November 27
Where the River Begins
Sun Position
The Sun is in Sagittarius near -22° declination. Northern Hemisphere is in its period of maximum darkness per day; Southern Hemisphere summer solstice is about three weeks away.
Sky Highlight
Late November evenings begin to show the winter constellations rising in the east: Orion's belt clears the horizon by 9–10 p.m. from northern mid-latitudes. This is also a good time to trace Eridanus, which begins near Rigel and winds southward; both Cursa (tonight's star) and the full course of the river are accessible through November and December.
Deep Sky Object
M42, the Orion Nebula, stellar nursery in Orion, about 1,350 light-years away. Though Orion rises later this month, by late November it clears the eastern horizon before midnight. The nebula is visible to the naked eye below Orion's belt as a fuzzy middle 'star' of the sword. From either hemisphere it is the most observable stellar nursery in the sky.
Featured Star
Cursa (β Eridani) is a white giant 89.1 light-years away, spectral class A3IIIvar, slightly variable, slightly evolved, sitting just above Rigel at the start of the great river Eridanus as it spills down from Orion's left foot toward the southern horizon and beyond. It is the river's source in the sky, even though the mythology has the water flowing from south to north.
Around This Date
- November 27, 1971The Soviet Mars 2 lander's descent capsule impacted Mars, becoming the first human-made object to reach the Martian surface, though it crashed rather than landing safely.
- November 28, 1659Christiaan Huygens sketched Martian surface features in enough detail to later calculate the planet's rotation period of roughly 24.6 hours.
Cursa sits at Orion's foot, marking where Eridanus begins its long fall toward the southern horizon and out of northern sight.