Board Astronomy (contains big images)

[Asbo Zaprudder]

And, in a regular supernova, that gold gets sucked into the black hole.

Sorry to ask this but can we stop using phraseology that imply that black holes do any sucking beyond gravitational attraction. Some folks around this subforum seem to think they do just that. I'm pretty sure you don't.

 

[think]

Sorry to ask this but can we stop using phraseology that imply that black holes do any sucking beyond gravitational attraction. Some folks around this subforum seem to think they do just that. I'm pretty sure you don't.

that was from the article in the link.. like the second paragraph.in the article lifted straight out and pasted there- .. so yeah. sucking is not something too typical at all as a vacuum does not really suck as well- but .. just gravitational forces at work yep.--

 

[Asbo Zaprudder]

In General Relativity, there is a minimum-size orbit that is stable (innermost stable circular orbit or ISCO) for an object of negligible mass orbiting a much more massive object, be it a star, planet, black hole, or whatever. Usually, the ISCO would be inside the massive object and so is irrelevant. However, this isn't the case for black holes. The ISCO radius is important for black hole accretion disks as it determines where the inner edge of the disk lies. For non-rotating black holes, the ISCO radius is 3 times the event horizon radius (2GM/(c^2)). For rotating ones, which are much more likely, it's of the same order of magnitude but depends on the direction of orbital rotation relative to the black hole - approaching 4.5 times the horizon radius for retrograde and approaching 1 times for prograde motion. Outside this radius, a body can orbit indefinitely, provided it doesn't lose kinetic energy due to collisions and the black hole doesn't gain in mass sufficiently for the ISCO radius to encompass the orbital radius of the object.

Black holes don't roam the Galaxy hoovering up stars like cosmic vacuum cleaners. Their tidal effects are disruptive, especially the small ones counterintuitively, and the more active ones spew out energetic particles along their rotation axes as polar jets and emit X rays from the accretion disk. As long as the event horizon is not approached too closely and any accretion disk and polar jets are avoided, black holes are not as fearsome as people tend to believe.

You need to have enough kinetic energy to escape the gravity field and if you're effectively falling into the field from a very large distance following a parabolic or hyperbolic path, the main problem is to manoeuvre sufficiently to avoid the dangerous zones. It's also possible to extract energy from the black hole and increase your velocity in a similar way as we use various planets in the solar system for gravitational assist.

 

[publiusr]

Magnetars would be more of a threat to metal spacecraft that can orbit black holes more closely than suns of similar mass to black holes.

Magnetic fields would reach out and grab you the way folks think black holes work.

Huge black holes
https://www.spacedaily.com/reports/...ion_shows_black_hole_ripping_at_star_999.html
https://www.spacedaily.com/reports/...lack_hole_and_quasar_in_the_universe_999.html

Our back yard
https://www.spacedaily.com/reports/..._solar_systems_original_architecture_999.html

Bennu body armor
https://phys.org/news/2022-06-nasa-spacecraft-asteroid-bennu-boulder.html

Deeper impact?
https://www.universetoday.com/15711...r-objects-should-leave-very-distinct-craters/

Out there:
https://www.spacedaily.com/reports/...asure_polarized_light_from_exoplanet_999.html
https://www.spacedaily.com/reports/..._cosmic_dust_in_the_distant_Universe_999.html
https://phys.org/news/2022-06-luminous-quasar-astronomers.html

Turbulence imagined
https://www.spacedaily.com/reports/...ver_supersonic_turbulence_simulation_999.html
https://www.spacedaily.com/reports/Energy_from_solar_wind_favours_the_north_999.html

Old star home
https://www.spacedaily.com/reports/A_Rocky_Planet_Around_One_of_Our_Galaxys_Oldest_Stars_999.html

Astro-Sat
https://phys.org/news/2022-06-stellar-populations-ngc-astrosat.html

The early universe revealed--a new tool
https://phys.org/news/2022-06-mathematical-tool-fractal-quark-gluon-plasma.html
https://phys.org/news/2022-06-machine-simulations-lifecycle-ancestor-galaxy.html

Eye of the universe
https://www.reddit.com/r/space/comments/vl7qe4/the_celestial_zoo_the_central_image_is_a/
https://www.ndtv.com/world-news/nas...g-remains-of-supernova-stuns-internet-3454890

 

[publiusr]

Betelgeuse has been downsized.
Smaller, but closer at 550 ly?
https://www.spacedaily.com/m/report...n_getting_in_the_way_astronomers_say_999.html

After Webb
https://www.space.com/james-webb-space-telescope-what-next-john-mather
https://www.space.com/habitable-worlds-observatory-first-glimpse

