X-flares on May 22nd.

Astro Picture of the Day:
May 22, 2014

Source:
Beautiful emission nebula NGC 6164 was created by a rare, hot, luminous O-type star, some 40 times as massive as the Sun. Seen at the center of the cosmic cloud, the star is a mere 3 to 4 million years old. In another three to four million years the massive star will end its life in a supernova explosion. Spanning around 4 light-years, the nebula itself has a bipolar symmetry. That makes it similar in appearance to more common and familiar planetary nebulae - the gaseous shrouds surrounding dying sun-like stars. Also like many planetary nebulae, NGC 6164 has been found to have an extensive, faint halo, revealed in this deep telescopic image of the region. Expanding into the surrounding interstellar medium, the material in the halo is likely from an earlier active phase of the O star. The gorgeous skyscape is a composite of extensive narrow-band image data, highlighting glowing atomic hydrogen gas in red and oxygen in blue hues, with broad-band data for the surrounding starfield. NGC 6164 is 4,200 light-years away in the right-angled southern constellation of Norma.

[Bluearrowll]

Re: Terry's Astronomy Thread.

Daily Suspicious0bserver's Weather Post:
May 23, 2014

What's in the sky tonight?
May 23, 2014

-A possible strong meteor shower may arrive in the early-morning hours of Saturday the 24th, timed for North America (perhaps peaking around 3 a.m. EDT, midnight PDT). For just a few hours we'll pass through the predicted debris trail of Comet 209P/LINEAR, which is making an unusually close flyby of Earth. There's even a (slim) possibility that the shower could approach "meteor storm" proportions. The comet itself is closest on May 29th, but it's very small and faint and may reach 11th magnitude at best.

-As dawn brightens on Saturday morning the 24th, look for Venus well to the lower left of the waning crescent Moon, as shown above.

-It is often said that this is a new shower, and no one has ever seen a Camelopardalid meteor before. Well...maybe just one. "We searched through our database of several thousand bright meteors and found a likely candidate," reports Bill Cooke of NASA's Meteoroid Environment Office. "Back on May 9th of 2012, one of our all-sky cameras caught it burning up at an altitude of 66 kilometers." "Peaking at a magnitude of -2 (Mars brightness), our now-extinct visitor was about 3.3 cm in diameter - a little smaller than a ping pong ball," continues Cooke. "We believe it was a May Camelopardalid because it had an orbit that greatly resembles that of parent Comet 209P/LINEAR." The diagram, below, shows the match.

"So why is this good?" asks Cooke. "Looking back to 2012, our computer models show very little comet debris near Earth. We predicted nothing, yet got one meteor. Does this mean that a legion of his siblings will show up this year, when the models suggest the potential of a full-fledged meteor outburst? I'm getting excited about Friday night/Saturday morning."

Earth won't be the only body passing through the debris zone. The Moon will be, too. Meteoroids hitting the lunar surface could produce explosions visible through backyard telescopes on Earth. The inset in this picture of an actual lunar meteor shows the region of the crescent Moon on May 24th that could be pelted by May Camelopardalids.

According to NASA's Meteoroid Environment Office, the best time for amateur astronomers to scan the Moon for lunar meteors is after 0800 UT (4 a.m. EDT) on May 24th.

There is much uncertainty about the strength of this shower, both on Earth and on the Moon. As far as we know, our planet has never passed directly through a debris stream from Comet 209P/LINEAR, so no one knows exactly how much comet dust lies ahead. A magnificent meteor shower could erupt, with streaks of light in terrestrial skies and sparkling explosions on the Moon--or it could be a complete dud.

Astro Picture of the Day:
May 23, 2014

Source:
The Rosetta spacecraft captured this remarkable series of 9 frames between March 27 and May 4, as it closed from 5 million to 2 million kilometers of its target comet. Cruising along a 6.5 year orbit toward closest approach to the Sun next year, periodic comet 67P/Churyumov-Gerasimenko is seen moving past a distant background of stars in Sagittarius and gobular star cluster M104. The comet's developing coma is actually visible by the end of the sequence, extending for some 1300 km into space. Rosetta is scheduled for an early August rendezvous with the comet's nucleus. Now clearly active, the nucleus is about 4 kilometers in diameter, releasing the dusty coma as its dirty ices begin to sublimate in the sunlight. The Rosetta lander's contact with the surface of the nucleus is anticipated in November.

