The scale of things

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Ancient Astronomical Calendar Discovered in Scotland Predates Stonehenge by 6,000 Years
Universe Today, David Dickinson | August 7, 2013


^ A wintertime rising gibbous Moon. (Image credit: Art Explosion).

A team from the University of Birmingham recently announced an astronomical discovery in Scotland marking the beginnings of recorded time.

Announced last month in the Journal of Internet Archaeology, the Mesolithic monument consists of a series of pits near Aberdeenshire, Scotland. Estimated to date from 8,000 B.C., this 10,000 year old structure would pre-date calendars discovered in the Fertile Crescent region of the Middle East by over 5,000 years.

But this is no ordinary wall calendar.

Originally unearthed by the National Trust for Scotland in 2004, the site is designated as Warren Field near the town of Crathes. It consists of 12 pits in an arc 54 metres long that seem to correspond with 12 lunar months, plus an added correction to bring the calendar back into sync with the solar year on the date of the winter solstice.


^ A diagram of the Warren Field site, showing the 12 pits (below) and the alignment with the phases of the Moon plus the rising of the winter solstice Sun. Note: the scale should read “0-10 metres.” (Credit: The University of Birmingham).

“The evidence suggests that hunter-gatherer societies in Scotland had both the need and sophistication to track time across the years, to correct for seasonal drift of the lunar year” said team leader and professor of Landscape Archaeology at the University of Birmingham Vince Gaffney.

We talked last week about the necessity of timekeeping as cultures moved from a hunter-gatherer to agrarian lifestyle. Such abilities as marking the passage of the lunar cycles or the heliacal rising of the star Sirius gave cultures the edge needed to dominate in their day.



For context, the pyramids on the plains of Giza date from around 2500 B.C., The Ice Man on display in Bolzano Italy dates from 3,300 B.C., and the end of the last Ice Age was around 20,000 to 10,000 years ago, about the time that the calendar was constructed.

Read much more here.

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GRB Lights Up Ancient Hidden Galaxy
Universe Today, Tammy Plotner | August 7, 2013


^ This artist’s illustration depicts a gamma-ray burst illuminating clouds of interstellar gas in its host galaxy. By analyzing a recent gamma-ray burst, astronomers were able to learn about the chemistry of a galaxy 12.7 billion light-years from Earth. They discovered it contains only one-tenth of the heavy elements (metals) found in our solar system. Credit: Gemini Observatory/AURA, artwork by Lynette Cook

Once upon a time, more than 12.7 billion years ago, a star was poised on the edge of extinction. It made its home in a galaxy too small, too faint and too far away to even be spotted by the Hubble Space Telescope. Not that it would matter, because this star was going to end its life before the Earth formed. As it blew itself apart, it expelled its materials in twin jets which ripped through space at close to the speed of light – yet the light of its death throes outshone its parent galaxy by a million times.

“This star lived at a very interesting time, the so-called dark ages just a billion years after the Big Bang,” says lead author Ryan Chornock of the Harvard-Smithsonian Center for Astrophysics (CfA).

“In a sense, we’re forensic scientists investigating the death of a star and the life of a galaxy in the earliest phases of cosmic time,” he adds.

When this unsung star expired, it created one of the scariest things in astronomy… a gamma-ray burst (GRB). However, it wasn’t just a normal, garden variety GRB – it was long one, lasting more than four minutes. After century upon century of travel, the light reached our little corner of the Universe and was detected by NASA’s Swift spacecraft on June 6th. Chornock and his team quickly organized follow-up observations by the MMT Telescope in Arizona and the Gemini North telescope in Hawaii.

“We were able to get right on target in a matter of hours,” Chornock says. “That speed was crucial in detecting and studying the afterglow.”

Time to kick back and have a smoke? In a sense. The “afterglow” of a GRB happens when the jets impact the surrounding gas in an almost tsunami-like effect. As it sweeps up the material, it begins to heat and glow. As this light traverses the parent galaxy, it impacts clouds of interstellar gas, illuminating their spectra. Through these chemical signatures, astronomers are able to ascertain what gases the distant galaxy may have contained. As we know, all chemical elements heavier than hydrogen, helium, and lithium are the product of stars. Researchers refer to this as “metal content” and it takes a certain amount of time to accumulate. In the scheme of creation, the elements necessary for life – carbon and oxygen – didn’t exist. What Chornock and his team discovered was the GRB galaxy was host to only about a tenth of the “metals” in our solar system. What does that mean? In the eyes of the astronomers, rocky planets might have been able to form in that far away galaxy, but chances are good that life could not.

