IC 2118 Region in Eridanus
December 2023 - Picture of the Month
I thought that Adam's RGB image of this region would be suitably colourful for the time of year. The feature of this image is the Witch Head Nebula (IC 2118) which is illuminated by Rigel (β Orionis), both of which are at the top of the frame. This suspected supernova remnant is about 50 light-years in extent. Both nebula and star are about 900 light-years away.
This image also covers about a 6 degree field of view, from Rigel all the way to η Orionis at the bottom of the frame, and clearly shows how much more nebulosity there is in this part of Orion and Eridanus. Beverly T. Lynds certainly found plenty to add to her Catalog of Bright Nebulae. There are many LBN objects marked on the line between the aforementioned stars to the right in this image, and LBN 923, a popular imaging target, lies just over halfway between the tip of IC 2118 and the bottom edge.
Much of this dust and gas captured by the camera is beyond the visual observer I suspect. Despite being relatively bright IC 2118 itself is a tricky proposition due to its size. So low magnification widefield views might be the answer for those with good enough skies. IC 2118 featured as the Deep Sky Forum Object of the Week back in December 2018, and many observations came from binoculars and finders.
In that same thread Owen Brazell also pointed out Harold Corwin's suggestion that NGC 1909 and IC 2118 can't be the same object. What William Herschel saw as NGC 1909 to the east of Rigel is a mystery.
James Whinfrey - Website Administrator.