Terry's Astronomy Thread.

[Sky Kitten]

Re: Terry's Astronomy Thread.

What's in the sky tonight?
May 20, 2012

-Partial/annular eclipse of the Sun! This afternoon, all but easternmost North America will experience at least a partial eclipse of the Sun. So will the Pacific and (on the morning of May 21st local date) the eastern half of Asia. The eclipse will become annular — with the rim of the Sun a brilliant ring surrounding the dark silhouette of the Moon — along a path from south China and parts of Japan across the Pacific to the California-Oregon coast and from there southeastward to end at sunset in Texas. Go here to read more about the eclipse. Also see the Upcoming Events tab in the main post for more specific information.

-Arcturus shines high in the southeastern sky after dark. Vega, equally bright, shines lower in the northeast. A third of the way from Arcturus to Vega, look for dim Corona Borealis, the Northern Crown, with its one modestly bright star, Alphecca. Two thirds of the way from Arcturus to Vega is the dim Keystone of Hercules.

-New Moon (exact at 7:47 p.m. Eastern Daylight Time).

Astro Picture of the Day:
May 20, 2012

Source:
Did you see that flash? Lasting only about 15 seconds, it's possible that nobody you ask can confirm it, but what you might have seen is sunlight reflecting off an orbiting Iridium satellite. Satellites of all types have been providing streaks and glints visible only since the launch of Sputnik I in 1957. Of these, flares from any of the 66 Iridium satellites can be particularly bright, sometimes even approaching the brightness of the Moon. If the Iridium satellites are programmed to re-enter the Earth's atmosphere, they might provide even brighter flares as they burn up. Pictured above, the streak from an Iridium satellite punctuates a picturesque sunset in San Sebastian, Spain. Then again, that sky-flash you saw? If it lasted only a second or two, it might have been a meteor.

[Sky Kitten]

Re: Terry's Astronomy Thread.

What's in the sky tonight?
May 21, 2012

-Can you pick up this month's thin crescent Moon yet? During twilight in the Americas it's barely 24 hours old. (After all, it was in front of the Sun yesterday afternoon!) Using binoculars, look for it no more than a half hour after sunset well below Venus in the west-northwest, as shown at lower right.

Astro Picture of the Day:
May 21, 2012

Source:
How can two stars create such a strange and intricate structure? Most stars are members of multiple-star systems. Some stars are members of close binary systems where material from one star swirls around the other in an accretion disk. Only a handful of stars, however, are members of an intermediate polar, a system featuring a white dwarf star with a magnetic field that significantly pushes out the inner accretion disk, only allowing material to fall down its magnetic poles. Shown above is an artist's depiction of an intermediate polar system, also known as a DQ Hercules system. The foreground white dwarf is so close to the normal star that it strips away its outer atmosphere. As the white dwarf spins, the columns of infalling gas rotate with it. The name intermediate polar derives from observations of emitted light polarized at a level intermediate to non-disk binary systems known as polars. Intermediate polars are a type of cataclysmic variable star system.

[Jerry DB]

Re: Terry's Astronomy Thread.

damn that close binary system be lookin hawt

[Bluearrowll]

Re: Terry's Astronomy Thread.

What's in the sky tonight?
May 22, 2012

-After sunset, look for the thin two-day-old Moon left of Venus, as shown here. This is the last chance to see the moon and Venus beside each other for an entire year, so if weather permits you, don't miss out.

Astro Picture of the Day:
May 22, 2012

Source: My camera
This is part 1 of 3 of photos that I am posting from my adventures over the weekend. Part 1 is the annular solar eclipse that occured at sunset on the 20th for me. As I was still very far east I was unable to see the whole show, but I still came up with this. For some, this was the first chance to see a solar eclipse in about a decade. Something about watching this occur while seeing the reflection on the water slowly adjust with the real spectacle was stunning, nature at its finest. Oh and the best part is I didn't blind myself in the process! This was taken at Cyprus Lake near Tobermory.

[Bluearrowll]

Re: Terry's Astronomy Thread.

What's in the sky tonight?
May 23, 2012

-Using the Moon and Venus as your guides, what fainter stars in the area can you identify with the chart here? Binoculars help. You will be looking at the stars of Gemini. Pollux and Castor are the 'heads' of the Gemini twins.

