Terry's Astronomy Thread.

[Bluearrowll]

Re: Terry's Astronomy Thread.

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

-The gibbous Moon shines in the south-southeast after dark. Look well to its lower left for orange Antares. Nearly halfway between the Moon and Antares is the row of three stars marking the head of Scorpius. There will also be a partial eclipse of the moon on the 4th of June.

Astro Picture of the Day:
June 2, 2012

Source:
The 51st entry in Charles Messier's famous catalog is perhaps the original spiral nebula - a large galaxy with a well defined spiral structure also cataloged as NGC 5194. Over 60,000 light-years across, M51's spiral arms and dust lanes clearly sweep in front of its companion galaxy (top), NGC 5195. Image data from the Hubble's Advanced Camera for Surveys has been reprocessed to produce this alternative portrait of the well-known interacting galaxy pair. The processing has further sharpened details and enhanced color and contrast in otherwise faint areas, bringing out dust lanes and extended streams that cross the small companion, along with features in the surroundings and core of M51 itself. The pair are about 31 million light-years distant. Not far on the sky from the handle of the Big Dipper, they officially lie within the boundaries of the small constellation Canes Venatici.

[Bluearrowll]

Re: Terry's Astronomy Thread.

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

-Venus is now virtually impossible to see this week as it is hidden in the glare of the sun, that is except for 6 hours and 20 minutes on June 5th when it crosses the path of the sun.

-Mercury is beginning to emerge into view low in the sunset. By late this week, look for it low in the west-northwest about 30 minutes after sundown. Don't confuse it with Capella well to its right, in the northwest.

Astro Picture of the Day:
June 3, 2012

Source:
The rare transit of Venus across the face of the Sun in 2004 was one of the better-photographed events in sky history. Both scientific and artistic images flooded in from the areas that could see the transit: Europe and much of Asia, Africa, and North America. Scientifically, solar photographers confirmed that the black drop effect is really better related to the viewing clarity of the camera or telescope than the atmosphere of Venus. Artistically, images might be divided into several categories. One type captures the transit in front of a highly detailed Sun. Another category captures a double coincidence such as both Venus and an airplane simultaneously silhouetted, or Venus and the International Space Station in low Earth orbit. A third image type involves a fortuitous arrangement of interesting looking clouds, as shown by example in the above image taken from North Carolina, USA. Sky enthusiasts worldwide are abuzz about the coming transit of Venus on Tuesday. It is perhaps interesting to wonder whether any person will live to see - and remember seeing - both Tuesday's Venus transit and the next one in 2117. If they were born today, they would be 105 before they get to see the next one!

[Bluearrowll]

Re: Terry's Astronomy Thread.

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

-This evening, look for red Antares about 4° lower right of the full Moon (as seen from North America).

-Partial eclipse of the Moon before and during dawn Monday morning for central and western North America. The partial eclipse begins at 3:00 a.m. PDT; mid-eclipse (with 38% of the Moon's diameter in shadow) is at 4:03 a.m. PDT; partial eclipse ends at 5:07 a.m. PDT.

Astro Picture of the Day:
June 4, 2012

Source:
Will our Milky Way Galaxy collide one day with its larger neighbor, the Andromeda Galaxy? Most likely, yes. Careful plotting of slight displacements of M31's stars relative to background galaxies on recent Hubble Space Telescope images indicate that the center of M31 could be on a direct collision course with the center of our home galaxy. Still, the errors in sideways velocity appear sufficiently large to admit a good chance that the central parts of the two galaxies will miss, slightly, but will become close enough for their outer halos to become gravitationally entangled. Once that happens, the two galaxies will become bound, dance around, and eventually merge to become one large elliptical galaxy -- over the next few billion years. Pictured above is an artist's illustration of the sky of a world in the distant future when the central parts of each galaxy begin to destroy each other. The exact future of our Milky Way and the entire surrounding Local Group of Galaxies is likely to remain an active topic of research for years to come.

