Terry's Astronomy Thread.

[Bluearrowll]

What's in the sky tonight?
November 3, 2012

-Fomalhaut, the "Autumn Star," culminates (reaches its highest point due south) around 9 p.m. daylight saving time. The western side of the Great Square of Pegasus, high above, points almost down to it. The other side of the Great Square points down roughly to Beta Ceti (Diphda), not quite so far.

-Standard time returns (for most of North America) at 2 a.m. tonight. Clocks "fall back" an hour.

Astro Picture of the Day:
November 3, 2012

Source:
How and why are all these stars forming? Found among the Small Magellanic Cloud's (SMC's) clusters and nebulae NGC 346 is a star forming region about 200 light-years across, pictured above by the Hubble Space Telescope. A satellite galaxy of the Milky Way, the Small Magellanic Cloud (SMC) is a wonder of the southern sky, a mere 210,000 light-years distant in the constellation of the Toucan (Tucana). Exploring NGC 346, astronomers have identified a population of embryonic stars strung along the dark, intersecting dust lanes visible here on the right. Still collapsing within their natal clouds, the stellar infants' light is reddened by the intervening dust. A small, irregular galaxy, the SMC itself represents a type of galaxy more common in the early Universe. But these small galaxies are thought to be a building blocks for the larger galaxies present today. Within the SMC, stellar nurseries like NGC 346 are also thought to be similar to those found in the early Universe.

[Choofers]

This is probably one of my favorite threads to read while I listen to Pale Blue Dot.

[Bluearrowll]

What's in the sky tonight?
November 4, 2012

-This is the time of year when the W of Cassiopeia stands on end (its fainter end) high in the northeast in early evening. This is also when the Big Dipper lies level low in the north-northwest.

-Mars (magnitude +1.2, in Ophiuchus) remains low in the southwest in evening twilight.

Astro Picture of the Day:
November 4, 2012

Source:
New research from scientists using NASA's Spitzer Space Telescope suggests that a mysterious infrared glow across our whole sky is coming from stray stars torn from galaxies. That glow, known as the cosmic infrared background (CIB), has mysterious sources either too far away or too individually faint (or both) to resolve. Astronomers have long hoped that the CIB might tell something about the very first stars and galaxies that set the universe alight. But a new paper published last week in Nature suggests that finding such early evidence might be much harder than previously thought. When galaxies grow, they merge and become gravitationally tangled in a violent process that results in streams of stars being ripped away from the galaxies. Such streams, called tidal tails, can be seen in this artist's concept. Scientists say that Spitzer is picking up the collective glow of stars such as these, which linger in the spaces between galaxies. This artwork is adapted, in part, from galaxy images obtained from the NASA/ESA Hubble Space Telescope. Image credit: NASA/JPL-Caltech.

[Bluearrowll]

What's in the sky tonight?
November 5, 2012

-By 8 p.m. Vega is shining in the west-northwest. It's the brightest star there. Look well left of it for Altair in the west-southwest. Above Altair, by a little more than a fist-width at arm's length, is the dim but distinctive little constellation Delphinus, the Dolphin.

-Saturn will emerge from the glow of the sunrise by the end of the week.

Astro Picture of the Day:
November 5, 2012

Source:
On some nights, the sky is the best show in town. On this night, the sky was not only the best show in town, but a composite image of the sky won an international competition for landscape astrophotography. The above winning image was taken on March 2011 over Jökulsárlón, the largest glacial lake in Iceland. The photographer combined six exposures to capture not only two green auroral rings, but their reflections off the serene lake. Visible in the distant background sky is the band of our Milky Way Galaxy, the Pleiades open clusters of stars, and the Andromeda galaxy. A powerful coronal mass ejection from the Sun caused auroras to be seen as far south as Wisconsin, USA. As the Sun progresses toward solar maximum in the next few years, many more spectacular images of aurora are expected.

[Bluearrowll]

What's in the sky tonight?
November 6, 2012

-Last-quarter Moon tonight (exact at 7:36 p.m. EST). The half-lit Moon rises around 11 p.m. or midnight local time. Once it's well up, look left of it for the Sickle of Leo and right of it for the dimmer Head of Hydra.

-Venus (magnitude –4.0, in Virgo) rises due east in darkness more than an hour before the first glimmer of dawn. By dawn it's shining brightly fairly high.

