In the latest news from 3I/Atlas it appears the "comet" may be producing its own light which is odd and it may be much smaller than current estimates imply.
![[Image: hector-rojo-spock-pp2.jpg?1603461976]](https://cdnb.artstation.com/p/assets/images/images/031/385/467/large/hector-rojo-spock-pp2.jpg?1603461976)
Not saying it's Spock ... but it might be.
The Angry Astronaut takes a closer look at the story.
Quote:Figure 3 of the analysis paper (accessible here) shows a steep surface brightness profile of the glow with a projected power-law slope of -3, which implies a three-dimensional emissivity profile with a radial power-law slope of -4. Such a slope is steeper than observed in solar system comets. Together with my brilliant colleague, Eric Keto, we realized that the observed slope of -4 is consistent with an alternative model in which the dust outflow around 3I/ATLAS is illuminated by a central source. This model naturally accounts for the steep brightness profile, since the outflow density slope of -2 is accompanied by the radial decline of the illuminating radiation flux with an additional declining slope of -2.
If 3I/ATLAS generates its own light, then it could be much smaller than expected from a model in which it reflects sunlight. The reflection model requires a diameter of up to 20 kilometers, which is untenable given that the limited reservoir of rocky material in interstellar space can only deliver such a giant rock once per 10,000 years or longer (see the calculation in my paper.
The simplest interpretation is that the nucleus of 3I/ATLAS produces most of the light. I calculated that the nucleus cannot be a thermal emitter with an effective surface temperature below 1000 degrees Kelvin or else its peak emission wavelength would have been longer than 3 micrometers with an exponential cutoff at shorter wavelengths, incompatible with the data. At higher effective temperatures, the required luminosity of 3I/ATLAS can be obtained from a source diameter smaller than 100 meters. A compact bright emitter would make 3I/ATLAS of comparable size to the previous interstellar objects 1I/`Oumuamua or 2I/Borisov, making more sense than the 20-kilometer size inferred in the model where it reflects sunlight.
https://avi-loeb.medium.com/does-3i-atla...775594afc5
Not saying it's Spock ... but it might be.
The Angry Astronaut takes a closer look at the story.