2024, January 14:  Orion After Sunset

Orion Nebula (NASA Photo)
Photo Caption – Orion Nebula (NASA Photo)

PODCAST FOR THIS ARTICLE

by Jeffrey L. Hunt

Chicago, Illinois:  Sunrise, 7:16 a.m. CST; Sunset, 4:43 p.m. CST.  Check local sources for sunrise and sunset times. Times are calculated by the US Naval Observatory’s MICA computer program.

Summaries of Current Sky Events
Summary for Venus as a Morning Star, 2023-24

Orion after Sunset

Orion after sunset - 2024, January 14: Orion, with bright Betelgeuse and Rigel, is in the east after sunset.
Chart Caption – 2024, January 14: Orion, with bright Betelgeuse and Rigel, is in the east after sunset.

On winter evenings, the famous constellation Orion the Hunter is visible in the eastern sky after sunset.  The pattern is easily identified.  Three stars of nearly equal brightness line up in a short row. They outline his belt.

A bright rosy star named Betelgeuse is to the upper left of the belt stars, while bright blue-white Rigel is to the lower right. Betelgeuse marks one of the Hunter’s shoulders and Rigel marks a knee.

After the Big Dipper, Orion is the next famous celestial pattern introduced to school-aged children. The constellation makes its first entry into the evening sky during November each year.  Betelgeuse rose at sunset on January 2nd and Rigel was opposite the sun two nights later.

Here at mid-January, the constellation is about 20° up in the east-southeast by one hour after sunset, and appears farther westward during the night.  It is in the south around five hours after sunset and before midnight, setting in the west around sunrise.

Extend the line the belt stars make upward to the sideways “V” of Taurus, made by topaz Aldebaran and the Hyades cluster, and the Pleiades star cluster, resembling a miniature dipper.  Following it downward, points toward Sirius that is still below the horizon at this hour.  The Dog Star rises before two hours after sunset tonight.

Binocular View

Orion after sunset - 2024, January 14: Through a binocular find the Orion Nebula (M42) to the lower right of the belt stars.
Chart Caption – 2024, January 14: Through a binocular find the Orion Nebula (M42) to the lower right of the belt stars.

Use a binocular to explore the pattern’s wonders.  First look at the contrasting star colors, especially Betelgeuse and Rigel. Betelgeuse, meaning “the armpit of the white-belted sheep,” is rosy, indicating a surface temperature of about 6,000° F.

Betelgeuse is one of the largest stars in the sun’s neighborhood.  If Betelgeuse where in the sun’s place, the orbits of Mercury, Venus, Earth, and Mars would be inside the star.  Shining from a distance of 500 light years, Betelgeuse is about 25,000 times brighter than the sun.  It is the seventh brightest star visible from the mid-northern latitudes.

In contrast, Rigel, Orion’s knee, is blue-white, indicating a temperature of 20,000° F.  Contrary to the artists impression of color, blue stars are hotter than red ones.  At 900 light years from Earth, Rigel, the fifth brightest star for mid-northern sky watchers, has an intrinsic brightness of over 90,000 suns.

The Orion Nebula, cataloged as Messier 42 (M 42 on the chart) is easy to locate through a binocular.  Place the belt stars to the upper left in the field of view, the nebula’s greenish haze is visible to the lower right.  The beautiful reds and blues from the glowing gas are only found in time exposures.

Find the season’s flagship Orion constellation after sunset.

LATEST ARTICLES

Leave a Reply