[Bluearrowll]

Re: Terry's Astronomy Thread.

Daily Suspicious0bserver's Weather Post:
May 24, 2014

What's in the sky tonight?
May 24, 2014

-Low in the dawn of Sunday the 25th for the Americas, Venus shines beautifully below the thin crescent Moon, as shown below. Look east.

-Solar activity is low. Two sunspots (AR2071 and AR2073) have 'beta-gamma' magnetic fields that harbor energy for M-class solar flares, but both are stable. A quiet weekend seems likely.

-As predicted, during the early hours of May 24th Earth passed through a cloud of debris from from Comet 209P/LINEAR. The encounter produced some fine meteors. However, contrary to some forecasts, there was no intense outburst. Meteor rates in many places were no more than 5 or 10 per hour.

Photographing such a sparse shower can be tricky. Nevertheless, Glen Wurden of Los Alamos, New Mexico, managed to catch one.

"I photographed this Camelopardalid through clouds using a 30 second exposure," says Wurden. "We saw about one meteor every 10 minutes."

Although this is a far cry from predictions, it is hardly a surprise. The parent comet, 209P/LINEAR, is faint and currently produces only a small amount of dust. Most forecasters acknowldged that there might be less dust in Earth's path than the models suggested.

Another possibility is that the shower is not a dud, just delayed. If models mis-located the debris zone, an outburst could still occur later on May 24th.

Astro Picture of the Day:
May 24, 2014

Source:
Why would clouds appear to be different colors? The reason here is that ice crystals in distant cirrus clouds are acting like little floating prisms. Sometimes known as a fire rainbow for its flame-like appearance, a circumhorizon arc lies parallel to the horizon. For a circumhorizontal arc to be visible, the Sun must be at least 58 degrees high in a sky where cirrus clouds are present. Furthermore, the numerous, flat, hexagonal ice-crystals that compose the cirrus cloud must be aligned horizontally to properly refract sunlight in a collectively similar manner. Therefore, circumhorizontal arcs are quite unusual to see. This circumhorizon display was photographed through a polarized lens above Dublin, Ohio in 2009.

[Bluearrowll]

Re: Terry's Astronomy Thread.

Daily Suspicious0bserver's Weather Post:
May 25, 2014

What's in the sky tonight?
May 25, 2014

-At dusk this evening, Mercury appears the same distance lower right of Jupiter and lower left of Capella.

-Solar activity ticked upward on May 24th with the eruption of an M1-class solar flare from sunspot AR2065. Sunspot AR2073 also poses a threat for M-class flares, so the weekend might not be as quiet as previously supposed.

-On May 24th, as predicted, Earth passed through a stream of debris from Comet 209P/LINEAR, and the encounter did produce a number of fine meteors. However, contrary to some forecasts, there was no intense outburst. Typical naked-eye meteor rates were no more than 5 or 10 per hour, a far cry from the "meteor storm" some headlines anticipated.

"Even though the meteor shower was less than spectacular, it was still nice to spend the night camping out under dark skies," says Kevin Palmer of Illinois. " I captured this fireball over the Green River State Wildlife Area at 2:24 am."

The modest display was hardly surprising. The parent comet, 209P/LINEAR, is faint and currently produces only a small amount of dust. Most forecasters acknowledged that there might be less debris in Earth's path than their models suggested.

It is worth noting, and perhaps marveling, that forecasters correctly predicted the onset of a never-before-seen meteor shower. They got the timing almost perfectly correct; only the rates were off. Such a prediction would have beeen impossible only 20 years ago before the development of physics-based dust stream models. In this respect, the May Camelopardalids were a success if not a spectacle.

Astro Picture of the Day:
May 25, 2014

Source:
From a camp on the northern shores of the Great Lake Erie, three short bright meteor streaks were captured in this composited night skyscape. Recorded over the early morning hours of May 24, the meteors are elusive Camelopardalids. Their trails point back to the meteor shower's radiant near Polaris, in the large but faint constellation Camelopardalis the camel leopard, or in modern terms the Giraffe. While a few meteors did appear, the shower was not an active one as the Earth crossed through the predicted debris trail of periodic comet 209P/LINEAR. Of course, the long bright streak in the image did appear as predicted. Early on May 24, the International Space Station made a bright passage through northern skies.