Terry's Astronomy Thread.

[Bluearrowll]

Re: Terry's Astronomy Thread.

What's in the sky tonight?
October 29, 2012

-Full Moon (exact at 3:49 p.m. Eastern Daylight Time). Look a fist-width above the Moon for the brightest stars of Aries, lined up nearly horizontally.

-Algol should be at minimum light for a couple hours centered on 10:03 p.m. EDT.

-Jupiter's Great Red Spot (pale orange-tan) crosses Jupiter's central meridian around 11:32 p.m. Eastern Daylight Time.

Astro Picture of the Day:
October 29, 2012

Source:
Oh what a tangled web a planetary nebula can weave. The Red Spider Planetary Nebula shows the complex structure that can result when a normal star ejects its outer gases and becomes a white dwarf star. Officially tagged NGC 6537, this two-lobed symmetric planetary nebula houses one of the hottest white dwarfs ever observed, probably as part of a binary star system. Internal winds emanating from the central stars, visible in the center, have been measured in excess of 1000 kilometers per second. These winds expand the nebula, flow along the nebula's walls, and cause waves of hot gas and dust to collide. Atoms caught in these colliding shocks radiate light shown in the above representative-color picture by the Hubble Space Telescope. The Red Spider Nebula lies toward the constellation of the Archer (Sagittarius). It's distance is not well known but has been estimated by some to be about 4,000 light-years.

[Bluearrowll]

Re: Terry's Astronomy Thread.

What's in the sky tonight?
October 30, 2012

-The "Summer Star" Vega is still the brightest star in the west during fall evenings. Higher above it is Deneb. Farther off to Vega's left or lower left is Altair, the third star of the Summer Triangle.

-Mars (magnitude +1.2, in Ophiuchus) remains low in the southwest in evening twilight. It's upper left of similar-looking Antares; they widen from 6° to 10° apart this week.

Astro Picture of the Day:
October 30, 2012

Source:
Lake Tekapo on South Island in New Zealand is arguably one of best night sky locations in the Southern Hemisphere. The significance of its pristine night sky without light pollution is recognised world-wide and is being included in the list of UNESCO Starlight Reserves. This shot centres around the setting milky way, upside down to how most northern are used to seeing it; this how the milky way looks like when deep in the southern hemisphere. Lake Tekapo has water so clear that most of the stars and the milky way would be visible in the mirror-like reflection of the waters.

[Bluearrowll]

Re: Terry's Astronomy Thread.

What's in the sky tonight?
October 31, 2012

-The Halloween Moon, waning gibbous, rises around the end of twilight. The Pleiades are above it. Once it rises higher, Aldebaran sparkles is below it and bright Jupiter shines to its lower left, as shown here.
Just after dark, the faint, slow-moving asteroid 35 Leukothea should occult a 10.6-magnitude star in Aquarius fairly high in the south for up to 39 seconds, for observers along a track from Florida through Michigan.

Astro Picture of the Day:
October 31, 2012

Source:
Described as a "dusty curtain" or "ghostly apparition", mysterious reflection nebula VdB 152 really is very faint. Far from your neighborhood on this Halloween Night, the cosmic phantom is nearly 1,400 light-years away. Also catalogued as Ced 201, it lies along the northern Milky Way in the royal constellation Cepheus. Near the edge of a large molecular cloud, pockets of interstellar dust in the region block light from background stars or scatter light from the embedded bright star giving parts of the nebula a characteristic blue color. Ultraviolet light from the star is also thought to cause a dim reddish luminescence in the nebular dust. Though stars do form in molecular clouds, this star seems to have only accidentally wandered into the area, as its measured velocity through space is very different from the cloud's velocity. This deep telescopic image of the region spans about 7 light-years.

[Bluearrowll]

Re: Terry's Astronomy Thread.

What's in the sky tonight?
November 1, 2012

-The bright "star" above the Moon this evening is Jupiter. Although they look close together, Jupiter is 1,500 times farther away. Aldebaran, to their right, is 930,000 times more distant than Jupiter!

-Jupiter (magnitude –2.7, in Taurus) rises in the east-northeast shortly after dark, with Aldebaran to its right. Above Aldebaran are the Pleiades.

Astro Picture of the Day:
November 1, 2012

Source:
The suggestively shaped Witch Head Nebula is a reflection nebula and is associated with the bright star Rigel in the constellation Orion. More formally known as IC 2118, the Witch Head Nebula spans about 50 light-years and is composed of interstellar dust grains reflecting Rigel's starlight. In this cosmic portrait, the blue color of the Witch Head Nebula and of the dust surrounding Rigel is caused not only by Rigel's intense blue starlight but because the dust grains scatter blue light more efficiently than red. The same physical process causes Earth's daytime sky to appear blue, although the scatterers in Earth's atmosphere are molecules of nitrogen and oxygen. Rigel, the Witch Head Nebula, and gas and dust that surrounds them lie about 800 light-years away.

[Bluearrowll]

Re: Terry's Astronomy Thread.

What's in the sky tonight?
November 2, 2012

-Once the waning gibbous Moon rises high late this evening, look lower right of it for wintry Orion making his sparkly appearance.

-The Great Red Spot's side of Jupiter is busy indeed. On October 29th when Christopher Go shot this below image from the Philippines, bright orange Oval BA and the little dark red dot following it had finished passing south of (below) the Great Red Spot. Huge turbulence roils the South Equatorial Belt behind the Great Red Spot, and in the midst of this, notice the tiny dark marking next to a bright little white outbreak.

-The South Temperate Belt is barely visible along some of its length but prominent elsewhere. Four white ovals dot the South South Temperate Belt. On the north (lower) side of the planet, the North Equatorial and North Temperate belts have become cleanly separated by the North Tropical Zone's return to whiteness. An extremely wide blue festoon intrudes into the bright Equatorial Zone north of the Great Red Spot.

Astro Picture of the Day:
November 2, 2012

Source:
At the center of our Milky Way Galaxy, a mere 27,000 light-years away, lies a black hole with 4 million times the mass of the Sun. Fondly known as Sagittarius A* (pronounced A-star), the Milky Way's black hole is fortunately mild-mannered compared to the central black holes in distant active galaxies, much more calmly consuming material around it. From time to time it does flare-up, though. A recent outburst lasting several hours is captured in this series of premier X-ray images from the orbiting Nuclear Spectroscopic Telescope Array (NuSTAR). Launched last June 13, NuSTAR is the first to provide focused views of the area surrounding Sgr A* at X-ray energies higher than those accessible to Chandra and XMM observatories. Spanning two days of NuSTAR observations, the recent flare sequence is illustrated in the panels at the far right. X-rays are generated in material heated to over 100 million degrees Celsius, accelerated to nearly the speed of light as it falls into the Miky Way's central black hole. The main inset X-ray image spans about 100 light-years. In it, the bright white region represents the hottest material closest to the black hole, while the pinkish cloud likely belongs to a nearby supernova remnant.

[Bluearrowll]

Re: Terry's Astronomy Thread.

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]

Re: Terry's Astronomy Thread.

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

[Bluearrowll]

Re: Terry's Astronomy Thread.

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]

Re: Terry's Astronomy Thread.

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]

Re: Terry's Astronomy Thread.

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]

Re: Terry's Astronomy Thread.

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]

Re: Terry's Astronomy Thread.

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]

Re: Terry's Astronomy Thread.

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

[Bluearrowll]

Re: Terry's Astronomy Thread.

@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]

Re: Terry's Astronomy Thread.

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.