1888 Isaac Roberts – Nebula in the Pleiades
The First Successful Photograph of a Reflection Nebula – A New Way of Seeing the Stars
On 8 December 1888, Isaac Roberts captured a long-exposure photograph of the Nebula in the Pleiades using his 20-inch reflector telescope. Taken from his private observatory in Crowborough, Sussex, this image is one of the earliest known photographs to successfully reveal the faint nebulosity surrounding the Pleiades star cluster. It marked a new phase in astronomical imaging, showing that interstellar dust could reflect starlight—something previously suggested by theory but never directly recorded.
This breakthrough image demonstrated the potential of astrophotography to make visible what the eye alone could not perceive. Roberts’ careful alignment and prolonged exposure allowed diffuse structures to emerge on the photographic plate with unprecedented clarity. His work not only helped confirm the existence of reflection nebulae but also paved the way for photography to become central to astronomical discovery.
Preserved and digitised by ETH Bibliothek in Zürich, the Pleiades plate is a key example of how visual observation gave way to photographic evidence. With this image, Roberts redefined what it meant to "see" in astronomy—capturing the hidden architecture of starlight for the first time.
Credit: ETH Bibliothek, Zürich (E-Pics Bildarchiv Online), Accession No. ETH Bibliothek_Ans_02775-126
Author: Roberts, Dr. Isaac
Title: Nebula in the Pleiades
Date: 8 December 1888
Archive: ETH Bibliothek E-Pics Bildarchiv
Source: ETH Bibliothek, Zürich
Physical Original: Paper print mounted on cardboard; 13 × 13 cm
Available information: Photographed by Dr Isaac Roberts using a 20-inch reflector telescope, this long-exposure image captured the nebulosity around the Pleiades star cluster—revealing for the first time the reflection of starlight off interstellar dust. Digitised and preserved by ETH Bibliothek, the plate exemplifies Roberts’ pioneering role in astrophotography and the emergence of photographic methods as tools of astronomical discovery.
Image Credit: ETH Library Zurich, Image Archive / Ans_02775-132, Author: Roberts, Isaac, Title: Nebula in Andromeda, Date: 29.12.1888
The First Photograph to Reveal the Spiral Form of a Galaxy
On 29 December 1888, just 21 days after photographing the Pleiades, Isaac Roberts captured a long-exposure image of the Andromeda Nebula (M31). This was the first photograph to reveal a spiral structure in a nebula—a striking and unprecedented form that would reshape the understanding of the cosmos.
At the time, the nature of spiral nebulae was still debated. Roberts’ image offered compelling visual evidence that these objects might be vast systems of stars, separate from the Milky Way. Though the true nature of galaxies would not be confirmed until decades later, this photograph helped shift astronomy from speculation to observable structure—expanding both the reach and ambition of astrophotography.