The Messier Catalog
April 10th, 2019 — the day a fuzzy, unremarkable image of a circular ring took the world by storm. Except this image was nothing like anything else. In fact, this was an image of an object which was never seen before. And yet, here it was in all it's blurry glory - the Black Hole at the center of the M87 Galaxy.
The M87 Galaxy, or Virgo A as it's more commonly known is a
distant galaxy some 54 million light years away. Today, we have enough
advanced equipments and people to make such fascinating observations of
the furthest reaches of our universe. Every discovery is heralded as a
new frontier for science and humanity, every new successful observation
rightfully lauded as advancing our understanding of the universe. But
what of the failures? For every successful experiment, there are
countless failed ones — hours upon hours seemingly spent in vain
chasing illusions in the vast space. As the saying goes,
Nobody remembers failures
. But there was such a failure
everyone remmebers. Even you read about it - right at the
beginning of this paragraph. It's the M in M87. What is
the M, and why do we use it?
Let's go back some 250 years, when a great way to make a name for yourself involved doing nothing other than staring at the sky. Astronomers and hobbyists were obsessed with discovering comets. You might remember some astronomers just by the piece of rock they found - Edmond Halley being a prime example. One such astronomer was a guy named Charles Messier. Charles' interest in comets was stimulated by the sighting of the spectacular six-tailed comet in 1744. Little did he know that the comet would change his life forever.
Discoveries & Failure
To pursue his interest, Charles became an understudy of a French Navy astronomer in 1751, and started keeping detailed observations of everything he saw in the sky. He co-discovered his first comet in 1758, and made his first independent discovery in 1760. In total, he discovered or co-discovered 20 or 21 comets (depending on the sources). Here's a list of all the comets, along with their observation times, spread across Charles' lifetime.
As he made progress though, he was constantly frustrated by spotting objects that looked like comets but weren't. So he decided to make a list. He added all the "definitely not comets but look like comets" objects he observed from his 4″ telescope in Paris. His list grew and grew to 45 objects which he published in 1774. The objects he observed and recorded till the first publication are shown below.
Bit by bit, this catalog became his go-to "objects to ignore while looking in the sky" list. With time, the list grew even bigger, and by 1781, it had burgeoned to include 103 objects. 7 other objects were added to the list in the 20th century as they were determined to have been discovered by him but never published. The current, and hopefully final, list now stands at 110 objects.
A Higher Purpose
By the end, Charles Messier laid sole claim to 13 comets — not an insignificant achievement in itself. But his lasting legacy to the world of astronomy is the Messier Catalog. It has become so popular that the objects in the Messier Catalog are still used by professional and amateur astronomers today and in early spring in Europe, astronomers sometimes gather for "Messier marathons", when all of the objects can be viewed over a single night. The study of these objects by astronomers has led, and continues to lead, to important, incredible discoveries such as the life cycles of stars, the reality of galaxies as separate 'island universes,' and the possible age of the universe. The Messier Catalog has been far more influential on the succeeding two and a half years of astronomy than his comets could ever be.
The list has a very special place in astronomy and history. In his quest to catalog all the boring non-Comet objects he might be fooled by, Charles Messier inadvertantly created the first comprehensive and reliable list of galaxies and star clusters in the world. His observations were very accurate, and he included the correct positions of each object in our sky. The world's most beautiful nebulae and other deep sky objects can be found in the Messier Catalog.
Here is the full list of objects and their locations in the the sky. Feel free to explore the sky, and read more about the objects which pique your interest.
Congratulations! You've made it to the end of the story. Now you can scroll up and see details of each comet and catalog object by clicking the chart items.