top of the lawn
urban footpath | pavement | sidewalk astronomy from Central Park, New York City
Monday, December 25, 2006
Sunday, December 24, 2006
On two different occasions, a group passed by Kin, TP-10, and myself, stopping a few yards down from us. We could hear them talking and looking up. In each group someone pointed straight up and said, "Look. There. It's the Dipper - the Little Dipper." Kin and I exchanged glances. I couldn't hold it and told them it was Pleiades then invited them to have a look in the scope.
Sunday, December 17, 2006
Recently I started taking pictures of the tree limbs silhouetted in the filtered view of the Sun. I found it best to chase the setting Sun by following the disappearing shadows to get the right view.
This day I am scurrying with equipment southward on East Drive. A female jogger approaches, gets eye contact, asks brightly, "Didya get the shot you wanted?"
I didn't yet couldn't help reply to her enthusiasm, "Yeah."
"U bet!" she trumpeted as the distance between us increased.
20061216 - Daytime Venus
Click on image for skyscape of Venus sighting. The marked up image is not entirely accurate because I took a landscape photo prior to observing Venus.
Amid the hustle and bustle of holiday season in New York, I set up on a Manhattan schist outcropping known as Cat Rock. From here time is suspended and my imagination flies. I overlook Wollman Rink, the Dairy is nestled in trees behind me, and an overwhelming feeling, fleetingly, puts me on top of the world, at least the top of some world. This location is ideal because it still relatively close to home and it has the vantage to look over the skyscrapers that obstruct the southern view.
I set out for this session to observe Sun and Moon. With very little contrast I abandoned Moon, observed Sun, and discovered in Planetarium for the Palm that Venus was do-able.
The Sun had apparently moved well west (we all know Earth turned on her axis) by the time I started the look for Venus with an elongation of 13°. At 12:27pm I had the scope set on Sun where it was situated at alt/az = 25°24'/188°35'. Venus was about 1° lower, her alt/az being 25°04'/174°09'. I simply put the single sunspotted solar disk up to the top of the field of view in the Tele Vue Ranger and panned the azimuth about 14° relying in the Bogen 410 geared head mount's axis markings, they're in 15° increments. Real easy when Venus showed up clearly as a disk at its appointed location. Currently it is 10.2" in angular size, where my field log notes that she is obviously bigger than the Jovian satellites.
During the observation period some high thin clouds would pass through. Actually seeing was not good at all with boiling on the limb of Sun and Venus dancing slightly under high magnification. I was never able to make out Venus naked eye - even with some effort - in spite of looking very bright in the eyepiece.
What other times had I observed Venus?
Ian of Astroblog also reports on his Venus sighting from other side of the world. Last year he provided us a nice photo montage of Venus showing the phases over time.
Sunday, December 10, 2006
sometimes the stars are on the ground
Session name: 20061209.2000
I was on the fence about observing at TotL after speaking with Charlie. He described a few celestial events that were happening and he was weighing in on doing the planetary conjunction visible in the morning. A deepening dark, clear, blue sky was too inviting for me. I decided to head up to TotL.
It wasn't as cold as previous nights and it was apparently clear. As I was setting up the scope, Jerome, the young Frenchman, arrived. We talked for a while about cameras, photography, friends, and family while the arduous task of unpacking and assembling scope was going on. As we chatted clouds came in from the west like cotton threads that fray from worn blue jeans. Nothing to worry about.
Mark the Literary Agent arrived on rollerblades. On his approach he slowed down performed a small twist and stopped right at the eyepiece. He looked in asking, "What are we looking at?" We were looking the 5th open cluster since we arived. Earlier, Jerome had pointed out the Pleiades using Aldebaran and Hyades for the start of a short naked eye starhop.
For those who will allow, I like to offer a tour of different open clusters each which exhibit their unique qualities. I could describe them in terms of the Trumpler classification but instead I show-n-tell using words like sparse, loose, concentrated, embedded, colorful, bright, stardust, etc to describe each. A limited, simple vocabulary that reinforces the observation in the eyepiece. (Trumpler developed his classification while studying open clusters from photographic plates.) I place the clusters in context saying how they are found in the spiral arms of galaxies. Open clusters express youth. I complete the lesson by extending my arm from not quite overhead in the northwestern sky, tracing an arc from Cassiopeia down to Auriga in the northeast and describe where the Milky Way would be.
