A Cosmic Zoo in the Large Magellanic Cloud

Astronomers often turn their telescopes to the Large Magellanic Cloud (LMC), one of the closest galaxies to our own Milky Way, in their quest to understand the Universe. In this spectacular new image from the Wide Field Imager (WFI) at ESO?s La Silla Observatory in Chile, a celestial menagerie of different objects and phenomena in part of the LMC is on display, ranging from vast globular clusters to the remains left by brilliant supernovae explosions. This fascinating observation provides data [...]

Full story at http://spacefellowship.com/news/art20612/a-cosmic-zoo-in-the-large-magellanic-cloud.html

Is Betelgeuse about to blow?

I was going to wait to write about this, but I’m getting a lot of emails about it, so I’ll say something now, and followup when I get more information.

The story:

BABloggee Alereon (and many others) sent me to an interesting site: Life After the Oil Crash Forum — a forum that apparently has a lot of doomsday-type scuttlebutt posted to it.

An anonymous poster there says he has heard that the star Betelgeuse is about to go supernova, maybe as soon as a few weeks:

I was talking to my son last week (he works on Mauna Kea), and he mentioned some new observations (that will no doubt get published eventually) of “Beetlejuice”; it’s no longer round. This is a huge star, and when it goes, it will be at least as bright as that 1054 supernova…except that this one is 520 light years away, not 6,300 [...]

When it collapses, it will be at least as bright as the full moon, and maybe as bright as the sun. For six weeks. So the really lucky folks (for whom Betelgeuse is only visible at night) will get 24 hour days, everybody else will get at least some time with two suns in the sky. The extra hour of light from daylight savings time won’t burn the crops, but this might. Probably, all we’ll get is visible light (not gamma rays or X-rays), so it shouldn’t be an ELE. It’s sure gonna freak everyone out, though…..

Then it will form a black hole, but we’re too far away for that to matter.

The buzz is that this is weeks/months away, not the “any time in the next thousand years” that’s in all the books.

The basic takeaway:

OK, folks, first: when news like this comes from an unnamed source on some random forum, and that source is not even a primary one, and that secondary source quoted is also unnamed, and that person heard it from a third party that is also unnamed… well, oddly enough my skeptic alarm bell in my head rings loudly enough that my eardrums explode outward in every direction at the speed of light.

I hope I’m being clear here.

The first important thing to note here is that if Betelgeuse explodes, we’re in no danger at all. It’s too far away to hurt us. Got that? It’s the most important thing to remember here, because I’m quite sure this story will get wildly exaggerated as it gets repeated.

So, what’s the deal with Betelgeuse? What is it, will it explode, and if so, when?



The details:

Betelgeuse is one of the brightest stars in the sky. That’s because it’s an intrinsically luminous star, and one that’s relatively close by. By luminous, I mean something like 100,000 times that of the Sun, and by close I mean roughly 600 light years away if not more. That’s 6 quadrillion kilometers, or almost 4 quadrillion miles. In other words, quite a hike.

Betelgeuse is a red supergiant. It has a mass of something like 20 times the Sun’s, and is near the end of its life. When it dies, it will explode as a supernova, a titanic event that is among the most violent in the Universe. For details on how this happens, read this essay I wrote about it.

It’s hard to know just when a star will explode when you’re on the outside. Betelgeuse might go up tonight, or it might not be for 100,000 years. We’re just not sure.

Betelgeuse isn’t round, and it’s shrinking!

In the bulletin board post, he talks about the star not being round. It’s unclear, but it sounds like he’s referring to observations which show that there is a big plume coming from the surface of Betelgeuse. That was exciting news when it was released, but not hugely surprising; stars are active, and massive stars even more so. Also, note that those "new" observations are a year old!

That image above is from even earlier, and shows a Hubble observation of Betelgeuse taken in 2005. Note here that the star doesn’t look round, but that’s an illusion. The image shows a hot spot in Betelgeuse’s swollen atmosphere, and that makes it look like a bump is hanging of the side. In reality, that’s just because of the way the image is printed, and isn’t an actual physical bump. But the hot spot (probably due to a big ol’ bubble of hot gas rising near the surface) in itself shows that things on the star change all the time; just recently two such spots were found.