Space manatee and more:
https://phys.org/news/2022-07-extremely-energetic-particles-space-manatee.html
https://www.space.com/super-earth-alien-planet-formation-explanation

Cosmology
https://phys.org/news/2022-08-universes.html
https://phys.org/news/2022-08-explosive-neutron-star-merger-captured.html
https://phys.org/news/2022-08-supernovae-progenitors-contributed-solar-nebula.html
https://www.space.com/test-electromagnetism-rainbows-from-sun-twins
https://www.space.com/x-ray-image-super-powerful-stars
https://www.space.com/bluewalker-3-bright-satellite-alarming-astronomers

Stars halfway to Andromeda
https://www.universetoday.com/15957...he-milky-way-but-theyre-halfway-to-andromeda/
https://www.universetoday.com/159536/blue-straggler-stars-are-weird/

A rotating universe allows Time travel
https://www.universetoday.com/159537/how-a-rotating-universe-makes-time-travel-possible/

To Boldly Go
https://www.universetoday.com/15943...tion-continues-actress-legacy-of-inspiration/

Disneyspace

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Detailed Moon images
https://www.space.com/green-bank-radar-highest-resolution-moon-photos

A nearby home?
https://www.spacedaily.com/m/report...tary_systems_second_Earth_size_world_999.html

 

[Asbo Zaprudder]

Betelgeuse has been downsized.
Smaller, but closer at 550 ly?

Here's a source for that statement:
"Standing on the Shoulders of Giants: New Mass and Distance Estimates for Betelgeuse through Combined Evolutionary, Asteroseismic, and Hydrodynamic Simulations with MESA" https://iopscience.iop.org/article/10.3847/1538-4357/abb8db

A 25% systematic error in the previously accepted distance seems very large although this new estimate is more consistent with parallax measurements made by Hipparcos. Unfortunately, it seems that Betelgeuse is probably too bright to have its distance measured by Gaia.
See https://www.aanda.org/articles/aa/pdf/2016/11/aa29272-16.pdf section 6.5

ETA: another comment - MESA was used to model Betelgeuse in the first paper cited above. However, Betelgeuse has a high rotation rate and an unusually high nitrogen composition, which some researchers speculate is the result of a merger with another star that added angular momentum and stirred up deeper layers. From what I recall, MESA doesn't support modelling such a scenario. It would probably require specially written code run on a supercomputer.

 

['Q']

Betelgeuse has been downsized.
Smaller, but closer at 550 ly?

Also means its mass may be lower, so we can add 250-500,000 years to that expected supernova event.

 

[think]

https://www.abc.net.au/news/2020-08...-no-danger-hitting-earth-us-election/12605590

Asteroid 2018VP1 is heading towards Earth but NASA says it's nothing to worry about

https://indianexpress.com/article/e...l-buzz-cut-earth-before-us-elections-6790201/

Explained: Asteroid 2018VP1, which Neil deGrasse Tyson says will ‘buzz-cut’ Earth before US elections

2018VP1, dubbed the election day asteroid, has been known to planetary researchers since 2018, and NASA had played down its risk to our planet recently.

 

[think]

NASA Science Live: Our First Attempt to Sample Asteroid Bennu,..

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again with asteroids --- 200,000,000 miles away --- we got a sample of it and it will be back on earth sept 24 2021. this is the footage.. of that sample taking .. on its way back to earth.. the sample thing.--- this is real and this is happening might be --- like a round earth after all. hehe.. LOL

 

[StarCruiser]

Last I heard, the sample collector was jammed (probably from the impact) and they were suspecting it was loosing the sample.

I hope that's not the case.

 

[publiusr]

List to keep an eye out for
http://astronimate.com/list/next-star-go-supernova/

 

[Owain Taggart]

@Timelord Victorious, just wondering if you're planning on trying to image the Jupiter/Saturn conjunction? A friend of mine is doing so, and conversation turned to this in my local club and to the difficulty of capturing both properly given that Jupiter would be much brighter than Saturn. So, this friend of mine is planning on cheating a bit by first taking an image of both for their positions, image both of them separately, then combining both together. Of course, this requires some access to big telescopes, but this friend has access to a fairly good one that allows him to stop it down if necessary.

 

[Timelord79 (he/him)]

@Timelord Victorious, just wondering if you're planning on trying to image the Jupiter/Saturn conjunction? A friend of mine is doing so, and conversation turned to this in my local club and to the difficulty of capturing both properly given that Jupiter would be much brighter than Saturn. So, this friend of mine is planning on cheating a bit by first taking an image of both for their positions, image both of them separately, then combining both together. Of course, this requires some access to big telescopes, but this friend has access to a fairly good one that allows him to stop it down if necessary.

