Potentially the biggest scientific story in history?

[barbos]

Size of the antenna is proportional to distance. So if you want to get alien satellite TV transmission fro 1000 light years away you will need antenna which is 1000.*365.*24*3600*300000./30000. = 315360000000 times bigger than normal one.
that's 315 billions time bigger. Ordinary SatTV antenna is 0.5 meter in diameter then you will need antenna with 1 astronomical unit in diameter.
So we will need to build a Dyson sphere here to get their signals.

Or just an array of antennae that has a diameter of 1 AU. We could simply launch a few hundred or a few thousand such antennae to orbit the sun evenly spaced at a distance of 75 million km (0.5AU) to achieve this - not cheap, but much cheaper than a Dyson Sphere

That would not really help. that would give you better spatial resolution but not better Signal/Noise ratio

The bandwidth would suck, but it's OK if we just want to detect whether there is a signal

Unfortunately digital signals are hard to distinguish from noise even without actual noise.

 

[skepticalbip]

I wonder if it could be an instrument not behaving itself on Kepler? We need other telescopes to detect this change in brightness as well before we can even say it is changing.

Kepler is monitoring something like 100,000 stars and KIC8462852 is the only one showing this unexplained light curve so it is unlikely an instrument anomaly.

I can't help but wonder if anyone has suggested that it may be something abnormal about the behavior of the star itself. It would, however, be difficult to impossible to support the suggestion since nothing we think we know about stellar evolution would support it and scientists don't like to offer possibilities unless they can be supported by current theory.

 

[DBT]

Here's what Brian Cox has to say:

"I emphasise, it probably isn't solar panels, but it's data that isn't explained at the moment and it wouldn't be horrendously surprising if it turned out there was an advanced alien civilisation there that was way ahead of us and had built some big solar panels. I wouldn't go 'that's impossible' – it isn't – in fact I would like to say I wouldn't be surprised at all."

 

[Harry Bosch]

Here's what Brian Cox has to say:

"I emphasise, it probably isn't solar panels, but it's data that isn't explained at the moment and it wouldn't be horrendously surprising if it turned out there was an advanced alien civilisation there that was way ahead of us and had built some big solar panels. I wouldn't go 'that's impossible' – it isn't – in fact I would like to say I wouldn't be surprised at all."

Wow, that was a tortured sentence!

 

[Loren Pechtel]

Don't be stupid! The unkonwn is always proof of God. Don't you know anything?

Don't be stupid! Is God human? Certainly not! Therefore he is an alien! Logic 101, don't you know anything?

 

[fromderinside]

C'mon people. A phenomenon which is seen to some degree elsewhere is not even a big story.

Now if we somehow linked dark matter to a reciprocal 'bang' that would be a big story, especially if it turned out that's haw bangs occur.

 

[braces_for_impact]

I think if we're going to find something, Breakthrough Listen will have the best chance to find it.

From the website:

Breakthrough Listen is the largest ever scientific research program aimed at finding evidence of civilizations beyond Earth. The scope and power of the search are on an unprecedented scale:
The program includes a survey of the 1,000,000 closest stars to Earth. It scans the center of our galaxy and the entire galactic plane. Beyond the Milky Way, it listens for messages from the 100 closest galaxies to ours.
The instruments used are among the world’s most powerful. They are 50 times more sensitive than existing telescopes dedicated to the search for intelligence.
The radio surveys cover 10 times more of the sky than previous programs. They also cover at least 5 times more of the radio spectrum – and do it 100 times faster. They are sensitive enough to hear a common aircraft radar transmitting to us from any of the 1000 nearest stars.
We are also carrying out the deepest and broadest ever search for optical laser transmissions. These spectroscopic searches are 1000 times more effective at finding laser signals than ordinary visible light surveys. They could detect a 100 watt laser (the energy of a normal household bulb) from 25 trillion miles away.
Listen combines these instruments with innovative software and data analysis techniques.

Bolding is mine.

