Ship immersed in the crown of a star ???

[WhiteLion]

little curiosity, I read about extreme scifi series, such as the xeelee, and a question came spontaneously:

According to you, the shields of a ship immersed in the crown of a star for 1 hour, how much energy should they absorb?

I read that the crown has a temperature of 6-7 million degrees Kelvin, and a star like the sun has a radiance of 2.009 × 10e7 watts / m2

Assuming a ship like the Mandator IV, about 8 km, how could I calculate the surface of the ship, in order to derive the energy absorbed by the shields?


Also, how relevant do you think the temperature of the star's crown on the shield would be?

[Batman]

What IS the 'crown' of a star? The sun's 'corona' is no more than 6000K/C or so same as the surface.
As for the surface area of the ship, assuming we have a halfway accurate bottom up/top down view of the hull you can use the length and the formula for the area of a triangle for a close approximation

[Batman]

What IS the 'crown' of a star? The sun's 'corona' is no more than 6000K/C or so same as the surface.
As for the surface area of the ship, assuming we have a halfway accurate bottom up/top down view of the hull you can use the length and the formula for the area of a triangle for a close approximation

Okay apparently I didn't completely read that article so the corona 'is' in the million degree rage.

[WhiteLion]

yes the temperature of the corona of the sun is 5 × 10e6 K, for the calculation of the area of the triangle the problem is just that, I don't know the base, I only know the length

[Eternal_Freedom]

The temperature of a star's corona is one of those weird things in astrophysics where a number sounds massive but it's nowhere near as impressive in reality. The million-Kelvin range refers to the energy each particle has - but a star's corona is really not very dense. At all. So while the "temperature" is really high, the actual effect of being in that region will have a lot more to do with being that close to a star (the normal thermal/visible/UV/X-ray radiation) not the temperature of the medium (It's like the thermosphere in Earth's atmosphere, technically very hot but the air is very, very thin).

[Sky Captain]

It just occurred to me for most soft sci fi warships flying into an outer atmosphere of a Sun like star shouldn't be a major problem at all since shields are supposed to be able to absorb weapon fire that in itself may be in a stellar range. If anything star should be more gentle because energy is evenly distributed across the exposed side and comes in steady flow rather than concentrated in small spots and in high energy pulses like weapon fire would do.

If for example shields on a few km sized warship can safely dissipate sustained weapons fire about 1% of what our Sun puts out then flying into an outer atmosphere of sun would be a complete non issue because shields would never be exposed to that 1% of solar output. A ship would absorb a very small amount like 0.000001 % of solar output, it just intercepts a really tiny fraction of total radiation coming from a star.

[WhiteLion]

in reality on wikipedia it says temperature of the corona 5 million degrees kelvin, not of each particle but of the corona: https://it.wikipedia.org/wiki/Sole

For the amount of radiation it says they are 2.009 × 10e7 W / m2

it is not a little energy to sustain

assuming a ship length of 7 km and a base of 4, we will have an area of 14 km2, or 14000 meters, which is one of the exposed surfaces absorbing 2.009x10e7 watt-sec / m2

14000 x 2x10e7 = 28x10e10 watt-sec / m2

I don't know if the calculation is right

[Batman]

The one that has to 'sustain' that energy is the 'star', the 'ship' just has to 'withstand' it. And neither the italian (and thus useless to most people here) link nor the english language entry on the sun give the number you quote, they just give radiation intensity at various 'distances' from the sun, none of which seem to be in the corona. Where'd you get 2.009 × 10e7 W / m2 from?

[WhiteLion]

the link is in Italian, just do "translate page" with the browser, why is it useless?
The data 2.003 10e7 I have read on the right of the page, there is a summary column of the physical data, it is reported after the brightness

[Sky Captain]

in reality on wikipedia it says temperature of the corona 5 million degrees kelvin, not of each particle but of the corona: https://it.wikipedia.org/wiki/Sole

Temperature of corona is irrelevant, it is almost vacuum, while individual particle energy are high there aren't very much particles present. Think of it as going into sauna vs jumping in a tank of boiling water. Same temperature, different particle density.

Ran a little math, divided solar luminosity by solar surface area and got 6.29e+13 watts radiating per square km. If ship has 10 square km exposed area than it is 6.29e+14 watts. In weapon terms that is somewhere around 100 - 200 kt nuke striking every second. Pretty much nothing compared to firepower shields of a large soft sci fi warship are supposed to be able to withstand.

