Tiny Red Dwarf Star Has a Magnetic Field Several Hundred Times Stronger Than Our Sun

[Ichingcarpenter]

Not these Red Dwarf Stars



Our Sun is a relatively quiet star that only occasionally releases solar flares or blasts of energetic particles that threaten satellites and power grids. You might think that smaller, cooler stars would be even more sedate. However, astronomers have now identified a tiny star with a monstrous temper. It shows evidence of much stronger flares than anything our Sun produces. If similar stars prove to be just as stormy, then potentially habitable planets orbiting them are likely to be much less hospitable than previously thought.

“If we lived around a star like this one, we wouldn’t have any satellite communications. In fact, it might be extremely difficult for life to evolve at all in such a stormy environment,” says lead author Peter Williams of the Harvard-Smithsonian Center for Astrophysics (CfA).

The research team targeted a well-known red dwarf star located about 35 light-years from Earth in the constellation Boîtes. The object is so small and cool that it’s right on the dividing line between stars (which fuse hydrogen) and brown dwarfs (which don’t). One of the things that makes this small star remarkable is that it spins rapidly, completing a full rotation about every 2 hours. Compare that with our Sun, which takes nearly a month to spin once on its axis.

Previous data from the Karl G. Jansky Very Large Array in Socorro, NM showed that this star. This puzzled astronomers because the physical processes that generate the Sun’s magnetic field shouldn’t operate in such a small star.

http://scitechdaily.com/tiny-red-dwarf-star-has-a-magnetic-field-several-hundred-times-stronger-than-our-sun/

The star is fairly tiny, just 10 percent of the whole mass of the Sun but spins quickly and creates a storm like environment. Scientists say that the star completes a rotation in just two compared to Sun which takes about 25 days to complete the process

http://www.i4u.com/2015/11/98613/astronomers-discover-red-dwarf-star-more-powerful-sun

[Android3.14]

1. It being right on the line between brown and red

Makes me wonder if that, combined with the rapid spin, makes it more likely to emit CMEs, a bit like a car with an engine that just won't quite catch, but backfires whenever you turn the key.

[longship]

2. M-class stars, not to be confused by Star Trek planet classifications.

I am posting about star classifications.

OBAFGKM! The O's are the hottest, the shortest lived, and the most massive. We see lots of them, but they blow up soon. Such is their lives.

Those M-class stars are wimpy and small, but they burn hydrogen so gently that all M-class stars ever birthed since the Big Bang are likely still extant, slowly and surely burning their hydrogen, as they will for billions of years.

It is something that Annie Jump Cannon understood in the early 20th century when she came up with this star classification. OBAFGKM! And don't get me started about her understudy, Henrietta Swan Leavitt who single handedly overturned Cosmology. By the way, they were both deaf when they single-handedly changed cosmology.

Remember, OBAFGKM! And the Hertzsprung-Russell Diagram, which without Annie Jump Cannon would not exist. Nor would Edwin Hubble's expanding universe without Henrietta Swan Leavitt's discovery of Cepheid Variables on which his research was based.

Women in science. So often ignored.

R&K



Of course, Neil de Grasse Tyson related their story in probably the greatest episode of the Cosmos reboot, "Sisters of the Sun".

Here, enjoy:

[MillennialDem]

3. We don't see that many O stars because they're so rare. Pretty sure most stars you can see are A or

B, provided they're on the main sequence. They're common enough to see lots of them (yet still rare. Think B is about 1 in 800 stars and A is about 1 in 100) and also bright.

[longship]

4. Well, the bright massive stars have the advantage of their brightness.

Which is why we see so many of them in the sky. Sirius is a type A star, which puts it at a fairly high end of mass, and lower end of lifetime of stars.

OBAFGKM. Sol is a type G. Some 75% of stars in the galaxy and universe are type M, which live pretty much forever as these things go. So Sol is not in any way a typical star because the higher the mass, the fewer stars there are, and the smallest life they have. O stars don't live very long and end theirs quite spectacularly. M stars? Probably all ever made still exist. But they're so dim they are so dim they are difficult to see.

[MillennialDem]

7. All M ever made still exist, unless they got destroyed by a companion.

[eppur_se_muova]

5. O are rare, but so bright that they get "overcounted".

There are only six O-type stars of magnitude 3.5 or brighter (four are in Orion, surprise!), out of 287 stars total -- better than 1 in 50. One of them is 1900 ly away; the nearest (probably) is 62 ly away. Our own Sun would be invisible to the naked eye (i.e. less than magnitude 6) at only 60 ly. Given that volume (and hence number of stars) goes as the cube of distance ... well, Type O stars are a lot rarer than they appear to the eye. In contrast, the closest red dwarfs are only a few ly away, and *none* of them are naked-eye visible -- yet they make up maybe 75% of our galaxy's stars. So, Houston, we've got a sampling problem.

Quite right about A and B; K is next most common. Here's a sortable table !

BTW, I'm type O+ myself.

[MillennialDem]

8. Overcounted and some are visible yes. But most of the visible are, like I said A and B. I'm

type O+ also.

And which type O star is only 62 ly away? That's in the kill zone for a supernova or gamma ray burst, which O end their lives with.

I'm guessing most of the K visible are in the giant stage?

[eppur_se_muova]

9. You just pointed out a typo in the table I was using !

I thought that number looked odd -- type O, mag. 3.4 at that distance ?? A quick check with The Google shows that star (lamda Ori, or Meissa) at 1060 ly! Good thing, too -- it's an X-ray emitter that's causing molecular clouds 150 ly away to glow. At 62 ly away, that would give a hell of a sunburn! Oh, and it had a former companion that went supernova already -- geez, what a bad neighborhood !

Don't know about the K stars -- I barely get the one-letter designation, never mind the Roman numerals etc.

[MillennialDem]

10. I looked. The Ks (except for Alpha Centauri B) are all giants or subgiants. The roman numerals indic

ate size (volume). The letters represent color (simplifying, but meh).

So a class M I would be a huge giant that is also red.

A class M V would be a dwarf that is red.

[eppur_se_muova]

6. Hmmm ... how much would centrifugal force help expand this star ?

As it loses spin, maybe the resultant contraction will push it to higher densities and temperatures. Would there be a gradual or sudden brightening ? That would certainly be interesting to observe.