[Bluearrowll]

Re: Terry's Astronomy Thread.

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

-Transit of Venus across the face of the Sun this afternoon for North and Central America; on June 6th local date for Asia, Australia, and much of Europe. Go here to see more details.

You may or may not have heard already that on June 5th, (6th if you are in the eastern side of the world) the planet Venus is going to cross the Sun in a dramatic 6 and a half hour show. The first thing you need to know is are you in the area where it is going to be displayed to the world? Use the following map courtesy of SkyandTelescope to see:

In other words, unless you live in South America, West Africa, Spain or Portugal, or Antarctica, you have a chance to see this event, weather permitting.

Their article here puts it best: http://www.skyandtelescope.com/obser...134332798.html

However, if you do not wish to click the link, you can also read some of the article in this spoiler.

Often we're told about a particular astronomical event — eclipses and planet line-ups, for example — that happen only rarely. But Venus crossing the face of the Sun on June 5–6, 2012, takes "rare" to a new level. Don't miss the chance to see this, because you'll never have another chance in your lifetime.
June's celestial spectacle, called a transit of Venus, happens only four times every 243 years. However, the spacing between each occurrence is very uneven: it's 121½ years, then 8 years, then 105½ years, then 8 years again. The last transit occurred in June 2004 — and after this June's event there won't be another until December 2117.

Fortunately, unlike the narrow, fleeting path of visibility for a total solar eclipse, the upcoming transit by Venus will last for about 6½ hours and can be seen from more than half of Earth's surface.


For most of North America, the transit of Venus will begin on the afternoon of June 5th and still be in progress at sunset. Those in western Pacific, eastern Asia, and eastern Australia see the whole show from beginning to end on June 6th (local date). Click on the image for a larger, worldwide map.
Michael Zeiler / Eclipse-maps.com
As the map here shows, North Americans are positioned to see at least a portion of it on the afternoon of June 5th. Unfortunately, almost everyone in South America will miss out. On the other side of the globe (click on the map), portions of the transit are observable at or after sunrise on June 6th from Europe, northeast Africa, west and south-central Asia, and western Australia.
The best-positioned skygazers are those in eastern Asia, eastern Australia, Alaska, New Zealand, and all of the Pacific from Hawaii westward. They have ringside seats for watching the entire transit, including the crucial events around both its start and finish.

People living in the Northern Hemisphere will see a longer show due to the parallax of Venus. The reason for this is illustrated in the following image, where one watching in north america sees Venus cross a lower portion of the sun, than someone in austrailia who sees Venus crossing a higher portion of the sun.

So what time does it all happen?

It depends on your location. Here are three tables of major cities where the times of the transit will begin and end.

Some definitions:
External Ingress: Venus touches the edge of the sun. The Transit starts here.
Internal Ingress: Venus completely enters the sun, and appears as a silhouette.
Greatest Transit: The deepest point of the transit.
Internal Egress: The time of the exact moment Venus begins to depart the sun's image.
External Egress: The time of the exact moment Venus leaves the sun's image. The Transit ends here.

CANADA:

http://eclipse.gsfc.nasa.gov/OH/tran/TOV2012-Tab02.pdf

UNITED STATES:

http://eclipse.gsfc.nasa.gov/OH/tran/TOV2012-Tab03.pdf

WORLD:

http://eclipse.gsfc.nasa.gov/OH/tran/TOV2012-Tab04.pdf

----------------------------------------

Now this is likely the last transit of Venus you are going to see in your lifetime, unless you plan to live for another 105 years after this year. Unless you get clouded over, I recommend making an attempt to see this twice in a lifetime (for us) event. Some generations live their full lives without ever seeing what it looks like. To the untrained person, they won't realise what's happening as Venus covers just 3% of the surface of the Sun. Unless they're looking straight at the sun, it will appear to be a normal day.


