February 18
The Southern Beacon
Sun Position
The Sun crosses from Aquarius into Pisces around this date (varies by year by a day), near +7° declination. Days in the northern hemisphere are near 11 hours.
Sky Highlight
No annual meteor shower today. Canopus is circumpolar for observers south of about 37°S, never setting, but for northern observers it barely grazes the horizon on winter evenings, if at all.
Deep Sky Object
NGC 2516, an open cluster about 1,300 light-years away. A rich, bright open cluster in Carina, visible to the naked eye as a hazy patch and easily resolved in binoculars, one of the finest southern clusters. Southern hemisphere only; invisible from most northern latitudes.
Featured Star
Canopus (α Car) is a white-yellow bright giant 310 light-years away, spectral class A9II, the second brightest star in the night sky and so stable it is used as a navigation star by spacecraft including Mars rovers. What once guided ships around the Cape now orients robots on another planet.
Around This Date
- February 18, 1930Clyde Tombaugh discovered Pluto at Lowell Observatory, comparing blink-comparator plates from January and spotting the point of light that shifted position between exposures.
- February 19, 1473Nicolaus Copernicus was born in Royal Prussia, the astronomer who proposed a heliocentric model of the solar system, shifting Earth from the center of the cosmos.
A star 310 light-years away now helps land rovers on Mars, not bad for an ancient navigation beacon.