Our sun is a weirdly 'quiet' star — and that's lucky for all of us

rod

Oct 22, 2019
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Very interesting report. Here is another link on the subject, The Sun is less active than other solar-like stars

"Activity levels of Sun-like stars Magnetic activity on the Sun leads to solar flares, coronal mass ejections, and other space weather that affects Earth. Similar activity on other stars may determine the habitability of any orbiting exoplanets. Reinhold et al. analyzed brightness variations of stars observed with the Kepler and Gaia space telescopes to infer their activity levels (see the Perspective by Santos and Mathur). They found that the Sun was less active than most of the 369 solar-type stars in their sample (those with the most similar physical properties). It remains unclear whether the Sun is permanently less active than other stars of its type or if its activity levels vary over many thousands or millions of years. Abstract The magnetic activity of the Sun and other stars causes their brightness to vary. We investigated how typical the Sun’s variability is compared with other solar-like stars, i.e., those with near-solar effective temperatures and rotation periods. By combining 4 years of photometric observations from the Kepler space telescope with astrometric data from the Gaia spacecraft, we were able to measure photometric variabilities of 369 solar-like stars. Most of those with well-determined rotation periods showed higher variability than the Sun and are therefore considerably more active. These stars appear nearly identical to the Sun except for their higher variability. Therefore, we speculate that the Sun could potentially also go through epochs of such high variability."

The Sun spins about 2 km/s at its equator, some stars in this study spin near 3 km/s. Another report shows the Sun is a very round object, Sun's Almost Perfectly Round Shape Baffles Scientists Folks can compare our Sun to other stars reported where the exoplanets are located, http://exoplanet.eu/ Looks like our Sun is very good for life here on Earth.
 

rod

Oct 22, 2019
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Observations over 12 years show the Sun is a very stable star for life on Earth, “An instrument on the European/NASA SOHO solar observatory has imaged the Sun some 500,000 times in the past 12 years. This consistent, easily compared series of images shows that the Sun’s size has been rock-steady since 1998 to about 1 part in 50,000. This despite the fact that the Sun’s brightness varies by about 1 part in 1,000 during the 11-year sunspot cycle, due to the waxing and waning of surface activity.”, ref - The Rock-Steady Size of the Sun, News Notes, Sky & Telescope 120(3):16-18, 2010. As the space.com report title says *...and that's lucky for all of us*. Luck as a cause and effect mechanism is basically an appeal to *stuff happens* :)
 

Wolfshadw

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Apr 1, 2020
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Given that our star is in a relatively quiet part of the galaxy neighborhood, one wonders where in the galaxy are these other stars that are being observed. Are they in more dense clusters of stars in a spiral arm of the galaxy?

-Wolf sends
 
Jan 31, 2020
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We may have one more term to add to the Drake Equation here. Actually this is the kind of thing that makes me seriously doubt the usefulness/truthfulness of the Drake Equation. You never really know how many terms you actually need when you have a sample of one. Consequently I don't lose any sleep being bothered by the Fermi Paradox either since that's just as questionable of a concept and for the same reason.
 
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We may have one more term to add to the Drake Equation here. Actually this is the kind of thing that makes me seriously doubt the usefulness/truthfulness of the Drake Equation. You never really know how many terms you actually need when you have a sample of one. Consequently(,) I don't lose any sleep being bothered by the Fermi Paradox either since that's just as questionable of a concept and for the same reason.
What does this have to do with the topic? We are discussing
"Our sun is a weirdly 'quiet' star — and that's lucky for all of us".
 
Jan 31, 2020
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What does this have to do with the topic? We are discussing
"Our sun is a weirdly 'quiet' star — and that's lucky for all of us".
It's because this discovery about the Sun could cause those who think about the Drake equation to change the number of terms. If we have a wierd (rare) sun that needs to be taken into account. Unexpected needs to change the Drake equation erodes at its credibility which also erodes at the significance of the Fermi Paradox since it stands otop the Drake equation.
 
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rod

Oct 22, 2019
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It's because this discovery about the Sun could cause those who think about the Drake equation to change the number of terms. If we have a wierd (rare) sun that needs to be taken into account. Unexpected needs to change the Drake equation erodes at its credibility which also erodes at the significance of the Fermi Paradox since it stands atop the Drake equation.
Good observation. The recent report on Proxima Centauri b exoplanet shows similar problems for red dwarf star hosts. This red dwarf has some 400x more flares in X-rays than our quiet Sun, https://forums.space.com/threads/proxima-b-the-closest-alien-planet-we-know-may-be-even-more-earth-like-than-we-thought.31442/
 
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Jan 31, 2020
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Good observation. The recent report on Proxima Centauri b exoplanet shows similar problems for red dwarf star hosts. This red dwarf has some 400x more flares in X-rays than our quiet Sun, https://forums.space.com/threads/proxima-b-the-closest-alien-planet-we-know-may-be-even-more-earth-like-than-we-thought.31442/
Although the extra 400x flares and the X-rays would be a threat to life as we know it, it sure would be fantastic to look at. Our ordinary boring sun is my favorite star in the sky and I often do the forbidden and use my red Edmond Scientific bong-shaped astroscan 4" telescope as a projector to project 2 foot size images of the sun on handy surfaces to look at whatever solar features are visible. More sunspots, flares, and prominences would be amazing to see. Still, its better the way it is. :)
 
The Sun's unusually weak number of sunspots over the last decade should not be considered as a measure of the Sun's energy output (ie luminosity). I think it still doesn't change by more than about 0.1%, so don't look for a cool summer. :)

The weak sunspot cycle does produce a weak solar mag. field. This weaker magnetic field will allow an increase in the number of cosmic particles (e.g. very high energy protons) that slam into our atmosphere. There is research that shows these particles can cause cloud formation, thus reflecting more of the Sun's radiation, thus help cool our atmosphere. I don't know if mainstream holds this helps in a big or only a tiny way, or not at all.

It was discovered that there was one cosmic ray (proton)that hit our atmosphere having the energy of a Nolan Ryan fast ball. Given the size of a proton, that's just incredible to me.
 
Jan 31, 2020
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It was discovered that there was one cosmic ray (proton)that hit our atmosphere having the energy of a Nolan Ryan fast ball. Given the size of a proton, that's just incredible to me.
Yea, our supercolliders are nothing compared to what nature can throw at us. It's good to be humbled from time to time. It helps us keep the right perspective of our true status in the universe. :)
 
Yea, our supercolliders are nothing compared to what nature can throw at us. It's good to be humbled from time to time. It helps us keep the right perspective of our true status in the universe. :)
Yes, and "honor follows humilty", as well.

I think, however, our accelerators do produce results similar to this example, but only a proton at a time, not trillions upon trillions, of course.
 

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