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APOD: Pixels in the Sun (2021 Jun 26)

Posted: Sat Jun 26, 2021 4:06 am
by APOD Robot
Image Pixels in the Sun

Explanation: These two panels, composed of video frames made with a safe solar telescope and hydrogen alpha filter, show remarkably sharp details on the solar disk and giant prominences along the Sun's edge on June 6 (top) and June 18. Taken from Beijing, China, they also show a transit of the International Space Station and China's new Tiangong Space Station in silhouette against the bright Sun. The International Space Station is near center in the bottom panel, crossing the solar disk left of bright active region AR2833 and below a large looping solar filament. The Chinese space station is below solar active region AR2827 and right of center in the top panel, seen as a smaller, combined "+" and "-" shape. The pictures of the transiting orbital outposts were taken with the same equipment and at the same pixel scale, with the International Space Station some 492 kilometers away. The Chinese space station was over 400 kilometers from the camera.

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Re: APOD: Pixels in the Sun (2021 Jun 26)

Posted: Sat Jun 26, 2021 7:08 am
by sardastro
Great shots from Wang Letian, as usual.
It would be great to know what tool he used to predict the Tiangong solar transit. I've been trying to find one myself for some time now, with no luck.

Have a good one,
Antonio

Re: APOD: Pixels in the Sun (2021 Jun 26)

Posted: Sat Jun 26, 2021 12:47 pm
by orin stepanek
Almost couldn't find this one; Tiangong Space Station :shock:

ISS_CSSsolarTransit_1070.jpg

Re: APOD: Pixels in the Sun (2021 Jun 26)

Posted: Sat Jun 26, 2021 4:39 pm
by Confused
I also could not find the Tiangong Space Station until I realized it might be in the top panel and then I saw in the description that it is and then I saw it.

Hydrogen alpha dominance?

Posted: Sat Jun 26, 2021 5:50 pm
by neufer
https://en.wikipedia.org/wiki/Dominance_hierarchy wrote:
<<A dominance hierarchy, formerly and colloquially called a pecking order, is a type of social hierarchy that arises when members of animal social groups interact, creating a ranking system. In social living groups, members are likely to compete for access to limited resources and mating opportunities. Rather than fighting each time they meet, relative rank is established between members of the same sex. Based on repetitive interactions, a social order is created that is subject to change each time a dominant animal is challenged by a subordinate one. In mammals, a dominant individual is sometimes called an alpha.

Given the benefits and costs of possessing a high rank within a hierarchical group, there are certain characteristics of individuals, groups, and environments that determine whether an individual will benefit from a high rank. These include whether or not high rank gives them access to valuable resources. Age, intelligence, experience, and physical fitness can influence whether or not an individual deems it worthwhile to pursue a higher ranking in the hierarchy, which often comes at the expense of conflict. Hierarchy results from interactions, group dynamics, and sharing of resources, so group size and composition affect the dominance decisions of high-ranking individuals and hierarchy type. For example, in a large group with many males, it may be difficult for the highest-ranking male to dominate all the mating opportunities, so some mate sharing probably exists. These opportunities available to subordinates reduce the likelihood of a challenge to the dominant male.>>

Re: APOD: Pixels in the Sun (2021 Jun 26)

Posted: Sat Jun 26, 2021 7:35 pm
by johnnydeep
The silhouette of Tiangong looks like that of a WWI biplane!

Also, for being "just a big ball of fusing hydrogen and helium", the Sun sure has some pretty complex stuff going on!

Re: APOD: Pixels in the Sun (2021 Jun 26)

Posted: Sat Jun 26, 2021 9:42 pm
by BillBixby
I would like to know the reason today's APOD is using the term CSS rather than TSS or TSS3? Neither would be confused with ISS. Just curious.

Re: APOD: Pixels in the Sun (2021 Jun 26)

Posted: Sun Jun 27, 2021 12:57 pm
by johnnydeep
BillBixby wrote: Sat Jun 26, 2021 9:42 pm I would like to know the reason today's APOD is using the term CSS rather than TSS or TSS3? Neither would be confused with ISS. Just curious.
I don't see the acronym CSS used here. Well, there is one use of "CSS" in the linked-to WikiPedia article about the Tiangong Space Station.