Terry's Astronomy Thread.

[elvis236]

Originally Posted by Bluearrowll

What did you use for solar observing? Must be quite neat to see the picture of the day for yourself

I actually saw it through two separate telescopes. One of them was a really neat little Questar that the university has, and the other is one of the larger telescopes that they keep in a dome on the roof. I'm not really sure of the specifications of the telescopes since I don't work with them very often, but I'm pretty sure the Questar was filtered to be an H-alpha telescope while the other was viewing in a broader band.

[Bluearrowll]

What's in the sky tonight?
August 24, 2012

-First-quarter Moon this evening. Look for Antares to its lower left. The other stars of upper Scorpius are scattered around them.

Astro Picture of the Day:
August 24, 2012

Source:
Rising in the dark hours before dawn, wandering Venus now shines as the brilliant morning star. Its close conjunction with the Moon on August 13 was appreciated around planet Earth. But skygazers in eastern Asia were also treated to a lunar occultation, the waning crescent Moon passing directly in front of the bright planet in still dark skies. This composite image constructed from frames made at 10 minute intervals follows the celestial performance (vimeo video) from above the city lights and clouds over Taebaek, Korea. The occultation begins near the horizon and progresses as the pair rises. Venus first disappears behind the Moon's sunlit crescent, emerging before dawn from the dark lunar limb.

[Bluearrowll]

What's in the sky tonight?
August 25, 2012

-The Moon at nightfall shines about equidistant from Antares to its lower right and the Teapot of Sagittarius pouring to its left.

-This evening — before the Moon becomes too bright for the rest of the week — you can still use binoculars to try for the Lagoon and Swan nebulae, M8 and M7, above the Sagittarius Teapot as shown here. To the naked eye, the Teapot is roughly the size of your fist at arm's length.

Astro Picture of the Day:
August 25, 2012

Source:
In cosmic brush strokes of glowing hydrogen gas, this beautiful skyscape unfolds across the plane of our Milky Way Galaxy and the center of the northern constellation Cygnus the Swan. Recorded from a premier remote observatory site (ROSA) in southern France, the image spans about 6 degrees. Bright supergiant star Gamma Cygni near image center lies in the foreground of the complex gas and dust clouds and crowded star fields. Left of Gamma Cygni, shaped like two luminous wings divided by a long dark dust lane is IC 1318, whose popular name is understandably the Butterfly Nebula. The more compact, bright nebula at the lower right is NGC 6888, the Crescent Nebula. Some distance estimates for Gamma Cygni place it at around 750 light-years while estimates for IC 1318 and NGC 6888 range from 2,000 to 5,000 light-years.

[Bluearrowll]

What's in the sky tonight?
August 26, 2012

-The Moon shines above the Sagittarius Teapot in the south after dark.

-Mercury (about magnitude –1.2) remains in view at dawn but lower each day. It's above the east-northeast horizon, far lower left of brilliant Venus. Look about 45 minutes before sunrise, the earlier in the week the better.

Astro Picture of the Day:
August 26, 2012

Source:
A human first set foot on another world on July 20, 1969. This world was Earth's own Moon. In honor of Armstrong's death, today's picture of the day is a digitally restored video of this milestone in human history. Pictured above is Neil Armstrong preparing to take the historic first step. On the way down the Lunar Module ladder, Armstrong released equipment which included the television camera that recorded this fuzzy image. Pictures and voice transmissions were broadcast live to a world wide audience estimated at one fifth of the world's population. The Apollo Moon landings have since been described as the greatest technological achievement the world has known.

Source:
On that same July 20, 1969, Apollo 11 astronauts Neil Armstrong and Edwin "Buzz" Aldrin became the first to walk on the Moon. This panorama of their landing site sweeps across the magnificent desolation of the Moon's Sea of Tranquility, with their Lunar Module, the Eagle, in the background at the far left. East Crater, about 30 meters wide and 4 meters deep, is on the right (scroll right), and was so named because it is about 60 meters east of the Lunar Module. Armstrong had piloted the Eagle safely over the crater. Near the end of his stay on the lunar surface Armstrong strayed far enough from the Lunar Module to take the pictures used to construct this wide-angle view, his shadow appearing at the panorama's left edge. The object near the middle foreground is a stereo close-up camera.

