Log, Nov 16, 2001

21 People. Despite weather forecasts calling for "mostly clear" weather, the skies at FDO this Friday started out mostly cloudy and just got worse as the public arrived. We expected clearing eventually (and got it, as you will see) but early guests and the staff were very disappointed not to be able to do much observing prior to about 10 PM, when the clearing began to move in. Staff members included Les, Doug and Steve, and we had several families on hand with children in tow. All we could really show them was a dim look at Saturn, seen through clouds so thick that the planet was often invisible to the naked eye. But first timers were impressed nonetheless as even under the worst conditions, the ringed planet shows its stuff!

During occasional patches of partial clearing we did get a peak at the globular M2 (barely) and the fine bright double star Zeta Aquarii. We had hoped to show the public comet Linear WM1, now an easy target in binoculars, but the skies around Perseus refused to clear even for a moment. With next to nothing to see in the sky, Les had an eager crowd gather around the computer for some fine animations courtesy of Sky Chart III. Imaginary trips through the solar system on the back of a comet and journeys to Alpha Centauri amazed and entertained everyone - as we held out hope for some clearing overhead.

Just after many of the public left, we noticed that the wind was picking up, the temperatures were dropping, and the skies were beginning to clear steadily. By 11:30 PM it was totally clear from horizon to horizon, although the transparency remained only fair. Those who remained were treated to some fine views of Saturn, with its moons Titan, Rhea, Dione, Iapetus, and Enceladus. We looked for the dim Mimas, near eastern elongation, but couldn't spot it this night. Jupiter was also well seen, but there were no transits to watch and the Great Red Spot wasn't due to come around until quite late at night.

We did eventually get a look at Comet Linear WM1, but in the still hazy air it was not impressive - no tail seen. It was easy to see in binoculars - between mag. 6.5 and 7.0, and will surely be better seen on a clearer night. Nearby we enjoyed a look at the open cluster NGC1342. While observing it, Steve and Doug noted that the true field of view in the 40 mm Konig is not as large as expected (by about 25% or more). We have noticed this before, but not thoroughly checked out the cause. It may be a case of exaggerated claims by the manufacturer, or it could have something to do with the JMI electronic focuser, which sits in the light path and increases the scope's effective focal length. A little detective work will reveal all.

With several guests still on hand and Orion rising we turned the scope to the marvelous M42 - the Orion Nebula. It was simply spectacular, as usual, especially with the Oxygen III filter in place. We also observed the much dimmer, comet shaped, M78. The outline was faint yet distinct. Still in Orion we checked the 16" scope's recently recollimated optics with splits of the difficult double stars Zeta (Alnitak), Eta Ori, 52 Ori, and 32 Ori. The last is the most difficult, with a separation of just 1.0 arc second and magnitudes of 4.5 and 5.7. But the big scope spit it fairly easily at 303 X, indicating that the collimation is rather good. A crowd favorite, the dazzling Rigel, was a wide and clean split.

Doug took a moment to check out open cluster NGC2112 in Orion. His memory was that this is a poor cluster in his 8" SCT, and indeed, even in the 16" the cluster is not very impressive - fairly large in area, with 50 or so faint stars scattered about. More interesting were the twin clusters NGC1807 and 1817, just over the line into Taurus. Many brighter members as well as lots of dimmer stars superimposed on the Milky Way background. NGC1817 is the more attractive of the two.

Moving into Gemini Steve and Doug revisited the ever popular "Eskimo" or "Clown Face" planetary nebula NGC2392. Doug could make out both the Eskimo's parka and face; Steve could see only the parka. (A little imagination may have helped Doug!) Nearby the very rich, though dim, open cluster NGC2420 put on quite a show in the 16" - over 100 stars, though none are brighter than magnitude 11. In Doug's 8" SCT this is always a disappointing cluster - not so with the big eye at FDO!

With a Saturday all-nighter for the Leonids in mind, Steve hit the road at about 12:30 AM, leaving just Les and Doug to enjoy the improving skies for a bit longer. Leo was rising in the east, so Les reclined outside on meteor patrol, snug as a bug in his sleeping bag and lawn chair. During periods of silence, Doug suspected that Les may have nodded off, but the occasional "WHOA!!", or "WOW!!!!" dispelled that thought! There weren't many Leonids seen, but the few that were were quite bright, some with trails extending well across the sky. Inside the dome, Doug killed all the lights for an attempt at the elusive Horsehead Nebula. The first step is to carefully identify the surrounding star field - which is now becoming quite familiar to several FDOers. Once done, you go to averted vision to see if you can spot this very challenging, low contrast object. With the 40 mm Konig, unfiltered, Doug had no luck. Dropping the OIII filter in darkened the overall view, as expected, but there was still no trace of the Horse's head. This attempt proves how important a totally dry and transparent sky is for seeing the Horsehead. Doug had seen it only once before, for sure, and that was on an exceptionally dark and clear night last winter. We'll certainly make further attempts at this famous object in the coming weeks and months.

