From: TerryMoselat

Date: 9 October 2008 18:54:09 BST

Subject: Dave McDonald discovers an asteroid!

Hi all,


MAJOR NEWS: Irish amateur astronomer Dave McDonald has just discovered an asteroid - the first one to be discovered in Ireland for 160 years!


This is a phenomenal achievement when you consider that there are so many professional automated asteroid-search programmes using much larger telescopes in some of the best and least light-polluted observing locations in the world!  Dave's observatory in Celbridge in Co Kildare is favoured neither with dark skies, nor good weather! And the object was unbelievably faint - about magnitude 19.8 - 20.0. That is about 400,000 times fainter than the faintest stars usually visible to the unaided eye! It's a testament to Dave's expertise and dedication that he was able to image such a faint object, and to detect its slight motion from night to night, even though it was barely above the background limiting magnitude on the CCD image.


The object has been designated by the Minor Planet Centre of the IAU as "2008 TM9", and Dave will have the honour of giving it a proper name in due course. He can't name it after himself, but that doesn't matter as he has just had one (originally 1999 RV239) named after him by the IAU, after a proposal by John McConnell: I had the honour of presenting the commemorative certificate for that one to him at the Whirlpool Star Party in Birr last month! He said to me afterwards "Now I'll just have to discover one myself!" - I have to admit that I didn't think that his chances were very good, because of his poor observing location, and the competition described above. But that's just what he has done!


He rang me this morning to tell me, but I don't think that it had quite sunk in with him at that stage, as he just sounded quite pleased, rather than absolutely elated - I'm sure that with all the congratulations that should flood in, that will soon change!


Dave discovered it in the constellation of Pegasus in a series of CCD images using his 14" telescope last night (8/9 October). It's a main-belt asteroid, and more details may emerge after any pre-discovery images by other telescopes have been found and measured.


You can read more about Dave's work at


The only other asteroid ever discovered in Ireland was 9 Metis, by Andrew Graham at Markree Observatory in Co Sligo, on 25 April 1848.


Very hearty and well-deserved congratulations to Dave for this magnificent achievement!


Clear skies,