[Bluearrowll]

What's in the sky tonight?
August 27, 2012

-This is the time of year when the Big Dipper, swinging down in the northwest in evening, catches water dumping from the bowl of the dim Little Dipper high above it. Much of the Little Dipper is made of 4th- and 5th-magnitude stars and requires a fairly dark sky.

Astro Picture of the Day:
August 27, 2012

Source:
Three thousand light-years away, a dying star throws off shells of glowing gas. This image from the Hubble Space Telescope reveals the Cat's Eye Nebula to be one of the most complex planetary nebulae known. In fact, the features seen in the Cat's Eye are so complex that astronomers suspect the bright central object may actually be a binary star system. The term planetary nebula, used to describe this general class of objects, is misleading. Although these objects may appear round and planet-like in small telescopes, high resolution images reveal them to be stars surrounded by cocoons of gas blown off in the late stages of stellar evolution.

[Bluearrowll]

What's in the sky tonight?
August 28, 2012

-As twilight fades, spot Arcturus high in the west. Look far to its lower left for Saturn, Spica below it, and Mars to Saturn's left. This triangle is lengthening each evening Saturn and Spica move to the lower right.

Astro Picture of the Day:
August 28, 2012

Source:
Why is the sky near Antares and Rho Ophiuchi so colorful? The colors result from a mixture of objects and processes. Fine dust illuminated from the front by starlight produces blue reflection nebulae. Gaseous clouds whose atoms are excited by ultraviolet starlight produce reddish emission nebulae. Backlit dust clouds block starlight and so appear dark. Antares, a red supergiant and one of the brighter stars in the night sky, lights up the yellow-red clouds on the lower center. Rho Ophiuchi lies at the center of the blue nebula near the top. The distant globular cluster M4 is visible just to the right of Antares, and to the lower left of the red cloud engulfing Sigma Scorpii. These star clouds are even more colorful than humans can see, emitting light across the electromagnetic spectrum.

[Bluearrowll]

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

-Fomalhaut, the "Autumn Star," rises in the southeast in mid- to late evening; the time depends on your location. Watch for Fomalhaut coming into view below or lower left of the Moon.

Astro Picture of the Day:
August 29, 2012

Source:
There is something very unusual in this picture of the Earth - can you find it? A fleeting phenomenon once thought to be only a legend has been newly caught if you know just where to look. The above image was taken from the orbiting International Space Station (ISS) in late April and shows familiar ISS solar panels on the far left and part of a robotic arm to the far right. The rarely imaged phenomenon is known as a red sprite and it can be seen, albeit faintly, just over the bright area on the image right. This bright area and the red sprite are different types of lightning, with the white flash the more typical type. Although sprites have been reported anecdotally for as long as 300 years, they were first caught on film in 1989 - by accident. Much remains unknown about sprites including how they occur, their effect on the atmospheric global electric circuit, and if they are somehow related to other upper atmospheric lightning phenomena such as blue jets or terrestrial gamma flashes.

[Frank Munoz]

There's so much stuff I do not know about in here... and the "Red Sprite" is freaking amazing... It's now another phenomenon I wish to see now.

[Bluearrowll]

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

-Full Moon tonight and tomorrow night (exactly full at 9:58 a.m. EDT tomorrow morning). The Moon tonight is in dim Aquarius.

-As sunrise approaches Friday morning, bring binoculars or a wide-field telescope to a spot with a view of the east-northeast horizon to try for the difficult conjunction of Mercury with Regulus, illustrated here.

Astro Picture of the Day:
August 30, 2012

Source:
As far as pulsars go, PSR B1509-58 appears young. Light from the supernova explosion that gave birth to it would have first reached Earth some 1,700 years ago. The magnetized, 20 kilometer-diameter neutron star spins 7 times per second, a cosmic dynamo that powers a wind of charged particles. The energetic wind creates the surrounding nebula's X-ray glow in this tantalizing image from the Chandra X-ray Observatory. Low energy X-rays are in red, medium energies in green, and high energies in blue. The pulsar itself is in the bright central region. Remarkably, the nebula's tantalizing, complicated structure resembles a hand. PSR B1509-58 is about 17,000 light-years away in the southern constellation Circinus. At that distance the Chandra image spans 100 light-years.