Scientist's can use the transit to calculate precisely the circumference of the Sun, and other characteristics of the sun. The sun is crucial to our understanding of measuring more distant objects, and -everyone- is being invited to participate in a measurement where you can calculate the exact moment Venus exteranlly ingressed and egressed the sun. Read more about this here.

http://transitofvenus.nl/wp/getting-involved/measure-the-suns-distance/

I am prepared for the Transit, assuming I have good weather. Are you?

If you do not have good weather, or you live in an area where there is no transit:

You can watch the transit online from -anyone- of the online broadcasts found in this link. Don't let poor weather hamper your experience!
http://www.skyandtelescope.com/obser...154213475.html

More updates will be posted in my astronomy thread, as well as this thread.

Astro Picture of the Day:
June 5, 2012

Source:
Today Venus moves in front of the Sun. One way to follow this rare event is to actively reload the above live image of the Sun during the right time interval and look for an unusual circular dark dot. The smaller sprawling dark areas are sunspots. The circular dot is the planet Venus. The dark dot will only appear during a few very specific hours, from about 22:10 on 2012 June 5 through 4:50 2012 June 6, Universal Time. This transit is the rarest type of solar eclipse known -- much more rare than an eclipse of the Sun by the Moon or even by the planet Mercury. In fact, the next transit of Venus across the Sun will be in 2117. Anyone with a clear view of the Sun can go outside and carefully view the transit for themselves by projecting sunlight through a hole in a card onto a wall. Because this Venus transit is so unusual and visible from so much of the Earth, it is expected to be one of the more photographed celestial events in history. The above live image on the Sun is being taken by the Earth-orbiting Solar Dynamics Observatory and can be updated about every 15 minutes.

[Bluearrowll]

Re: Terry's Astronomy Thread.

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

-Look very high in the south after dark for bright Arcturus. Much lower, and perhaps a bit right, are Saturn and (below it) Spica. Farther down to their lower right is the four-star pattern of Corvus, the Crow.

Astro Picture of the Day:
June 5, 2012

Source:
A setting full moon rarely looks like this. Monday morning just before a fully lit Strawberry Moon dropped behind the Absaroka Mountain Range near Cody, Wyoming, USA, the shadow of the Earth got in the way. A similarly setting partial lunar eclipse was visible throughout most of North and South America, while simultaneously the same partially darkened moon was visible throughout eastern Asia. Pictured in the foreground is a snowbank formation known as the Horse's Head off a tributary of the Shoshone River. Lunar eclipses occur about twice a year, and the next one -- a penumbral eclipse -- will occur in late November.

My Photos of the Transit of Venus:

[Bluearrowll]

Re: Terry's Astronomy Thread.

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

-Have you ever explored the swarm of galaxies awaiting your telescope by the head of Serpens? See if you can find out how many Messier objects and objects on the NGC you can find here!

-Mars (magnitude +0.5) shines orange near the hind foot of Leo, high in the southwest at dusk and lower in the west as evening grows late. It's now roughly a third of the way from Regulus (off to its lower right) to the Saturn-and-Spica pair (left). Mars is heading east against the stars to pass right between Saturn and Spica in mid-August.

Astro Picture of the Day:
June 7, 2012

Source:
Occurring in pairs separated by over a hundred years, there have now been only eight transits of Venus since the invention of the telescope in 1608. The next will be in December of 2117. But many modern telescopes and cameras were trained on this week's Venus transit, capturing the planet in rare silhouette against the Sun. In this sharp telescopic view from Georgia, USA, a narrowband H-alpha filter was used to show the round planetary disk against a mottled solar surface with dark filaments, sunspots, and prominences. The transit itself lasted for 6 hours and 40 minutes. Historically, astronomers used timings of the transit from different locations to triangulate the distance to Venus, while modern astronomers actively search for planets that transit distant suns.

[Bluearrowll]

Re: Terry's Astronomy Thread.

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

-With June well under way, the Big Dipper has swung around to hang down by its handle high in the northwest during evening. The middle star of its handle is Mizar, with little Alcor right next to it. On which side of Mizar should you look for Alcor? As always, on the side toward bright Vega, which is now shining in the east-northeast.

