Non-gas giant has 73 times Earth’s mass, bewildering its discoverers
arstechnica.com
arstechnica.com
Going up the scale slightly are Actinium (10.07), Molybdenum (10.22), and Silver (10.501). (That last is noted in the subhead of the article.)
My suspicion is that there's possibly a core of Lead (11.342) or Thorium (11.72) (both fairly abundant on Earth, and stable), though Mercury (13.5336) and Tungsten (19.25) give some interesting possibilities, surrounded by a crust (or ocean) of less-dense materials.
Oh, and surface temperature is ~1,200°C.
Quite a conundrum.
Elements listed by density (at standard temperature & pressure: 100 kPa & 0°C): <https://www.thoughtco.com/elements-listed-by-density-606528>
Conditions on TOI-1853 b would somewhat exceed these.
I would like to see what people who do know what they're talking about think might be the case, and what experimental / observational basis they have for thinking that.
Based on understanding of the Earth's inner core, which is thought to be comprised of iron-nickel, at a density of ~13 g/cm^3 at its centre, under 330--360 GPa (3.3 -- 3.6 million atmospheres). Iron and nickel have densities of 7.8 and 8.9 g/cm^3 at STP. I'm not sure what NiFe's STP density is, but suspect it's well below 13 g/cm^3, which would suggest density roughly doubles at those pressures.
How much further solid matter compresses with 73x greater mass (so ... 73x greater pressure? Are we talking 24,000 -- 26,000 GPa?), I don't know. There's also the question of other phase-changes. TFA discusses water as "a high-pressure solid". If I'm reading this phase-diagram correctly, probably as Ice X, "Proton-ordered symmetric ice":
<https://en.wikipedia.org/wiki/Ice#/media/File:Phase_diagram_...>
<https://en.wikipedia.org/wiki/Ice#Phases>
Wikipedia's high-pressure physics article notes that diamond anvils are good to about 1,000 GPa (approaching the range of interest here), and that shockwaves have registered over 100,000 GPa. So we could in theory recreate conditions near TOI-1853 b's core, at least momentarily.
<https://en.wikipedia.org/wiki/High_pressure>
Another limit I'm aware of is electron degeneracy, where atoms are compressed beyond the limits of their electron shells. This occurs in white dwarfs, up to the Chandrasekhar limit (1.44 solar masses). What I don't know is that the minimum pressure required is, though I suspect 73 Earth masses is insufficient. The Wikipedia article discusses Fermi temperature rather than pressure:
<https://en.wikipedia.org/wiki/Electron_degeneracy_pressure>
More on that: <https://en.wikipedia.org/wiki/Fermi_energy#White_dwarfs>
(I know some of the words, I don't really follow the discussion however.)
Who need chains or tractor beams? A planet gravity is the perfect restraint one needs for these kinds of inmates. Low maintenance and high effectiveness. Let just hope they aren't getting any jailbreaking going on now that we have disturbed the quantum harmony of the prison by observing it...