Caldwell Objects

A New 109 Deep-Sky Object challenge

for the

Observer, Astro-photographer and CCD Imager

A new collection of deep sky targets for the modern amateur astronomer was long overdue. The traditional catalogue of deep sky objects, i.e. that produced by Messier over 200 years ago, has become a victim of its own success. Those objects have now become far too well known, over-viewed, over-imaged and over-published. More importantly they have often resulted in more interesting objects being totally overlooked. It was time for a fresh approach.

Spotting a gap in the market was Patrick Moore, presenter of BBC TV’s Sky at Night. Drawing on this almost unrivalled experience, he has produced his own 109 object catalogue (ignoring the Messier objects) stretching from virtually pole-to-pole. No matter where you live, northern or southern hemisphere, you will have your own Caldwell objects to observe. The vast majority of the objects in Patrick’s collection are eminently suitable for binocular observers. If you are wondering why they should be named Caldwell, the answer is that Patrick’s surname is actually Caldwell-Moore. It would have been too confusing to use Moore as that would have created another set of “M” objects.

The Caldwell Controversy

As the the author of the first book on the Caldwell Objects, I inadvertently got caught up in a controversy as to who actually compiled the list! Since Patrick is no longer with us it is perhaps time to explain what went on. I'll start at the beginning.

The original article (S&T,December 1995) announcing the Caldwell Catalogue was in fact written by Barlow Pepin - Wiki and several others wrongly credit Patrick with the article but he didn't write it. He just added an introduction. No sooner had my book come out (2000) than Mr Peppin contacted me claiming much of the credit for deriving the list. He wanted the second edition of the book to credit him with its compilation. How much of the list is due to Patrick and how much was due to Mr Pepin it is probably impossible to say now.

One fact that lends some support to Mr Pepin's claim is that shortly after my book was published (2000) Patrick wrote to me asking for the corrected Caldwell list which I promptly sent him. The original article had contained several errors, which I had to correct for my book - Steve Lee helped me with one object. Wiki is wrong again in crediting the corrections to a later published book. So if Patrick had created the list why would he ask me for a corrected copy? He could have consulted his original. I guess we will never know the answer,

The Book


The 109 Objects


Poster of all 109 Object


Sky Chart of all Objects

  • Conceived by Patrick Moore

  • Original Book by David Ratledge

  • 109 Objects excluding all the Messier Objects

  • Ordered by Declination – Pole to Pole

  • Observe all 5° above your horizon or...

  • Travel and see them all

  • Over 100 visible in binoculars

The Iris Nebula

The Iris Nebula - Caldwell 4

Return to deep-sky.co.uk