The post also talks about Betelgeuse shrinking. That claim is from observations made over the course of many years. Those data indicate the star is shrinking, but it’s unclear what they mean. While it may mean the star is in fact shrinking, starspots (sunspots on another star) may be fooling us, for example. Also, red supergiants aren’t like marbles, with a clean, sharp surface. They are balls of gas, extended and bloated, so there is no real surface. It’s therefore entirely possible the astronomers aren’t even really measuring the surface of the star at all, and it’s just the highly extended atmosphere that’s changing.

Surface tension, rotten to the core

The point I’m making is that a lot of stuff can happen on the surface of the star that has nothing to do with the core. Since it’s the core that generates the star’s energy and eventually causes it to explode, what’s happening on the surface is not an indication of any impending explosion.

Mind you, the surface and the core do "talk" to each other, though slowly. As the core changes, that information does leak to the surface, but it takes centuries. Until, that is, the core collapses. When that happens, the shock wave takes hours or days to get to the surface, and the star explodes. But that’s hardly a slow event taking decades! So any changes we see happening now probably have little to do with what’s happening hundreds of millions of kilometers deep in the star.

Also, it’s been known for a long time that Betelgeuse is a variable star; its light output changes. This shrinking may just be a part of that natural cycle, and again no indication of an explosion.

Having said all that, I’ll note that someday, Betelgeuse will explode. That’s for certain! But it’s also way too far away to hurt us. A supernova has to be no farther than about 25 light years away to be able to fry us with light or anything else, and Betelgeuse is 25 times that distance (which means its power to hurt us is weakened by over 600x). It’s the wrong kind of star to explode as a gamma-ray burst, so I’m not worried about that either.

At that distance, it’ll get bright, about as bright as the full Moon. That’s pretty bright! It’ll hurt your eyes to look at it, but that’s about it. The original post says it may get as bright as the Sun, but that’s totally wrong. It won’t even get 1/100,000th that bright. Still bright, but it’s not going to cook us. Even if it were going to explode soon. Which it almost certainly isn’t.

Conclusion:

So my personal opinion is that this is just another breathless rumor of astronomical doomsday that we get every couple of years. Even if any of the science of it is right, it doesn’t mean Betelgeuse is about to explode any day now. And since this is a rumor three times removed, I don’t put any stock in it. I’ll wait until I hear from named scientists with published or publishable data before I start to wonder if the star is about to blow.

And if and when it does explode, it can’t hurt us. Someday it will — maybe not for a hundred thousand years, but someday — and every astronomer on the planet hopes it happens in their lifetime! It will be a scientific bonanza unlike any ever seen.

Image credits: NASA, ESA, ESO

Full story at http://feedproxy.google.com/~r/BadAstronomyBlog/~3/2rTVTq81r7I/

Picture of the Day - Scattered Light from the Boomerang Nebula

The Hubble Space Telescope caught the Boomerang Nebula in this image taken with the Advanced Camera for Surveys in early 2005. This reflecting cloud of dust and gas has two nearly symmetric lobes of matter that are being ejected from a central star.



Each lobe of the nebula is nearly one light-year in length, making the total length of the nebula half as long as the distance from our Sun to our nearest neighbors - the alpha Centauri stellar system, located roughly 4 light-years away. The Bo [...]

Full story at http://spacefellowship.com/news/art20564/picture-of-the-day-scattered-light-from-the-boomerang-nebula.html

This Week On The Space Show

The Space Show, hosted by David Livingston under www.TheSpaceShow.com, will have the following guests this week:


1. Monday, May 31, 2010, 2-3:30 PM PDT (21-22:30 GMT)
Diane Murphy of the Rocket Racing League comes to the show.
Diane Murphy is a senior executive with a unique portfolio of achievement in designing and implementing marketing, communications, education, issue management and public outreach campaigns for private industry, the federal government, US Congress, political candidat [...]

