The enhanced, English version of my comprehensive study on the history of the NGC has been published in August 2010 by Cambridge University Press. The 660-page book is titled Observing an Cataloguing Nebula and Star Clusters - from Herschel to Dreyer's New General Catalogue. Look here for more details.

My Historic IC is now online, giving the data of all IC-discoveries for the first time!

The latest versions (2010) of my Revised NGC/IC, Historic NGC, and the biographical data about the NGC/IC Observers will be found only here - and not on the website of the NGC/IC project! Particularly the "Historically Corrected NGC" (HCNGC, Bob Erdmann), presented there, is a mere copy of an outdated version of my "Historic NGC" (without giving any acknowledgment).

My NGC/IC data are used in the recently published NGC-IC Photographic Catalogue by Numazawa and Wakyia. The large-format, 720 page book shows DSS-images of all objects!

My German book Sternwarten. 95 astronomische Observatorien in aller Welt on observatories was published by Oculum-Verlag in 2008. I'm responsible for the text, Stefan Binnewies and Jens Moser, both eminent astrophotographers, contributed large format pictures. 95 places throughout the world are presented with their instruments, history and astronomical work.

Paper about William and John Herschels problems in cataloging M 81 and M 82 (pdf).

A short biography of John Louis Emil Dreyer (pdf).