[Bluearrowll]

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

-Full Moon (exact at 9:58 a.m. EDT). This is a "blue Moon," when the term means the second full Moon in a calendar month. Blue Moons come every 2.7 years on average. The next is in July 2015.

-This week, right after dark is the time when the Big Dipper descends to the same height in the northwest as Cassiopeia rises in the northeast. After this, it'll officially be Cassiopeia season.

Astro Picture of the Day:
August 31, 2012

Source:
The Cat's Eye Nebula (NGC 6543) is one of the best known planetary nebulae in the sky. Its haunting symmetries are seen in the very central region of this tantalizing image, processed to reveal the enormous but extremely faint halo of gaseous material, about 6 light-years across, which surrounds the brighter, familiar planetary nebula. Made with narrow and broadband data the composite picture shows the remarkably strong extended emission from twice ionized oxygen atoms in blue-green hues and ionized hydrogen and nitrogen in red. Planetary nebulae have long been appreciated as a final phase in the life of a sun-like star. But recently many planetaries have been found to have halos like this one, likely formed of material shrugged off during earlier active episodes in the star's evolution. While the planetary nebula phase is thought to last for around 10,000 years, astronomers estimate the age of the outer filamentary portions of this halo to be 50,000 to 90,000 years.

[Bluearrowll]

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

-Bright Vega passes the zenith as twilight fades away — if you live in the world's mid-northern latitudes. Vega goes right through your zenith if you're at north latitude 39°: near the latitudes of Baltimore, Kansas City, Lake Tahoe, Sendai, Beijing, Athens, Lisbon.

-Mercury is lost low in the glow of sunrise.

Astro Picture of the Day:
September 1, 2012

Source:
Rising at sunset, the gorgeous Full Moon of August 31 became the second Full Moon in a month. According to modern reckoning, that makes it a Blue Moon. In fact, parts of the Full Moon do look a little blue in this sharp lunar portrait. Taken just hours before the exact full phase in delightfully clear skies over Nottingham, UK, it features eye-catching bright rays extending from the prominent young crater Tycho in the Moon's southern hemisphere. The slightly color enhanced image also brings out subtle shades of blue, a real characteristic of terrain with a high content of titanium oxide and iron. The blue lunar terrain on the right includes the dark flat expanse of the Sea of Tranquility and the Apollo 11 landing site.

[Bluearrowll]

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

-The waning gibbous Moon rises in late twilight. It's beneath the uptilted Great Square of Pegasus.

-Mars (magnitude +1.2, in Libra) and Saturn (magnitude +0.8, in Virgo) are low in the west-southwest in twilight. This week they widen from 10° to 13° apart: a fist-width at arm's length or more. Look for them far lower left of bright Arcturus. Saturn is the one on the right. You may still be able to see Spica twinkling 5° below Saturn.

Astro Picture of the Day:
September 2, 2012

Source:
This graceful arc traces a Delta rocket climbing through Thursday's early morning skies over Cape Canaveral Air Force Station in Florida, USA. Snug inside the rocket's Centaur upper stage were NASA's twin Radiation Belt Storm Probes (RBSP), now in separate orbits within planet Earth's Van Allen radiation belts. Reflected in the Turn Basin from a vantage point about 3 miles from Space Launch Complex 41, the scene was captured in a composite of two exposures. One highlights the dramatic play of launch pad lighting, clouds, and sky. A subsequent 3 minute long exposure records the rocket's fiery trail. While most spacecraft try to avoid the radiation belts, named for their discoverer James Van Allen, RBSP's mission will be to explore their dynamic and harsh conditions.

[Bluearrowll]

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

-As twilight fades, spot bright Arcturus high in the west. Look far to its lower left for Saturn and Mars. They're about a fist-width at arm's length apart. Mars is the one on the left.

