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Are stars being recorded constantly?

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#1 petes21

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Posted 25 October 2020 - 02:50 PM

Hello I'm new here and I have a pretty basic question I believe and maybe a bit weird.

 

I'd like to know if stars are constantly being recorded just in case some events happen, for example Betelgeuse going supernova but what I'd like to know is if they are recorded with video and if there's a framerate that they get recorded at? Because if for example there's a fast flash and the recording is happening at 30fps then the video may not capture the event. Also I'd like to know what stars are recorded like this or the criteria used to record them.

 

 



#2 sg6

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Posted 25 October 2020 - 02:56 PM

I would say the sky is being recorded constantly and so if a star decides to do something "odd" then the event is hopefully recorded and then monitored.

 

Sloan Survey and many others exist. Surveying the sky is these days relatively straightforward for an automated system and a nice big camera and an equally nice big computer.

 

One easy survey is for a star going nova and even better super nova.

 

Since no 1 system can monitor the whole sky at once what happens is that hopefully 1 system sees something of interest and notifies the others and they slew to collect data. Again super nova is the one they hope to catch.

 

Sloan Digital Sky Survey sdss

So not exactly the stars specifically, just the sky and maybe specific regions of the sky.

 

Put "sky surveys" in to a search engine, quite a few results.


Edited by sg6, 25 October 2020 - 03:10 PM.


#3 wrnchhead

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Posted 25 October 2020 - 02:59 PM

The GAIA mission is. But I don’t know of anything constantly recording the entire sky, especially at any kind of video level framerates. There’s A LOT of sky out there. (And we have militaries to fund! Lol)

#4 GeneT

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Posted 25 October 2020 - 03:08 PM

Interesting question. I believe that among all the telescopes worldwide, that the every part of the sky is being recorded in some fashion daily/nightly. 



#5 Astrojensen

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Posted 25 October 2020 - 03:17 PM

There are NO stars, apart from our own Sun, that are being constantly recorded on a second to second basis, at least that I'm aware of. 

 

 

Clear skies!

Thomas, Denmark


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#6 BrooksObs

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Posted 25 October 2020 - 03:33 PM

Hello I'm new here and I have a pretty basic question I believe and maybe a bit weird.

 

I'd like to know if stars are constantly being recorded just in case some events happen, for example Betelgeuse going supernova but what I'd like to know is if they are recorded with video and if there's a framerate that they get recorded at? Because if for example there's a fast flash and the recording is happening at 30fps then the video may not capture the event. Also I'd like to know what stars are recorded like this or the criteria used to record them.

 

On a nightly basis, absolutely! An this is not only done by satellites and professionals, but amateur organizations as well. In many instances, however, this does not mean that the images are all examined immediately to detect new, unanticipated, events.

 

As to the monitoring to detect such as Betelgeuse for it going supernova, this is simply more media hype than reality as, if it were ever to occur at all, it will only like be "sometime in the next 10,000 years", or so. Any worry as to if we'll catch it in progress right at the start is needless as neither you nor I are likely to be around to see it!

 

BrooksObs


Edited by BrooksObs, 25 October 2020 - 03:34 PM.


#7 RazvanUnderStars

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Posted 25 October 2020 - 03:34 PM

The LSST survey performed by https://en.wikipedia...bin_Observatory will perform frequent (every ~3 days) captures of the southern sky. Read the article to get a  sense of the technological challenges of such an endeavour. 


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#8 petes21

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Posted 25 October 2020 - 04:32 PM

Ok so I guess it's impossible to prove it, but I think I saw a flash from Betelgeuse a few days before it started dimming last year and I was trying to figure out if it was possible because NASA said it was most likely caused by an immense amount of hot material ejected into space.

 

So I thought there maybe was an explosion or it tried to go supernova for a fraction of a second, but I don't know how these things work. Someone else would also have noticed it probably.



#9 PKDfan

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Posted 25 October 2020 - 05:37 PM

Hi Petes21! You may have seen a momentary satellite flare very near Belelgeuse. To see a flare from the star itself would be uber-rare if not impossible for a star like that.

Clear skies and Good seeing

#10 Sketcher

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Posted 25 October 2020 - 05:56 PM

Try Googling "Astronomical Seeing" and "Solar Flare Duration".