After the naked eye views Jerome and I turned the scope with a low power eyepiece on the Muscleman Cluster, then the Double Cluster on to M38 in the cheek of the asterism we call the Cheshire Cat. This was the cluster that Mark was greeted by. He commented that it was a little cloudy. Cloud cover was gradually increasing its reach with less "wispi-ness" but it hadn't reached entirely to the east.
I scrutinized the area around where a nose could go on the Cheshire Cat. This is where NGC1907 could be. I was encouraged that I could see a knot of stars in that area but don't believe it was the cluster. I don't recall ever having seen this one. Lastly since I was there I popped on over to M36. It's funny that I don't stop at M37 more frequently, which I didn't last night. It's my favorite of the trio but for reason I consider the hop not as easy - which is truly not the case. It is a very easy hop where all 3 having separations of 2° & 3° can be seen easily within the binoculars 7.5° field of view. Just a mental block I haven't discarded.
All the while, Mark and Jerome spoke of the best beer in France, crossing borders into Belgium. I've come to learn that Stella Artois is not the best beer though it's so common in the brasseries and bistros around here - I guess like Budweiser, popular but I wouldn't keep it in the fridge.
Afterwards I looked onto M35 to see if all was all right in Castor's toe. Tonight this cluster has a terrific charm. Much different than the other clusters observed so far this one has a good range of bright to dim stars down to twinkling stellar dust. It is also good size and obvious in the low power; higher power dials down the twinkling with better resolution. And Mark discovered focus on the scope. He saw it cloudy again and showing him how to "operate" the scope, he focused it. "Wow! I can see clearly now the rain is gone."
Twice in the session guy from Maine would come by. On his first visit we invited him to looks of M42 and the Trapezium. We talked of the how these objects are like the visible scab of a huge molecular gas cloud that we can't see. Pointing out Orion's sword it was obvious the clouds were covering more area and thickening. The temperature was dropping.
Carol & Dog E came by with a large group of other dogowners. There may have been half a dozen people with dogs whose names included Taxi, Brooklyn, and Highway. Most had peeks through the telescope. Carol & Dog E do laps around the Lawn,
For a short while I was on my own. I moved the scope west to get a better shot at the rising moon. The sky was pretty much overcast and the waning gibbous was completely shrouded in the clouds. An indistinct bright glow disclosed its location. Before packing up I wanted to see how bad it was. Another group of people passed by asking what's to see with all the clouds. I spoke of earlier with all people, clearer skies, and some of the objects that cast their light into our eyes. Perhaps that inspired "Ev" because in spite of the clouds she walked up to the scope that was pointing the direction of Moon. Not tonight. At least, not now.
I could make Saturn directly below Moon, hovering above the tree line. I pointed the scope, swapped eyepieces, to offer Ev a look. Too much cloud. I could make out the form but I don't think she was able to. Her friends called and off the group went.
The night was finished. I began to pack my gear when dog pack Andy & Masha arrived. While talking of the Central Park people Masha would have a playful episode with another dog. I was also looking for my eyepiece cover. (Those things are like socks, go missing very easily.) The guy form Maine would pass a second time, looking up to the sky and then back to us. Words were not necessary. Hugo would pass by on his regular late night walk across the park. He stopped and we had some laughs about the Astronomy Seminar a few days prior. Later, on walking out with Andy, Masha would find it which I rewarded her with a pet under the chin.
I realize I have a wonderful place with stellar friends and acquaintances from the park. I thank my lucky star that I have such a stellar time at TotL.
sometimes the star is nearby
Session name: 20061210.1400
a couple of acts: Creating silhouettes
Final Act: Just before the curtain close.
Friday, December 08, 2006
Lately I schlep my pc around ready to show photos of moon shots to anyone who has astrophotography experience. I am hungry for some tips wanting the wisdom of a someone who can make these look like Sky-n-Telescope material. Everyone seems to be saying that post-processing can fix most things. Like most things, I am a believer of GIGO: Garbage In, Garbage Out. But hey! I'm open if any one can help with some of my garbage and make it gold.
Recently I found someone who says they have been videotaping the Moon for years. They can help me out. I fire up the computer ready to show some of the shots. While the computer boots, he mentions that he has been recording these black spots that surround the maria. He considers these to be holes and they show themselves only when it is a Full Moon. I tell him that I have seen black spots pepper the terrae south of Oceanum Procellarum. He nods but continues saying how light travel straight down and caught in the hole, but on waxing or waning the Sun delivers light oblique to the axis of the hole.
"Didn't the astronauts visit areas near the edge of maria?", I ask.
"Yeah, but they can't tell us everything." I didn't think twice about this.
