Please help. Supernovae database?

[Andre]

of course I know that google knows the answer to any question, but it seems that there are limits.

So when I want to test a certain hypothesis I need to have an overview of all known supernovaes, distance, size, etc, dated from say 30-50,000 years ago. So I typed in super nova index and that sort of thinks, and the result was millions of them, pop groups, games, clubs, anything, the whole nine yards except a single super nova index. There must be an answer to the question, but how to ask to correct question.

Can anyone help?

[xAbsoluteZerox]

The NASA/IPAC EXTRAGALACTIC DATABASE (maintained by CalTech) is a great tool for stuff like this, and just in general an amazing catalog.

http://nedwww.ipac.caltech.edu/

Try their All-Sky Search (http://nedwww.ipac.caltech.edu/forms/byparams.html) and Limit it to Supernovae...when i did it i came up with 3744 objects. Good Luck.

Edit: Here is my search results just by limiting to supernovae only:

http://nedwww.ipac.caltech.edu/cgi-bin/nph-allsky?z_constraint=Unconstrained&z_value1=&z_value2=&z_unit=z&flux_constraint=Unconstrained&flux_value1=&flux_value2=&flux_unit=Jy&frat_constraint=Unconstrained&ot_include=ANY&in_objtypes3=Supernovae&nmp_op=ANY&ra_constraint=Unconstrained&ra_1=&ra_2=&dec_constraint=Unconstrained&dec_1=&dec_2=&glon_constraint=Unconstrained&glon_1=&glon_2=&glat_constraint=Unconstrained&glat_1=&glat_2=&out_csys=Equatorial&out_equinox=J2000.0&obj_sort=RA+or+Longitude&of=pre_text&zv_breaker=30000.0&list_limit=5&img_stamp=YES

*Note this is for supernovae, not supernovae remnants, thats another category you can select in the Advanced All-Sky Search.

[Labguy]

This only goes back to 1885, but it is a LONG list.

http://cfa-www.harvard.edu/iau/lists/Supernovae.html

[Andre]

That's great, guys. Thanks very much. Now, if I only could figure out distance and date of explosion from those data.

You see, I'm looking for this one:

http://www.lbl.gov/Science-Articles/Archive/NSD-mammoth-extinction.html

They also found evidence of the supernova explosion’s initial shockwave: 34,000-year-old mammoth tusks that are peppered with tiny impact craters apparently produced by iron-rich grains traveling at an estimated 10,000 kilometers per second. These grains may have been emitted from a supernova that exploded roughly 7,000 years earlier and about 250 light years from Earth.

“Our research indicates that a 10-kilometer-wide comet, which may have been composed from the remnants of a supernova explosion, could have hit North America 13,000 years ago,” says Firestone. “This event was preceded by an intense blast of iron-rich grains that impacted the planet roughly 34,000 years ago.”

In support of the comet impact, Firestone and West found magnetic metal spherules in the sediment of nine 13,000-year-old Clovis sites in Michigan, Canada, Arizona, New Mexico and the Carolinas. Low-density carbon spherules, charcoal, and excess radioactivity were also found at these sites.

“Armed with only a magnet and a Geiger counter, we found the magnetic particles in the well-dated Clovis layer all over North America where no one had looked before,” says Firestone.

Analysis of the magnetic particles by Prompt Gamma Activation Analysis at the Budapest Reactor and by Neutron Activation Analysis at Canada’s Becquerel Laboratories revealed that they are rich in titanium, iron, manganese, vanadium, rare earth elements, thorium, and uranium. This composition is very similar to lunar igneous rocks, called KREEP, which were discovered on the moon by the Apollo astronauts, and have also been found in lunar meteorites that fell to Earth in the Middle East an estimated 10,000 years ago.

“This suggests that the Earth, moon, and the entire solar system were bombarded by similar materials, which we believe were the remnants of the supernova explosion 41,000 years ago,” says Firestone.

Nice piece of scientific method, observations, a clever hypothesis worked out which leads to a prediction of a supernova 41,000 years ago at a distance of 250 light years. But what about the last phase? Testing the prediction? So that's why I asked those questions.

[Nereid]

Well, getting a handle on some (historical, older) SNe in the LMC likely won't help you, but there was a very interesting discovery (http://www.ctio.noao.edu/supermacho/lightechos/) (last year?) of faint light echos which, when analysed, pointed to old SNe (and gave pretty tightly constrained dates for when the were seen - on Earth - to go bang).

[Andre]

Thanks Nereid, good to see you.

Interesting indeed, unfortunately the numbers are some orders of magnitude different. With more googling I found:

http://snrcat.cfa.harvard.edu/snrcat_gal.html

but the link doesn't work for me. Perhaps some insider knows the status of that page?

[Andre]

With some persistence: http://www.astro.uiuc.edu/~rosanina/preprints/n206.pdf

The expansion velocity obtained from optical echelle spectroscopy of 202 km s-1, however, leads to a calculated age of 41,000 yr.

Spot on, however:

We assume the remnant to be roughly spherical, with a radius of 21 pc, at a distance of 50 kpc

That's kilo-parsec, innit? That would get us at ~160,000 light years?. 3 orders of magnitude too far away. But if we can spot them at that distance at that age, shouldn't know about one within the correct parameters, 250 light years, 41 ky ago?

[Jheriko]

This composition is very similar to lunar igneous rocks, called KREEP, which were discovered on the moon by the Apollo astronauts, and have also been found in lunar meteorites that fell to Earth in the Middle East an estimated 10,000 years ago.

“This suggests that the Earth, moon, and the entire solar system were bombarded by similar materials, which we believe were the remnants of the supernova explosion 41,000 years ago,” says Firestone.


Why does it suggest this? Isn't it much more plausible that a Lunar metorite hit the Earth? Or at least a similar object of solar system origin? That would be more plausible in my opinion, in which case you might be chasing a white rabbit.

Is there any more information on this? I would like to know if there is some more compelling reasoning behind this hypothesis, or if I missed something in the original article that I should have picked up on.

I will google and come back later...

EDIT: I read the whole original article... I am also confused by the iron grains, wouldn't they have had to have started out being much bigger in order to make it through the atmosphere intact? This would require a second ejection of densely packed material to conveniently line up with the Earth.

[Jheriko]

Didn't find anything much except two copies of the original article...

[Andre]

Thanks for your efforts,

Would it indicate that the chances of finding Supernovae remains within the constraints of the date and distance parameters are very remote. Would that mean that the Firestone hypothesis can be considered falsified?

[Chronos]

I think it's too early to dismiss the Firestone hypothesis. The error bars are pretty forgiving, from what I've seen.

[TheMuses]

Andre,

If you are looking for SNRs, you have to be looking for websites that supports telescopes that detects in the x-ray part of the electromagnetic spectrum. A good telescope to look at is the Chandra Telescope.
The BIGGEST help I got about SNRs came from this Chandra website:

http://www.astro.psu.edu/users/green/Main/

Now you could explore around here if you want, it tells you a LOT about SNRs. If you want to get an index of certain SNRs, click on "Supernova remnants in our Galaxy and Magellanic Clouds." It has a sum of all known SNRs recorded by Chandra Telescope in our galaxy and magellanic clouds. I've worked with this website for almost six months now and it hasn't let me down.

If you are looking for resources on certain SNR parameters (ex: distance, size, temperature, etc), you could look around any Chandra websites, OR (what I'm doing right now) download a software called "ds9" (Deep Space 9) and do some research yourself!!