Wednesday, October 06, 2010

20101005 - Happy Anniversary Team TotL!

fireworks over skyline05 October 2003.

7 years of sidewalk astronomy, observing and sharing the Solar System and well beyond to other galaxies with Team TotL. I've had a wonderful time at the lawn with Charlie, Ben, Tom, Ken, Kin, V, Hawaiian George, Gregory, Debbie & Ben, Andy, Mitch, Carol, TimesUP, Alexander the mathematician, Mark, Hannah, Alberto & Genie, Didier, Stan, Alexandra, and Hugo, to mention a few. Wishing all the TotL'ers a great year, clear skies, and many opportunities to look up.

A timestamp that marks the beginning when TotL began at TPO, on the other end of the lawn.

We are still active, regularly observing from the top of the Great Lawn in Central Park.

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Sunday, May 16, 2010

20100515 - Crescent Moon & Venus over NYC

Session name: 20100515.1900
Location: TotL

Objects observed:
Satellites: ISS, 1 unknown satellite through Bootes
Solar System: Moon, Venus, Mars, Saturn, meteor passing Arcturus
Deep sky: M3, M13, M57, M65*, M66*, M81, M82 (* attempted, not observed)

At sunset looking west over NYC, Venus and the crescent Moon.

Session Details:
Optics: Teleport 10" reflector; magnifications used 32x, 75x, 98x, 181x
Observing party: Peter, Tom, George, 'D'
Visitors: 4 dozen++
Weather: Mostly clear, 1 ¼ day Moon in Taurus, occasional light breeze; high, thin cirrus clouds and faster moving sheets of altostratus; cool comfortable temperature
Seeing: I
Transparency: Good; no Milky Way
NELM: --

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Sunday, May 02, 2010

20100430 - Planets Continue To Please

Session name: 20100430.1900
Location: TotL
Objects observed
Satellites: International Space Station, Iridium 42 Flare, 2 unknown satellites
Solar system: Moon in Sco, Venus in Tau, Mars in Cnc, and Saturn in Vir
Constellations: Gem, Leo, Virgo, Lib, Sco, UMi, UMa, Boo, Com, CrB,
Deep sky: M3, M44, M65*, M66*, NGC 2903*, Melotte 111* ("*" indicates attempted not seen)

[public observing Saturn]
This session began with setting up the scope prior to sunset at the top of the lawn. Screams and cheers for the softball teams filled the air and a few kids played soccer in the midst of reclining people on blankets. Warm temps and clear skies brought people out in numbers.

Within minutes of opening the Teleport, it drew many questions from those nearby and stopped curious persons walking past. Ken strolled up while I setup and Tom C would arrive early, too, and each helped answer questions from the passersby. It wasn't that much longer that we had Venus in the scope and Tom prepared everyone for an 8:02PM passing of the International Space Station. Shortly after sunset in the twilight sky we all observed the ISS, about -2 magnitude, lumbering across a clear sky from southwest to northeast. It was visible for at least 30 - 40 seconds, maybe longer. With Venus setting into the trees to our west, the scope was turned to Saturn, high in our eastern sky. A line formed to see Saturn with two attendant moons trailing close by just off the rings. To finish off the Solar System tour, we pointed out Mars high above our heads. In the scope, many could easily see the reddish-orangy hue and that it was a disk.

Through the eyepiece, Mars appears much smaller than Venus and Saturn. To begin with, it is physically small and our distance from Mars increases as earth travels faster in its orbit around the Sun, its size shrinks and brightness dims in the coming months.

Transparency was only fair even though there was no visible cloud cover. The handle stars of the Little Dipper were very difficult and cores of brighter galaxies were lost on a background sky that didn't offer enough contrast. Open cluster M44 and globular cluster M3 were the only deep sky objects shared with the public.

Saturn captured the most scope time satisfying the many who stopped. In addition to the planets, we observed the brighter constellations without telescope or binoculars. Using the Big Dipper, we starhopped following the familiar jingle, "Arc to Arcturus and spike to Spica". We traced out constellations like Bootes, Leo, and the upper half of Gemini. We noted where invisible Cancer and faint Virgo occupy areas of the sky.

