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1500 questions
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Is it true that we see the center of the milky-way for only half of the year?
I'm not an astronomer, please excuse my non-formal language.
Since we are located in one of the arms of the Milky way, the center of the galaxy should be in one direction from our location, while in the other direction, we stare into the "other…
riorio
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What effects besides "mass defect" cause the alpha ladder beyond iron-56/nickel-56 to be endothermic?
Many sources state that fusion beyond iron-56/nickel-56 (and certainly beyond nickel-62) is impossible due to them being among the most tightly bound nuclei. For example, in the Wikipedia article on the iron peak…
HeatherB
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Where can I find a catalog of all stars in the Milky Way?
Is there a catalog of all known stars or brightest stars in our galaxy? Preferably with some sort of galactic coordinates instead of just night sky coordinates (right ascension, etc.) I'm trying to make a model of the milky way, explorable with an…
Axiverse
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Why there are no terrestrial planets with a subsurface ocean?
Subsurface oceans in satellites are pretty common: Europa, Enceladus, Ganymede, Callisto, maybe Pluto... This is due to tidal heating of their host planet, Jupiter and Saturn, which heats up the inner ice of those satellites. However, planets don't…
Carlos Vázquez Monzón
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How can the Sun block an X-ray telescope from observing a QPO galaxy "for several years"?
Phys.org's Black hole's heart still beating says:
X-ray satellite observations spotted the repeated beat after its signal had been blocked by our Sun for a number of years.
and links to the Open Access PNAS paper (Jin, Done and Ward 2020)…
uhoh
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During solar eclipses on Jupiter, can the moon(s)' shadow(s) on the surface be seen from Earth with a telescope?
All of the Galilean moons are large and close enough to Jupiter that they can completely eclipse the sun and allow a solar eclipse to happen.
My question is can an observer from Earth, see the moon(s)' shadow(s) on the surface of Jupiter with a…
user177107
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Why does the closest approach of star S2 to Sgr A* not appear to be near the focus of its elliptical orbit?
Phys.org's Very Large Telescope sees star dance around supermassive black hole, proves Einstein right links to several ESO videos, including The star S2 makes a close approach to the black hole at the centre of the Milky Way.
In the screen shot…
uhoh
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Has radio astronomy ever been done on objects that appear very close to the Moon? Is this avoided?
This answer to Which kinds of astronomical observations most need to avoid the Moon being up? mentions
For completeness - radio, mid-infrared and mm-wave observations are unaffected (unless the Moon is in the way!)
The Moon is of course opaque to…
uhoh
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The compatibility of the Grand Tack hypothesis with the "core-warping impact" theory of Jupiter's diffuse core
In recent years, the Juno mission revealed that Jupiter's core was much more diffuse than astronomers had expected.
One theory is that "within a few million years" of its formation, Jupiter experienced a head-on collision with a planetesimal of…
Astrid_Redfern
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Space telescope located in outer solar system
I want to pose a question from someone who's astronomy knowledge would fit neatly onto a single piece of paper so please bear this in mind with any comments or answers. I am interested and want to learn. I could not find a sane answer to this via a…
AndyF
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How "fast" do astronomical events occur?
I've seen quite a few news about astronomy but I'm not deep into knowing how it works or how people observe it. It got me thinking: if I want to watch a supernova for example, how long will I have to look for it to watch the whole "event"? Or events…
Washington A. Ramos
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Is it possible to do moon sighting in advance for 5 years with 100% accuracy?
It is Ramzan and the usual heated disagreements between clerics here in Pakistan as to the sighting of the crescent. This time the minister of Science and Technology (who is not a scientist himself btw) has intervened and formed a committee…
Bibrak
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M87 Black hole. Why can we see the blackness?
So, as the title states, why are we able to actually see the 'blackness' of the black hole? I get that what we are actually seeing is the event horizon, or accretion disk. But should this not extend all the way round? Surely the black hole is not a…
MCG
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What is the evidence that galaxies rotate?
Do all galaxies rotate? If so, do they rotate in the same direction?
What observations have been made of galaxy rotation?
user8
15
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Does a star fuse helium to beryllium on the main sequence?
When a star has finished fusing all its hydrogen into helium, it will then start fusing helium into beryllium and so on and so forth up until iron.
When the star is fusing to beryllium, will the star still be in the main sequence phase and will it…
MiscellaneousUser
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