-Compare Mars with similarly bright and similarly colored Antares ("Anti-Mars" in Greek), three fists to its left and perhaps higher. Which of the two looks deeper orange?

Astro Picture of the Day:
September 3, 2012

Source:
Perhaps the most famous star cluster on the sky, the Pleiades can be seen without binoculars from even the depths of a light-polluted city. Also known as the Seven Sisters and M45, the Pleiades is one of the brightest and closest open clusters. The Pleiades contains over 3000 stars, is about 400 light years away, and only 13 light years across. Quite evident in the above photograph are the blue reflection nebulae that surround the brighter cluster stars. Low mass, faint, brown dwarfs have also been found in the Pleiades. (Editors' note: The prominent diffraction spikes are caused by the telescope itself and may be either distracting or provide aesthetic enhancement, depending on your point of view.)

[Bluearrowll]

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

-Face south soon after dark and look high. The brightest star there is Altair, with dimmer Tarazed a finger-width at arm's length above it and a bit to the right. Look left of Altair, by a bit more than a fist-width, for the dim but distinctive little constellation Delphinus, the Dolphin, splashing in the edge of the Milky Way.

Astro Picture of the Day:
September 3, 2012

Source:
Should you be worried about hurricanes? To find out, it is useful to know where hurricanes have gone in the past. The above Earth map shows the path of every hurricane reported since 1851, Although striking, a growing incompleteness exists in the data the further one looks back in time. The above map graphically indicates that hurricanes - sometimes called cyclones or typhoons depending on where they form - usually occur over water, which makes sense since evaporating warm water gives them energy. The map also shows that hurricanes never cross - or even occur very near - the Earth's equator, since the Coriolis effect goes to zero there, and hurricanes need the Coriolis force to circulate. The Coriolis force also causes hurricane paths to arc away from the equator. Although incompleteness fogs long term trends and the prevalence of hurricanes remains a topic of research, evidence is accumulating that hurricanes are, on the average, more common and more powerful in the North Atlantic Ocean over the past 20 years.

[Bluearrowll]

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

-One of the nicest star clusters for binoculars or a telescope is M11 in Scutum just off the tail of Aquila, the Eagle, as most amateur astronomers know. But can you also spot dimmer, more difficult M26 less than 4° below it?

-Jupiter (magnitude –2.3, in Taurus) rises in the east-northeast around 11 or midnight daylight saving time. Once it's well clear of the horizon, look for fainter orange Aldebaran twinkling 6° or 7° to its right. By dawn Jupiter shines very high in the south-southeast, 40° or 45° upper right of brighter Venus.

Astro Picture of the Day:
September 5, 2012

Source:
Does air glow? It does, but it is usually hard to see. When conditions are right, however, a faint glow about 90 kilometers up can be observed, most easily with a wide-angle long-duration camera exposure. The same airglow can also frequently be seen looking down - in pictures taken from Earth orbit - as a faint arc hovering above the surface. Pictured above between the beige clouds, above the curving Earth, behind the streaking airplane, and in front of the sparkling stars are some green bands of airglow. The glow is predominantly created by the excitation of atoms by ultraviolet light from the Sun, with the bands resulting from density fluctuations caused by upward moving atmospheric gravity waves. The above image was taken in mid-July above Weikersheim, Germany. Lightning and aurorae can also cause air to glow, but result from particle collisions and are more fleeting.

[Bluearrowll]

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

-Whenever Vega is near the zenith, as it is just after dark now, you know Sagittarius is at its highest and best in the south — displaying the deep-sky riches of the summer Milky Way to their best advantage. The Teapot asterism of Sagittarius is tilting to pour to the right. The richest big patch of the Milky Way, the Large Sagittarius Star Cloud, is just above its spout.

Astro Picture of the Day:
September 6, 2012

Source:
In this serene night skyscape, the Milky Way's graceful arc stretches over prominent peaks in the Italian Alps known as Tre Cime di Lavaredo. A 180 degree wide-angle panorama made in four exposures on August 24, the scene does look to the north and the sky is suffused with an eerie greenish light. Still, the subtle glowing bands are not aurorae, but airglow. Unlike aurorae powered by collisions with energetic charged particles and seen at high latitudes, airglow is due to chemiluminescence, the production of light in a chemical reaction, and found around the globe. The chemical energy is provided by the Sun's extreme ultraviolet radiation. Like aurorae, the greenish hue of this airglow does originate at altitudes of 100 kilometers or so dominated by emission from excited oxygen atoms. More easily seen near the horizon, airglow keeps the night sky from ever being completely dark.

