Brown Dwarfs: “Over-Achieving Jupiters” not “Failed Stars”


Why is the term “failed star” synonymous with brown dwarfs? On the one hand, brown dwarfs lack the mass to sustain nuclear fusion in their cores. On the other hand, who said brown dwarfs were trying to be stars? Who ever said that becoming a star was the pinnacle of stellar living? Perhaps brown dwarfs are perfectly happy the way they are. In a world of equality and political correctness, brown dwarfs could be viewed as “over-achieving Jupiters”, or gas supergiants
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Are Brown Dwarfs More Common Than We Thought?

A brown dwarf plus aurorae (NRAO)

In 2007, a very rare event was observed from Earth by several observers. An object passed in front of a star located near the centre of the Milky Way, magnifying its light. Gravitational lensing is not uncommon in itself (the phenomenon was predicted by Einstein in 1915), but if we consider what facilitated this rare “microlensing” event, things become rather interesting.
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WR 104: Not The Killer It Used To Be

WR 104. A killer? Not so much.

WR 104. A killer? Not so much.

It’s interesting how astronomical harbingers of doom have the ability to pop up more than once on the ‘net. However, the doom isn’t quite as terrifying when you’ve sat through a conference presentation by a scientist who has exhaustively given every reason as to why this particular killer won’t hurt you.

Enter WR 104.

To be honest, if it wasn’t a Wolf-Rayet star, I probably wouldn’t be writing about it (as we all know, or you should know, Wolf-Rayets are my favourite stellar objects), but this little fact combined with the fact that I know the Earth is no longer on the WR 104 hit-list, I feel compelled to correct an article that has just popped up on the web referencing out-of-date source material.

So, let’s wind this back the clock to January 2009 when I sat in on a very reassuring this-star-isn’t-actually-going-to-kill-us-after-all astro presentation…
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Star Formation: The Game


Dave Mosher, I’m pointing my finger at you for this late night effort! Usually I stay up late to write articles, but for the last 30 minutes I’ve been playing this game after Dave sent a message on Twitter saying he had been playing a “simple” and “addictive” star formation game. No kidding! I shouldn’t have even clicked the link. But like a caffeine-infused moth to a super-shiny flame, off I went for some simple star-creation fun.

It looks like the Star Formation game is part of Discover Magazine’s featured article about the mysteries of star birth (it’s a great read, check it out). The game is simple, yet captivating (despite a few minor bugs). You play the role of supernova progenitor, dropping some massive star fury on an unsuspecting nebulous cloud of hydrogen. According to the game developers, the situation is physically accurate, it is just up to you to create the perfect conditions for stars to form in the dense cloud. It would appear the lectures I attended on star formation paid off, as I speak I’m on top of the leaderboard with a whopping 21122 points (see the screengrab above, I saved it posterity, I doubt I’ll be at #1 for much longer).

I’m all for games with an educational element, and I can’t think of a better way to spend an evening (well, I can, but if you’re stuck in the office, this is a great alternative to work). I’m off to create some more stars, check out Discover so you can do the same (just you try to knock me from the #1 slot!).

What Will Happen When the Sun Turns into a White Dwarf?

Strong tidal interactions are thought to shred any asteroids or comets as they get too close to a white dwarf (NASA)

All the way back in January, I had the great fortune to attend the American Astronomical Society’s (AAS) conference in Long Beach, California. I had a lot of fun. However, between the free beer and desperately searching for wireless Internet signal, I also did some work. During my travels, I spent some time browsing the poster sessions, trying to get inspiration for an article or two. You’d think that when presented with hundreds of stunning posters that inspiration wouldn’t be that far away. However, I was repeatedly frustrated by information overload and defaulted to a clueless meander up and down the pathways walled with intense science debates.

But then I saw it, right at the end of one of the poster walls, a question that got my imagination bubbling: “Will The Sun become a Metal Rich White Dwarf After Post Main Sequence Evolution?” The Sun? After the Main Sequence? Metal rich? To be honest, these were questions I’d never really pondered. What would happen when the Sun turns into a white dwarf? Fortunately, I had Dr John Debes to help me out with the answers…
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Small but Mighty: KPD 0005+5106, the 200,000K White Dwarf

Sirius B1 - one of the more famous white dwarf stars (Frank Gregorio)

A white dwarf called KPD 0005+5106 has been identified as the hottest star observed, ever. KPD 0005+5106 lives in the globular cluster M4, 7,200 light years away, and astronomers have always been intrigued by this stellar lightweight as its emissions have previously hinted it was quite toasty. Now, astronomers using data from the defunct NASA Far-Ultraviolet Spectroscopic Explorer (FUSE), have studied the white dwarf in more detail. KPD 0005+5106 emits radiation in the far-ultraviolet, indicating that its surface has a temperature of 200,000K. This is an unprecedented discovery, far-ultraviolet emissions are usually reserved for superheated stellar coronae. It may be small, but it’s a record-breaker
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New Addition to the Exoplanetary Menu: The WASP-12b Sizzler

The hotspot: A very, very hot Jupiter has been discovered (ESA/C Carreau)

The hotspot: A very, very hot Jupiter has been discovered (ESA/C Carreau)

So how hot is the hottest known planet? Usually the temperature of a planet orbiting another star is of little concern to us. At the end of the day, are we really looking for an interstellar getaway? The chance that we’ll be colonizing any extra-solar planets in the near future is pretty low, but that won’t stop us from peering up the the heavens studying “Hot Jupiters” orbiting stars hundreds of light years away. However, astronomers have just discovered a planet I doubt we’ll ever want to visit. Enter WASP-12b, the hottest, and fastest gas giant ever observed…
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