"Black holes can also trek through space as rogue black holes, so it is not impossible for them to be flung into the void."

Great another thing to keep me up at night

Imagine waking up to an article posted on this sub saying "the sun is getting smaller"

I just can't. I love astronomy but it also terrifies me

If we detect a rogue blackhole getting closer early enough, we could use it as a large lens and get some great astronomy out of it, till it really gets closer. Silver lining.

Yes I was just thinking about that! We would have access to the universe's greatest telescope for a bit. Silver lining LOL

So would all of this graveyard material be considered at least a partial candidate of dark matter? It seems to be found in halos around the Galaxy, it would be made up of dead stars and other matter that might not be very visible, and examples like the bullet cluster that seemed to be devoid of dark matter may have just had a run in with a local Galaxy that stripped it away or kicked it out. Or would this amount of material be orders of magnitude too small to explain a reasonable proportion of expected dark matter?

[removed]

It's like out of (celestial) body experience people experience before they die.

This material is both already accounted for and just too small a quantity. I’m no expert though.

Yep, they would. Pretty sure these would qualify as MACHOS. Probably still not enough matter but can't know until we measure it.

And we get to meet 5th dimensional beings

I'm not an expert on this topic but wasn't it just proven that we can't see the universe past the 3rd dimension.

[deleted]

Go read (or my preference was to listen to) Project Hail Mary. Great book

On a cosmic scale, we don't exist

[removed]

So you're saying there's a chance.

Whats factual is that our system is on the tail end of the spiral, you'd expect alot of material anomalies would make its way there.

Given the mass of black holes, we'd be likely seeing the effects of it's gravity for years if not decades or centuries before that happened.

Although it would make for an interesting scifi story. Iirc that's a subplot in Dragon's Egg.

Also, check out "Death by Neutron Star", which I think was on Discovery.

Hail Mary!

[removed]

We are actually pretty much at the half-way point (maybe just a little more than halfway) along the Orion Spur -- which itself is halfway along the Sagittarius spiral arm. That puts us generally half way (again, maybe a little more than half way) between the galactic center and the outer edge.

An illustrated galactic map here: https://www.nasa.gov/jpl/charting-the-milky-way-from-the-inside-out

[removed]

Stellar mass black holes are similar to large stars and these are what are roaming around. SMBH are basically only found at the centre of galaxies and due to that are exceedingly rare. Black holes pose was less of a threat to us than stars do as stars outnumber black holes a million to one or something else ridiculous.

Any matter we can see with light isn’t a candidate for Dark Matter. It also has to outnumber all the visible matter 5:1.

I've seen another chart that describes from my previous expression, somehow your link for the Nasa charts makes me feel much much better.

[removed]

Source? Interested in this. Googled but could find.

Not an astronomer, but I would guess probably not, since we need several times as much dark matter as ordinary matter. Also, judging from the picture, it looks like the graveyard mass is still concentrated in the center, not in a ring surrounding the galaxy.

It's also important to remember that galaxy rotation is just one of several phenomenon that dark matter explains. These stellar graveyards inside galaxies wouldn't explain the dynamics of galaxy clusters or the CMB