“At the time this star died, the universe was still getting ready for life. It didn’t have life yet, but was building the required elements,” says Chornock.

At a redshift of 5.9, or a distance of 12.7 billion light-years, GRB 130606A is one of the most distant gamma-ray bursts ever found.

“In the future we will be able to find and exploit even more distant GRBs with the planned Giant Magellan Telescope,” says Edo Berger of the CfA, a co-author on the publication.

Original Story Source: Harvard Smithsonian Center for Astrophysics News Release.

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Deep and Wide: Stunning Amateur View of the Lagoon and Trifid Nebulae
Universe Today, Nancy Atkinson | August 9, 2013


^ The Lagoon Nebula M8 (NGC 6523) , The Trifid Nebula M20 (NGC 6514), Star cluster M21 and star forming region NGC6559. Credit and copyright: Terry Hancock/Down Under Observatory.

Here’s a beautiful deep look at a wide-field view of the Lagoon Nebula (M8, NGC 6523) and the Trifid Nebula (M20, NGC 6514) along with star cluster M21 and star forming region NGC6559. Amateur astronomer and astrophotographer Terry Hancock from Michigan says this is one of his favorite fields of view to observe. However, right now it’s very low in the southern sky and therefore limited to a couple of hours each night. Just wait until next month, and this region will be higher in the sky for better northern hemisphere viewing.

Terry captured this view in H-Alpha plus RGB over 4 nights.

I’ll let him explain the view:


“Both of these objects are intensely rich with HII regions. Right of center is The Lagoon Nebula, a giant emission Nebula and HII region, bottom center can be seen the star forming region NGC6559 , these are estimated at 4,000 to 6,000 light years from us in the constellation Sagittarius.

Upper left in this image can be seen M20 or NGC 6514 known as The Trifid Nebula also in the constellation of Sagittarius and lies at a distance of approximately 5000 light years from us.

This object is a combination of emission nebula (the red area), reflection nebula (the blue area) and dark nebula (the dark jagged lines within the Trifid Nebula). Below left of M8 is the Star cluster M21.”

Just a really stunning “deep and wide” view of this region of the sky. See more of Terry’s work at his website, The Down Under Observatory (he’s originally from Australia) or on Flickr or Google +.

He’s also got a great video of some of his work:

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Beautiful Noctilucent Clouds 2013 — The Movie
Universe Today, Nancy Atkinson | August 12, 2013


^ music composer | Leon Felekyan, Russian

Intrigued by mysterious noctilucent, or night-shining clouds? This beautiful new film from TWAN (The World At Night) photographer P-M Hedén combines timelapse and real-time footage to provide a stunning compilation of his month in the field in Sweden this summer to capture these lovely blue electric clouds. Noctilucent clouds are visible sometimes low in the northern sky during morning and evening twilight, usually through late May through August, and they seem to be increasing the past few years.

Enjoy the stunning, tranquil views (lots of wildlife and night sky imagery too!) and lovely music in this new film, just published yesterday.

For more information about NLCs, Bob King wrote a great overview for us earlier this year about these “Visitors from the Twilight Zone”!

[justdrew]

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Drew, great minds travel in similar paths though almost two months apart.

[justdrew]

ahhh, I suspected so

[norton ash]

^^^ I'll defer to the more astronomy-expert on this, butbutbutbut...

...wouldn't Jupiter and Saturn at 384k away from us look more sky-overwhelmingly huge than those in the animation? It just seems like they would if one put them so relatively close to Earth.

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^ I posted the vid as a kind of tongue-in-cheek followup to the images in the previous post, after reading and somewhat trusting the vid maker's Ytube notes. But, yeah, I've thought too that Jupiter and Saturn would be larger than what's viewed in the vid, maybe covering an entire background of blue sky. And that's spoken by one whose aptitude for comparing astronomical objects and camera positions don't compare to my present claim to fame for preparing fine salads .

[norton ash]

Thanks, A. I'd trust you with the salad, stereo or answers on the proximity of heavenly bodies any old time.

[Pele'sDaughter]

http://www.universetoday.com/104103/bri ... inoculars/



Looking around for something new to see in your binoculars or telescope tonight? How about an object whose name literally means “new”. Japanese amateur astronomer Koichi Itagaki of Yamagata discovered an apparent nova or “new star” in the constellation Delphinus the Dolphin just today, August 14. He used a small 7-inch (.18-m) reflecting telescope and CCD camera to nab it. Let’s hope its mouthful of a temporary designation, PNVJ20233073+2046041, is soon changed to Nova Delphini 2013!

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