Tähtsåga

Tähtsåga is a term used in speculative astronomy and in some Finnish-language science fiction glossaries to denote a class of variable stellar phenomena that exhibit a serrated, sawtooth-like pattern in their light curves. The concept combines the Finnish word tähti, meaning star, with a phonetic adaptation of the Swedish såga, meaning to saw, to reflect the distinctive jagged brightness changes described in fictional or theoretical work.

Etymology and naming conventions center on the characteristic photometric signature. In the described pattern, the star undergoes recurrent changes in brightness with relatively abrupt rises or falls, followed by slower reversals, producing a cadence reminiscent of a sawblade. In fictional treatments, the period can range from days to weeks, and amplitudes are typically moderate, though individual depictions vary.

Physical interpretation within fiction often attributes the effect to episodic accretion events in a protostellar disk, magnetospheric interactions, or cyclic instabilities in a circumstellar environment. The term provides a convenient shorthand for discussing time-domain behaviors that are more dramatic than smooth pulsations but less extreme than classical outburst events.

Status and usage note: tähtsåga is not a widely adopted term in real astronomical literature and is primarily found in speculative or fan-created glossaries. In those contexts, it serves as a storytelling and conceptual device, while real-world observers might describe similar light curves using established categories of variability without adopting the neologism.