The attached poster contains 25 of the most interesting young stellar objects (YSOs) that I have found. These are small objects in our apparent view, with sizes ranging from 1 to 3 arc-minutes.  The actual sizes average about 1 light year in width.  Note that there are various naming conventions used for these objects, which, along with their small size and faintness, often presents a challenge in trying to find them in the sky.

A YSO is a star in its early stage of evolution. This early stage includes objects in both the first (protostar) stage and the second (pre-main sequence) stage.  Most stars spend only a small fraction of their lives in this early YSO stage.

The protostar grows by collecting mass from its enveloping molecular cloud. This protostar stage may last from 100,000 to 10 million years, depending on the mass of the star being formed. The star becomes optically visible when the protostar blows away its surrounding envelope. At this point, the pre-main sequence stage begins.

I believe that most, if not all, of the objects in the poster are pre-main sequence stars.  These stars have accumulated all of their mass by this point but the nuclear fusion of hydrogen has not yet begun.  Over time, the pre-main sequence star begins to contract and its temperature rises.  The contraction continues until hydrogen fusion begins, which is the start of the stable main sequence stage within which stars spend the vast majority of their lives.

These YSOs are associated with many interesting phenomena, including cometary nebulae, bipolar jet outflows, Herbig–Haro objects, and protoplanetary disks.   I love how all of these early stars are obscured by dust, which creates beautiful reflection nebulae patterns that can change quickly through the years. 

Speaking of quickly changing patterns, Revision C compares 3 images of PV Cep over 70 years -  the original 1952 image, a 2015 image taken by the late Rick Johnson, and my 2020 image on this poster. Although there are brightness and color differences between these images, the nebula shape change is apparent. The shape change is likely due to the varying reflections of the young star off of the surrounding evolving dusty cloud.  I am amazed that my 2020 image is so similar to the 1952 image, yet so different from the 2015 image.

The location and data for the nebulae on this poster is shown in Revision B.  Many YSOs such as these can be found by close examination of your existing wider field images for bright stellar objects that appear somewhat distorted.

Below is an alphabetical list of the 27 objects seen in the poster:
AB Aur
CW Tau
FS Tau
FU Ori
HBC 547
HK Ori
HP Tau
LkHa 208
Parsamian 21
Parsamian 22
PV Cep
R Mon
RY Tau
SU Aur
T Tau
V0375 Lac
V0376 Cas
V0380 Ori
V0565 Mon
V0628 Cas
V0633 Cas
V1023 Tau
V1331 Cyg
V1352 Aql
V1793 Ori
V1982 Cyg
XY Per