Moravian instruments, Inc., source: https://www.gxccd.com/art?id=450&lang=409, printed: 18.04.2024 20:08:52

Main pageObservations

Cave Nebula, Sharpless 155 and Herbig-Haro 168
 A wide-field image of the portion the constellation Cepheus, spanning three full Moons of sky area, was published as the Astronomy Picture of the Day on June 11, 2015. Its' author Herbert Walter needed more than 12 hours of exposure time with G2-8300 camera on FSQ106ED telescope to capture this image.

If we look to this portion of the constellation Cepheus with a telescope, we can hardly notice anything but a lot of stars, because the field of view lies within the plane of our Galaxy. But patient integration of light during long exposures shows us faint details in both dark and light nebulae.

The dark “Cave Nebula” in the upper-left corner is surrounded by Sharpless (Sh) 155 nebula, glowing in the deep-red color of hydrogen H-alpha spectral line, stimulated by light of young and hot stars. Other nebulae appear as black, covering light of background stars or they are reflecting blue light of nearby stars, like the VDB 155 close to image center.

A small bright blob in the lower left portion of the image is a Herbig-Haro object (HH) 168. HH objects mark locations, where a star is born, still surrounded by a nebulosity, already shaped into rotating disk. Such remnants of the material, from which the star was created, block the light of the new-born star and the pressure can be released only through the disk poles. Jets of material, escaping from the northern and southern poles, reveal a place where a star was born and are typical for HH objects.

Image was acquired with G2-8300 camera on the FSQ106ED telescope. Total exposure time exceeds 12 hours. More detail are available on the author's web site.