The computer finally boots and shortly afterward I begin to show him my shots. He's impressed. He says work with brightness, contrast, and gamma to get the levels right. He mentions a program I've never heard of. He suggests sending him a couple so he can do his magic.
"Hey, ya know I can get these published for you in a UFO magazine."
"Errrr. No thanks."
17 day 4 hour moon from the Statues
Session name: 20061207.2200
This session was a cold one.
After the seminar, I returned home under a bright, clear moonlit sky. I decided to have a quick photo and observing session nearby at the Statues. Not thinking it was so bad weather-wise I didn't bundle up. I even asked the wife if it was cold and she replied, "You just came in..." Arissa said it was cold. I could have heeded advice from that statement. Not.
This time I set up on the western side of the park entrance at the Statues. Instead of that nasty smel on the eastern side, I could smell funny cigarettes burning - ya know "mary jane". It was on more than one occasion I smelled it but never figured out from where it came. To get a clear shot of Moon over the treetops I set up right on the curb of the sidewalk. Funny enough not many persons stopped by mainly because there was not that much pedestrian traffic.
Altogether there may have been half dozen that stopped by. One young guy, Anthony, stopped by just after two English tourists took interest in the photo setup. Thinking that they would like to look through the eyepiece I removed and replaced the camera with both low and medium power eyepieces. I think they all gotta kick out of it. While there a drunk guy left his nearby party to deliver the punchline: "Do you see Uranus?". And if that wasn't enough, his drunk friend, shouted from a distance with the more original: "Do you see Uranus?" Let's have a drumroll and cymbal crash, please. After that a few individuals and a couple of couples would stop by.
Seeing was not good causing boiling along the moon's limb and the wind caused some shake. The boiling along the limb can be seen in the photo as a soft edge. Regardless, Moon was fantastic and I continue to be impressed by what the hobbyist/amateur can accomplish these days. Even the few pedestrians that stopped remarked about how incredible the moon looked in the tiny lcd.
The photo below is a mosiac of three photos showing most of the 17 day 4 hour waning gibbous moon - it's obvious. I fooled with levels to get the midtones to agree with the upper right photo where the terminator crosses into Moon's southeast quadrant.It is also a lesson in field rotation. Since my equatorial mount was not exactly aligned a small error from north is introduced. This becomes very evident when try to overlap features in GIMP.
Crater Tycho is one the youngest craters, the evidence radiates from the
crater extending across the lunar disk as ejecta material from the impact. If there were younger craters of the magnitude they would have covered the ejecta material. The material closest to the crater rim is material from deep within and the ejecta to the far reaches was closer to the surface.
The other large ray crater Copernicus is seen on the edge of the top and right panel. Its diameter spans 58 miles with a rim that betters a half of mile. When its near the terminator the ray system is less pronounced and one can see the multiple peaks, which rise as high as 3/4 of a mile, and slumping walls more clearly. Ray crater Kepler is the smallest of these three landmarks seen
The second photo below is not a nice, sharp photo at all. But it doesn't lack in information and it validates the notes and sketches I recorded in my log book. What attracted my attention were the ridges that ran concentric with the outer wall. In the eyepiece, I could see the shadow which revealed the dorsae presence. The shadows shows softly above the larger crater on Mare Crisium's floor. The shadow cast by Dorsum Termier was almost as strong as that cast by Rupes Recta. The larger crater on the mare floor (on the left edge of the photo) is Picard (23km) and to the right are two smaller ones: Peirce (18.5km) and Swift (11km). It was much more clear looking through the eyepiece than what the camera shows. To the north Dorsum Oppel is seen just outside of the twin, smaller craters mentioned above.
The capes of Lavinum and Olivium open the western rim allowing sunlight to continue pouring in. As night falls across Crisium features on the floor becoming increasingly more evident with dramatic, sharp shadows cutting in from the west.
Crater Cleomedes has fallen over the horizon into darkness, only its central peak strains to catch photons from the Sun.
in the seat: new york astronomy seminar
Session name: 20061207.1900
This Thursday evening I attended a NYSkies Astronomy Seminar with Kin where three presenters spoke on various topics. First was Dr. Alfred Bennun, retired professor of Biochemistry of Rutgers University. Dr. Bennun, visiting from Argentina, began a talk about a process which could describe the continuum from the Planck energy limit to today's Cosmic Microwave Background. John Pazmino delivered a presentation about the "Wedge of Light", a design element of the new World Trade Center. During memorial hours between 8:46 am to 10:29am EDT on every 11 Sept, the Sun is supposed to illuminate an area of this campus. John discussed the local horizon and buildingscape of the surrounding area and showed celestial maps illustrating the Sun's altitude and azimuth at the bookmarked timestamps. Finally, Claudio Velez provided an informal description of his recent work at Kitt Peak, where he was collecting data for light curves of various stars, and descriptions of cataclysmic variables.
