Comments on: Astronomers Spy Oldest Object In Universe

Satellites Catch Gamma-Ray Burst From Star's Death That Occurred Over 13 Billion Years Ago

[Void_Master]

As I understand it, the rate of expansion is increasing. Is that not correct? How accurately do we "know" the rate of expansion?

[realnews12]

Still I would like to better understand the method they are using. Parallax will not work that far away and I am aware of no other method that actually measures (rather than logically deduces) a radial distance.

Posted by Void_Master at 6:08 PM : Apr 28, 2009

The Universe is expanding at a known rate. In other words, the expansion velocity is a function of distance. The radial velocity (i.e., along the line of sight to the object) can be measured by the Doppler shift of the object's spectral lines. Hence, the distance of the object is determined.

[Void_Master]

Parallax works. You take a measurement in summer while you are at one sector of the orbit around the sun, and another measurement in winter when you are aproximately 180 million miles on the other side. Of course you have to take into consideration the suns motion and relativistic effects. But Parallax works really well.

Posted by McHineguy
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I know Parallax that and how works. I have done the calculations before. But Parallax only works out to about 1600 light years. Using the Hippaccaros probe, I think they expect to expand that to something like 15,000. But beyond that extreme, Parallax cannot work because the angles you are measuring become to narrow to distinguish them. So as far as I can tall, measuring the distance of anything beyond that is an educated guess at best.

[McHineguy]

Ok, after re-reading your post, that sort of makes sense. Still I would like to better understand the method they are using. Parallax will not work that far away and I am aware of no other method that actually measures (rather than logically deduces) a radial distance.
Posted by Void_Master at 6:08 PM : Apr 28, 2009

Parallax works. You take a measurement in summer while you are at one sector of the orbit around the sun, and another measurement in winter when you are aproximately 180 million miles on the other side. Of course you have to take into consideration the suns motion and relativistic effects. But Parallax works really well.

[Void_Master]

Your headline... Do ya' mean like that 'stunt' flyover of the statute of Liberty?

Posted by virulent3
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Was that not a great practical joke or what?

[Void_Master]

There is a phrase for people who believe science is a waste of time: less evolved.

[Void_Master]

Astrology is worthless and a waste of our tax money. Astrology is a occupation invented for lazy people to make money sightseeing and making up stories to make us believe their are intelligent. Unemployed astrologist are so lazy they become clergy or bird watchers.

Posted by sky_five
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What does astrology have to do with this story?

[pepperwood2]

Astronomers Spy Oldest Object In Universe........probably was Hagliary out in space riding her broom. cackle cackle cackle

[virulent3]

Your headline... Do ya' mean like that 'stunt' flyover of the statute of Liberty?

[Void_Master]

A few hours later, Tanvir's team confirmed the distance using one of the European Very Large Telescopes on Cerro Paranal in Chile.

Posted by legacyabq
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Ok, after re-reading your post, that sort of makes sense. Still I would like to better understand the method they are using. Parallax will not work that far away and I am aware of no other method that actually measures (rather than logically deduces) a radial distance.

[Void_Master]

Using astrology to date stars usually begins by asking the actress what her sign is.

Posted by erb0087
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I almost blew coffee on my keyboard over that - lmao.

[Void_Master]

Spectral shift maybe; I'm not sure how that works exactly. But dopper effect, if I am not mistaken would only show if the object is moving towards or away from the observer, at what speed, whether it was accelerating or decelerating and at what rate.

They may be using a combination of things to "guestimate" its radial distance, but I honestly do not see how any current method would be very accurate that far out.

[erb0087]

"You people obviously know nothing about astrology and how the dating of stars is done."
Posted by astranger-2009 at 2:47 PM : Apr 28, 2009

Using astrology to date stars usually begins by asking the actress what her sign is.

