Explosions from White Dwarf Star RS Oph (APOD 26 Jul 2006)

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Galactic Groove
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Explosions from White Dwarf Star RS Oph (APOD 26 Jul 2006)

Post by Galactic Groove » Wed Jul 26, 2006 7:20 pm

http://antwrp.gsfc.nasa.gov/apod/ap060726.html

So regarding the info about it going nova roughly every 20 years and it becoming visible the the unaided eye... I was just wondering if you happened to be watching that area of the sky during the moment that it went nova, would you really see anything dramatic or would it just be another faint spec of light suddenly appearing, hiding itself amongst all the other regular looking stars?

(by dramatic i don't mean being able to see strings of plasma being flung out into space, but rather like someone just turned a flashlight on in your face, a small one at that.... basically would it suddenly outshine all else in the sky)

Also does anyone think this event could be predicted more precisely so that we could observe it on a given night?

regards :D

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Post by harry » Thu Jul 27, 2006 12:35 pm

Hello All


You would easily see it with your eye.

We should look at this,,,,,,,,,,,,,its a once in a life time.
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Post by Galactic Groove » Thu Jul 27, 2006 3:12 pm

well if you're already 80 years old it's a once in a lifetime thing :lol:
It says it happens roughly every 20 years so you could see this happen several times throughout your life, it'd be awesome just to catch it once though!

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Post by Qev » Thu Jul 27, 2006 5:58 pm

I doubt you'd see a 'burst of light' or anything particularly spectacular to the unaided eye during one of these nova outbursts. You'd likely observe the star brighten to visibility, to whatever its maximum apparent magnitude is, then slowly fade away again over several days.
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Post by Dr. Skeptic » Thu Jul 27, 2006 11:29 pm

There is a multitude of observations to aid in the understanding of such events.

- Light spectroscopy to identify the energy, speed and change in element composition of the ejected nebula.

- Collect data on neutrino burst, neutrino bursts can precede the visible light of a nova event by ~ .00001%. It is not known if neutrinos bursts precede the nova event or if neutrinos are traveling faster then the electromagnetic radiation.

Watching the event with the naked eye would not be of scientific value :roll: .
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Post by Qev » Fri Jul 28, 2006 2:30 am

Dr. Skeptic wrote:- Collect data on neutrino burst, neutrino bursts can precede the visible light of a nova event by ~ .00001%. It is not known if neutrinos bursts precede the nova event or if neutrinos are traveling faster then the electromagnetic radiation.
Well, it'd have to be the former, since as massy particles, neutrinos are restricted to velocities below that of light.

As far as supernovae go, the neutrinos from the event trail behind the initial burst of light, since over such a long distance, the electromagnetic radiation can easily outpace the neutrinos, despite their near-lightspeed velocities.
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Post by Dr. Skeptic » Fri Jul 28, 2006 4:06 am

First, the evidence of neutrinos having mass is not in.
Second, neutrino detectors have a pattern of increased activity prior to electromagnetic detection of supernovae (novae may not produce enough or additional neutrinos).
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Post by Qev » Fri Jul 28, 2006 5:14 am

Actually, it's pretty much settled that neutrinos have mass. They wouldn't be able to oscillate between flavors if they were massless, and since neutrino oscillation has been observed, that pretty much clinches it (and solves that annoying Solar Neutrino Problem).

I could very well be wrong about the order of detection for neutrinos and optical events in supernovae. I'll hafta look that one up again. :)
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Post by davehardy » Fri Jul 28, 2006 8:12 am

In reply to Galactic Groove, the artist who painted this RS Oph image isn't 80 -- but he is 70! (I should know :) -- see my website). But I'm sorry to say I haven't seen this nova with my own eyes. . .
My astronomical work was first published in 1954. Three of my (digital) images have appeared on APOD to date. I'm European Vice President of the International Association of Astronomical Artists (IAAA).

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Post by harry » Fri Jul 28, 2006 8:13 am

Hello All

Hi Qev,,,,,,,,,,,,,,,I'm sorry that I have not spent time on

Info on neutrino http://www.sallymckay.ca/oscillation/neutrinos.html

http://hyperphysics.phy-astr.gsu.edu/hb ... no.html#c1

http://hyperphysics.phy-astr.gsu.edu/hb ... o2.html#c2

http://hyperphysics.phy-astr.gsu.edu/hb ... o3.html#c1

Nuclear Synthesis
http://hyperphysics.phy-astr.gsu.edu/hb ... yn.html#c1

Rather than discussing the issue,,,,read about it


http://www2.arnes.si/~gljsentvid10/supn1.html

Code: Select all

In a few minutes the collapsing core is converted from nickel and iron nuclei to mostly alpha particles (helium nuclei). Deprived of support from the core, the overlying mass of the star freefalls. As this mass impacts onto the now largely Helium core it is further compressed and heated. The Helium is then dissociated into the fundamental subatomic particles - protons, neutrons, and electrons; and for a brief time the electrostatic force of the electrons resists the pressure of the star's overlying weight. But this resistance, known as electron degeneracy pressure, is not enough to resist the force of gravity given the tremendous mass of the star. In a white dwarf star electron degeneracy pressure is able overcome by gravity only if the mass is under a limit close to the Chandrasekhar limit. When the core approaches this limit the proton finds itself in a sea of electrons that cause the proton to be unstable against electron capture or "inverse beta decay". Electrons are absorbed into protons transmuting each electron-proton pair into a single neutron and releasing a neutrino in the process. Within fractions of a second the core is converted to a mass of neutrons at near nuclear density -- the core is literally a giant neutron-rich atom! 