The traffic flow was busiest early in the session and I stopped counting after the first dozen or so people. A steady flow of people continued to stop by the crowd density was much thinner later into the night.

[image of Moon shot with point-n-shoot]
Concluding the session, with the telescope packed, we observed the rising Moon just east of Antares, Scorpio's alpha star. We enjoyed observing with naked eye and monopod-mounted 7x50 binoculars. The honey-colored Moon provided an opportunity to test our visual acuity with hard to see lunar features. W.H Pickering, an American astronomer in early twentieth century, designed a list of 12 lunar features for naked eye observers ordered by increasing difficulty. Though Charlie and I were not following this list, I'd say confidently we reached #9, Sinus Medii. I can't say I saw #11, a dark feature on the Appennine Bench but we could discern the curving line of the Appennine Mountain range.

Observing details
M3. A bright globular cluster in CVn, easily seen in 7x50 handheld bins as a fuzzy object in the base of a long, narrow isoceles triangle; at 75x, distinctly a globular cluster with a bright central nucleus and smooth brighness contour extending out from core, some granularity and mostly unresolved; at 181x, cluster resolves stars along the edge and hovering above the cluster. Used Arcturus for starhopping.

M44, Beehive Cluster, Praesepe. A bright, large, loose open cluster in Cnc., shaped like a Xmas tree or wedge with multiple groupings of nearly equally bright stars, a faint glow of unresolved stars filled in a small area in the NE end of cluster; used Mars for starhopping.

NGC 2903, M65, M66. Attempted but not observed, three galaxies in Leo that have been observed in the past from this location with this scope; found starfields relatively easy but couldn't say with confidence that the galaxies were detected; starhopped from epsilon Leo for NGC 2903, from Chort (theta Leo) for M65/66.

Saturn with four moons. Mostly viewed at 181x; Titan and Rhea on the trailing side, Tethys and Dione, may have glimpsed Enceladus near the ring, on leading side; shadow apparent as narrow black line adjacent to the upper side (field of view) of the ring; shallow ring inclination apparent; graduated darkening/shading from ring to pole on upper hemisphere,most pronounced on the pole; a subtle, broad stripe across the lower hemisphere but not edge to edge.

Mars. Observed at 181x; a small round disk, no phase discerned, fiery, reddish-orange color; could see a croissant-shaped dark patch on face of disk, extending from top right of center across the left and down.

Session Details
Optics: Teleport 10" reflector; magnifications used 32x, 75x, 98x, 181x; Fujinon 7x50
Observing party: Charlie, Ken, Tom, Peter
Visitors: 3 dozen++
Weather: Clear skies, no clouds,16 ½ day Moon in Sco, calm air to light breeze
Seeing: II - III (Antonaldi); atmospheric steadiness good with regular noticeable air turbulence at high magnification
Transparency: Fair; 3-4 stars of Little Dipper
Manhattan Skyline: Broad, diffused light cone spanning from Citigroup Bldg to Times Square; Citigroup Bldg and adjacent bldg hidden from our view, GE Bldg, Times Sqaure worst offenders
NELM: 4.2

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Thursday, April 29, 2010

TotL Observing Schedule

Top of the Lawn (TotL) astronomical observing sessions occur on clear, weekend nights (Fri - Sun) at the Great Lawn in Central Park. Meeting times vary but we try to arrive at or around sunset on the sidewalk at the north end of the Great Lawn. We've been known to stay until park curfew, at least a few hours past sunset unless the weather takes a turn for the bad early. The core group has been pretty consistent showing up over the years though our size waxes and wanes. This affects the number and variety of optics available.

I usually have a telescope setup while others may bring telescopes, tripod-mounted or handheld binoculars - and, we all have a desire to share. We don't hawk views to passersby but those that express an interest or ask, we invite them to the eyepiece and answers their questions. Many of them share stories of their experiences of the stars and planets.

