Archive for January 16, 2023

01/16/2023 – Ephemeris – Orion’s great nebula

January 16, 2023 Comments off

This is Bob Moler with Ephemeris for Dr. Martin Luther King Jr. Day, Monday, January 16th. Today the Sun will be up for 9 hours and 13 minutes, setting at 5:29, and it will rise tomorrow at 8:15. The Moon, 2 days past last quarter, will rise at 3:52 tomorrow morning.

The brightest interstellar cloud visible in our skies is the Great Orion Nebula. The word nebula is related to the Latin “nebulum” for cloud. The constellation of Orion is filled with nebulae, most of it are dim or dark. The Great Orion Nebula is in Orion’s sword. The sword is what looks like three stars that look dimmer than the three belt stars hanging from the belt. And there are more than three stars here. Around the stars that appear as the center of the sword stars, to the eye, can be seen a haze in binoculars. A telescope with a wider aperture and low power can see detail in the cloud. With more magnification, a clutch of four baby stars can be spotted in the brightest part of the nebula. They light up the nebula and are called the Trapezium.

The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EST, UT –5 hours). They may be different for your location.


Orion's nebulae

Orion is lousy with gas and dust. A regular star factory, or nursery. The red nebulae show the predominance of hydrogen in here. In actuality, the Great Orion Nebula vastly outshines all the other nebulae in Orion. The white nebulosity to the right of Rigel is the Witches Head nebula, probably the reflection of Rigel’s light off a dust cloud. Base image by Bernal Andreo, via Wikipedia. Annotations were created by myself.

The Great Orion Nebula (M42) long exposure photograph

The Great Orion Nebula (M42) long exposure photograph by Scott Anttila. Includes all the sword stars.