atestar

Atestar is a term used in speculative astrophysics to denote a class of star-like objects whose energy output is sustained by non-standard processes beyond conventional nuclear fusion. In these models, an atestar could maintain luminosity over extended periods through mechanisms such as exotic particle interactions, dark matter heating, or alternative fusion pathways, yielding different mass–luminosity relationships than ordinary main-sequence stars.

The name combines the Greek root a- meaning not or beyond with star, signaling a deviation from standard stellar models.

In proposed properties, atestars would have masses similar to solar-type stars but exhibit a distinct energy budget. They might resemble ordinary stars in size and surface temperature, yet show spectra with weak or unusual hydrogen lines and enhanced infrared emission. The internal structure could include non-nuclear heat sources in the core, altering convection and energy transport.

Formation and evolution ideas describe atestars arising in environments with abundant exotic matter or conditions that enable dark matter–related heating. Their lifetimes could outlast typical main-sequence phases, and their evolutionary endpoints might differ, potentially skipping certain post-main-sequence stages.

Observational status: atestars remain hypothetical. Some infrared sources with atypical spectra have been proposed as candidates, but no confirmed detections exist. Distinguishing features would include persistent luminosity with non-standard spectral signatures and inconsistencies with conventional H-R diagram locations, requiring precise spectroscopy and long-term monitoring.

See also: star, stellar evolution, brown dwarf, white dwarf, neutron star.