Contributed by: Brent A Archinal Sat, 21 Apr 2001 A Successful Messier Marathon On Saturday/Sunday March 24/25, I attended my first "All Arizona Messier Marathon". This is an event I've seen publicized for several years (see http://www.seds.org/messier/xtra/marathon/results.html for summaries from previous years). It is put on by the Saguaro Astronomy Club, although in practice it is A. J. Crayon and Jack Jones that apparently do most of the organizing for the star party. In any case, now that I'm living in Arizona, it finally made sense to try to attend. I've long had an interest in the Messier Marathon itself, having first done one in 1979 and several more in following years in the early 1980's, eventually observing 109 Messier objects in a one night. I also helped to publicize the idea somewhat, publishing the first detailed article on the subject in the March 1982 issue of _ Deep Sky Monthly _ magazine. I planned on other occasions in the late 1980's and the early 1990's to do the marathon again from the northern Virginia area, but was essentially clouded out every single time. Still, I always figured that I had done well enough in seeing 109 objects; it seemed impossible that one could observe all 110 Messier objects in one night. However, by the mid '90's it had become clear that under ideal conditions, as hard as it was to believe, several amateurs had achieved that goal. So, with all this in mind, I planned to attend the "All Arizona" event. I figured I would try the marathon once again, and weather and other conditions permitting try to repeat my 109 object count and maybe even get lucky and observe 110 objects. More importantly, in my mind, I was looking forward to seeing again, or meeting for the first time, a lot of the Arizona observers who were likely to be present. Further I was looking forward to observing at a "reasonably warm" site. The temperatures were likely to be in the 40's F, rather than the usual temperature of Flagstaff, normally about 20-30 degrees colder at night this time of year. Finally, the date itself was just about ideal, with a new Moon and at essentially the best possible time to see the difficult evening and morning objects, M 74 and M 30 respectively. [An aside here ? when I refer to the "110" Messier objects, I mean the catalog with the usual modern designations and assumptions accepted. This version is not necessarily compatible with Messier's true list. For example it's clear to me that M 102 does not exist as a separate object ? Messier clearly stated it was a duplicate observation of M 101. However I, like lots of other folks, accept NGC 5866 as a "stand-in" for M 102, since many people in the past considered it as Messier's real M 102. For an explanation of the modern identifications, see my _ Deep Sky Monthly _ article, or any other current reference on the Messier objects such as Stephen O'Meara's or Harvard Pennington's book on the subject.] So on Saturday morning, March 24, with the car loaded up, I checked the weather and made the "go" decision to drive down to the star party site. Arizona was pretty much completely overcast with cirrus clouds, but the satellite maps showed a clearing was likely to arrive in southern Arizona that evening. I left about 11:30 AM for the 4 hour or so (240 miles) drive to the site. This turned out to be a beautiful trip, with the Sonoran desert, particularly just north of Phoenix, in full bloom after a wet winter. The desert was actually green, except for large patches of color, which were in fact fields of wildflowers of every color and description. On all the roadsides it was clear that ADOT had done a rather obvious job of covering the areas with wildflower seeds. In some of the road cuts it was as if one were driving through an orange tunnel of flowers. Somewhere in Phoenix, with lighter traffic than usual, I was thinking of the night's observing. It was then the revelation came to me that although I had all the observing and camping equipment I could possibly need, I had managed to forget part of my 10-inch telescope! I'd left the struts (that connect the mirror box to the front assembly) at home. I decided though that it certainly wasn't worth the trip back to get them. I would instead try observing with my 11x80 binoculars, and try to filch some looks through people's telescopes for all the objects I probably wouldn't be able to find. The trip was otherwise uneventful. I exited the interstate at Arizona City (a town nowhere near the observing site, but for which it is often named), and continued the final 30 miles or so (15 paved, 15 dirt road) to the observing site. The site itself was on a large ranch, at this point about 80 miles south of Phoenix, and maybe 60 miles northwest of Tucson. The "observing field" was a several acre area pretty much clear of vegetation. Fortunately recent rain had kept the dust down at the site reasonably well. Arriving about 4 PM, I quickly set up next to Bill Ferris, who had driven down the day before from Flagstaff. As expected (since I wasn't there?) everyone began telling us what a good night it had been Friday. In fact it was so good that Bill had been able to observe all 110 Messier objects with his 10-inch telescope! The other big news was that a light plane had made an emergency landing on the observing field that afternoon, even throwing a tire in the process. However the pilot had surprisingly got the aircraft repaired and back up just before I arrived. I quickly touched base with a number of other Arizona amateurs who I had previously met, including e.g. Brian Skiff, Tom Polakis, Diane Hope, and A. J. Crayon. I also eventually spent time checking out many of the telescopes