IC 417 (Nebula) & Stock 8 (Open Cluster) in Auriga
Seeing the Unexpected
The subtle Emission Nebula, IC 417, with the embedded Open Cluster, Stock 8, is located
at the center of a celestial-Y with the outer ends of the Y consisting of M36, M38 and the
Flying Minnow Asterism. This was my last drawing for the night, and it turned out to give me
the most trouble.
I usually predate my observations/drawings by doing at least some background work. This
often makes the object come alive in my mind when observing it, but once at the telescope I
strive to be open-minded as to what I am seeing and realize that observational biases can
easily creep in. Before drawing/observing a Celestial Object, a balance must be reached,
in knowing enough not to miss something interesting or important, but on the other hand not
to develop preconceived notions about what it will look like. One often “falsely” sees what
one is looking for when dealing with objects on the fringe of visibility. If I had not researched
into IC 417 and Stock 8, there is a good chance that I would not recognize that it consisted
of both an Open Cluster and an Emission Nebula.
I struggled with IC 417 and Stock 8, because they did not appear as I had expected. To
begin with, in older star atlases, Stock 8 is out of position with IC 417. Even when this is
corrected for, the given sizes of the cluster and nebula were far greater than what appeared
in the eyepiece. Most likely, this was due to literature measurements of the nebula and
open cluster using far larger telescopes or photographic images. Whatever the reason, the
cluster appeared so much smaller than I expected, that at first, I did not recognize it. The
nebula, IC 417, was even worse. I expected, using a nebula filter, to see it spreading large
in my field-of-view. Separating the sub-resolved star-haze of the open cluster (Stock 8) and
the haze of the nebula (IC 417) around it was not possible visually from my backyard without
the use of nebula filters. The only way that I was sure both were present was by using an
Oxygen-3 filter that enhanced the nebula and diminished the Open Cluster. By switching
between no-filters and nebula filters, I was finally able to separate both in the eyepiece
(even though they are at the same location). One final note; in my drawing the sizes of both
Stock 8 and IC 417 are my estimates done visually using a 6-inch refractor from suburbia. I
realize that they are far smaller than what is recorded in the literature.
at the center of a celestial-Y with the outer ends of the Y consisting of M36, M38 and the
Flying Minnow Asterism. This was my last drawing for the night, and it turned out to give me
the most trouble.
I usually predate my observations/drawings by doing at least some background work. This
often makes the object come alive in my mind when observing it, but once at the telescope I
strive to be open-minded as to what I am seeing and realize that observational biases can
easily creep in. Before drawing/observing a Celestial Object, a balance must be reached,
in knowing enough not to miss something interesting or important, but on the other hand not
to develop preconceived notions about what it will look like. One often “falsely” sees what
one is looking for when dealing with objects on the fringe of visibility. If I had not researched
into IC 417 and Stock 8, there is a good chance that I would not recognize that it consisted
of both an Open Cluster and an Emission Nebula.
I struggled with IC 417 and Stock 8, because they did not appear as I had expected. To
begin with, in older star atlases, Stock 8 is out of position with IC 417. Even when this is
corrected for, the given sizes of the cluster and nebula were far greater than what appeared
in the eyepiece. Most likely, this was due to literature measurements of the nebula and
open cluster using far larger telescopes or photographic images. Whatever the reason, the
cluster appeared so much smaller than I expected, that at first, I did not recognize it. The
nebula, IC 417, was even worse. I expected, using a nebula filter, to see it spreading large
in my field-of-view. Separating the sub-resolved star-haze of the open cluster (Stock 8) and
the haze of the nebula (IC 417) around it was not possible visually from my backyard without
the use of nebula filters. The only way that I was sure both were present was by using an
Oxygen-3 filter that enhanced the nebula and diminished the Open Cluster. By switching
between no-filters and nebula filters, I was finally able to separate both in the eyepiece
(even though they are at the same location). One final note; in my drawing the sizes of both
Stock 8 and IC 417 are my estimates done visually using a 6-inch refractor from suburbia. I
realize that they are far smaller than what is recorded in the literature.