Astro Picture of the Day:
November 6, 2012

Source:
Why is this moon shaped like a smooth egg? The robotic Cassini spacecraft completed the first flyby ever of Saturn's small moon Methone in May and discovered that the moon has no obvious craters. Craters, usually caused by impacts, have been seen on every moon, asteroid, and comet nucleus ever imaged in detail -- until now. Even the Earth and Titan have craters. The smoothness and egg-like shape of the 3-kilometer diameter moon might be caused by Methone's surface being able to shift -- something that might occur were the moon coated by a deep pile of sub-visual rubble. If so, the most similar objects in our Solar System would include Saturn's moons Telesto, Pandora, Calypso, as well as asteroid Itokawa, all of which show sections that are unusually smooth. Methone is not entirely featureless, though, as some surface sections appears darker than others. Although flybys of Methone are difficult, interest in the nature and history of this unusual moon is sure to continue.

[Bluearrowll]

What's in the sky tonight?
November 7, 2012

-The tiny black shadow of Io crosses Jupiter's face tonight from 10:11 p.m. to 12:21 a.m. EST, with Io itself following behind from 10:49 p.m. to 12:58 a.m. EST.

-Uranus (magnitude 5.8, in Pisces) and Neptune (magnitude 7.9, in Aquarius) are in in good view in the south during evening.

-If you have a large scope, have you ever tried for the moons of Neptune and Uranus? The brightest are about magnitude 13.5. Read more, and print charts for your time and date, at http://www.skyandtelescope.com/obser.../13795272.html and http://www.skyandtelescope.com/obser...s/3310476.html .

Astro Picture of the Day:
November 7, 2012

Source:
In the distant universe, time appears to run slowly. Since time-dilated light appears shifted toward the red end of the spectrum (redshifted), astronomers are able to use cosmological time-slowing to help measure vast distances in the universe. Above, the light from distant galaxies has been broken up into its constituent colors (spectra), allowing astronomers to measure the redshift of known spectral lines. The novelty of the above image is that the distance to hundreds of galaxies can now be measured on a single frame using the Visible MultiObject Spectrograph operating at the Very Large Telescope array in Chile. Analyzing the space distribution of distant objects will allow insight into when and how stars, galaxies, and quasars formed, clustered, and evolved in the early universe.

[Bluearrowll]

What's in the sky tonight?
November 8, 2012

-Early riser's sky sights: Before and during dawn Friday morning, the waning Moon shines high in the southeast. Venus blazes far to its lower left. Look upper left of Venus by a similar distance for Arcturus. Down below Venus is fainter Spica..

Astro Picture of the Day:
November 8, 2012

Source:
Sometimes a morning sky can be a combination of serene and surreal. Such a sky perhaps existed before sunrise this past Sunday as viewed from a snowy slope in eastern Switzerland. Quiet clouds blanket the above scene, lit from beneath by lights from the village of Trübbach. A snow covered mountain, Mittlerspitz, poses dramatically on the upper left, hovering over the small town of Balzers, Liechtenstein far below. Peaks from the Alps can be seen across the far right, just below the freshly rising Sun. Visible on the upper right are the crescent Moon and the bright planet Venus. Venus will remain in the morning sky all month, although it will likely not be found in such a photogenic setting.

[supermousie]

Damn, Terry. I just found my new desktop background. That's beautiful.

[Bluearrowll]

@Supermousie - here is the high resolution version of that image. Enjoy!

What's in the sky tonight?
November 9, 2012

-The Moon has moved closer to Venus before and during dawn Saturday morning, as shown here.

-Tonight, Jupiter's moon Europa disappears into eclipse by Jupiter's shadow around 1:11 a.m. Saturday morning EST (10:11 p.m. Friday evening PST). A small telescope will show it fading out of sight a little off the planet's western limb.

Astro Picture of the Day:
November 9, 2012

Source:
Cosmic clouds seem to form fantastic shapes in the central regions of emission nebula IC 1805. Of course, the clouds are sculpted by stellar winds and radiation from massive hot stars in the nebula's newborn star cluster, Melotte 15. About 1.5 million years young, the cluster stars are toward the right in this colorful skyscape, along with dark dust clouds in silhouette against glowing atomic gas. A composite of narrow and broad band telescopic images, the view spans about 30 light-years and includes emission from hydrogen in green, sulfur in red, and oxygen in blue hues. Wider field images reveal that IC 1805's simpler, overall outline suggests its popular name - The Heart Nebula. IC 1805 is located about 7,500 light years away toward the constellation Cassiopeia.

[Bluearrowll]

What's in the sky tonight?
November 10, 2012

-Jupiter's moon Ganymede reappears out of eclipse from the planet's shadow around 10:35 p.m. EST, only to disappear behind Jupiter's western limb 20 minutes later. A small telescope will show these proceedings.