A frequently asked question is how we alert others when we will be out. Currently, we don't. In fact, rarely do we contact each other and it's by chance we meet at TotL. This arrangement has been working for more than 7 years and even familiar, repeat visitors show up to say hello and take in what the season's sky has to offer. If we're not there at least there is a stunning view of New York's skyline and you have a large unencumbered view of the sky from the world's greatest urban park.

I think it's time to put together a notification system using email, google calendar, twitter, or the like. If you are interested send me a note to "tags_p" at yahoo and let me know what could work best for you.

Come out and see us sometime.


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Thursday, February 26, 2009

21-hour Crescent Moon

Session name: 20090225.1730

Attempted a 21-hour crescent Moon from TotL but was clouded out on the western horizon. !! Above our heads, a deep blue sky surrounded us. With respectable altitude pearly white Venus shone brilliantly in our south southwest. Venus was spectacular in the bins, a perfectly shaped smile with that soft gradient evening terminator. Michele from the museum stopped by and shared in the observations.

Wednesday, February 25, 2009

Comet Lulin from Battery Park, NYC

Session name: 20090224.2130

This was my second observation of Comet Lulin using the Tak 22x60 binoculars. An easy starhop from Saturn to xi Leonis (Leo) 5° northwest and finalky landing on 59 Leo** abour a degree and a half west..
A very pale patch light could be seen by the experienced observers about one quarter to a third of a degree northeast of 59 Leo. The comet appeared to be at least 10', maybe as large as 15' in size. I felt something central register on my eye, occurring multiple times I suspected it may have been a steliar nucleus.
Unfortunately many of the others were unable to see Lulin and no wonder. Our observing party was setup directly beneath streetlamps where a blustery cold wind came off the Hudson River. Scope shake and eyepiece glare frustrated many attempts. The low surface brightness was no help. As consolation they were provided a magnificent view of Saturn and 3 moons in John's 6" scope.
After the comet a few diehards, Rich R. and John S., remained to take in some of the brighter open clusters in the immense space above our heads and over New Jersey.

** 59 Leo may ring a bell, it was occulted by the Moon during the 3-4 March 2007 lunar eclipse.

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Sunday, February 22, 2009

C/2007 N3, Comet Lulin observed from Central Park

Session name:20090221.2250

Eyed Comet Lulin for the first time with a pair of tripod-mounted Takahashi 22x60 binoculars from Drip Rock in Central Park. The comet appeared as a very, very faint, featureless blob, however, it had an appreciable dimension. My guess is about 15 ~ 20 minutes of arc, not quite as large as a full Moon, as judged in a 2.1° field of view (FoV). At that size it surface brightness is low resulting in very low contrast with our bright NYC background sky.

The comet was so faint doubt crept in, but repeated observations after moving off and returning to the field of view (FoV) offered the reassurance to call this a positive sighting.

The skies were mostly clear during the half hour observing session. There appeared to be some alto stratus and cirrus clouds, but nothing significant to call disruptive or obstructive. Temps were cool in the 30's (° F) with light to gentle breezes (B2 ~ B3).

The night before I conducted a short session from the same spot and scrutinized this same area. The comet was not observed since it was located nearly 7° further east along the ecliptic. I had the wrong ephemerides for that date, 20090220.2230.

Get a finder chart star for Comet Lulin from and give it shot. If you're a city observer, let me know how well you fared.

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Saturday afternoon at the Great Lawn

Session name: 20090221.1300

Gather round the scopePedestrians approach with curiosity and take in views of crescent Venus through the scope and binoculars. Tom describes why Venus is in crescent phase.

Many are astounded that Venus can be observed with the unaided eye in the day. Where do we look?

Conveniently a plane flies nearby. Serving as a "landmark", we can use this to guide people where to look. In its absence, we described Venus locations in terms of light and dark gradients in the clouds. Can you see the plane flying towards Venus in this wide field (click the image above for larger version)?

Same image as above but cropped Here's another image shortly after the plane passed Venus. Look above the contrail at an 8:45 ~ 9 o'clock direction (to the left) of the plane.

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