The sky around LDN 897 at true scale, north up and east left, with stars to magnitude 8, the Lynds bright and dark nebulae, and the NGC and IC objects in the field. The box marks a circle of the same area as the cloud; the cloud itself is irregular.
LDN 897 is a dark nebula in Cygnus, 3,220 light-years away
LDN 897 is a dark nebula in the constellation Cygnus, 3,220 light-years away. It covers 0.11 sq deg of sky, about the area of a circle 23′ across, or 21.1 light-years at its distance, and Lynds gave it opacity 4 of 6, dark. It is a faint cloud that shows best in wide-field photographs, and it is highest in the evening sky in September.
Dark nebula: a cold cloud of gas and dust, a few degrees above absolute zero, dense enough to block the light of the stars behind it. Dark clouds are where new stars form, and they show only by contrast against a rich star field.
Finding LDN 897 from Sadr
LDN 897 lies 2.0° north of Sadr, the magnitude 2.2 star. That is within one binocular field.
A dark nebula shows only by contrast, as a patch with fewer stars than the field around it. Use the lowest power and widest field you have, from a dark site with the Milky Way high in the sky; a nebula filter does not help, because there is no light from the cloud to pass.
LDN 897 is highest in the evening in September
The chart gives its height above the horizon at 9 pm through the year, from 60°N to 40°S. It can be seen from the whole northern hemisphere and south to about 48°S, and never sets north of 48°N.
LDN 897 is 3,220 light-years away
The light seen from LDN 897 tonight left it about 3,220 years ago. Distance source: Cygnus X, Gaia DR2 dust, Zucker et al. 2020 (median of 2 nearby sightlines, 988 pc).
97 Lynds bright nebulae and 51 Lynds dark nebulae lie within 5° of LDN 897