Les and Doug talked about staying longer, but with better skies in store for Saturday night - to say nothing of some VERY long hours - they decided to close up and head out "early", locking the gate at 1:50 AM. Leaving was difficult, as the skies were still improving. And sure enough, on the way home Doug spotted several bright Leonids whizzing over his car, including a brilliant fireball just above the MA / CT line at 3 AM. So hopes are high for the shower peak in the predawn hours of Sunday AM!

-Doug Stewart


Leonid Meteor Shower Event

Saturday/Sunday November 17/18 70-100 people. Comet Tempel-Tuttle has an elongated orbited which takes it from just inside the Earth's orbit [T-T = 0.98 AUs; Earth = 1.00 AU] to just outside the orbit of Uranus [T-T = 19.68; Uranus = 19.19 AUs]. Uranus causes a series of perturbations to T-T's orbit. Instead of exactly tracing the same path over and over, T-T takes a series of nearby trails. As the Earth passes through the orbit of the comet, we have a brilliant shower if Earth hits a specific trail or a poor one if Earth misses them. We could predict the showers better if this was all there was to the calculation but outgassing by the comet and the solar wind also have an effect of the particles that become meteors.

This year the predictions were that the northeastern United States would be the target of several trails laid down in the 18th and 19th centuries. Judging by the show on Sunday morning, the prediction was fine.

The sky was clear all night but not exceptionally dark. Coma Bernices, the Beehive, Andromeda, and M35, M6, and M37 were instantly identifiable to the naked eye. I could make out seven of the Pleiades but a few folks said they could see another star as well. We've been having very dry weather and pollution and dust are beginning to cause a very thin haze. All in all, I rate the sky about magnitude 6.0 and on our scale of 0 to 10 about a 6.5 [which is quite good]. Upper level winds had been bad the night before but were quite gentle on this evening which was a good thing with the temperature dropping into the upper 20s. FRom scattered reports across the web, FDO may just have had about the best viewing in the north east. Clouds obscured many parts of northern New England and although Massachussetts and New York had partly cloudy conditions, we were blessed with cloudeless conditions and only a bit of haze.

FDO members have talked about holding an all night event of Saturday and Sunday for quite some time. Here and there people showed modest interest. We expected that between a dozen and a score of people would show up. We came closer to that many arriving per hour. We don't have an exact count but for the first time in memory, people had to park a sizable distance away. The lawn was covered with recliners and beach chairs on the side where the park trees didn't obscure the view. Our best guess is that over seventy people stayed a substantial part of the night with maybe thirty more come and went. In some ways it was more like a party or a pot luck supper with lots of folks bringing goodies. (Many Thanks!) Coffee, tea, and cocoa was availble in the Nature Center. The Nature Center provided a warm area for a number of folks who got chilled by the subfreezing air, along with a snooze area (scarcely used) and facilities.

Most people heeded the warning and brought plenty of blankets, sleeping bags, heavy clothing, jugs of various warm brown beveridges and more mittens, gloves, ear muffs and hats than Bartholomew Cubbins. Some of the beach and lawn chairs had seen better days. A shift of weight brought more than one to an ignominius end to the amusement and "helpful" comments of those in the area.

Useless events of the night included renaming the stars with English terms that reminded one of the Latin or Arabic names. My favorites were "Pasture and Cowlicks", "Pro Siren", "Poles R Us", "Alpha Hydroxy", "Gamma Gobulin", "Bell of Tricks" and "Al&Debbie's Barn". Somehow I doubt the IAU has much reason for concern. And even more bizarre cause for concern had something to do with the adherance of a pan of brownies to a belt buckle. No I won't attempt to explain it. It was funny at the time, but it certainly made no sense.

The actual meteor shower was wonderful. We have no definitive count. No one wanted to be stationed looking at constellations where the action wasn't. And counting action in the constellations around Leo became overwhelming. A not too scientific sampling for several minutes us a figure in excess of 1800 per hour, but it did not include periods before and after which were much less dramatic. My guess is we saw altogether more than two thousand and less than five thousand but I won't back that figure with more than a shrug.

Many of the meteors were large and brilliant. Those who attended the Perseids early in the year where taken by the fact that these meteors were faster moving in appearance and brighter of average. Bright meteors with green/blue tails and yellow/orange globes were not uncommon. At least a dozen long duration meteors left glowing trails which faded very slowly. The longest duration was somewhat over nine minutes. The glow had to be associated with the meteor because there was no moonlight to cause an illumination. One meteor appeared directly in the circle of Leo's sickle. It was headed directly at us and it appeared as a bright dot rather than a streak.

Rather than trying to capture many people's ideas about what happened, we are going to collect every message about our night watching the Leonids and create a spot for them on the website. More about this when we get it up and running.

-Les Coleman

Leslie Coleman
Leslie Coleman
Entry Date:
Nov 16, 2001
Published Under:
Leslie Coleman's Log
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