This is the first picture taken with the camera TS2600 Color attached to the Samyang 135 telephoto lens, mounted on a Star Adventurer-GTI. The tuning of this portable setup is proving to be more difficult than expected: the mount is not easy to drive, and I am still working to find PHD2 optimal parameters to avoid oscillations along the declination axis. Fine-tuning the back-focus with spacer rings and reducing the Samyang's aperture with stop rings improved, but did not completely eliminate, the optical coma visible on the largest stars in the corners of the image. I suppose I have to live with that, but if you have technical suggestions, these are more than welcome!

This plain HOO picture has been taken during four nights across the end of August and the beginning of September 2023, under a rare sequence of clear nights from my location.

This magnificent landscape, placed on the border between Cepheus and Cassiopeia, is famous for the suggestive "Question Mark" shape, assumed by the two main nebulae Sh2-171 and 170, respectively north and south in the image. An alternative interpretation could be: an ear with a drop earring.
In addition to these two large emission nebulae, several other Sh2's, planetary nebulae, and open clusters are present in the field, and described in more detail below.

A detail of the core of Sh2-171, taken with my Newtonian 200/1000 in 2022 is visible here below (Picture 1).

Sh 2-171
This expanding shell of gas and dust was created by the original star cluster at the heart of the Cep OB4 association, which has now dispersed. It is now lit and ionized by the young star cluster Berkeley 59 (forming the bright nebula called Cederblad 214) and it is expanding into the fainter diffuse nebula NGC 7822. Berkeley 59 is surrounded by another dark region of disturbed gas and dust containing the radio source W1.
Distance estimates are in the range of 800-1000 pc, that is 2600 - 3200 ly.

Sh 2-170, also called LBN 577
Sh 2-170 lies in the direction of the Cas OB5 supershell, and is ionized by a member of the Stock 18 open cluster. It lays much further away than Sh2-171, being at 2200-2600 pc.

Sh 2-167
There is very little information in the scientific literature on this faint nebula. Sh 2-167 was previously listed as a planetary nebula but is now believed to be an HII region. It appears in the direction of a large expanding shell around Cas OB5, but the available distance estimates (6400 pc) suggest that it may lie much further away in the Outer/Norma arm.

Sh 2-175, also called LBN 596
Sh 2-175 appears in the direction of a supershell of molecular and atomic hydrogen clouds surrounding the Cas OB5 association, which is part of the Perseus arm. A widely varying range of distances to this nebula and its potential ionizing star has been published in the scientific literature. Distance estimates range from 1700 to 2700 pc.

PN G121.6+03.5 Planetary Nebula
Distance is evaluated to be 5800 pc.

PK 119+06 1 Planetary nebula
Its distance is around 2500pc.

SH 1-118 Planetary Nebula, also called PK 118+02.1
It is visible just above left of Sh2-170 in the picture here.
Its distance is estimated to be 1160pc

NGC 7762
It is a young open cluster placed at 800 pc. It was discovered in 1788 by William Herschel.

Reference: Data taken by galaxymap.org and Simbad DB.


Picture 1: My 2022 starless image of Sh-171 core, displaying its characteristic horizontal dark clouds.