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APOD: Our Increasingly Active Sun (2023 Feb 22)
Posted: Wed Feb 22, 2023 5:06 am
by APOD Robot
Our Increasingly Active Sun
Explanation: Our Sun is becoming a busy place. Only two years ago, the Sun was emerging from a
solar minimum so quiet that
months would go by
without even a single
sunspot. In contrast, already this year and well ahead of schedule, our Sun is
unusually active, already nearing solar activity levels seen a decade ago during the last
solar maximum. Our increasingly active Sun was captured two weeks ago sporting numerous
interesting features.
The image was recorded in a single color of light called
Hydrogen Alpha, color-inverted, and false colored.
Spicules carpet much of the Sun's face. The brightening towards the Sun's edges is caused by increased absorption of relatively cool solar gas and called
limb darkening. Just
outside the Sun's disk, several scintillating
prominences protrude, while prominences on the Sun's face are known as
filaments and show as light streaks. Magnetically tangled
active regions are both dark and light and contain cool
sunspots. As our
Sun's magnetic field winds toward solar maximum over the next few years, whether the
Sun's high activity will continue to increase is unknown.
Re: APOD: Our Increasingly Active Sun (2023 Feb 22)
Posted: Wed Feb 22, 2023 7:13 am
by AVAO
Re: APOD: Our Increasingly Active Sun (2023 Feb 22)
Posted: Wed Feb 22, 2023 3:07 pm
by Chris Peterson
AVAO wrote: ↑Wed Feb 22, 2023 7:13 am
Interesting when I compare the picture to the photo of Jose Carballada taken on almost the same date.
While images of the Sun are always interesting, what is it in particular you find interesting in comparing these particular images?
Re: APOD: Our Increasingly Active Sun (2023 Feb 22)
Posted: Wed Feb 22, 2023 3:38 pm
by johnnydeep
The brightening towards the Sun's edges is caused by increased absorption of relatively cool solar gas and called limb darkening.
Huh? Oh right, this is a color inverted image (and false colored after - or maybe before? - that apparently).
Re: APOD: Our Increasingly Active Sun (2023 Feb 22)
Posted: Wed Feb 22, 2023 3:45 pm
by Ann
The Sun may be getting increasingly active, but it is still pretty much as well-mannered as a choir boy:
Did you know that the Sun is one of the absolutely most perfectly spherical objects that astronomers know of?
John von Radowitz of Independent wrote:
A mystery surrounds the shape of the Sun - it is just too perfectly round, say scientists.
In fact the Sun turns out to be one of the roundest objects ever measured.
Scaled down to the size of a beach ball, the difference between the Sun's widest and narrowest diameters would be far less than the width of a human hair...
Lead researcher Dr Jeff Kuhn, from the University of Hawaii, said: "For years we've believed our fluctuating measurements were telling us that the Sun varies, but these new results say something different. While just about everything else in the Sun changes along with its 11-year sunspot cycle, the shape doesn't."
So the Sun is nothing like those flattened, fast rotating hot blue stars, and it is nothing like the irregularly shaped big blobs of red giant stars either.
The Sun is simply well-behaved! Even when it throws a tantrum or two, it is very rarely truly frightening. That makes it very different from a lot of angry stars out there!
The Sun throwing a tantrum. There's normally no cause for concern.
Ann
Re: APOD: Our Increasingly Active Sun (2023 Feb 22)
Posted: Wed Feb 22, 2023 4:31 pm
by AVAO
Chris Peterson wrote: ↑Wed Feb 22, 2023 3:07 pm
AVAO wrote: ↑Wed Feb 22, 2023 7:13 am
Interesting when I compare the picture to the photo of Jose Carballada taken on almost the same date.
While images of the Sun are always interesting, what is it in particular you find interesting in comparing these particular images?
I like the photos of Mehmet Ergün very much. And today's apod has an exceptional quality, especially in the surface details.
But I was a little surprised that there were so few dark areas of sunspots visible on today's APOD. Much more are visible in Jose Carballada's image taken 10 days ago. If you look at the solar activity at this time on Helioviewer, you will also see high activity around the entire solar axis. I had therefore asked myself whether the time specification in the APOD text can be correct...
Re: APOD: Our Increasingly Active Sun (2023 Feb 22)
Posted: Wed Feb 22, 2023 4:36 pm
by Chris Peterson
AVAO wrote: ↑Wed Feb 22, 2023 4:31 pm
Chris Peterson wrote: ↑Wed Feb 22, 2023 3:07 pm
AVAO wrote: ↑Wed Feb 22, 2023 7:13 am
Interesting when I compare the picture to the photo of Jose Carballada taken on almost the same date.
While images of the Sun are always interesting, what is it in particular you find interesting in comparing these particular images?
I like the photos of Mehmet Ergün very much. And today's apod has an exceptional quality, especially in the surface details.
But I was a little surprised that there were so few dark areas of sunspots visible on today's APOD. Much more are visible in Jose Carballada's image taken 10 days ago. If you look at the solar activity at this time on Helioviewer, you will also see high activity around the entire solar axis. I had therefore asked myself whether the time specification in the APOD text can be correct...
Well, the images were made four days apart, which means that there was significant rotation of features as well as a lot of time for structure to change.
Re: APOD: Our Increasingly Active Sun (2023 Feb 22)
Posted: Sun Feb 26, 2023 7:06 am
by VictorBorun
Ann wrote: ↑Wed Feb 22, 2023 3:45 pm
So the Sun is nothing like those flattened, fast rotating hot blue stars, and it is nothing like the irregularly shaped big blobs of red giant stars either.
The Sun is simply well-behaved! Even when it throws a tantrum or two, it is very rarely truly frightening. That makes it very different from a lot of angry stars out there!
Ann
I wonder how Sun ended so slowly rotating. Did it shed its spin driving Saturn and Jupiter to outer orbits? Did it drive another gas giant so far that we have not discovered it yet?