Astronomy Picture of the Day: 04/01/2026

Object Name: SL-17

Copyright: Elizabeth Armarego

Location: Boondooma, QLD

Skill level: Intermediate (2-4 years)

Image Title

The Dark Wolf

Artists' statement

The Dark Wolf nebula is located in Scorpius. A thick, dense cloud is blocking out the background stars.

How This Image Was Captured

Gear used

Skywatcher ED80, HEQ5PRO, ZWO585MM, Antlia V-PRO LRGB

Exposure details

300 seconds, gain 101, 14 hours total integtration

Processing notes

Flats, darks, bias, stacked in WBPP and processed in Pixinsight

Exploring SL-17

SL-17 (Sandqvist & Lindroos 17), often called the Dark Wolf Nebula, is a striking dark nebula in the constellation Scorpius. Rather than glowing on its own, SL-17 is revealed by extinction: dense clouds of cold dust and molecular gas absorb background starlight and nebular emission, carving a dramatic silhouette against the rich star fields and glowing hydrogen clouds behind it.

These dark structures contain the raw material needed for future star formation. Within SL-17, gravity slowly gathers gas and dust into denser regions, marking the earliest stages of stellar birth long before stars ignite and light up their surroundings. Observing dark nebulae like this helps astronomers understand how stars form in heavily obscured environments where visible light cannot easily escape.

What makes SL-17 particularly compelling is its strong contrast with nearby bright emission regions. Its wolf-like outline stands out sharply against the luminous background, emphasising the ongoing balance between light and shadow in our galaxy. It’s a reminder that some of the most important processes shaping the cosmos take place quietly, hidden within the darkest corners of the night sky.

Behind the Selection

The composition beautifully captures the contrast between light and shadow, with the dense, dust-filled silhouette carving a powerful, recognisable shape through the surrounding emission. The framing draws the eye naturally into the scene, highlighting both the nebula’s dramatic form and the rich stellar environment around it.