[Solauren]

Yeah, hiding in a star is not a big deal. Bloody hell, in - Redemption, Part 2. The Star Trek TNG Season 5

We see one bird of pray, that is losing shields, fly through the Chronos of a star, to what looks like fairly close to the Chromosphere (the next layer down)(it might have reached the Photosphere, but I don't think the chase went on that long), and activate it's Warp drive to cause a Solar flare.

Surviving the upper levels of a stars atmosphere, in Sci-fi, is not that big a deal. It's surviving down into the Convection zone or deeper, where you have a much, much higher particle density, and smaller area, that it gets harder.

[Composeure]

Yeah I think the problem with some so-called ""higher tiers of scifi"" (and believe you me man do they get wanked to high heck and back on other boards like SB where they have attained Sacred Cow status) is that when the numbers get crunched they're actually nowhere near as powerful as they get wanked to be. Also, the inane claim that they are totes ""hard scifi !!11!!1!" when they are not nearly that.

And frankly I don't understand the appeal of wanking them anyways-- I could easily write up my own thing and claim its stronger. Better yet, actually write a good story and setting of your own.

[Tribble]

Another variable is the nature of the ship’s shields/armour.

For instance, as per the main site Star Trek shields seems to be made of some exotic particles surrounding the ship that are vibrating at whatever frequency they are set to. Apparently this makes them more vulnerable to gases/plasma (to the point where shields may not even working at all in a nebula) unless specifically calibrated to “metaphasic shielding” mode. IIRC prior to that development the Enterprise D was in danger of being destroyed within a couple of million kilometres of a neutron star, while several years later Voyager was able to beat the odds and survive flying in between two binary neutron stars. Presumably they don’t use this setting all the time because it isn’t calibrated to the weapons they are used to dealing with.

Star Wars shields in the other hand are explicitly divided into particle and ray shields. Presumably both would have to be running to offer full protection?

Meanwhile the Tardis runs off a black hole and can siphon off the energy of a supernova to open up a portal to a parallel universe, so I doubt it would be that much affected by a typical star’s corona

[Composeure]

Fwiw "power source/energy usage" isn't necessarily a direct analogue to "can tank that." It's actual "what did it actually do" that counts imo. Also, fwiw, the Tardis/Time Lord "eye of harmony" isn't a normal black hole.

I still agree that "sitting in a star" isn't that big of a "feat" and that the GE could do it.

[Batman]

What's the power draw of walls/armour? Those have proven pretty resilient in the past.

[Composeure]

I mean, at a certain point I suppose we run into the problem of trying to equate one kind of "fantasy/scifi physics" with another kind of "fantasy/scifi physics". Which is why I suposse calcs are important, as well as taking into account outliers, exaggerations, etc. considering how certain debaters will seemingly try to shift any debate in their favor by using their side's "technobabble."

My base opinions have not changed.

[puskas78]

The corona of a star might have an extremely high temperature, but the density will be very low. Most of the thermal load on the shield will come from the star's usual light, which comes from the photosphere. With the high temperature, the corona will provide a lot of high energy particles which will make things more complicated by putting an entirely different kind of load.

You will need extremely advanced technology to deal with both the extreme radiation (from far infrared to somewhere into ultraviolet, depending on the star's temperature) and the high energy particles.

[Composeure]

Yeah but the ""advanced technology"" thing is something a large amount of scifi already has, as has already been pointed out. Point being, this is a very vague phrase, especially in scifi.

[Marko Dash]

i can't remember which, but IIRC one of the early books of the Yuuzahn Vong war had a ship drop the main characters onto a Vong held planet and then hid in the stars outer layers until it was called in for pick-up.

[Composeure]

Well, there you go.

(I assume this is not a necro)

Frankly I think one shouldn't really overestimate this kind of thing in terms of expectations at least.

(Ps: fwiw, op seems to know practically nothing about the topic anyways so probably that is why the question is somewhat confusing/stilted)

[EnterpriseSovereign]

In the Stargate episode "Enemies", a Goa'uld Ha'tak's was able to hide in the corona of a blue giant for approximately nine hours before the star's radiation would overwhelm the shields. Blue giants have a surface temperature of around 30,000 K and a luminosity some 100,000 times that of sol.