# Tag Info

12

None of those stars can go supernova, so the question is rather moot. If you look at the classifications, the most luminous is Sirius A (an A sequence star even) you can get an idea of its mass. If you look at your source page, and link to the explanation you see that A stars range from 1.4 to 2.1 stellar masses. In order to go supernova though, you need ...

10

It's a matter of size and stellar evolution. There are many, many types of stellar explosions. The University of Arizona has one page that describes these types. generally, a Novs is not what we think of (i.e. a star exploding). That's actually a Type II Supernova. According to that site: Novae are frequently (perhaps always) members of binary ...

6

Given the description, that light patch was probably Pleiades. It is a star cluster in the constellation of Taurus which is inspired from a popular Greek mythology of Seven Sisters. You can read more about it here. EDIT: One of the great softwares, free and open source, for amateur level observational astronomy, though professionals use it as frequently ...

6

As you say, SN 1572 is not very bright in the optical. There are some Hα regions that have been observed with world-class optical telescopes, but they do not look like the X-ray and infrared images that you normally see. In fact, images from the Palomar Optical Sky Survey 2 (with a limiting magnitude of ~22) do not reveal any nebular emission from ...

6

Your question is a bit oversimplified because there are many types of supernovae based on the size and configuration of the star. But I can answer your question about "why iron" by considering what keeps a star from exploding in the first place. In the simplest terms of star formation, when material from an interstellar nebula starts to collapse under its ...

5

The current supernova is a supernova of type Ia. Supernovae of type Ia are used as standard candles for distance estimates, especially used to determine the Hubble constant. Hence by a better calibration of this kind of supernovae, more about the reliability and accuracy of distance estimates can be learned. The expansion rate (in relation to the distance) ...

5

It does not appear to be practical to photograph with amateur equipment. According to the Wikipedia article the remnant was viewed visually with Palomar telescope. Links to studies of the remnants were done using 2m + telescopes. So trying to get a visible light photo would require an extremely large telescope. This table does not list a magnitude for ...

4

According to this website the peak visible magnitude will be about 10.5 around February 2nd. Earlier estimates had been a little brighter around the same date.

3

For a star to become a nova, it needs to have a mass at least 8 times greater than our sun. For a supernova, it needs to be larger. The first stage is the hydrogen fusion into heavier elements. The energy created pushes the hydrogen outwards. If there was no fusion, the star would be a low smaller. When the hydrogen fusion in the core slows down (due to a ...

3

I see two real questions here. First, whether it's possible to have a black dwarf with a companion object. For a given black dwarf, this is unlikely, since the orbits would likely be unstable at the time scale required to produce a black dwarf. Given the size of the universe, however, it's not out of the question. A black dwarf could even capture a companion ...

3

It's very likely, that we don't have discovered every non man-made element. For some elements there exist only very short-lived isotopes. Plutonium... is the heaviest primordial element by virtue of its most stable isotope, plutonium-244, whose half-life of about 80 million years is just long enough for the element to be found in trace quantities in ...

3

The paper "Frequency of nearby supernovae and climatic and biological catastrophes" by Clark, McCrea, and Stephenson published in Nature estimates (at 50% probability) that the Solar System passes within 10 parsecs of a supernova every 100 million years. This supernova would be part of a 20-parsec strip in which an estimated 50 supernovae occur. They do ...

2

A hypernova is just a really, really big supernova. UMass has a (tacky designed) web page that explains it. A hypernova explosion typically has a mechanical energy output of ~ 10^53 ergs, or about a factor of 100 greater than a supernova. Regarding aftereffect, the page says this: The age of the hypernova remnant NGC5471B is about 30 thousand ...

2

The binding energy per nucleon is among the highest for iron-56. Therefore nuclear fusion as well as fission/photodisintegration of iron-56 consumes energy. Heat production is needed to prevent a star from collapsing to a much denser state. Iron-56 provides no way to produce heat by nuclear reactions. Hence core collapse is unavoidable. If the star isn't ...

2

Not that easy way. Only stars heavy enough will undergo a supernova explosion. The majority of stars is too light. The lifetime of a star is mostly determined by its mass. In some cases (supernova type Ia) a companion star provides mass to white dwarf, which originally has been too light to explode as a supernova. Hence your technique can only work, if it ...

2

Only a very small fraction of the elements in the core the supernova get converted into heavier elements. Most of the matter remains unchanged.

2

You were so close! The answer was actually given lower down on the Wikipedia page: roughly 20 parsecs. Since one parsec is about 3.26 light-years, we can calculate that that comes out to about 64 light-years, as this seems to corroborate. The outer layers of the remnant are expanding outward at an outrageous rate - 11 million miles per hour, according to ...

2

The difference is based on the different efficiency of the processes. We can describe the luminosity by: $L = \eta m c^2$ where $\eta$ is the conversion efficiency, and describes how much matter can be converted into luminosity (photons). Main sequence stars (if you mean this by "normal operation") extract energy from matter by nuclear fusion. The ...

2

Be careful when saying "nearby stars". The scales involved in "nearby" are beyond what most people imagine. If our Sun was the size of a soccer ball located in California, the nearest star would be another soccer ball located in Greenland. Let's say the average distance between "nearby" stars is a few light years. Let's say an average supernova is like the ...

1

It would be good if you referenced your sources, because you may be misunderstanding them. We'd be able to see what they actually say, and help you understand them. Nucleosynthesis of iron does not use more energy than it produces. It is, however often referred to as the heaviest element created in fusion that results in more energy produced than consumed. ...

1

I would expect that the further away a supernova is, the "longer" we observe it will be active because of an increased red shift. Objects in the universe that are further away are generally going away from us faster than objects that are close, hence the increased red shift. This increase in time due to redshift is very similar to the Doppler effect, where ...

1

Actually yes, gravity is too weak to do the job by itself. But as you mention, another force is acting on the system too, in a very strong way: it is the pressure that pushes outwards. In fact, the energy released by the explosion of the supernova, helps to compress the layers of released material (gas and clouds). You have shocks between the expelled gas ...

1

The AAVSO data seems to indicate that it might have already peaked, at around 10.5 (visual). The infrared is quite a bit brighter, partly because it penetrates dust better. Sky and Telescope says it peaked on Jan 31.

1

Actually i read some where that in the entire time of humankind on earth, the earth has just covered 1/10th of a percent around the milky way galaxy, so assuming earth would survive that long and humankind would survive to witness it, i would say it would take billions-billions of year, before earth would move to closer to giant stars. As for the supernova ...

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