Comments on: One Ring to Rule Them All

By: Blondin

Blondin — Tue, 21 Jun 2005 21:32:05 +0000

I had the pleasure of meeting Dr Ian Shelton last year when he was the keynote speaker at our annual Gateway to the Universe star party. He explained how he discovered supernova 1987A purely by accident. He had been taking photos of the LMC with an older, neglected telescope using up some old discarded film at Las Campanas, Chile. He noticed a 5th magnitude star in one of his photos that had been only 12th magnitude only 25 hours previous. It was just luck that he was the first to recognize what he was seeing.

By: Nigel Depledge

Nigel Depledge — Sat, 11 Jun 2005 17:22:21 +0000

I was just re-reading this blog entry and associated comments, and I suddenly noticed something that I had not noticed before.

From whence does the magnetic field of a neutron star come?

I’d never really thought about it before, but I have just done so. If the gravitational field is strong enough to overcome electron degeneracy pressure and force electrons and protons to combine into neutrons, there will, I assume, be very few charged particles in a neutron star. Since magnetic fileds are related to current flowing (or at least the movement of an electrically conductive fluid), doesn’t this require charged particles that are free to move around? As I understand it, the surface of a neutron star is coated in a crust of iron. I had assumed this was solid (and so the mechanism that generates Earth’s magnetic field would not apply) and, since lumps of iron on Earth do not generate magnetic fields unless current flows through them, I just wondered what generates the strong magnetic fields around neutron stars.

Can anyone out there could provide me with an answer?

By: CR

CR — Thu, 09 Jun 2005 17:21:19 +0000

I remember when it happened, and my initial reaction thinking “how cool!” But I don’t recall if anyone had actually expected it to happen. Admittedly, I’d forgotten about it over the years, so this BA bolg entry was a nifty reminder about that event, and as usual a reminder about what an amazing & mysterious universe we live in.

By: Kebsis

Kebsis — Thu, 09 Jun 2005 04:07:46 +0000

…or did we know beforehand that it was gonna blow?

(sorry for the double post)

By: Kebsis

Kebsis — Thu, 09 Jun 2005 04:07:05 +0000

How did that play out? Was it like, one day some unspectacular star just exploded?

By: JPax2003

JPax2003 — Wed, 08 Jun 2005 19:27:46 +0000

Would it be possible to locate a planet orbiting 1987A in current or old images using reflected x-rays similar to the x-ray reflection analysis Chandra used on Saturn (which was announced by NASA on May 25, 2005)? Would such images reveal an x-ray “source” orbitting the remnants, or would it be completely obscured by x-ray absorbing or emitting debris? If it is visible would it appear to go through “phases” like the moon and could it ecplipse some of the debris in transit?

By: Malte

Malte — Wed, 08 Jun 2005 15:27:24 +0000

Hey dR bAdastro, I think that should be supernova 1987A….

By: The Bad Astronomer

The Bad Astronomer — Wed, 08 Jun 2005 04:44:39 +0000

Kebsis– no, this is the first time we’ve ever known the star that blew up before it blew up. It was identified later, from older images.

Jpax, I suspected early on that a planet orbiting the original star may be behind the formation of the rings; I studied a similar (but not terribly similar) object for my Masters degree, and my advisor was very big on wondering if planets got engulfed by their parent stars, made them spin faster, and caused the formation of weird structures like rings. I think he was right; it explains a lot of things we see.

By: JPax2003

JPax2003 — Wed, 08 Jun 2005 04:32:08 +0000

Are there any planets orbiting this star remnant? Would a large planet induce enough wobble in the neutron star to make it optically indistinct. Would a large planet’s gravity and orbit create the observed anomalies in the debris clouds?

By: Kebsis

Kebsis — Wed, 08 Jun 2005 04:29:40 +0000

Well, what I mean is, have we ever seen the whole process from beginning to end like this before. Watched the star nova and then the aftermath.

By: The Bad Astronomer

The Bad Astronomer — Wed, 08 Jun 2005 03:23:11 +0000

There are lots of neutron stars in supernova remnants, like the Crab, Vela, and Cas A. Check out the Chandra X-ray observatory website.

By: Kebsis

Kebsis — Wed, 08 Jun 2005 02:50:10 +0000

Have we seen other supernova turn into neutron stars in the past? Or is the first time we’ve ever observed a supernova, and it isn’t doing what we assumed it should be doing?

By: The Bad Astronomer

The Bad Astronomer — Tue, 07 Jun 2005 17:49:38 +0000

In the paper linked from the press release, they say that if the neutron star were a pulsar (unlikely, actually, since it takes many years for the pulsar to “turn on”), it would be dumping a lot of energy into the surrounding gas, lighting it up. That is not seen, so it’s unlikely that there is a pulsar in there.

There are lots of weird things about the supernova and its environs. Read the essays to which I linked in the entry and you’ll get a taste of them. Even after all this time, 87a is one of the weirdest and most exciting beasties in the sky.

By: aiabx

aiabx — Tue, 07 Jun 2005 14:28:29 +0000

Pardon the question if the answer is obvious, but would we see anything if the neutron star was a pulsar pulsing in the wrong direction? I couldn’t help noticing that the ring’s polar axis (if the ring is circular) doesn’t seem to point at us.
-Andy B

By: sophia8

sophia8 — Tue, 07 Jun 2005 12:36:25 +0000

Thanks for telling us about this. This isn’t Bad Astronomy – this is Weird Astronomy!

By: George

George — Tue, 07 Jun 2005 12:20:05 +0000

Thanks for your illumination of one of the great heavenly bright spots of our times. It’s a treat to be so mystified by such dynamics.

By: woja

woja — Tue, 07 Jun 2005 09:25:17 +0000

You have intrigued me. I was aware of a supernova where a neutron star couldn’t be found but I must have read the reports that it had been found and lost interest. Now I’m all amazed again.

This will be something else to bore my friends with.

[Thanks for "Bad Astronomy", always a good, stimulating read]

By: Jason

Jason — Mon, 06 Jun 2005 23:24:23 +0000

If you look at the picture just right….You can see god. Ha.

By: anonymous

anonymous — Mon, 06 Jun 2005 21:50:08 +0000

I think it must be aliens. Since science can’t explain it, aliens are the next best explanation!

By: The Bad Astronomer

The Bad Astronomer — Mon, 06 Jun 2005 21:37:54 +0000

Thanks, I fixed it. And thanks for the compliment!

By: Tobin Dax

Tobin Dax — Mon, 06 Jun 2005 21:36:39 +0000

Phil, it looks like there’s a typo in the third paragraph from the end. In the sentence that says, “or maybe the magnetic field of the neutron is too weak,” shouldn’t that read “neutron star” instead?

Other than that, great article. Your blog entries are wonderful to read.

By: Avian

Avian — Mon, 06 Jun 2005 18:34:59 +0000

Why I like the Bad Astronomy Blog:

Generally, a young neutron star is bright because gas and junk left over from the explosion fall onto it.