set up and meeting some new folks. All this time the sky was still overcast with cirrus clouds, but by 5:30 PM or so, a clearing had begun in the west, pretty much as predicted. Telescopes (and in my case binoculars) were set up, everyone served up their own dinner, and the wait for twilight began. A common pastime while waiting for the sky to darken was to examine the telescopic view of Kitt Peak and all of its telescope domes, about 40 miles to the south. In doing so we were all surprised to find that the seeing was rock solid steady, with no turbulence visible even in that view across the desert. It was also nice to watch the sunset, in the one patch of clearing sky. I have never yet seen one of the brilliant green sunset flashes that others have described. However at least this evening (about 6:42 PM), Bill and I saw the last bit of the Sun turning a convincing green color as it disappeared between some mountains to the west. So it was "green" but not necessarily a "flash". At about 7:45 everyone seemed to begin observing in earnest. The bright Seyfert galaxy M 77 was the first object I managed to spot in my 11x80 binoculars at 7:50 PM, and then surprisingly only a minute later I suspected the galaxy M 74. Bright zodiacal light also appeared in this area about that time, keeping the vicinity of the western horizon somewhat difficult to observe. The clouds continued to dissipate, and before long it was completely clear ? a condition fortunately kept for the remainder of the night. I started observing some other M objects, but kept going back to the M 74 area. I also confirmed the view of it in Bill Ferris's 10-inch telescope, although with its much greater magnification mostly only the nuclear region and a nearby faint star were seen. Finally I became convinced that although it was extremely difficult, by 8:15 through the binoculars with averted vision I was seeing M 74 as a spot about 20-30% of the time. Having gotten the difficult evening object, it now became relatively easy to start picking off the other evening Messier objects. I won't continue here with a blow-by-blow account of observing the rest of the night. In general however, there were other difficult objects as the night went on, although not (as it turned out) as problematic as M 74. These objects included M 110, M 98, M 91, and ? in the morning twilight - M 73 (more on which below). Other nearly stellar objects had to be confirmed against star charts or in the 10-inch. These included M 32, M 76, M 1, M 57, M 88, M 69, M 54, and M 72. 11 power is obviously not the ideal magnification for looking at some of these things! I will mention though one particular late-night observation of an object I had never seen before. While waiting for the summer Milky Way objects to rise high enough to start seriously observing them, between about 2:30 and 3:30 AM, I spent some time talking to Brian Skiff and examining the sky carefully with the unaided eye. Having spent my life usually observing from more northern sites, the upper part of the constellation of Centaurus, now up in the south, was certainly interesting to see ? particularly with the fuzzy "star" Omega Centauri appearing as an obvious object. I was also impressed to see the large 15-20 degree oval glow of the gegenschein ? something I've seen only maybe half a dozen times in my life. It was now starting down in the west from the meridian, in the area of eastern Virgo and western Libra. However, Brian showed me convincingly that on this night the gegenschein was just a larger and brighter portion of the entire zodiacal band ? something I'd _ never _ definitely seen before. It ran from the western horizon all the way into the brighter zodiacal light and light pollution of Tucson in the east. I was impressed that I was finally able to see it, from a good site, yes, but one with some notable light pollution. I suspect that as with many types of observing, this was a case where having an object pointed out will make it easier to see in the future. That has certainly been true for me in the case of the gegenschein ? we'll see if it true for observing the zodiacal band as well. In any case, the Milky Way was up before we knew it, so I went back to observing with my binoculars and slowly worked my way south along it, picking off the many bright objects of Scutum and Sagittarius. The sky seemingly started to brighten as I found M 2 about 4:15 AM, although this was still early enough that I must have mostly been observing through the Tucson glow and Zodiacal light. Around 4:45, M 73 gave me a bit of a scare when I couldn't see it at first. I had observed all these faint galaxies and might now be stopped on a group of 4 faint stars! Fortunately more time spent observing the area and checking the field against an Uranometria 2000.0 chart showed that I was seeing it. It was visible about 30-40% of the time with averted vision, along with the nearby green planetary nebula NGC 7009, which appeared stellar. Now it was time to find the "holy grail" of the morning Messier marathon, M 30 ? but a quick check of charts for the area showed it was still a few degrees below the horizon! So a seemingly long wait began, as I watched many faint stars preceding M 30 slowly climb above the horizon, and M 30 approach the same point, degree by degree. The field rose at 5 AM, and by 5:05 we had convincingly seen it in Bill's 10-inch. Finally, after years of observing, I had actually seen all 110 Messier objects in a single night! But, would M 30 be visible in the 11 x 80's? Only more waiting would tell. After only a few minutes I suspected it in the binoculars, although I assumed it was visible due more to wishful