Neutron Stars are real!

[Soron Silin]

Absolutely not so. Luminosity is intrinsic, proportional to the surface area

Precisely.
Luminosity is proportional to surface area.

You have two suns with the same luminosity. A has a surface area a million times bigger than B. Therefore each unit area of B must emit a million times more light than each unit area of A.

When seen as point sources, they have the same luminosity. However when you can see individual unit areas, A will appear dimmer than B.

Say I buy a lighting unit consisting of 100 1 watt LEDs, I also buy a single 100 watt LED. If I look at them from far enough away, they look identical. They both emit 100 watts of light. However if I look at each LED individually, the 100 watt LED is much brighter than each 1 watt LED.

I have yet to encounter a type O star but the codex entry for it looks much like a very bright (but not blindingly bright) type A (those I have seen), with discernible surface features. The neutron star I encountered appeared a great deal brighter, and the OP's images show that NSs show no surface detail when seen closer in. It is portrayed as vastly brighter in the visual wavelengths, even when seen at distances comparable to those at which Type O stars are easily seen in detail.

It's quite the impressive beast. I wouldn't say it was much brighter than an B, A or even F, it's just bigger. In fact they are rather disappointing until you play with the light they emit.

Spoiler

To see a neutron star "at distances comparable to those at which Type O stars are easily seen in detail" you would have to be about 10km from them.
The OP's images don't show no surface detail, they certainly show coronal ejections and there are hints of the surface detail. But at that scale, maybe tens of pixels across, they mostly merge into an average. There's two reasons for that. Frontier has almost certainly just used a scaled down blue-white star skin because nobody is ever going to get close enough to see more than a bright light. Also their composition is very different from a large star. The outer shell of stars is a gas. The surface of neutron stars is more solid than the solidest solid. They are probably featureless spheres. No cracks or hills would survive. The only detail you would see would be the matter falling onto it.

 

[Captain Willard]

Dem bees some saweet pitchures.

 

[Spaceman Si]

I haven't looked through an eyepiece for a long time now, but I think it should be theoretically possible to see the Crap Pulsar using a very large Dobsonian telescope from a very dark place.

Well I thought it was a very good pulsar myself

Apologies for taking the cheap comedy shot in amongst what is one of the most interesting threads I’ve read for a long time. I am especially impressed with the image stacking results and the methods behind them, that is a real achievement.

If you are spending time in the Crab Pulsar system, the two planets in there were both mapped by yours truly, nabbed the night of the 3.3 drop, and then the data Buckyballed over to the Jellyfish nebula for sale

 

[WeComeInPeace]

I'm at another neutron star now, eating lunch, before I try to approach it. This one is in darker surroundings without nebulosity (older I guess), so it shows some interesting ejected whispy gas clouds.

Edit: The exclusion zone of this NS is at 725 km. A lot further out than the Crab Pulsar? Could there be NS in ED with an exclusion zone of less than 270 km? Only one way to find out I guess. Kind of strange, it is. I found a video from another CMDR showing his approach to a black hole, which ended up at the exclusion zone of 42.4 km. That was the same I found, so the exclusion zone of black holes seems consistent. Not so with the NS.

As expected, this NS is a lot older than the Crab Pulsar. I think the age must be calculated from when the original star was born. More importantly, and in line with the thread, it's a lot "colder" by a factor of almost 1/100:

For comparison:

Body Crab Pulsar - EDDB

Body Crab Pulsar in Elite: Dangerous

eddb.io

2nd Edit:

This one has slightly different characteristics. It still shows zero information in the blue channel, but more detail in the green channel. A quick CC:

Red channel:

Green channel:

A timelapse might be interesting...

 

[Soron Silin]

Edit: The exclusion zone of this NS is at 725 km. A lot further out than the Crab Pulsar? Could there be NS in ED with an exclusion zone of less than 270 km? Only one way to find out I guess. Kind of strange, it is. I found a video from another CMDR showing his approach to a black hole, which ended up at the exclusion zone of 42.4 km. That was the same I found, so the exclusion zone of black holes seems consistent. Not so with the NS.

As expected, this NS is a lot older than the Crab Pulsar. I think the age must be calculated from when the original star was born. More importantly, and in line with the thread, it's a lot "colder" by a factor of almost 1/100:

Neutron stars do cool, by a large ratio. Above I found that M1 and Geminga differed by a factor of a million. So it's not surprising that the temperature is different. The exclusion zone is rather less understandable though. Maybe they are looking for a similar brightness in each case?

 

[WeComeInPeace]

I waited ~10 min at the latest NS, taking a lot of exposures, to see if I could see any rapid development. One of them showed some coronal arcs that I haven't seen before (red channel):

(ED currently has a bug making large blocks when doing high res screenshots)

I'm high above the galactic plane, where all the NS clump together for some strange reason (~gameplay). I think I'll try a few more and see if I can find one with a smaller exclusion zone.

 

[Soron Silin]

That's fascinating. Maybe they aren't just re-used skins.

 

[ChipStar65]

You have two suns with the same luminosity. A has a surface area a million times bigger than B.

