Coincidentally, the catalog of the ancient Greek inventor of the magnitude system
, Hipparchus, includes about 850 stars.
The ancient Greek astronomer Hipparchus introduced the magnitude system
The magnitude system
began about 2,100 years ago when the Greek astronomer Hipparchus divided stars into brightness classes.
All objects have been placed on a scale relating to their brightness,or luminosity,known as the magnitude system
Today the magnitude system
is based on photometry, and it seems a little confusing that a higher magnitude number means a dimmer object, but that is the custom.
Volume 1, like Burnham's, begins with a roughly 100-page introduction to the astronomy that an amateur really needs to know: the celestial sphere and the sky's motions, the magnitude system
, angular measures, and so on, along with lots about the various types of objects to be seen in amateur scopes.
Now let's turn the ancient magnitude system
around, so that brighter objects get higher numbers.
Estimating the brightness of stars dates back to the second century BC, when the Greek astronomer Hipparchus devised a magnitude system
that's still in use today.
For this, you should change the values for central wavelength (WA in microns on line 40), the peak transmission (TF expressed as a fraction on line 3080), the full-width-half-maximum transmission of the filter (DL in microns on line 3020), the quantum efficiency at the central wavelength (Q given as a fraction on line 60), and the zero of the magnitude system
(MO on line 80).