Astro Picture of the Day:
June 8, 2012

Source:
This dramatic telephoto view across the Black Sea on June 6 finds Venus rising with the Sun, the planet in silhouette against a ruddy and ragged solar disk. Of course, the reddened light is due to scattering in planet Earth's atmosphere and the rare transit of Venus didn't influence the strangely shaped and distorted Sun. In fact, seeing the Sun in the shape of an Etruscan Vase is relatively common, especially compared to Venus transits. At sunset and sunrise, the effects of atmospheric refraction enhanced by long, low, sight lines and strong atmospheric temperature gradients produce the visual distortions and mirages. That situation is often favored by a sea horizon.

[Jerry DB]

Re: Terry's Astronomy Thread.

hmmm that is very interesting about our galaxies colliding. I am not a good at astrology at all but I always thought since our universe is expanding faster and faster, that our galaxies were too far away at this point to be sucked in by each others gravity. How does all of that work exactly?

[darklordsarumon9]

Re: Terry's Astronomy Thread.

^

http://en.wikipedia.org/wiki/Metric_expansion_of_space#Understanding_the_expansion_of_Universe

tl;dr but there's some reading for you (:

[Bluearrowll]

Re: Terry's Astronomy Thread.

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

-Binocular observers are often told to recognize a globular cluster as "a fuzzy star." How fuzzy? You can make the comparison very directly between the globular cluster M5 and the star 5 Serpentis just southeast of it. The star is magnitude 5.1; the cluster is 5.7 in total.

Astro Picture of the Day:
June 9, 2012

http://apod.nasa.gov/apod/ap120609.html

As its June 6 2012 transit begins Earth's sister planet crosses the edge of the Sun in this stunning view from the Hinode spacecraft. The timing of limb crossings during the rare transits was used historically to triangulate the distance to Venus and determine a value for the Earth-Sun distance called the astronomical unit. Still, modern space-based views like this one show the event against an evocative backdrop of the turbulent solar surface with prominences lofted above the Sun's edge by twisting magnetic fields. Remarkably, the thin ring of light seen surrounding the planet's dark silhouette is sunlight refracted by Venus' thick atmosphere.

[Bluearrowll]

Re: Terry's Astronomy Thread.

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

-After nightfall, Vega is the brightest star shining on the eastern side of the sky. Deneb is the brightest to its lower left. Look for Altair farther to Vega's lower right, still rather low. These three form the big Summer Triangle.

-This season there's another, temporary "summer triangle" in the southwest: bright Arcturus high on top, the Saturn-Spica pair below it, and Mars off to the pair's right or lower right.

-Last quarter Moon tonight (exact at 6:41 a.m. Monday morning EDT). The Moon, half-lit, rises in Aquarius in the middle of the night. By that time the Summer Triangle is very high in the east, high above it.

Astro Picture of the Day:
June 10, 2012

Source:
What if you were given a new Hubble telescope for free? How about two? The astronomical community is abuzz with just this opportunity as the US National Reconnaissance Office has unexpectedly transferred ownership of two space-qualified Hubble-quality telescopes to NASA. The usefulness of these telescopes in addressing existing science priorities has begun, but preliminary indications hold that even one of these telescope could be extremely useful in searching for extrasolar planets as well as distant galaxies and supernovas that could better explore the nature of dark energy. Although they start out as free, making even one telescope operational and fitting it with useful cameras would be quite expensive, so NASA is being decidedly careful about how to fit these new telescopes into its existing budget. Pictured above, the original Hubble Space Telescope floats high above the Earth during a servicing mission in 2002.

[Bluearrowll]

Re: Terry's Astronomy Thread.

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

-The two brightest stars of late spring and summer are Arcturus, now almost overhead toward the south or southwest after dark, and Vega, shining partway up the eastern sky. Arcturus is an orange giant 37 light-years away. Vega is a hot, white main-sequence star 25 light-years distant.