This illustrates your misunderstandng of my point. Stars of roughly equal temperature (e.g., type O and NSs) will have emissions in the visual range of roughly similar overall color (determined by temperature). But if they are of vastly different sizes, they cannot have the same luminosity, because they do not have the same surface area. The luminosity of the smaller object will be less. Apparent brightness is a function of luminosity and viewing distance from the object. Thus a type O and a NS cannot show the same apparent brightness when viewed at the same distance. Yet in ED, the apparent brightness of a NS is much greater than than of a type O when dropping into a system, just the inverse of what should be seen. One can approach the exclusion zone of a type O or A and not have them become as bright as a NS seen from much farther away. This is not accurate even given ED's general adjustments of star brightness for graphic interest. To me the image in post #12 with approaching ships seems much more accurate given these circumstances.

 

[WeComeInPeace]

That's fascinating. Maybe they aren't just re-used skins.

I don't think they are. I think they are "not finished" versions of something that might have been in the game, then covered up with lens flare, making them pretty fascinating to study. Not like the real thing of course, but still interesting. Especially because you can use some of the same "tools" as you would with a real NS. Keep the inner child, and don't forget how to play when you grow older. You just get better toys. If you can even learn something while playing, win-win, and I already learned a lot

 

[Soron Silin]

This illustrates your misunderstandng of my point. Stars of roughly equal temperature (e.g., type O and NSs) will have emissions in the visual range of roughly similar overall color (determined by temperature). But if they are of vastly different sizes, they cannot have the same luminosity, because they do not have the same surface area. The luminosity of the smaller object will be less. Apparent brightness is a function of luminosity and viewing distance from the object. Thus a type O and a NS cannot show the same apparent brightness when viewed at the same distance. Yet in ED, the apparent brightness of a NS is much greater than than of a type O when dropping into a system, just the inverse of what should be seen. One can approach the exclusion zone of a type O or A and not have them become as bright as a NS seen from much farther away. This is not accurate even given ED's general adjustments of star brightness for graphic interest. To me the image in post #12 with approaching ships seems much more accurate given these circumstances.

They are nowhere near the same temperature.

Body: S171 19
Class: O
Temperature: 53,667 K

Body: Crab Pulsar
Class: Neutron Star
Temperature: 877,764,736 K

And from the screen capture above:
Body: Hypiae Aihm HN-H D11-0
Class: Neutron Star
Temperature: 9,182,854 K

The light from a neutron star peaks at 3 angstroms. That's 0.3nm. Visible light runs from 600 to 800 nm, or 6000 to 8000 angstroms. We see a neutron star as blue because that's all that we can see. We can't see the ultraviolet or x-rays. All we can see is the tiny tail, way down in the visible light, that consists of all visible colours with a slight tilt toward the blue because we are seeing the curve on the far left of those black-body graphs.

Neutron stars are around 10,000 to 100,000 times hotter than an O class star.

 

[Sapyx]

Hate to spoil all the science, but if you want to know what a neutron star "looks like up close", just open the system map. For normal stars, just like for planets, the game uses the exact same model of the star in the system map as it does from the cockpit view. I don't see why neutron stars would be any different.

Neutron stars in the system map are a different model to that used for B or O class stars. They are "fuzzier", and the prominences are more, well, prominent than on regular stars; it can "look like" they're more numerous, but they're probably the same number, just jammed into a smaller surface area.

 

[Shinji Ikari]

Since I rather do some physics than my calculus (too much abstraction) homework, I'll try to calculate the flux of energy a ship may receive:

First, I'll grab a well known neutron star, the Crab Pulsar. It appears that neutron star sizes are not well determined as they are too small to be directly observed (perhaps the angular momentum it has can give away some info) so theoretical models come in place, however, many such models exist so I'll make two calculations with the extremes, so according to this preprint we have the following:

Now lets calculate the black body radiation luminosity, also known as the bolometric luminosity or luminosity for short.

PS1: For a surface temperature of 1.61x10^6 we use the Stefan-Boltzmann law to compute the radiant exitance at the surface, we get 3.81x10^17 W/m^2. Now, this is not a single point source (nothing is) but we can treat it as such (the inverse square law relates flux densities outside the source) and consider the distance to the center which is the radius, then according to the inverse square law, the flux density is proportional to the inverse square of distance, we can use the radius as a unit, so at twice the distance you get a quarter of the flux, so we compute the fraction of distance (50 Km) to radius (16.1) to get a ratio of 3.1 so the flux at that distance is flux/3.1^2 so the flux at 50 Km is 3.96x10^16 W/m^2.

PAL(kaon): To summarize:

r = 7, T = 2.55x10^6, radiant exitance = 2.397x10^18 W/m^2, fraction = 7.14, flux at 50 Km = 4.7x10^16 W/m^2.

Now, the amount absorbed by the ship is a whole other issue, that'll depend on the material and the wavelenght distribution of the radiation, some will be reflected, some pass through and other absorbed, although some ionizing radiation like gamma rays can pass through a lot of materials, it shouldn't or else we'd get fried inside the ship. Now, if we give the benefit of the doubt and make the ship's surface a magical dielectric mirror which reflects 99.999% of all* light the absorbed amout is between 3.96x10^11 W/m^2 and 4.7x10^11 W/m^2.

*That's the magic part, mirrors (especially dielectric) reflect a fraction of the spectrum and depend on angles of incidence.