-Venus and the waning crescent Moon shine low in the east early Sunday morning, from pre-dawn to sunrise, as shown here. Can you follow them even past sunrise? Binoculars help — but be careful not to sweep up the Sun itself by accident!

Astro Picture of the Day:
November 10, 2012

Source:
NGC 660 is featured in this cosmic snapshot, a sharp composite of broad and narrow band filter image data from the Gemini North telescope on Mauna Kea. Over 20 million light-years away and swimming within the boundaries of the constellation Pisces, NGC 660's peculiar appearance marks it as a polar ring galaxy. A rare galaxy type, polar ring galaxies have a substantial population of stars, gas, and dust orbiting in rings nearly perpendicular to the plane of the galactic disk. The bizarre-looking configuration could have been caused by the chance capture of material from a passing galaxy by a disk galaxy, with the captured debris eventually strung out in a rotating ring. The violent gravitational interaction would account for the myriad pinkish star forming regions scattered along NGC 660's ring. The polar ring component can also be used to explore the shape of the galaxy's otherwise unseen dark matter halo by calculating the dark matter's gravitational influence on the rotation of the ring and disk. Broader than the disk, NGC 660's ring spans over 50,000 light-years.

[Bluearrowll]

What's in the sky tonight?
November 11, 2012

-On Monday morning before sunrise, look below bright Venus in the east for the thin waning Moon with Saturn to its left, as shown here. Binoculars will help. Saturn is just beginning its year-long 2012–13 apparition.

Astro Picture of the Day:
November 11, 2012

Source:
Just before the Sun blacks out, something strange occurs. As the Moon moves to completely cover the Sun in a total solar eclipse - like the one set to occur over parts of Australia on Tuesday - beads of bright sunlight stream around the edge of the Moon. This effect, known as Baily's beads, is named after Francis Baily who called attention to the phenomenon in 1836. Although, the number and brightness of Baily's beads used to be unpredictable, today the Moon is so well mapped that general features regarding Baily's beads are expected. When a single bead dominates, it is called the diamond ring effect, and is typically seen just before totality. Pictured above, horizontally compressed, a series of images recorded Baily's beads at times surrounding the 2008 total solar eclipse visible from Novosibirsk, Russia. At the end of totality, as the Sun again emerges from behind the moon, Baily's beads may again be visible - but now on the other side of the Moon.

[Bluearrowll]

What's in the sky tonight?
November 12, 2012

-Fomalhaut, the "Autumn Star," culminates (reaches its highest point due south) not long after dark now. The western side of the Great Square of Pegasus, high above, points almost down to it. The other side of the Great Square points down roughly to Beta Ceti (Diphda or Deneb Kaitos), not quite so far.

Astro Picture of the Day:
November 12, 2012

Source:
The Kreutz Group of comets has resulted in more than ten bright comets and many hundreds of small fragments that have only been observed by dedicated solar satellites. The last Great Sungrazer was White-Ortiz-Bolelli seen in 1970. The attached shows Comet White-Ortiz-Bolelli (S&T july 1970, p16) and the new record holder, Comet Lovejoy, photographed Christmas eve from Wagga Wagga, Australia, by Dr Graeme White; the co-discover of Comet White-Ortiz-Bolelli (some 40 years earlier) and Michael Maher. Note the striking similarity of the structure – these two comets are truly sisters. The photo was taken at Christmas eve, at 04:00 local Summer time using a Nikon D90 at 18 mm, f/3.5, maximum ISO and with full noise reduction. Losmandy mount.

[Bluearrowll]

What's in the sky tonight?
November 13, 2012

-Orion is up in the east by about 9 p.m. now, depending on where you live in your time zone. Orion's three-star Belt is nearly vertical. Orange Betelgeuse is to the Belt's left and white Rigel is to its right. Earlier in the evening, keep watch for Betelgeuse rising far below Jupiter.



On 2012 November 13/14, a total eclipse of the Sun is visible from within a narrow corridor that traverses Earth's southern Hemisphere. The path of the Moon's umbral shadow begins in northern Australia and crosses the South Pacific Ocean with on other no landfall. The Moon's penumbral shadow produces a partial eclipse visible from a much larger region covering Australia, New Zealand, and the South Pacific.

For those traveling to Australia for the eclipse, please note that the eclipse occurs on the morning of Nov. 14 local time.

