Orion and Sirius visible before dawn in August
Constellation Orion stars photo by Matthew Spinelli.
Wednesday, August 27, 2008
As seen from around the world at this time of year, the constellation Orion the Hunter rises in the east in the wee hours before dawn.
After rising, the sky’s most majestic constellation continues to ascend in the east, even after early morning twilight starts to illuminate the sky. It’s not until dawn is well underway that the bright stars of Orion are washed from view.
Orion seems to be everybody’s favorite constellation. It’s most recognizable feature is Orion’s Belt – which consists of three moderately bright blue-white stars. These stars lie on the celestial equator. Orion also has two very bright supergiant stars – Betelgeuse and Rigel – which shine on opposite sides of Orion’s Belt.
Like all stars, the stars of Orion rise 4 minutes earlier every day. Because of this, Orion climbs a bit higher in the sky every 24 hours. Every day for the next several weeks, you can watch Orion ascending higher and higher into the predawn sky. By the time the equinox arrives this September 22, Orion will be at or near its highest point in the dawn twilight for the year.
So starting tomorrow, watch Orion’s ascent into the dawn sky from now through September.
As seen from the Earth’s equator, Orion will be straight overhead on these late September dawns. As seen from the northern latitudes around the equinox, Orion will be shining due south at dawn. And south of the equator, Orion will be sparkling in the northern sky.
When the Orionid meteor shower peaks around October 20 or 21, Orion will reach his highest point in the sky roughly an hour before the start of astronomical twilight (at mid-northern latitudes). Unfortunately, the moon will be at its waning gibbous to last quarter phase, washing away all but the brighter meteors. Click here for a list of this year’s major meteor showers.