 

How long (temporal duration) did the flare you (think you) saw last?  (I'm guessing it was a fraction of a second as opposed to minutes or hours.)

 

What were your seeing conditions like at the time?  What telescope aperture?  What magnification?  Was the seeing good enough (and the magnification high enough) to show a sharply defined Airy disk along with a clear first diffraction ring while the "flare"was in progress?

 

Or was the seeing "crappy" with lots of atmospheric scintillation?

 

In order to be obvious enough to see from earth, a flare or any other brightening event on Betelgeuse, would have to cover a large surface area on the star; and that would have to occur over a time-span considerably longer than that of a brief flash of light.

 

My best guess:  Your "flare" was the result of atmospheric scintillation -- poor seeing conditions -- and had nothing at all to do with events occurring on Betelgeuse.



#11 Tony Flanders

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Posted 25 October 2020 - 05:59 PM

Hello I'm new here and I have a pretty basic question I believe and maybe a bit weird.

 

I'd like to know if stars are constantly being recorded just in case some events happen, for example Betelgeuse going supernova but what I'd like to know is if they are recorded with video and if there's a framerate that they get recorded at? Because if for example there's a fast flash and the recording is happening at 30fps then the video may not capture the event. Also I'd like to know what stars are recorded like this or the criteria used to record them.

Actually, the very brightest stars tend to be somewhat neglected, because they saturate the sensors of professional instruments.

 

Once the Large Synoptic Survey Telescope comes on line, a good fraction of all stars in the Milky Way (down to magnitude 24 and fainter) will be sampled twice a week, weather permitting. At the moment, we are very, very far from that capability. The general consensus is that the LSST will revolutionize many difference aspects of astronomy.

 

Judging by our knowledge of the Sun, which is indeed sampled constantly and frequently, there's no reason to go to sub-second time scales. Remember that the Sun is 5 light-seconds across, so any event lasting less than 1 second must necessarily involve only a very small part of the Sun's surface.


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#12 BrooksObs

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Posted 25 October 2020 - 06:17 PM

Ok so I guess it's impossible to prove it, but I think I saw a flash from Betelgeuse a few days before it started dimming last year and I was trying to figure out if it was possible because NASA said it was most likely caused by an immense amount of hot material ejected into space.

 

So I thought there maybe was an explosion or it tried to go supernova for a fraction of a second, but I don't know how these things work. Someone else would also have noticed it probably.

 

Just as others have already indicated, any "momentary flash" could not actually originate from Betelgeuse itself.

 

BrooksObs



#13 ButterFly

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Posted 26 October 2020 - 12:33 AM

So I thought there maybe was an explosion or it tried to go supernova for a fraction of a second, but I don't know how these things work. Someone else would also have noticed it probably.

There would be an unmistakable neutrino outburst before it goes supernova (on the order of a million hits in current detectors).  It would give everyone a few hours to point their scopes and capture at the highest rate they can.  Too bad for those in daylight who can't align their goto!


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#14 KBHornblower

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Posted 26 October 2020 - 09:42 AM

Whenever the core of Betelgeuse implodes, it will be in a matter of seconds and the neutrino burst will be similarly fast.  If I am not mistaken the visual flareup of the photosphere will take at least a few hours to become apparent.



#15 Voyager 3

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Posted 26 October 2020 - 09:57 AM

What do you mean by constantly recorded ? Do you mean each and every star upto a magnitude limit ?

#16 csrlice12

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Posted 26 October 2020 - 12:23 PM

Is the Earth being recorded constantly by others?



#17 Tony Flanders

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Posted 26 October 2020 - 03:42 PM

Whenever the core of Betelgeuse implodes, it will be in a matter of seconds and the neutrino burst will be similarly fast.  If I am not mistaken the visual flareup of the photosphere will take at least a few hours to become apparent.

Right. Stars' cores are actually quite small, allowing implosion on a few-second timescale. But like most stars ready to supernova, Betelgeuse itself is roughly the size of Jupiter's orbit, a bit more than one light-hour across. So even the very first burst of light from a supernova is smeared over a period of an hour of so, depending which part of Betelgeuse you're looking at. Then the light continues to ramp up as the neutrino front hits shells emitted from the star in previous sub-explosive episodes, and as emissions from various radioactive nuclei start to dominate the overall light output.




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