The total solar eclipse of 2012 occurs at the Moon's ascending node in central Libra. The path of the Moon's umbral shadow crosses the South Pacific Ocean where it makes no landfall except for northern Australia. The Moon's penumbral shadow produces a partial eclipse visible from a much larger region covering the South Pacific (including Australia and New Zealand), southern South America, and part of Antarctica (Figure 4: If you live in the green areas, you can see at least some of the eclipse! ).

The central eclipse path begins in Australia's Garig Ganak Barlu National Park in the Northern Territory about 250 kilometres east of Darwin at 20:35 UT (Figure 5: an expanded view of the Austrailian region that sees totality. ). Traveling southeast, the umbral shadow quickly crosses the Gulf of Carpentaria and reaches the Cape York Peninsula at 20:37 UT.

The first and only populated region in the path lies along the east coast of Queensland. Gateway to Australia's Great Barrier Reef, Cairns is about 30 kilometres south of the central line. Its residents and visitors will enjoy an early morning total eclipse lasting 2 minutes with the Sun just 14° above the eastern horizon. Observers on the central line can eek out another 5 seconds of totality, but local weather conditions will play a far greater role in choosing a viewing site than a few seconds of totality.

After leaving Australia, the umbral shadow glides over the ocean, undisturbed by further landfall for the remainder of its track. The instant of greatest eclipse [1] occurs in the South Pacific at 22:11:48 UT. At this instant, the axis of the Moon's shadow passes closest to Earth's centre. The maximum duration of totality is 4 minutes 2 seconds, the Sun's altitude is 68°, and the path width is 179 kilometres. Continuing across the vast South Pacific, the umbral shadow's path ends about 800 kilometres west of Chile at 23:48 UT.

Astro Picture of the Day:
November 13, 2012

Source:
Which feature takes your breath away first in this encompassing panorama of land and sky? The competition is strong with a waterfall, meteor, starfield, and even a moonbow all vying for attention. It is interesting to first note, though, what can't be seen -- a rising moon on the other side of the camera. The bright moon not only illuminated this beautiful landscape in Queensland, Australia last June, but also created the beautiful moonbow seen in front of Wallaman Falls. Just above the ridge in the above image is the horizontal streak of an airplane. Toward the top of the frame is the downward streak of a bright meteor, a small pebble from across our Solar System that lit up as it entered the Earth's atmosphere. Well behind the meteor are numerous bright stars and nebula seen toward the center of our Galaxy. Finally, far in the background, is the band of our Milky Way Galaxy, running diagonally from the lower left to the upper right in the image but also circling the entire sky.

[Bluearrowll]

What's in the sky tonight?
November 14, 2012

-Vega is the brightest star in the west in early evening. The brightest far left of it, in the southwest, is Altair. Altair's 3rd-magnitude companion Gamma Aquilae (Tarazed), a finger's width at arm's length from it, is now to Altair's right.

-Saturn (magnitude +0.6, in Virgo) is emerging into dawn view low in the east. Look for it below or lower left of bright Venus. They appear closer together every day.

Astro Picture of the Day:
November 14, 2012

Source:
This image of Saturn could not have been taken from Earth. No Earth based picture could possibly view the night side of Saturn and the corresponding shadow cast across Saturn's rings. Since Earth is much closer to the Sun than Saturn, only the day side of the planet is visible from the Earth. In fact, this image mosaic was taken in January 2007 by the robotic Cassini spacecraft now orbiting Saturn. The beautiful rings of Saturn are seen in full expanse, while cloud details are visible near the night-day terminator divide.

[Bluearrowll]

What's in the sky tonight?
November 15, 2012

-The thin waxing crescent Moon shines to the right of distant little Mars in evening twilight, as shown here.

Astro Picture of the Day:
November 15, 2012

Source:
This month's New Moon brought a total solar eclipse to parts of planet Earth on November 13 (UT). Most of the total eclipse track fell across the southern Pacific, but the Moon's dark umbral shadow began its journey in northern Australia on Wednesday morning, local time. But What does a solar eclipse look like from a plane? Above the clouds, it is very easy to see where the moon has covered the sun and where it has partially covered the sun. This neat solar eclipse photo was taken during a solar eclipse in 2010 and clearly demonostrates the dramatic darkening of the sky / ground as the shadow of the moon blankets the Earth. Under a total solar eclipse, the ground becomes almost night-like for a few minutes. Sunlight streaming through gaps in the rugged profile of the lunar limb creates the brilliant but fleeting Baily's Beads.

[massflavour]

i've actually been able to see 3 auroras from within the city this year, and they were pretty good too.

great images in this thread.