thinking than anything else. But finally, at about 5:16 AM, I became convinced I could see it with great difficultly, about 20-30% of the time, by putting the field of view slightly in motion. By 5:35 AM, it was more obvious, visible about 50-70% of the time, just before the field started to turn blue with twilight. So not only had I seen 110 Messier objects in a single night, but I had done it with a pair of 11 x 80 binoculars! We stayed up a little while longer, packing much of our observing gear away, and finishing off the check-off sheet that A. J. Crayon had provided and turning it in to him. After a few hours sleep, and a stop at a diner in Arizona City, I made an uneventful (but long) trip back to Flagstaff. A. J. later posted a summary of this event (see http://www.seds.org/messier/xtra/marathon/az01res.txt), partially based on the check-off sheets. People had attended the event not just from all over Arizona, but all over the western U. S. and even as far away as Ohio and Ontario, Canada. He was quite surprised to find that with 91 people attending using 79 telescopes, fully 25 people managed to observe all 110 objects! 20 more found more than 100 objects, and 12 others made reports of over 40 objects observed. The results are all the more impressive when one realizes that before 2001 only four people had reported observing 110 objects in a single night (see http://www.seds.org/messier/xtra/marathon/hall.html). Some final miscellaneous comments on doing a Messier marathon may be in order here. On the "Arizona observing" e-mail list, some have raised the issue of the best possible date for such an activity. With the 11 x 80 binoculars, M 30 was about as equally difficult as M 74 (or at best maybe only slightly easier). So there is no obvious indication any earlier or later date would be better with that aperture. In Bill's 10-inch however, M 30 seemed more obvious. So with larger (and more likely used!) apertures, an earlier date than March 24/25 might be better in order to see M 74. At this site, M 30 was also in the light pollution glow from Tucson, so the sky was a little brighter there than at other locations near the horizon. Therefore at other sites with equally dark eastern and western horizons an earlier date might also be best. Another interesting point is that the visibility of both M 74 and M 30 improved quite a bit with time. For M 74 the battle is between the lowering elevation and the darkening sky (but only to a point due to the bright zodiacal light there). I first thought I saw it at 7:51 PM, but saw it best about 8:15. For M 30, the battle is of course the opposite. As it rises it becomes more easily visible, but the sky is brightening too. As described above I first thought I saw it about 5:05 AM, but considered it easiest in binoculars just before the sky started to turn blue, about 5:35. Regarding the search sequence used for finding the Messier objects, pretty much all of the search sequences (e.g. I have checked the one John Kerns and I published in _ Deep Sky Monthly _ in March, 1982, H. Pennington's order in his Messier Marathon book, A. J. Crayon's list, and a listing in the Coconino Astronomical Society newsletter) seemed to be "out of whack" for the latitude of the site. Brian Skiff has also independently noted this problem. Several times during the night, and in particular when it came time to observe the southern Milky Way objects in the morning, it was clear that a number of objects were fairly well up already for viewing in the south. Yet the search sequences suggested observing some northern object either not up or just clearing the horizon. Developing custom search sequences based on latitude will improve the efficiency of observing for slower or less experienced observers, thus increasing the total number of objects observed. For this the set and rise times, as well as the usual "lessons learned" about Messier marathons (e.g. observing groups of objects together), all need taken into account. Still, there could be little argument with what objects had to be observed right at the start and end of the night. So the search sequence probably would not make much practical difference on the total number of objects an experienced observer sees, just the efficiency with which they're observed. Finally, and most importantly regarding the success of a marathon, it seems to me that one of the primary keys to observing the difficult evening and morning objects is to not only have a low east and west horizon, but also a very low humidity (e.g. desert) site. For me this made it much easier to see objects close to the horizon than in comparison to other sites where I regularly observed in the past in Ohio, Virginia, and other eastern states. While looking for M 30 in the 11 x 80's and waiting (seemingly forever, but actually for only 25 minutes after seeing M 73) for it to clear the horizon and get up several degrees into the sky, I noticed that 6th and 7th magnitude stars could be seen only 2 degrees or so above the (slightly raised) horizon. In any case, as a summary and with some hindsight, it was impressive to be part of such an event, where it was demonstrated that under very good conditions, a large number of people were able to complete the 110 object Messier Marathon. I had also finally achieved that goal myself, even using binoculars rather than a telescope! But perhaps just as, if not more importantly, I have to say it was a superb night to be observing, with warmer weather than we've been having at night in Flagstaff, from a good observing site with fine transparent skies, and with lots of wonderful folks present. - Brent Archinal barchinal at usgs.gov Flagstaff, AZ