Astro Picture of the Day:
May 23, 2012

Source: My camera
This is part 2 of 3 of photos that I am posting from my adventures over the weekend. Part 2 is the wonderful milky way that quietly greets us every night, yet we fail to see it in such light polluted skies. In the lands of Cyprus Lake, walking about 3km away from my campsite with no city lights anywhere, I used my red flashlight to navigate my way to this opening, where around 2am I was greeted by the rising milky way which was following a quick moving Scorpius. Being my first time witnessing the whole thing, I wish I had words to describe how it happened, but there is this amusing little story behind the discovery; it took about 20 minutes for my eyes to fully adapt to the milky way. Around this time I happened to be greeted by a few noticably drunk adventurers who were trying to find something in the woods, don't ask me what because I don't know. We look towards the North east, noting a faint cloud in the sky that appeared to have stars in front of it. I pointed my camera and shot the first photograph, and it was after looking at that photograph we all realised what we were seeing, and we could see it clearly immediately after this. The drunk guys said thanks for showing us, and decided to part ways, but not before one of them walked into a tree and needed help from someone to get back up. I don't know when, but I will return up here again.

[Bluearrowll]

Re: Terry's Astronomy Thread.

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

-In a telescope, Venus is a dramatic, thin crescent becoming more interesting all the time. This week it enlarges from 50 to 54 arcseconds tall while waning from 10% to just 4% sunlit. You may even see the crescent with firmly braced binoculars.

-This evening Pollux and Castor are lined up above or upper right of the crescent Moon.

Astro Picture of the Day:
May 24, 2012

Source: My camera
This is part 3 of 3 of photos that I am posting from my adventures over the weekend. The first image here shows a satellite that I managed to capture while viewing the night sky early in the evening. (When I say early, I mean around 10pm). Closer inspection of my satellite chart for objects brighter than magnitude 3 revealed this was COSMOS 1939 ROCKET flying overhead. Those rockets that are thrown off space shuttles and such don't always fall back down to the Earth you know - some of them are stuck in orbit. The other photo is a view from my campsite when you look up in the sky. It's a much nicer view than in the city where you simply see brown and maybe a select few stars. One thing I couldn't get over was how much brigher stars I thought I knew were - I had a hard time pointing out constellations that I see almost daily becuase of this! I would like to revisit sometime in October or the winter - when Orion and the Pleiades are in the sky, and the Winter Triangle dominates the night. What a sight that would be.

[Bluearrowll]

Re: Terry's Astronomy Thread.

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

-Well to the right of the Moon this evening shine Pollux and Castor, the heads of the Gemini twins. They're lined up almost horizontally. Look well below the Moon for Procyon, one of the last remaining stars of the winter triangle in the evening sky.

-Venus is now at the peak of its evening drama, dropping faster into the bright sunset every day. How many more days can you follow it with your naked eyes? With binoculars? Don't confuse it with Capella about 20° to its upper right.

In a telescope Venus is a dramatically thin crescent, just 4% sunlit on May 25th and 3% on the 30th, and about 55 arcseconds tall. You may be able to see its crescent shape in binoculars.

Astro Picture of the Day:
May 25, 2012

Source:
It was a typical Texas sunset except that most of the Sun was missing. The location of the missing piece of the Sun was not a mystery -- it was behind the Moon. Sunday night's partial eclipse of the Sun by the Moon turned into one of the best photographed astronomical events in history. Gallery after online gallery is posting just one amazing eclipse image after another. Pictured above is possibly one of the more interesting posted images -- a partially eclipsed Sun setting in a reddened sky behind brush and a windmill. The image was taken Sunday night from about 20 miles west of Sundown, Texas, USA, just after the ring of fire effect was broken by the Moon moving away from the center of the Sun. Coming early next month is an astronomical event that holds promise to be even more photographed -- the last partial eclipse of the Sun by Venus until the year 2117.

[Bluearrowll]

Re: Terry's Astronomy Thread.

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

-By late evening the summer constellation Scorpius is well up in the south-southeast, as shown at right. Look for its brightest star, fire-colored Antares, the Scorpion's heart. Antares' "outrigger" stars are just below it and to its upper right. Farther upper right is the diagonal three-star row of Scorpius's head, topped by Beta Scorpii.