 

[Shadowy Man]

I think if we're going to find something, Breakthrough Listen will have the best chance to find it.

From the website:

Breakthrough Listen is the largest ever scientific research program aimed at finding evidence of civilizations beyond Earth. The scope and power of the search are on an unprecedented scale:
The program includes a survey of the 1,000,000 closest stars to Earth. It scans the center of our galaxy and the entire galactic plane. Beyond the Milky Way, it listens for messages from the 100 closest galaxies to ours.
The instruments used are among the world’s most powerful. They are 50 times more sensitive than existing telescopes dedicated to the search for intelligence.
The radio surveys cover 10 times more of the sky than previous programs. They also cover at least 5 times more of the radio spectrum – and do it 100 times faster. They are sensitive enough to hear a common aircraft radar transmitting to us from any of the 1000 nearest stars.
We are also carrying out the deepest and broadest ever search for optical laser transmissions. These spectroscopic searches are 1000 times more effective at finding laser signals than ordinary visible light surveys. They could detect a 100 watt laser (the energy of a normal household bulb) from 25 trillion miles away.
Listen combines these instruments with innovative software and data analysis techniques.

Bolding is mine.

It's not just sensitivity that is important. It's contrast against ambient signals. So you'd have to look at what other signals might be coming across the radio spectrum and see how detectable an artificial signal would be above that baseline.

 

[KeepTalking]

Some more information on Tabby's Star from an article posted earlier this week on Space.com:

Kepler's 'Alien Megastructure' Star Just Got Weirder

On the planetary debris/comet swarm hypothesis:

So, until now the leading (natural) explanation of the strange light-curve has focused on the possibility of a huge swarm of comets passing in front of the star, blocking a substantial portion of starlight from Kepler's optics. Recently, this hypothesis was given a little more credence after observations by the Submillimeter Array and the James Clerk Maxwell Telescope in Hawaii revealed little evidence it might be caused by the debris cloud of some planetary smashup. But the "swarm of comets" explanation still fell short of fully explaining the phenomenon, though for now it remains the leading rationale.

The new weirdness to which the article's title refers:

So, in an effort to track down a rational explanation, Bradley Schaefer from Louisiana State University decided to study historical observations of KIC 8462852 in astronomical photographic plates from the past century to see if the star exhibited any bizarre fluctuations in brightness in the past. Sure enough, yes, the star is a bit of an oddball and has shown a long-term decreasing trend in brightness! Since the 19th Century, its brightness has decreased steadily by nearly 20 percent.

Now, astronomers Ben Montet (from Caltech) and Joshua Simon (from the Carnegie Institute) have released a paper to the arXiv preprint service detailing recent Kepler observations of KIC 8462852 since the space telescope was launched in 2009. Although the dataset for this time period is comparatively small, Monet and Simon found yet another surprise.

In the 4 years of Kepler's primary mission, the star showed an unprecedented dimming of 3.5 percent. So not only did Kepler detect transient dips in brightness of up to 20 percent, there also seems to be a very definite downward trend in brightness throughout our observational history of the star.

The article also reinforces that this is the only star Kepler has surveyed to exhibit this weird behavior, so it is not a problem with Kepler itself.

 

[DBT]

Here's what Brian Cox has to say:

"I emphasise, it probably isn't solar panels, but it's data that isn't explained at the moment and it wouldn't be horrendously surprising if it turned out there was an advanced alien civilisation there that was way ahead of us and had built some big solar panels. I wouldn't go 'that's impossible' – it isn't – in fact I would like to say I wouldn't be surprised at all."

Wow, that was a tortured sentence!

That's what it take to cover your arse for all possible eventualities.

 

[Don2 (Don1 Revised)]

Some more information on Tabby's Star from an article posted earlier this week on Space.com:

Kepler's 'Alien Megastructure' Star Just Got Weirder

On the planetary debris/comet swarm hypothesis:



The new weirdness to which the article's title refers:

So, in an effort to track down a rational explanation, Bradley Schaefer from Louisiana State University decided to study historical observations of KIC 8462852 in astronomical photographic plates from the past century to see if the star exhibited any bizarre fluctuations in brightness in the past. Sure enough, yes, the star is a bit of an oddball and has shown a long-term decreasing trend in brightness! Since the 19th Century, its brightness has decreased steadily by nearly 20 percent.