As for neutrinos,,,,,,,,,,,,,,,,,they have mass and are able to travel at the speed of light,,,,,,,,,,but not in all situations.
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Post by Dr. Skeptic » Fri Jul 28, 2006 3:55 pm

There is inadequate information on the quantum properties of neutrinos to discern between the interactions of the three types neutrinos and other matter, assigning a mass is "one" interpretation of the data. Regardless, if a neutrino has mass, it is many magnitude less than that of a photon.

The supernova event 1987A, the neutrino detectors recorded a culmination of hits 16 to 18 hours previous to any optical detection.
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Post by orin stepanek » Fri Jul 28, 2006 4:08 pm

here's a little imput on the neutrinow. http://www.ps.uci.edu/~superk/neutrino.html
Sounds like a very little; mass wise. :?
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Post by Qev » Fri Jul 28, 2006 5:56 pm

Dr. Skeptic wrote:There is inadequate information on the quantum properties of neutrinos to discern between the interactions of the three types neutrinos and other matter, assigning a mass is "one" interpretation of the data. Regardless, if a neutrino has mass, it is many magnitude less than that of a photon.
Photons have zero rest mass, actually.
The supernova event 1987A, the neutrino detectors recorded a culmination of hits 16 to 18 hours previous to any optical detection.
That actually makes sense, now that I think about it. The neutrino pulse is less interactive with the material of the exploding star than the EM radiation, and so should escape before the EM does. Neat!
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Post by Dr. Skeptic » Fri Jul 28, 2006 7:17 pm

Photons have zero rest mass, actually.
Using the same qualifiers, neutrinos are also massless.
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Post by Qev » Sat Jul 29, 2006 3:16 am

I'm not sure I follow that. Neutrinos have, according to current observation, a small, but non-zero rest mass, which is what's meant by them 'having mass'. It's really the only meaningful concept of mass for a subatomic particle.

Now, it's entirely possible for a photon to carry more energy than a neutrino, certainly, but that's not dealing with rest mass. :)
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Post by Dr. Skeptic » Sat Jul 29, 2006 1:50 pm

The Mass of a photon is a "Relativistic Mass" which depends upon its wavelength. The mass of a neutrino may also have only a relativistic mass, it parallels the concept of "is a photon a wave or a particle?" it depends on analytical technique.

For those who wish to read more:

http://www.autodynamics.org/main/index. ... tion=53:47
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RS Ophiuchi

Post by davehardy » Sat Jul 29, 2006 2:06 pm

With respect, I thought this discussion was supposed to be on my (Wednesday's) APOD image of RS Ophiuchi -- not the mass of neutrinos! :roll:
My astronomical work was first published in 1954. Three of my (digital) images have appeared on APOD to date. I'm European Vice President of the International Association of Astronomical Artists (IAAA).

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Post by Qev » Sun Jul 30, 2006 1:54 am

What? This is the Internet! You can't expect us to stay on topic! ;)
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RS Ophiuchi

Post by davehardy » Sun Jul 30, 2006 6:42 am

That's true, Qev. But you try painting a neutrino! :cry:

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Post by harry » Sun Jul 30, 2006 12:17 pm

Thank you for the link Dr Skeptic

http://www.autodynamics.org/main/index. ... tion=53:47

I like it.

and yours also Orin.
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Re: RS Ophiuchi

Post by Qev » Sun Jul 30, 2006 5:07 pm

davehardy wrote:That's true, Qev. But you try painting a neutrino! :cry:
I've tried! I can't find a fine-enough brush, though! :lol:
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Post by Qev » Sun Jul 30, 2006 5:16 pm

harry wrote:Thank you for the link Dr Skeptic

http://www.autodynamics.org/main/index. ... tion=53:47

I like it.

and yours also Orin.
You do realize that autodynamics is utter bunk, don't you? :)
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Post by Dr. Skeptic » Sun Jul 30, 2006 7:22 pm

You do realize that autodynamics is utter bunk, don't you?
Good websites can be right 90% of the time.

Bad websites can be wrong 90% of the time.

90% right ≠ 100% right

90% wrong ≠ 100% wrong
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Post by harry » Wed Aug 02, 2006 8:18 am

Hello Qev

Smile,,,,,,,,,,,,,what is bunk?

If I like something it does not make it right.
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Post by Qev » Fri Aug 04, 2006 4:11 am

Autodynamics just screams 'pseudoscience'. Every time someone does an experiment with results that contradict it, its supporters come out invariably insisting that the experiment was done wrong. That's never a good sign. :)
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