-Venus, having crossed the Sun from east to west during its transit on June 5th, is now very deep in the brightest glow of dawn. Don't confuse Venus with Jupiter, which is less low in the dawn and somewhat to the right. The two planets are 14° apart on the morning of June 9th and 9° apart by June 16th. Use binoculars as daylight brightens; look just above the east-northeast horizon. Jupiter and Venus are on their way up for a grand showing high in the morning sky this summer.

Astro Picture of the Day:
June 11, 2012

Source:
Few butterflies have a wingspan this big. The bright clusters and nebulae of planet Earth's night sky are often named for flowers or insects, and NGC 6302 is no exception. With an estimated surface temperature of about 250,000 degrees C, the central star of this particular planetary nebula is exceptionally hot though -- shining brightly in ultraviolet light but hidden from direct view by a dense torus of dust. This dramatically detailed close-up of the dying star's nebula was recorded by the Hubble Space Telescope soon after it was upgraded in 2009. Cutting across a bright cavity of ionized gas, the dust torus surrounding the central star is near the center of this view, almost edge-on to the line-of-sight. Molecular hydrogen has been detected in the hot star's dusty cosmic shroud. NGC 6302 lies about 4,000 light-years away in the arachnologically correct constellation of the Scorpion (Scorpius).

[Bluearrowll]

Re: Terry's Astronomy Thread.

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

-Look a third of the way from Arcturus to Vega for the dim semicircle of Corona Borealis, the Northern Crown. It has one modestly bright star, Alphecca. Two thirds of the way from Arcturus to Vega is the dim Keystone of Hercules.

-Mars (magnitude +0.6) shines orange near the hind foot of Leo, in the southwest at dusk and lower in the west as evening grows late. Mars is still less than halfway from Regulus (off to its lower right) to the Saturn-and-Spica pair (left). Mars will shoot the gap between Saturn and Spica in mid-August.

Astro Picture of the Day:
June 12, 2012

Source:
These are larger dust bunnies than you will find under your bed. Situated in rich star fields and glowing hydrogen gas, these opaque clouds of interstellar dust and gas are so large they might be able to form stars. Their home is known as IC 2944, a bright stellar nursery located about 5,900 light years away toward the constellation of Centaurus. The largest of these dark globules, first spotted by South African astronomer A. D. Thackeray in 1950, is likely two separate but overlapping clouds, each more than one light-year wide. Along with other data, the above representative color image from the 4-m Blanco telescope at Cerro Tololo, Chile indicates that Thackeray's globules are fractured and churning as a result of intense ultraviolet radiation from young, hot stars already energizing and heating the bright emission nebula. These and similar dark globules known to be associated with other star forming regions may ultimately be dissipated by their hostile environment - like cosmic lumps of butter in a hot frying pan.

[Bluearrowll]

Re: Terry's Astronomy Thread.

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

-Mercury is becoming more easily visible after sunset. Look for it low in the west-northwest in the fading twilight. It forms a long, vertical triangle with Pollux and Castor above it.

-Mercury (about magnitude –0.8) is very low in the west-northwest about 30 or 40 minutes after sundown. Don't confuse it with Capella well to its upper right, in the northwest.

Astro Picture of the Day:
June 13, 2012

Source:
Waiting years and traveling kilometers -- all to get a shot like this. And even with all of this planning, a good bit of luck was helpful. As the Sun rose over the Baltic Sea last Wednesday as seen from Fehmarn Island in northern Germany, photographer Jens Hackmann was ready for the very unusual black dot of Venus to appear superimposed. Less expected were the textures of clouds and haze that would tint different levels of the Sun various shades of red. And possibly the luckiest gift of all was a flicker of a rare green flash at the very top of the Sun. The above image is, of course, just one of many spectacular pictures taken last week of the last transit of the planet Venus across the face of the Sun for the next 105 years.

[MarioNintendo]

Re: Terry's Astronomy Thread.

Very cool thread.