-This week is the last chance to see Venus before the Transit of Venus June 5th. In a telescope Venus is a dramatically thin crescent, just 4% sunlit on May 25th and 3% on the 30th, and about 55 arcseconds tall. You may be able to see its crescent shape in binoculars.

Astro Picture of the Day:
May 26, 2012

Source:
This sharp cosmic portrait features NGC 891. The spiral galaxy spans about 100 thousand light-years and is seen almost exactly edge-on from our perspective. In fact, about 30 million light-years distant in the constellation Andromeda, NGC 891 looks a lot like our Milky Way. At first glance, it has a flat, thin, galactic disk and a central bulge cut along the middle by regions of dark obscuring dust. The combined image data also reveals the galaxy's young blue star clusters and telltale pinkish star forming regions. And remarkably apparent in NGC 891's edge-on presentation are filaments of dust that extend hundreds of light-years above and below the center line. The dust has likely been blown out of the disk by supernova explosions or intense star formation activity. Faint neighboring galaxies can also been seen near this galaxy's disk.

[Bluearrowll]

Re: Terry's Astronomy Thread.

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

-Look above the Moon this evening for Regulus and, higher and fainter, Gamma Leonis. To the left of these three is Mars.

-This week is the last chance to see Venus before the Transit of Venus June 5th. In a telescope Venus is a dramatically thin crescent, just 4% sunlit on May 25th and 3% on the 30th, and about 55 arcseconds tall. You may be able to see its crescent shape in binoculars. Venus is still a blazing magnitude -4.3, but will continue to get fainter as it sinks lower into the glare of the sun.

Astro Picture of the Day:
May 27, 2012

Source:
Can you spot the planet? The diminutive disk of Mercury, the solar system's innermost planet, spent about five hours crossing in front of the enormous solar disk in 2003, as viewed from the general vicinity of planet Earth. The Sun was above the horizon during the entire transit for observers in Europe, Africa, Asia, or Australia, and the horizon was certainly no problem for the sun-staring SOHO spacecraft. Seen as a dark spot, Mercury progresses from left to right (top panel to bottom) in these four images from SOHO's extreme ultraviolet camera. The panels' false-colors correspond to different wavelengths in the extreme ultraviolet which highlight regions above the Sun's visible surface. This was the first of 14 transits of Mercury which will occur during the 21st century. Next week, however, an event much more rare but easier to spot will occur - a transit of Venus across the Sun. Mercury is found moving left to right in these images.

[Bluearrowll]

Re: Terry's Astronomy Thread.

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

-Mars shines above the first-quarter Moon this evening.

-Saturn (magnitude +0.5, in Virgo) shines high in the south at nightfall. Below it by nearly 5° is Spica, fainter and bluer. They set in the west before dawn.

Astro Picture of the Day:
May 28, 2012

Source:
Have you contemplated your home star recently? Pictured above, a Sun partially eclipsed on the top left by the Moon is also seen eclipsed by earthlings contemplating the eclipse below. The above menagerie of silhouettes was taken from the Glenn Canyon National Recreational Area near Page, Arizona, USA, where park rangers and astronomers expounded on the unusual event to interested gatherers. Also faintly visible on the Sun's disk, just to the lower right of the dark Moon's disk, is a group of sunspots. Although exciting, some consider this event a warm-up act for next week's chance to comtemplate the Sun - a much more rare partial eclipse by the planet Venus.

[popsicle_3000]

Re: Terry's Astronomy Thread.

how have i never seen this thread b4??? this stuff is crazy. Does it work in the southern hemisphere as well??

[Bluearrowll]

Re: Terry's Astronomy Thread.

how have i never seen this thread b4??? this stuff is crazy. Does it work in the southern hemisphere as well??

Most of the things I mention are generally northern hemisphere based around 40 degrees north; however there are many items that are global.

The astro picture of the day, major upcoming events, light pollution maps, some of the "what's in the sky tonight?" events, the international space station tracker will all find their way in the southern hemisphere at some point. We are a week away from the Transit of Venus which WILL be seen in a good chunk of the southern hemisphere.


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

-Bright Arcturus shines southeast of the zenith after dark. Vega, equally bright, shines less high in the east-northeast.

