March 8
The False Cross
Sun Position
The Sun is in Pisces at declination near +11°; the gap between day and night is closing quickly in the Northern Hemisphere and opening in the Southern Hemisphere ahead of each respective equinox.
Sky Highlight
The False Cross (formed by Avior and three other stars in Vela and Carina) is well-placed in March evenings for Southern Hemisphere observers and has historically been mistaken for the Southern Cross by sailors unfamiliar with these skies. From northern latitudes above +30°, neither cross is visible at all.
Deep Sky Object
NGC 2516, a large, bright open cluster in Carina, about 1,300 light-years away, visible to the naked eye and resolvable into roughly 100 stars in binoculars; it rivals the Pleiades in apparent richness and is well-placed in March evenings for southern observers. Essentially invisible from northern Europe.
Featured Star
Avior (ε Car) sits about 632 light-years away as an unequal double: an orange giant (K3III) paired with a blue main-sequence companion (B2V), their combined spectral signature a unique blend of warm and hot. Its name has no ancient pedigree. It was assigned in the 1930s by the Royal Air Force to support aerial navigation tables in the southern sky.
Around This Date
- March 8, 1618Johannes Kepler recorded discovering the relationship now known as his Third Law of Planetary Motion, relating orbital period to semi-major axis, though he initially rejected it before confirming it days later.
- March 8, 1817Olbers's comet of 1815 passed through the inner solar system and was observed widely; Heinrich Olbers, who also posed the dark-sky paradox bearing his name, had discovered it two years prior.
A star named by navigators who needed the southern sky to stay alive, practicality and wonder are not so far apart.