LDN 138

LDN 138 is a dark nebula in Ophiuchus

LDN 138 is a dark nebula in the constellation Ophiuchus. It covers 1.03 sq deg of sky, about the area of a circle 1.1° across, and Lynds gave it opacity 1 of 6, the faintest. It is a faint cloud that shows best in wide-field photographs, and it is highest in the evening sky in July.

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 138 from θ Oph

LDN 138 lies 4.1° north of θ Oph, the magnitude 3.3 star. Three fingers held at arm's length cover about 5°.

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 138 is highest in the evening in July

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 southern hemisphere and north to about 69°N, and never sets south of 69°S.

The distance to LDN 138 is not well measured

No reliable distance has been measured for it yet.

0 Lynds bright nebulae and 110 Lynds dark nebulae lie within 5° of LDN 138

The nearest:

• LDN 131, dark nebula, 24′
• LDN 149, dark nebula, 42′
• LDN 117, dark nebula, 52′
• LDN 103, dark nebula, 1.0°
• LDN 112, dark nebula, 1.0°
• LDN 101, dark nebula, 1.1°
• LDN 102, dark nebula, 1.1°
• LDN 95, dark nebula, 1.2°
• LDN 99, dark nebula, 1.3°
• LDN 94, dark nebula, 1.3°

NGC and IC objects in the field that are brighter than magnitude 12.5 or have their own page:

• NGC 6342, globular cluster, 1.5°
• M9 Messier 9, globular cluster, 2.6°
• NGC 6356, globular cluster, 3.1°
• NGC 6369 Little Ghost Nebula, planetary nebula, 3.1°
• NGC 6325, globular cluster, 3.2°

LDN 138 catalog data