[Bluearrowll]

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

-Jupiter and the last-quarter Moon rise together around 11 or midnight, depending on where you live. Watch for them coming over the east-northeast horizon, and look for fainter Aldebaran to their right. They continue climbing high up the sky until dawn Saturday morning the 8th, as seen here.

Astro Picture of the Day:
September 7, 2012

Source:
South of Antares, in the tail of the nebula-rich constellation Scorpius, lies emission nebula IC 4628. Nearby hot, massive stars, millions of years young, radiate the nebula with invisible ultraviolet light, stripping electrons from atoms. The electrons eventually recombine with the atoms to produce the visible nebular glow, dominated by the red emission of hydrogen. At an estimated distance of 6,000 light-years, the region shown is about 250 light-years across, spanning an area equivalent to four full moons on the sky. The nebula is also cataloged as Gum 56 for Australian astronomer Colin Stanley Gum, but seafood-loving astronomers might know this cosmic cloud as The Prawn Nebula.

[Reincarnate]

Googled red sprites a bit more -- those things remind me of Giygas from Earthbound. :O

Super creepy

[Bluearrowll]

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

-It's still summer, but look low in the southeast this week after about 9 p.m. (depending on where you live) and there's 1st-magnitude Fomalhaut, the Autumn Star, already making its seasonal appearance.

Astro Picture of the Day:
September 8, 2012

Source:
Launched on a grand tour of the outer planets in 1977, by good fortune the twin Voyager spacecraft were also headed in the general direction of the Sun's motion relative to nearby stars. Thirty five years later, Voyager 1 appears to be nearing the boundary of the Sun's heliosphere and interstellar space. Of course the heliosphere is the realm of the Sun defined by the influence of the solar wind and the Sun's magnetic field. But how can you tell when your spacecraft crosses the boundary into interstellar space? One clue would be a sudden increase in the detection of energetic cosmic rays. The high energy particles stream through interstellar space accelerated by distant supernovae in our galaxy, but are normally deflected or slowed by the heliosphere. Covering a 12 month period (September 2011 to 2012), this plot does show a dramatic increase in the rate of cosmic ray particle detection in past months by the Voyager 1 spacecraft. Voyager 1 is now 18 billion kilometers (17 light hours, 122 Astronomical Units) from the Sun and may soon be the first spacecraft from Earth to enter the realm of the stars.

[Bluearrowll]

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

-This is the time of year when bright Vega shines closest to the zenith as the stars come out at dusk. Vega goes right through your zenith if you're at latitude 39° north (Baltimore, Kansas City, Lake Tahoe).

-Mars and Saturn (magnitudes +1.2 and +0.8) are low in the southwest and west-southwest, respectively, as evening twilight fades. This week they widen from 13° to 17° apart. Look for them well to the lower left of brighter Arcturus in the west. Can you still find Spica twinkling under Saturn? Mars ends the week just 1° below Alpha Librae, a wide binocular double star.

Astro Picture of the Day:
September 9, 2012

Source:
The famous Horsehead Nebula in Orion is not alone. A deep exposure shows that the dark familiar shaped indentation, visible just below center, is part of a vast complex of absorbing dust and glowing gas. To bring out details of the Horsehead's pasture, amateur astronomers at the Star Shadow Remote Observatory in New Mexico, USA fixed a small telescope on the region for over seven hours filtering out all but a very specific color of red light emitted by hydrogen. They then added the image to a full color frame taken over three hours. The resulting spectacular picture details an intricate tapestry of gaseous wisps and dust-laden filaments that were created and sculpted over eons by stellar winds and ancient supernovas. The Horsehead Nebula lies 1,500 light years distant towards the constellation of Orion. Two stars from the Orion's Belt can be found in the above image.