Full story at http://spacefellowship.com/news/art20568/this-week-on-the-space-show.html

City Lights at Night along the France-Italy Border From Space

The brightly lit metropolitan areas of Torino (Italy), Lyon, and Marseille (both in France) stand out amidst numerous smaller urban areas in this dramatic astronaut photograph. The image captures the nighttime appearance of the France-Italy border. The southwestern end of the Alps Mountains separates the two countries. The island of Corsica is visible in the Ligurian Sea to the south (image top).



The full moon reflects brightly on the water surface and also illuminates the tops of low patc [...]

Full story at http://spacefellowship.com/news/art20570/city-lights-at-night-along-the-france-italy-border-from-space.html

Claire de lune

I’ve been to France once, and only for a short time (basically, driving across the Large Hadron Collider site which straddles Switzerland and France, and only then to eat at a restaurant). I’d love to go and spend more time… especially when I see as lovely a view of L’hexagone as this one:

[Click to engrandenate.] C’est magnifique! C’est belle! It looks like a beach picture, the Moon shining down on the coastline, clouds gently wafting over the horizon…

Hey, wait a second. That isn’t a picture taken from the beach! That’s taken from space!

Oui. This shot, taken from the International Space Station, is looking southwest at France (and a little bit of Italy), but from several hundred kilometers above it. It was taken at nearly midnight on April 28. The view is not straight down, but at an angle; about 60° from straight down, or 30° down from horizontal (if I’ve done the math correctly; the law of cosines was a little tricky for this one, but I got the data from the NASA site). At the moment it was taken, the center of the picture was about 650 km (400 miles) away from the ISS.

I love this picture! What you think at first is the Moon is actually moonlight reflecting off the water of the Ligurian Sea, an arm of the Mediterranean between France and Italy. Corsica can be seen to the upper left. Also visible are Marseille (to the right), Lyons (at the bottom) and Torino in Italy to the left (bonus astronomy goodness: a decade ago, Torino hosted a meeting for astronomers, who concocted the Torino Scale of how dangerous an Earth-buzzing asteroid is). Since it was midnight, the lights of the cities glow softly from this distance. You can also see the gentle blue reflected moonlight off snow-capped Alps in the center, interspersed with the light cloud cover.

There is a lot we can learn from observing our home planet from space, but perhaps the most important — and the one with the most lasting impact — is just how beautiful it is.

P.S. I was listening to Debussy’s "Claire de Lune" as I wrote this, and when it ended, went right to "Prelude a L’Apres Midi d’un Faune". C’est vrai!

Cr�dit d’image: NASA

Full story at http://feedproxy.google.com/~r/BadAstronomyBlog/~3/LNSqLYqmytk/

Picture of the Day - Scattered Light from the Boomerang Nebula

The Hubble Space Telescope caught the Boomerang Nebula in this image taken with the Advanced Camera for Surveys in early 2005. This reflecting cloud of dust and gas has two nearly symmetric lobes of matter that are being ejected from a central star.



Each lobe of the nebula is nearly one light-year in length, making the total length of the nebula half as long as the distance from our Sun to our nearest neighbors - the alpha Centauri stellar system, located roughly 4 light-years away. The Bo [...]

Full story at http://spacefellowship.com/news/art20564/picture-of-the-day-scattered-light-from-the-boomerang-nebula.html

This Week On The Space Show

The Space Show, hosted by David Livingston under www.TheSpaceShow.com, will have the following guests this week:


1. Monday, May 31, 2010, 2-3:30 PM PDT (21-22:30 GMT)
Diane Murphy of the Rocket Racing League comes to the show.
Diane Murphy is a senior executive with a unique portfolio of achievement in designing and implementing marketing, communications, education, issue management and public outreach campaigns for private industry, the federal government, US Congress, political candidat [...]

Full story at http://spacefellowship.com/news/art20568/this-week-on-the-space-show.html