Tabby's star, more formally known as KIC 8462852, lies about 1,500 light-years from Earth and is a bit bigger and hotter than the sun. The star has been in the news a lot since Further observations added to the intrigue. For example, a different research group found that Tabby's star had also dropped in brightness overall by about 20 percent from 1890 to 1989.
How the hell do we know the brightness of a star back in 1890?
[–] Rellik88 0 points 1 point 1 point (+1|-0) ago (edited ago)
So your telling me we had the know how and the precise tools need to do it in 1890?
Edit: Well I guess so,
http://www.astronomy.ohio-state.edu/~pogge/Ast162/Unit1/bright.html
Flux Photometry Count the photons received from a star using a light-sensitive detector: Photographic Plates (old-school: 1880s to 1960s) Photoelectric Photometer (photomultiplier tube: 1930s to 1990s) Solid State Detector (e.g., photodiodes or CCDs) We now use solid-state detectors like CCDs and similar technologies (with very rare exceptions), as these detectors are far more sensitive and stable than any previous technology. Calibrate the detector by observing a set of "Standard Stars" of known brightness.
I'm just curious how can we tell the data taken from the 1890's using photographic plates is accurate. How do we know the star was brighter back then if our measurements with todays tech shows it dimmer?
[–] theoldones 0 points 2 points 2 points (+2|-0) ago
we all know it might still be a megastructure.