[legacyabq]

from sciencedaily

Beyond a certain distance, the expansion of the universe shifts all optical emission into longer infrared wavelengths. While a star's ultraviolet light could be similarly shifted into the visible region, ultraviolet-absorbing hydrogen gas grows thicker at earlier times. "If you look far enough away, you can't see visible light from any object," he noted.

Within three hours of the burst, Nial Tanvir at the University of Leicester, U.K., and his colleagues reported detection of an infrared source at the Swift position using the United Kingdom Infrared Telescope on Mauna Kea, Hawaii. "Burst afterglows provide us with the most information about the exploded star and its environs," Tanvir said. "But because afterglows fade out so fast, we must target them quickly."

At the same time, Fox led an effort to obtain infrared images of the afterglow using the Gemini North Telescope on Mauna Kea. The source appeared in longer-wavelength images but was absent in an image taken at the shortest wavelength of 1 micron. This "drop out" corresponded to a distance of about 13 billion light-years.

As Fox spread the word about the record distance, telescopes around the world slewed toward GRB 090423 to observe the afterglow before it faded away.

At the Galileo National Telescope on La Palma in the Canary Islands, a team including Guido Chincarini at the University of Milan-Bicocca, Italy, determined that the afterglow's so-called redshift was 8.2. Tanvir's team, gathering nearly simultaneous observations using one of the European Southern Observatory's Very Large Telescopes on Cerro Paranal, Chile, arrived at the same number. The burst exploded 13.035 billion light-years away.

"It's an incredible find," Chincarini said. "What makes it even better is that a telescope named for Galileo made this measurement during the year in which we celebrate the 400th anniversary of Galileo's first astronomical use of the telescope."

A few hours later, Tanvir's team confirmed the distance using one of the European Very Large Telescopes on Cerro Paranal in Chile.

The previous record holder was a burst seen in September 2008. It showed a redshift of 6.7, which places it 190 million light-years closer than GRB 090423.

Gamma-ray bursts are discovered by telescopes in space. After releasing their intense burst of high-energy radiation, they become detectable for a short while in the optical and in the near-infrared. This ?afterglow? fades very rapidly, making detailed analysis possible for only a few hours after the gamma-ray detection. This analysis is important in particular in order to determine the GRB's distance and, hence, intrinsic brightness.

Gamma-ray bursts are the universe's most luminous explosions. Most occur when massive stars run out of nuclear fuel. As their cores collapse into a black hole or neutron star, gas jets ? driven by processes not fully understood ? punch through the star and blast into space. There, they strike gas previously shed by the star and heat it, which generates short-lived afterglows in many wavelengths.

[legacyabq]

Posted by Void_Master at 4:53 PM :

doppler effect?

spectral shift?

not sure

[stn_sage]

No offense---but since this report comes from NASA---I'll "take it with a grain of salt"!

Unfortunately, they have a long and sordid history of touching up photos from both the moon and Mars to hide stuff---among other things---that makes believing them on anything---difficult!

[Void_Master]

Does anyone know how they are calculating distances that are well beyond the parallax boundary?

[John_Merritt]

Are you absolutely certain this star is dying? Maybe, just maybe, it is re-energizing. Think about it? Per se, how long have you been tracking it and what are its actual characteristics that are measurable, quantifiable and traceable?

[endurorob]

LOL that's funny. Hey guys I don't know if you have ever done this, but if you go to www.hubbletelescope.com, you actually travel through space as if you were sitting on top of the telescope watching the universe fly by. It is an awesome site and offers hours of Hubble's missions from past to present. Truly amazing and enjoyable.
Posted by Stuart2560 at 3:00 PM : Apr 28, 2009

You forgot the - between hubble and telescope.

[thetireguy1]

I marvel that the astronomers can be looking at a spot in the galaxy and see something that
happened millions of years ago and just like a flash bulb going off, they are able to witness
and calculate what they saw in a blink of an eye!
I wonder if they are so lucky to see that, do they ever go to Vegas and try their luck
at blackjack? GOD Speed to Star Trek