If I can.
My setup is not very good for planetary, so I won’t get much detail anyway.
I hope to at least resolve the two planets with their biggest moons.
I am already able to fit them both in one frame through my small refractor. In a well or so, my Newton should also get them both and then I’ll se what I can do.
I don’t want to wait till the 21st, since they will be too low over the horizon to catch them from my balcony, unless I get them during the last hour of daylight/twighlight.
And then it might just be too cloudy anyway.

 

[Owain Taggart]

Yeah, everyone's concerns are about the clouds. Seems to me, any major astronomical event is clouded over in our area. Well, I'll look forward to seeing your results with however you can manage

 

[publiusr]

I wonder if Hubble will have a go

https://www.spacedaily.com/reports/The_Great_Conjunction_of_Jupiter_and_Saturn_999.html

Old pic' of the skies
https://www.nationalgeographic.co.u...akeshift-camera-forgotten-inside-uk-telescope

Orion
https://bgr.com/2020/12/31/nebula-photo-orion-hubble-spitzer/

 

[publiusr]

Galaxy bubbles
https://www.quantamagazine.org/spac...axy-size-bubbles-over-the-milky-way-20210106/
https://www.spacedaily.com/reports/...Showcases_6_Beautiful_Galaxy_Mergers_999.html
https://www.cnet.com/news/astronomers-find-the-oldest-supermassive-black-hole/
https://www.wired.com/story/the-milky-way-gets-a-new-origin-story/

Inconstant Moons...
https://forum.cosmoquest.org/showthread.php?176555-Ep-590-Lunar-Hazards-Dust-Radiation-and-More
https://www.syfy.com/syfywire/in-774-ad-the-sun-blasted-earth-with-the-biggest-storm-in-10000-years

An oddball and more
https://forum.cosmoquest.org/showthread.php?176519-New-type-of-star-discovered-It-is-a-strange-one
https://forum.cosmoquest.org/showthread.php?169404-Tau-Ceti-the-story-so-far

Futurism.com has a Reddit page about a home made image of the Sun
https://futurism.com/the-byte/photo-sun-unlike-anything-youve-ever-seen

Black hole image
https://futurism.com/image-eht-black-hole-polarized-light
http://up-ship.com/blog/?p=46348
http://up-ship.com/blog/?p=46335

Hastur calling
https://www.space.com/hyades-star-cluster-dissolving-dark-matter.html
http://up-ship.com/blog/?p=46325

Betelgeuse
https://astrobites.org/2021/04/26/betelgeuse-going-critical/
https://twitter.com/betelbot?ref_src=twsrc^google|twcamp^serp|twgr^author

 

[publiusr]

It looks like Gliese 710 is going to give us a close shave--passing by at 4,125 AU ....magnitude -6....right around the magnitude of the crescent moon (and would probably seem brighter, since it would not be an extended object).
https://forum.cosmoquest.org/showthread.php?177197-Gliese-710-Close-Approach-Much-Closer-!

"Every time this calculation is revisited using new data, it gets closer."

Only 153 ly out....Stars that have gone missing from the Hyades cluster may have been torn away by a dark matter monster with the mass of 10 million Suns:

https://www.vice.com/en/article/epd...making-nearby-stars-vanish-scientists-propose


Along the shore the cloud waves break,
The twin suns sink behind* the lake,
The shadows lengthen
In Carcosa.

Strange is the night where black stars rise,
And strange moons circle through the skies
But stranger still is
Lost Carcosa.

Songs that the Hyades shall sing,
Where flap the tatters of the King,
Must die unheard in
Dim Carcosa.

Song of my soul, my voice is dead;
Die thou, unsung, as tears unshed
Shall dry and die in
Lost Carcosa.

 

[publiusr]

Chandra atlas and stellar research
https://phys.org/news/2021-05-chandra-discoveries-3d-platform.html
https://phys.org/news/2021-05-stunning-simulation-stars-born-realistic.html
https://phys.org/news/2021-05-space-instrument-captures-solar-eruption.html

A new way to cut stray light
https://phys.org/news/2021-05-revolutionary-method-drastically-stray-space.html

 

[Unicron]

"One hill over, a competing astrophotographer does a backflip over a commercial airliner while throwing a tray of plastic space stations into the air, through which a falcon swoops to grab the real one."

"The key to discovering life on Mars is to find someone who built a camera and landed it on Mars. Then you just look through the pictures for plants and dogs and stuff."

 

[Non Sync]

The space shuttle during launch...