[Bluearrowll]

What's in the sky tonight?
November 16, 2012

-Spot the crescent Moon in the west as twilight fades, and use it to guide your way down to little Mars, as shown here.

-The Leonid meteor shower, normally weak but occasionally surprising, should be at its best in the hours before dawn Saturday morning. Under a dark sky you may see about a dozen to 20 Leonids per hour. There is no Moon.

Astro Picture of the Day:
November 16, 2012

Source:
On the morning of November 14, the Moon's umbral shadow tracked across northern Australia before heading into the southern Pacific. Captured from a hilltop some 30 miles west of the outback town of Mount Carbine, Queensland, a series of exposures follows the progress of the total solar eclipse in this dramatic composite image. The sequence begins near the horizon. The Moon steadily encroaches on the on the reddened face of the Sun, rising as the eclipse progresses. At the total phase, lasting about 2 minutes for that location, an otherwise faint solar corona shimmers around the eclipsed disk. Recorded during totality, the background exposure shows a still sunlit sky near the horizon, just beyond a sky darkened by the shadow of the Moon.

[Bluearrowll]

What's in the sky tonight?
November 17, 2012

-With a small telescope, watch Jupiter's moon Ganymede slowly disappear into eclipse by Jupiter's shadow around 11:30 p.m. EST; 8:30 p.m. PST. Ganymede is just off Jupiter's western side.

-At roughly the same time, Jupiter's Great Red Spot (actually pale orange-tan) appears nearest to the center of the planet's disk.

Astro Picture of the Day:
November 17, 2012

Source:
This lovely view from northern Spain at Cape Creus on the easternmost point of the Iberian peninsula, looks out across the Mediteranean and up into the stream of the 2002 Leonid meteor shower. The picture is a composite of thirty separate one minute exposures taken through a fisheye lens. Over 70 leonid meteors are visible, some seen nearly head on. Bright Jupiter is positioned just to the right of the shower's radiant in Leo. Perched on the moonlit rocks at the bottom right, Leica, the photographers' dog, seems to be watching the on going celestial display and adds a surreal visual element to the scene. Sky watchers will have their best view under dark skies in early morning hours with Leo rising above the eastern horizon.

[Bluearrowll]

What's in the sky tonight?
November 18, 2012

-A low-altitude challenge: If the sky is very clear as twilight fades, aim your scope at tiny little Mars from a site with a low southwestern view. Follow Mars down as night falls. Can you detect the Lagoon Nebula, M8, and its embedded star cluster 1/3° or so to Mars's right?

-Algol in Perseus, the prototype eclipsing binary star, should be in one of its periodic dimmings, magnitude 3.4 instead of its usual 2.1, for a couple hours centered on 10:45 p.m. EST. Algol takes several additional hours to fade and to rebrighten.

Astro Picture of the Day:
November 18, 2012

Source:
How massive can a normal star be? Estimates made from distance, brightness and standard solar models had given one star in the open cluster Pismis 24 over 200 times the mass of our Sun, nearly making it the record holder. This star is the brightest object located just above the gas front in the above image. Close inspection of images taken with the Hubble Space Telescope, however, have shown that Pismis 24-1 derives its brilliant luminosity not from a single star but from three at least. Component stars would still remain near 100 solar masses, making them among the more massive stars currently on record. Toward the bottom of the image, stars are still forming in the associated emission nebula NGC 6357. Appearing perhaps like a Gothic cathedral, energetic stars near the center appear to be breaking out and illuminating a spectacular cocoon.

[Bluearrowll]

What's in the sky tonight?
November 19, 2012

-Fomalhaut, the "Autumn Star," culminates (reaches its highest point due south) around 7 p.m. now, depending on how far east or west you live in your time zone. High above, the western side of the Great Square of Pegasus points almost down to it. The other side of the Great Square points down roughly to Beta Ceti (Diphda or Deneb Kaitos), not quite so far.

Astro Picture of the Day:
November 19, 2012

Source:
What's happening in the sky over Monument Valley? A meteor shower. Over the past weekend the Leonid meteor shower has been peaking. The image - actually a composite of six exposures of about 30 seconds each - was taken in 2001, a year when there was a much more active Leonids shower. At that time, Earth was moving through a particularly dense swarm of sand-sized debris from Comet Tempel-Tuttle, so that meteor rates approached one visible streak per second. The meteors appear parallel because they all fall to Earth from the meteor shower radiant - a point on the sky towards the constellation of the Lion (Leo). Although the predicted peak of this year's Leonid meteor shower is over, another peak may be visible early tomorrow morning. By the way - how many meteors can you identify in the above image?