March 6
The Pointer
Sun Position
The Sun is in Pisces at roughly +10° declination; Northern Hemisphere days continue lengthening at their fastest pace of the year near the equinox, while the Southern Hemisphere heads into autumn.
Sky Highlight
The Big Dipper is now high in the northeastern evening sky from northern latitudes, a reliable annual signal of spring. The two outer stars of the Dipper's bowl (Dubhe and Merak) form the Pointer pair that directs the eye to Polaris five times their separation to the north.
Deep Sky Object
M97 (Owl Nebula), a planetary nebula in Ursa Major, about 2,000 light-years away; its round, low-surface-brightness disk requires dark skies and a telescope, but it sits conveniently near the Dipper's bowl. Visible from the entire Northern Hemisphere and northern parts of the Southern Hemisphere.
Featured Star
Dubhe (α UMa) is an orange giant of spectral class K0III, about 123 light-years distant, anchoring the outer rim of the Big Dipper's bowl as the key member of the Pointer pair. Unlike most of the Dipper's stars, Dubhe is not part of the Ursa Major Moving Group and is slowly drifting away from its bowl-mates over astronomical time.
Around This Date
- March 6, 1787William Herschel discovered Titania and Oberon, the two largest moons of Uranus, during his systematic survey of the sky.
- March 4, 1835William Henry Smyth recorded observations in what became the Cycle of Celestial Objects, one of the most used observing guides for 19th-century amateur astronomers.
Draw a line through the Pointers and it ends at the one star in the sky that doesn't move. Dubhe has been marking that path for every generation that looked up.