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Betelgeuse super nova


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1 minute ago, Paul M said:

Most of the intense radiation of the core collapse is screened from us by the outer layers of the star. Those take time to be disrupted and be ionized and eventually ejected into space by the core collapse. What does escape immediately is the glut of neutrinos created at that moment. They are effectively mass-less and beat everything else out of there. 

Don't worry. Apparently there are neutrinos passing through us in great numbers all the time. They won't wait to be focused by a telescope or captured by a CCD chip. They'll carry on their merry way, mostly!

Just finished reading the book Big Bang. I think I understood about a quarter of it. Your explanation of neutrino bursts from the sn makes me realise I need to read it again.

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2 hours ago, robin_astro said:

There would still be much of interest from a spectroscopic point of view though and something that bright would give professionals a big headache.  Even with my equipment I am not sure how I would cope. I would probably have to resort to defocusing and sampling the defocused image using the spectrograph slit as I did for Vega with this simple setup here for example

http://www.threehillsobservatory.co.uk/astro/spectroscopy_18.htm

(Off topic in this sub forum though)

Robin i looked at your work and it looked absolutely fascinating. i really liked the experiment which you ran looking at the crab nebula, at the frequency of pulses from the pulsar in the centre! More on topic, how would the spectra vary with time would the light to begin with be very low wavelength as the debris gets further away the photons get less energetic? how does it work?

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2 minutes ago, Alien 13 said:

Do we know what causes these dimming events, is it due to a large number of sunspots/change in size of the star or something else?

Alan

not sure whether Betelgeuse is a specific case but yes in general, my understanding is and please correct me if I'm wrong is that variable stars contract and expand and hence their brightness changes. the rate at which this happens is called the fundamental frequency, the higher frequency variables tend not to be as bright as the lower frequency variables however off the top of my head i cannot remember what that relationship is called.

hope this somewhat helps,

Luke.

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22 hours ago, lukeEdfarley said:

Robin i looked at your work and it looked absolutely fascinating. i really liked the experiment which you ran looking at the crab nebula, at the frequency of pulses from the pulsar in the centre! More on topic, how would the spectra vary with time would the light to begin with be very low wavelength as the debris gets further away the photons get less energetic? how does it work?

Supernova spectroscopy is a particular interest of mine. Most supernovae are very faint even at maximum so I am one of only a couple of amateurs who confirm and classify supernovae spectroscopically using a spectorgraph I specially modified for the job.  

http://www.threehillsobservatory.co.uk/astro/spectroscopy_20.htm

The spectrum changes quite rapidly in the first few days/months, mainly due to the hot material cooling (shifting from blue to red over all) and becoming more diffuse (giving a spectrum with strong emission lines like a nebula) . You also see different lines appearing as the new elements produced decay.  Most SN are too faint to be followed very long spectroscopically by amateurs but it is possible with the brightest ones. Here is one (a type II like Betelgeuse will become) which I followed for a year  from mag 13 to mag 18 (from from a BAA presentation I gave)

 

Cheers

Robin

supernova_spectrum_evolution.png

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Here is another spectrum of a type II about 1 month after it exploded (A very early spectrum of mine using a simple diffraction grating mounted directly in front of the camera. ) You can measure the velocity of the explosion from the blue shift in the material coming in our direction (about 8000km/s at this point)

http://www.threehillsobservatory.co.uk/astro/spectra_6.htm

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9 minutes ago, robin_astro said:

 You can measure the velocity of the explosion from the blue shift in the material coming in our direction (about 8000km/s at this point)

 

You can also tell the type of supernova from the spectrum  (Core collapse of a massive star or explosion of a white dwarf which exceeds critical mass) 

 

 

sn_type.png

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