February 20
The Blue Foot
Sun Position
The Sun is in Pisces near +10° declination. Northern hemisphere days are approaching 11.5 hours at mid-latitudes; southern hemisphere days are shortening noticeably.
Sky Highlight
No annual event today. Orion begins its early-evening descent toward the western horizon as February progresses, if Rigel is visible, February evenings are the last good chance before the constellation leaves the evening sky.
Deep Sky Object
M42, an emission nebula (Orion Nebula) about 1,344 light-years away. The most observed nebula in the sky, M42 is a stellar nursery actively forming new stars, the Trapezium cluster at its core is less than 300,000 years old. Visible from both hemispheres wherever Orion is above the horizon.
Featured Star
Rigel (β Ori) is a blue-white supergiant 860 light-years away, spectral class B8Ia, radiating roughly 120,000 times the Sun's luminosity, so luminous it would cast shadows if it were as close as Sirius. Orion's foot, a blue fire at 860 light-years, the light arriving tonight left well before European contact with the Americas.
Around This Date
- February 20, 1962John Glenn became the first American to orbit Earth, completing three orbits aboard Friendship 7 in a flight lasting just under five hours.
- February 20, 1994The Hubble Space Telescope captured early deep images of star-forming regions in Orion, directly resolving protoplanetary disks around young stars for the first time.
The light from Rigel that reaches us tonight left in the 1160s. It has been traveling since the Song Dynasty.