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Binary Star

|< < Prev #3203 (February 4, 2026)

Title text: The discovery of a fully typographical star system comes with a big asterisk.

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Explanation

Binary star systems, where two stars orbit each other, are common throughout the universe. In some cases, these are different types of stars, such as a neutron star co-orbiting with a "main sequence" star. Here, however, the comic depicts a system consisting of a real celestial object (just such a main sequence star), and a star which is instead a stylised five-pointed shape in which stars are often drawn, called a pentagram.

Pointed stars do not actually exist as astronomical bodies. Stars seen in the night sky can sometimes appear as though they have spikes coming out of them, but these are just optical illusions caused by the diffraction spike effect, and not something far weirder.

The title text puns on the * symbol (an asterisk - meaning little star), which is sometimes called a star, and is often used to indicate footnotes in text. A "big asterisk" is used as a metaphor for a rather large caveat or significant reservations about the statement being made, suggesting that such qualifications would form a long footnote. This could be interpreted as meaning that the existence of the "typographical star system" is significantly doubtful. Alternatively, it could be read as meaning that the "big asterisk" is a physically very large (astronomical scale) punctuation symbol, which forms part of a system composed of other bodies in the form of typography.

Drawing a star as a pentagram, as shown in the comic, is referenced in 1029: Drawing Stars.

The orbital paths shown are anomalous. The main sequence star follows a path that's nearly circular, while the five-pointed star follows an elliptical path, and they're at different locations along their paths. If the two stars were the most massive objects in their system by a significant margin, approximating a two-body system, their paths should be the same shape (albeit at different sizes, if their masses differ) centered on opposite sides of the shared focal point of their barycenter, with all four of the ellipses' foci collinear. Their locations along those paths should be directly in (anti-)phase, and collinear with the barycenter. That this isn't true implies that there's at least one other massive object, which isn't shown, in the system. The much smaller path of the main sequence star suggests that it's in a (relatively) close orbit with the other massive object, with the five-pointed star being much less massive than either, and essentially orbiting them both at a greater distance.

Transcript

[Graphical depiction of a binary star system. The orbits are shown with dashed lines. One star is revolving circularly close to the center of mass and is shown as a filled circle. The other has a very elliptic orbit further out. It is currently close to its furthest point from the other star. This star is depicted as a pentagram.]

[Caption below the image:]

Space news: astronomers have found the first known system with a main-sequence star orbited by a five-pointed one.

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