-A third of the way from Arcturus to Vega, look for dim Corona Borealis, the Northern Crown, with its one modestly bright star, Alphecca. Two thirds of the way from Arcturus to Vega is the dim Keystone of Hercules.

Astro Picture of the Day:
May 29, 2012

Source:
Who guards the north? Judging from the above photograph, possibly giant trees covered in snow and ice. The picture was taken last winter in Finnish Lapland where weather can include sub-freezing temperatures and driving snow. Surreal landscapes sometimes result, where common trees become cloaked in white and so appear, to some, as watchful aliens. Far in the distance, behind this uncommon Earthly vista, is a more common sight -- a Belt of Venus that divided a darkened from sunlit sky as the Sun rose behind the photographer. The Belt of Venus can be seen every day granted clear skies; it is the earthès shadow and the first signs of night sky. It can be found opposite the sun at sunset. Of course, in the spring, the trees have thawed and Lapland looks much different.

[Bluearrowll]

Re: Terry's Astronomy Thread.

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

-Saturn and Spica are well to the left of the Moon this evening. Less far below the Moon, look for the four-star pattern of Corvus, the Crow, as shown here.

Astro Picture of the Day:
May 30, 2012

Source:
What's that dark spot on planet Earth? It's the shadow of the Moon. The above image of Earth was taken last week by MTSAT during an annular eclipse of the Sun. The dark spot appears quite unusual as clouds are white and the oceans are blue in this color corrected image. Earthlings residing within the dark spot would see part of the Sun blocked by the Moon and so receive less sunlight than normal. The spot moved across the Earth at nearly 2,000 kilometers per hour, giving many viewers less than two hours to see a partially eclipsed Sun. MTSAT circles the Earth in a geostationary orbit and so took the above image from about three Earth-diameters away. Sky enthusiasts might want to keep their eyes pointed upward this coming week as a partial eclipse of the Moon will occur on June 4 and a transit of Venus across the face of the Sun will occur on June 5.

[Bluearrowll]

Re: Terry's Astronomy Thread.

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

-The gibbous Moon, Spica, and Saturn form an upward line this evening. How straight the line is will depend on when and where you're viewing from.

-In a telescope Venus is a dramatically thin crescent, just 4% sunlit on May 25th and 3% on the 30th, and about 55 arcseconds tall. You can see its crescent shape with firmly braced binoculars.

Astro Picture of the Day:
May 31, 2012

Source:
Comet Lovejoy (C/2011 W3) survived its close encounter with the Sun earlier this month, taking its place among wonders of the southern skies just in time for Christmas. Seen here before sunrise from Paranal Observatory in Chile, the sungrazing comet's tails stretch far above the eastern horizon. Spanning over 20 degrees they rise alongside the plane of the our Milky Way galaxy. A breathtaking spectacle in itself, Lovejoy performs on this celestial stage with southern stars and nebulae, including the Large and Small Magellanic clouds right of the telescope dome, and the glow of zodiacal light along the left edge of the frame. With Paranal's Very Large Telescope units in the foreground, this wide-angle scene was captured on December 23. Receding from the Sun, Comet Lovejoy's tails have continued to grow in length even as the comet fades.

[Bluearrowll]

Re: Terry's Astronomy Thread.

Less than a week away from the Transit of Venus! I may dedicate a thread to it later.

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

-By 10 or 11 p.m. (depending on your location) the Summer Triangle is up in the east. Its top corner is Vega: the brightest star in the eastern sky. Deneb is the brightest star to Vega's lower left. Look for Altair substantially farther to Venus's lower right.

Astro Picture of the Day:
June 1, 2012

Source:
These three bright nebulae are often featured in telescopic tours of the constellation Sagittarius and the crowded starfields of the central Milky Way. In fact, 18th century cosmic tourist Charles Messier cataloged two of them; M8, the large nebula left of center, and colorful M20 on the right. The third, NGC 6559, is above M8, separated from the larger nebula by a dark dust lane. All three are stellar nurseries about five thousand light-years or so distant. The expansive M8, over a hundred light-years across, is also known as the Lagoon Nebula. M20's popular moniker is the Trifid. Glowing hydrogen gas creates the dominant red color of the emission nebulae, with contrasting blue hues, most striking in the Trifid, due to dust reflected starlight. This broad skyscape also includes one of Messier's open star clusters, M21, just above and right of the Trifid.