Subject: Messier Marathon from Ottawa, March 16-17, 2002
Date: Tue, 19 Mar 2002 21:33:01 -0500
From: "Denis M. Legault" <denis.legault@cgi.ca>

Last Saturday night March 16 I did the Messier Marathon from Beckwith Park south of Carleton Place. This is a small town about 40km Southwest of Ottawa, Ontario. The co-ordinates are 45.5 latitude North and 75.5 longitude West. The weather conditions were perfectly clear skies with temperatures between -6 and -8 degrees C. The transparency and seeing were both pretty good. >From Ottawa, only 108 Messier objects are visible for the marathon on March 16. M30 is impossible and M55 becomes visible only by the end of March.

I successfully observed all 108 Messier objects using my 14" PDHQ Discovery dobsonian and a Telrad. I used the Sky Atlas 2000, Uranometria 2000 and my Messier Marathon schedule list that I posted on my astronomy observing group OAOG ( www.oaog.ca and groups.yahoo.com/group/oaog ). Official astronomical night started around 7:45pm EST and ended around 4:35am EST.

I started the Messier Marathon at 7:20pm with M79. The hardest object of the marathon was M74. It was close to the Moon and since it is one of the hardest Messier objects I needed averted vision to spot a glimpse of it. The star field matched the star pattern in Uranometria so I knew I had it. By 8pm I had observed 11 objects. From 8pm to 9pm I got 24 and I observed 30 others by 10:30.

At 10:30 the Virgo cluster was done. It was fairly easy using Uranometria 2000. After I found M85 in Coma at 9:56 I was able to navigate from galaxy to galaxy by using star patterns and smaller galaxies identified in Uranometria. So, I observed M100, M98, M99, M88, M91, M84, M86, M87, M89, M90, M58, M59, M60 and M49 in that order without even looking through my Telrad. I clocked M49 at 10:12. After observing all those galaxies at that speed I'll say having a detailed large atlas such as Uranometria is a must. I finished the Virgo galaxies with M61 at 10:23 and M104 at 10:28.

By 10:30 I was about 2.5 hours ahead of schedule. So I observed only 6 objects during the next 2.5 hours. Shortly after 1am I continued the marathon. I was observing at a much slower paste since I had to wait for the objects to rise. I got 11 others by 2am, 8 others by 3pm and 10 others by 4pm.

At 4:16, M7 was finally up. Then I say M69 at 4:20, M54 at 4:23, M70 at 4:24 and M2 at 4:30. Astronomical night ended around 4:35am. The last 3 were quite a challenge. I first found M72 at 4:41 and M73 at 4:42 then saw M75 at 4:52.

The only 2 objects that I missed were M55 in Sagittarius and M30 in Capricornus. These 2 objects are not visible from Ottawa on the morning of March 17. M55 was rising at 4:29 EST only 8 minutes before the end of astronomical night. Even if the object is very large it is too dim to see in the twilight. When twilight began it was only 0.5 degree above the horizon. There is a small chance it could be visible just before 5am but it would require a perfect clear horizon and a very dry stable sky. At 5pm, it was only 3 degrees above the horizon. That morning was too humid to give us that slight chance. At 5:05 I was on target. The star field matched the stars in Uranometria, I tried using averted vision but no success. M55 was just not visible. M30 was rising at 5:43 EST only 30 minutes before the Sun so I did not even attempt that one.

Before starting the marathon I observed comet Ikeya-Zhang. That night it was located near M74 in Pisces. This is a very nice bright comet with a well-defined core and a very long tail. It is a good way to start an observing session. I also saw a few other NGC objects during the night.

This was my most successful Messier Marathon ever. That was 108 Messier objects from latitude 45.5N. There were a lot of other observers attempting the marathon from that site. One of them observed 106 objects, another observer saw 104 and others got between 70 and 100. It might have been a little cold butcompared to January and February observing that night was quite warm. Some day I will drive down to the southern US to do the full Messier Marathon of 110
objects.

Denis Legault
Ottawa valley Astronomy and Observers Group (OAOG)