van den Bergh Nebula

While many catalogs focus on the fiery red of ionized gas, the van den Bergh Catalogue of Reflection Nebulae (vdB) is the definitive guide to the "blue" side of the galaxy. This database captures the moments where starlight hits dust clouds, scattering the light into ghostly, luminous shrouds.

History & Who Made It

The catalog was compiled by the prolific Canadian-Dutch astronomer Sidney van den Bergh (born 1929). In 1966, while working at the David Dunlap Observatory in Toronto, he performed a systematic search for reflection nebulae using the blue and red prints of the Palomar Observatory Sky Survey (POSS).

Van den Bergh was looking for stars that were embedded in or surrounded by fuzzy, glowing halos. Because he used the blue-sensitive plates, he was able to identify reflection nebulae that other surveys missed, as these objects are naturally biased toward the blue end of the spectrum.

The Purpose: The Physics of Dust

The primary purpose of the vdB catalog was to understand the relationship between stars and the Interstellar Medium (ISM).

1. Light Scattering: Reflection nebulae don't create their own light. Like the "beams" of a car’s headlights in fog, they reveal the presence of dust that would otherwise be invisible.

2. Stellar Evolution: By studying the types of stars that illuminate vdB nebulae, van den Bergh helped show how young stars are often still wrapped in the "cocoon" of gas and dust from which they formed.

3. Color Analysis: Van den Bergh categorized these nebulae by their color, noting that while most are blue, some illuminated by cooler stars appear yellow or orange.

What Objects Can Be Found In It?

The catalog contains 158 objects (plus an addendum, the vdBH, for the southern sky). These are almost exclusively found within the dense star fields of the Milky Way, particularly in regions like Orion, Cygnus, and Cepheus.

vdB Database Summary

Catalog Name: van den Bergh Catalogue of Reflection Nebulae (vdB)

Creator: Sidney van den Bergh

Year Published: 1966

Total Objects: 158

Primary Gear: Medium-to-large telescopes and high-dynamic-range cameras.

 Famous "vdB" Showpieces

vdB 14 & 15 (Camelopardalis): Two beautiful, ghostly patches of blue light surrounding hot, young stars in a relatively empty part of the sky.

vdB 142 (The Elephant's Trunk Nebula): Located within the much larger emission complex IC 1396, this is a classic example of dark, dusty pillars being rimmed with reflected light.

vdB 1 (Cassiopeia): A striking blue reflection nebula located near the star Beta Cassiopeiae; it is often the first target for people starting the vdB list.

vdB 123 (Serpens): Part of the massive Eagle Nebula region, showing how reflection and emission gas can mix.

The Observer's Challenge: The Contrast War

For the visual observer, vdB objects are extremely delicate. Unlike the Sharpless HII regions, which can be "popped" with a filter, vdB objects represent a different challenge:

1. Total Darkness: You cannot use an OIII or UHC filter to see a reflection nebula. These filters block the very blue light you need to see.

2. Baffling the Glare: The biggest enemy is the star itself. Because the star is so much brighter than the nebula, its glare often hides the "fuzz." Skilled observers often use high magnification to move the central star out of the field of view to see the nebula on the edges.

3. The Modern Camera Advantage: Reflection nebulae are the "runway models" of astrophotography. They require long exposures and perfect calibration to capture the subtle, dusty "veils" that van den Bergh first cataloged in the 1960s.

Sidney van den Bergh’s work turned our attention away from the "active" explosions of the universe and toward the quiet, beautiful interaction between starlight and cosmic dust.