Now, astronomers Ben Montet (from Caltech) and Joshua Simon (from the Carnegie Institute) have released a paper to the arXiv preprint service detailing recent Kepler observations of KIC 8462852 since the space telescope was launched in 2009. Although the dataset for this time period is comparatively small, Monet and Simon found yet another surprise.

In the 4 years of Kepler's primary mission, the star showed an unprecedented dimming of 3.5 percent. So not only did Kepler detect transient dips in brightness of up to 20 percent, there also seems to be a very definite downward trend in brightness throughout our observational history of the star.

The article also reinforces that this is the only star Kepler has surveyed to exhibit this weird behavior, so it is not a problem with Kepler itself.

Re this piece "Since the 19th Century, its brightness has decreased steadily by nearly 20 percent..." what kind of brightness measure did they have in the 19th century and how accurate and precise was it?

 

[aeebee50]

It is always good to see scientists sharing their thoughts. I am waiting to see more people traveling in space.

 

[KeepTalking]

Some more information on Tabby's Star from an article posted earlier this week on Space.com:

Kepler's 'Alien Megastructure' Star Just Got Weirder

On the planetary debris/comet swarm hypothesis:



The new weirdness to which the article's title refers:



The article also reinforces that this is the only star Kepler has surveyed to exhibit this weird behavior, so it is not a problem with Kepler itself.

Re this piece "Since the 19th Century, its brightness has decreased steadily by nearly 20 percent..." what kind of brightness measure did they have in the 19th century and how accurate and precise was it?

The same one they had for the 20 centuries or so prior to that:

The history of astrometry is linked to the history of star catalogues, which gave astronomers reference points for objects in the sky so they could track their movements. This can be dated back to Hipparchus, who around 190 BC used the catalogue of his predecessors Timocharis and Aristillus to discover Earth's precession. In doing so, he also developed the brightness scale still in use today.[1] Hipparchus compiled a catalogue with at least 850 stars and their positions.[2] Hipparchus's successor, Ptolemy, included a catalogue of 1,022 stars in his work the Almagest, giving their location, coordinates, and brightness.

 https://en.wikipedia.org/wiki/Astrometry

The Space.com article also notes that for data from the past century, photographic plates taken of the star over that time were examined. For that time period it would be a simple matter of comparing the star to other stars in the field of view, and noting the change in luminosity compared to those other stars.

 

[fromderinside]

The Space.com article also notes that for data from the past century, photographic plates taken of the star over that time were examined. For that time period it would be a simple matter of comparing the star to other stars in the field of view, and noting the change in luminosity compared to those other stars.

So here we are two thirds of the way out on a band of a spiral of a galaxy not around at the beginning measuring 'space' product, light traveling across great distances over time, and proclaiming brightness findings. So do we have an objective standard or is it still a subjective class thing (a certain type supernova) as a standard. And, and do we have any knowledge of the among of dark matter intervening between us and it or of that matter's rate of change.

 

[KeepTalking]

The Space.com article also notes that for data from the past century, photographic plates taken of the star over that time were examined. For that time period it would be a simple matter of comparing the star to other stars in the field of view, and noting the change in luminosity compared to those other stars.

So here we are two thirds of the way out on a band of a spiral of a galaxy not around at the beginning measuring 'space' product, light traveling across great distances over time, and proclaiming brightness findings. So do we have an objective standard or is it still a subjective class thing (a certain type supernova) as a standard.

The short answer is that yes, the standard candle is still based on type 1A supernovae, and there may still be issues with that standard candle, particularly for stars that a very far away. For closer stars the measurements can be more or less confirmed using parallax. By 'closer', I mean stars within about 2,000 light years (the star under discussion here falls within that range. The Hubble Telescope allows for parallax measurement to some stars as far out as 20,000 ly.

