Starship Asterisk*

The singularity is small (infinitesimal) but isn't the BH's "size" and hence the gravitational effect - and collision window - determined by how large the event horizon is? A black hole's "gravitational effect" is determined by its mass. The event horizon isn't a real thing, jus...

I edited my post with more queries... The mass of the black hole doesn't matter, except to the extent that it's a factor in determining the orbit. Whether it hits the star depends on whether its orbit intersects the interior of the star. This is basically no different than two stars passing by each...

Can a black hole cause a star to supernova? Is the tidal force of a black hole more powerful than a supernova, either squelching it or, like Q, not being affected by it at all other than merely sucking it in like anything else? The tidal force of a black hole, because it is so small, is also small....

Can a black hole cause a star to supernova? Is the tidal force of a black hole more powerful than a supernova, either squelching it or, like Q, not being affected by it at all other than merely sucking it in like anything else? The tidal force of a black hole, because it is so small, is also small....

I suppose the "everything vanishes" part is a manner of speaking. Everything falls out of sight perhaps, but nothing "vanishes", rather what's left of the star's mass is added to the black hole's mass, increasing very slightly the event horizon radius, and dare I add: increasing...

Okay, cool, but... https://apod.nasa.gov/apod/image/2405/BhShredder_NASA_1080.jpg APOD 5 May 2024 annotated.png Can anyone answer my questions? Ann I fear this is another "artist's representation" that is not very connected to reality. So what needs to change in order to make it more real...

https://apod.nasa.gov/apod/calendar/S_240505.jpg A Black Hole Disrupts a Passing Star If the star directly impacts a massive black hole, then the star falls in completely -- and everything vanishes . I suppose the "everything vanishes" part is a manner of speaking. Everything falls out of...

Ann wrote: ↑Sun May 05, 2024 4:27 am Okay, cool, but...

A Black Hole Disrupts a Passing Star. Illustration Credit: NASA, JPL-Caltech

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APOD 5 May 2024 annotated.png

Can anyone answer my questions?

Ann

I fear this is another "artist's representation" that is not very connected to reality.

Well, OK, temperature is based on molecular motion. The scale we use is based on some earthbound feature at sea level & 1 atmosphere plus desire for decimalization. What is really fascinating is : how do we know what is going on so far away, and what does that imply about how the system formed?...

Cousin Ricky wrote: ↑Fri May 03, 2024 5:10 pm I find it interesting that the trailing side is slightly hotter than the leading side.

I guess it would require an understanding of how the wind system works. It seems equally likely to me that either edge could be warmer, or that the entire face could be uniform.

Is there even a definition of a "bar" based on something other than mere appearance? Is it simply dust/gas that is apparently concentrated more or less predominantly along a line through the galaxy core? I think it's purely a subjective, visual definition. In a sense, we might argue there...

Still not much of a definitive bar in M61 at all compared to your other examples. And I'm not convinced of the "inner" bar in NGC 1365 either! "A bar is in the eye of the beholder" it seems. I just told you that I don't necessarily always trust Wikipedia, but now I'm going to qu...

abaca wrote: ↑Fri May 03, 2024 1:28 pm If Astrolabos, aka WASP-42b, is tidally locked then does that mean it possesses no magnetic field?

With a 19-hour rotation period, I'd think it likely to have a magnetic field.

You'd think at that orbital distance, the parent star would either wick matter from WASP-43b, or cause the orbit to decay until the planet broke apart, or given time, both. I'm no astrophysicist, though..... :' ) These are small, fairly dense bodies separated by many times their diameters. There ar...

I assume we have some justification for naming everything in our own solar system. And won’t we quickly run out of Earthly nomenclature to name objects elsewhere? There is also some hubris in our assuming it falls to us to name everything. I doubt the Wasp-43 system has its own intelligent life wit...

I was declaring the Snowman's height, not estimating. Well, yes... not really an option with most astronomical objects, though! Because no subtended angle was explicitly mentioned, my brain decided there were only 2 knowns in a 3-variable equation relating angle, distance and width, and the width e...

I think, regardless of the observer's distance to the object, its width, in light-years, is static. I.E. Q:"How tall is Snowman?" A: 2 meters Q: I've doubled my viewing distance from Snowman; now how tall is Snowman? A: 2 meters But in order to determine that the snowman is 2 meters high,...

"The absolute distance (which is a useful thing to know) is calculated from the angular size of the object. The majority of APOD images of deep sky objects present a physical (absolute) size based upon subtended angle and estimated distance". Yes, the descriptions usually give the angular...

Your last post mentions spanning an angle, which is reasonable. The article didn't - it mentioned an absolute width. I think the author should re-state the width as an angular diameter, or relative to something else E.G. Moon radius, not light-years. The absolute distance (which is a useful thing t...

I think, regardless of the observer's distance to the object, its width, in light-years, is static. I.E. Q:"How tall is Snowman?" A: 2 meters Q: I've doubled my viewing distance from Snowman; now how tall is Snowman? A: 2 meters But in order to determine that the snowman is 2 meters high,...

"At that distance, IC 1795 would span about 70 light-years across." I don't understand how a width, expressed here in absolute units, is related to distance. I believe the number is incorrect... but probably because they've identified the nebula incorrectly. IC 1795 is just the "head...

Bird_Man wrote: ↑Mon Apr 29, 2024 1:37 pm Are the different "rings" shown in this image from successive shedding events when it "evolves to throw off it's outer atmosphere"?

Most likely.

So, something similar will likely be the fate of our own Sun, correct? From the link - Planetary Nebulae Planetary nebulae (PN) represent the last stages of evolution for low- and intermediate-mass stars whose Main Sequence mass was less than about 8 solar masses. After evolving through the Asympto...

Interesting adjective "elongated". Implies ovoid, but outermost wisps are almost perfectly circular. We do not know the viewing aspect. Could be looking down the barrel of somethig like the butterfly nebula. In fact, we understand both the viewing aspect and the 3D structure of the Ring N...

The instruments of the observers of the 16th and 17th centuries were less precise than the 150 mm amateur telescopes, but with the desire to discover they solved it. When the Ring Nebula is observed with an amateur telescope, a milky circle appears to the eye with a dark center and nothing more res...