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Astronomers may have found the first exomoon

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Re: Astronomers may have found the first exomoon

#51

Post by nullsanity »

walrus01 wrote: post #33
Foskya wrote: post #29

Earlier quoted context omitted.

But... he literally said in the following sentence that adding more mass does not change size, implying that he is talking about diameter, not mass.

Correct, but the link for "super jupiter" also goes to something that astronomers are fairly sure is 1.38x the diameter of Jupiter. Much less massive of course. Meaning Jupiter's diameter is not an absolute hard limit nothing can be larger than. https://en.wikipedia.org/wiki/HAT-P-1b It also orbits its star in only under 5 days, so a few theoretical visualization/renderings of it would probably be quite spectacular.

Nobody said it was, he said it was "pretty much". Y'all can't read anymore.

Re: Astronomers may have found the first exomoon

#52

Post by ndarray »

codeddesign wrote: post #49

Outside of the small probability that this may assist us in the future, has looking beyond our moon ever benefitted or even affected humanity in any way?

No, but let's keep pouring billions into confirming that the laws of physics apply outside of our solar system - smaller objects orbiting larger ones? Who could have guessed?

I'm sympathetic to space colonization, which seems like the most optimistic long term future for humanity, but the focus on exoplanets, -moons, even signs of exo-civilizations feels like making up theories about the bottom of the ocean centuries before the invention of submarines.

Re: Astronomers may have found the first exomoon

#53

Post by __MatrixMan__ »

_joel wrote: post #25

Brown dwarfs fascinate me, they can be at room temperature (range from about 2,800 K down to 250 K (roughly 2,500 °C to -23 °C / 4,500 °F to -10 °F) You could basically have a bath in a brown dwarf, sure you might not last long, but still...

The idea of a black dwarf is also pretty wild. The universe isn't old enough for any black dwarves to exist yet, but eventually the brown ones will radiate enough heat away that they're no longer held up by the vibrational energy of the atoms they contain. They'll stop being fluffy and settle into a mode where they're held up only by electron degeneracy pressure (a.k.a the Pauli exclusion principle)... it's a bit like how neutron stars are stable because they're not so massive that they collapse to a black hole. Black dwarves will be stable because they're not so massive that they collapse to a neutron star.

What will this substance look like? Will it ring like a bell if struck? What color will it be? Will it conduct electricity? If so, how? Are the atomic nuclei now the charge carriers because the electrons are stuck? It would likely be a super-thermal-conductor, does that have any analogous properties to a super-electrical-conductor? Which of these can we observe without the sensor collapsing to degenerate matter itself?

I hope there's life around to conduct these experiments when they become possible.

Re: Astronomers may have found the first exomoon

#54

Post by ck2 »

delta_p_delta_x wrote: post #22

Worth noting that the artist's impression is... not accurate. Both CD-35 2722 b (the brown dwarf orbiting the primary star) and CD-35 2722 b I (the exomoon orbiting the secondary) should be much closer in size. It is estimated that Jupiter is essentially the largest any gas giant can get; adding more mass will simply increase density and interior temperature until deuterium and lithium fusion and brown dwarfdom, and…

NASA exoplanet catalog has a neat system/star view

* https://science.nasa.gov/exoplanet-catalog/cd-35-2722-b/

Re: Astronomers may have found the first exomoon

#56

Post by hparadiz »

delta_p_delta_x wrote: post #22

Worth noting that the artist's impression is... not accurate. Both CD-35 2722 b (the brown dwarf orbiting the primary star) and CD-35 2722 b I (the exomoon orbiting the secondary) should be much closer in size. It is estimated that Jupiter is essentially the largest any gas giant can get; adding more mass will simply increase density and interior temperature until deuterium and lithium fusion and brown dwarfdom, and…

If a brown dwarf is right on the edge of stardom would it start protium fusion in only the part of itself that is the right pressure and then slowly burn out or would that ignition precipitate a pressure wave through the entire body forcing fusion to begin everywhere?

Re: Astronomers may have found the first exomoon

#57

Post by elictronic »

codeddesign wrote: post #49

Outside of the small probability that this may assist us in the future, has looking beyond our moon ever benefitted or even affected humanity in any way?

Digital cameras for humanity as a whole, and satellite based telescopes for maintaining US dominance for the last 50 years and the long peace. Knowledge is power.

Before the late 70s satellites used film that was dropped back from orbit to the ground and developed to identify Cold War troop movements.

Re: Astronomers may have found the first exomoon

#58

Post by F3nd0 »

pelagicAustral wrote: post #3

I know this is besides the article and all, but why would the Chilean flag be the only one to have 8px left margin? This is killing me...

The flags have also all (except for Finland, which appears slightly wider?) been squeezed into a uniform 3:2 aspect ratio; some of them (e.g. Belgium, Switzerland, United Kingdom) properly ought to have different proportions. I understand they can look more aesthetically pleasing when they’re all the same size, but it’s another little detail to notice. :-)

Re: Astronomers may have found the first exomoon

#59

Post by F3nd0 »

delta_p_delta_x wrote: post #22

Worth noting that the artist's impression is... not accurate. Both CD-35 2722 b (the brown dwarf orbiting the primary star) and CD-35 2722 b I (the exomoon orbiting the secondary) should be much closer in size. It is estimated that Jupiter is essentially the largest any gas giant can get; adding more mass will simply increase density and interior temperature until deuterium and lithium fusion and brown dwarfdom, and…

I kind of assumed the artist’s impression was working with perspective? The images shown in the sidebar seem to picture them at different relative sizes.

Re: Astronomers may have found the first exomoon

#60

Post by jazzkingrt »

hdz wrote: post #12

A small dense planet, which orbits a star, is orbited by a larger gaseous moon. It's interesting the discovery is in Chile which has some of the best night skies, a Class 1 on the Bortle scale specifically in the Atacama Desert. Hoping to make it out there one day.

At some point I did some research and the Atacama was suggested to me as the best vantage point on earth for simple skygazing. Definitely on my bucket list.
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