And, and do we have any knowledge of the among of dark matter intervening between us and it or of that matter's rate of change.

We really don't even understand what Dark Matter is at this point, although recent research has ruled out three previous possibilities, making the list of candidates that much smaller. You can read about it here:

http://www.space.com/33755-dark-matter-candidates-fermi-space-telescope.html

I don't think Dark Matter is really going to change anything here, however, as the effects are generally only noticed in the CMB, and the space between galaxies.

 

[barbos]

The Space.com article also notes that for data from the past century, photographic plates taken of the star over that time were examined. For that time period it would be a simple matter of comparing the star to other stars in the field of view, and noting the change in luminosity compared to those other stars.

So here we are two thirds of the way out on a band of a spiral of a galaxy not around at the beginning measuring 'space' product, light traveling across great distances over time, and proclaiming brightness findings. So do we have an objective standard or is it still a subjective class thing (a certain type supernova) as a standard. And, and do we have any knowledge of the among of dark matter intervening between us and it or of that matter's rate of change.

I don't quite follow your criticism but the fact that the star has been weird is well established fact.

 

[fromderinside]

I don't quite follow your criticism but the fact that the star has been weird is well established fact.

I'm suggesting, like others, that part of that 'weird' is between observed and observer conditions. Also we have an inferred standard candle based on observed brightness of a particular class of supernovae. There is no direct measurement of brightness. So what we have is observed changes in brightness. important, but not conclusive, upon which we are making judgments. There should be other signatures indicating the whys of brightness change such as changes in chemical fractions. I didn't read that that was so. Nor did I read of any evaluations of conditions between observed and observer remaining consistent with other sighted 'change' stars. All of that kind of data should be available.

 

[Shadowy Man]

I don't quite follow your criticism but the fact that the star has been weird is well established fact.

I'm suggesting, like others, that part of that 'weird' is between observed and observer conditions. Also we have an inferred standard candle based on observed brightness of a particular class of supernovae. There is no direct measurement of brightness. So what we have is observed changes in brightness. important, but not conclusive, upon which we are making judgments. There should be other signatures indicating the whys of brightness change such as changes in chemical fractions. I didn't read that that was so. Nor did I read of any evaluations of conditions between observed and observer remaining consistent with other sighted 'change' stars. All of that kind of data should be available.

What do supernovae have to do with the brightness variations of KIC 8462852?

 

[barbos]

I don't quite follow your criticism but the fact that the star has been weird is well established fact.

I'm suggesting, like others, that part of that 'weird' is between observed and observer conditions. Also we have an inferred standard candle based on observed brightness of a particular class of supernovae. There is no direct measurement of brightness. So what we have is observed changes in brightness. important, but not conclusive, upon which we are making judgments. There should be other signatures indicating the whys of brightness change such as changes in chemical fractions. I didn't read that that was so. Nor did I read of any evaluations of conditions between observed and observer remaining consistent with other sighted 'change' stars. All of that kind of data should be available.

First of all, supernova standard candle is irrelevant here, they are for measuring distances to other galaxies. Second of all, there is no need for absolute brightness here, they are looking at changes in the brightness.

 

[fromderinside]

I'm suggesting, like others, that part of that 'weird' is between observed and observer conditions. Also we have an inferred standard candle based on observed brightness of a particular class of supernovae. There is no direct measurement of brightness. So what we have is observed changes in brightness. important, but not conclusive, upon which we are making judgments. There should be other signatures indicating the whys of brightness change such as changes in chemical fractions. I didn't read that that was so. Nor did I read of any evaluations of conditions between observed and observer remaining consistent with other sighted 'change' stars. All of that kind of data should be available.

First of all, supernova standard candle is irrelevant here, they are for measuring distances to other galaxies. Second of all, there is no need for absolute brightness here, they are looking at changes in the brightness.

To measure change in something one needs to know something.