In a message dated 12/28/03, Bill Ferris writes:
> You'll find the Cone nebula about one-half degree due south of 15
> Monocertois. I'm not aware of a catalog designation for the Cone
> nebula. Anybody?
>
> The object you describe as "comet-like...with a short but pronounced
> tail and brighter head," could be NGC 2261. More commonly known as
> Hubble's Variable nebula, this fascinating was discovered by William
> Herschel on December 26, 1783. Described as "considerably bright, fan-
> shaped and about 2' long from the center," Herschel assigned this
> object to his class IV, "Planetary nebulae."

Taking a look at the DSS a reasonable position for the Cone nebula is 06 41
15 +09 23 00. A pretty good match with this position is LDN (Lynd Dark
Nebula) 1613, which Beverly Lynd gave a rough position of 06 40.7 +09 27.
The dark Cone Nebula is a surprisingly difficult object, even in large scopes
although there is a mix of moderately bright nebulosity extending southwest
of the bright (multiple) star S Monocerotis at the north end of the Christmas
Tree cluster.

I believe the Cone is significantly more difficult than observing the
Horsehead, but here's my last observation of the Cone a few years back with
my 17.5-inch:

17.5" (12/28/00): besides the bright nebulosity extending SW of mag 4.7 S
Monocerotis, most of the central region of the cluster was set against a
weakly glowing background. At the southern end of the cluster (tip of the
"Christmas Tree"), this low surface brightness glow was more evident and
clearly extended beyond the tip towards the SE. The western edge of the weak
glow forms an edge of the Cone Nebula. There is a lack of faint stars within
the region of the Cone's dark lane but this area was not noticeably darker
than the background sky further west.

Steve Gottlieb