I met some familiar faces from last meeting as well as saw many more. The turnout of 17 persons doubled the size of the last one. Typically I'm not one for meetings but this is informal with good spirit and good pacing. I'm sure I'll attend again.
Wednesday, December 06, 2006
Coronas, Haloes, Moon and Saturn
Session name: 20061205.2015
In the sky, this session was a repeat of Saturday night though the persons and activities around the scope were very different. On both nights nearly Full Moons dominated the sky. Both nights clouds came and a huge 22° radius halo circumscribed the Moon. Saturday's was fainter and incomplete from the 1 ~ 4 o'clock section. I thought I might have seen a disconnected arc bowing in a direction away from the halo. This observing session's included a corona was apparent tight up surrounding the orb. It exhibited a straw yellowish color which was ringed with a purplish fringe. Charlie mentioned seeing, I think, as many as 5 concentric rings.
I' ve come to learn that halos are formed by light passing through ice crystals and coronae differ by light passing through water droplets and being refracted.
Field measurements were performed with extended thumb & pinky held at arm's length. The measurement could be approximated by the separation of some stars and Moon. About 8:10pm on Saturday, Algol was on the northeastern perimeter. Whereas this session's halo hosted a other bright, familiar stars just inside its rim: Betelgeuse and Bellatrix in the southwest and Castor and Pollux to the east southeast.
I arrived at Turtle Pond Observatory (TPO), having told the others that this is where I was going to observe. TPO has the advantage of a lower horizon to the northeast and east, and I wanted an early start on Saturn. But when I arrived the three street lamps on the liitle cul de sac are overwhelming. It didn't take long after looking northerly to see that TotL is substantially darker. There was a time when we put towels on the lamp - and this session I ensured I had Bulldog clips - but tonight I chose not to. Instead I walked the equivalent of 5 city blocks to the north end of the Great Lawn.
And on both evenings broke the park curfew observing Saturn rise in the east, unbothered by any patrols. The police did come by and waved to us on Saturday but this observing session, Charlie and I didn't see many people after the 7-dogs and their owners had visited. In addition to the normal features observed: rings, equatorial bands, polar caps, shadow, and division; there is one that I haven't made peace with. On the northern face of the planet, Saturn's rings cross the disk. A dark edge, which I assume to be the C-ring, contrasts with the planet's creamy white "surface". On the outer edge (more northerly) the ring casts another dark line, at least I am guessing it is the ring. Can't figure out why that would be dark, I don't think it to be shadow - particularly comparing to how the planet's orb casts its shadow on the rings.
Charlie arrived when I was completing snapping Moon. We would spend a good amount of time concentrating on the evening terminator of the waning 15d3h Moon, especially along the southeast. There was one crater, Boussingault, that we observed for a bit of time. At the time of observation we didn't identify it and incorrectly I assumed we were looking nearby Schickard. Charlie pointed out the two-toned floor crater in the southwestern quadrant, in addition to the nearby crater Schiller.
Back at Boussingagult, he crater exhibited an obvious interior concentric ring, a bit off center. I considered this a feature of heavily terraced walls, walls that slumped and there were pockmarks, or a string of craterlets, on the southern edge of this slumped wall. On the northern side, a craterlet in the rim was observed pretty easily.
The following picture shows the southeastern quadrant we were looking at.
We also cruised along the northeastern quadrant where the terminator provided more fascinating views. Most of the passersby who stopped and had some looks commented mostly about these obvious features. It was pretty hard not to notice crater Humboldt with its central peak and crater walls still catching light, but ready to fall in the precipice of darkness.
Maps of Moon available through LPI
Images of crater Boussingault from Digital Lunar Orbiter Photographic Atlas
Monday, December 04, 2006
leisurely pace on updating
This past weekend had a long session at Turtle Pond Observatory, better known as TPO. Observed the Moon with at least two dozen people and had some time shooting it. A young Frenchman, Jerome, spent some time observing the people and chatting. He was carrying a camera bag and I had hoped he'd offer tips but a hobby for him. Turns out some of the pics came out okay.
I went to Adorama on Sunday for the Celestron event (got another hat!) and to see Mike & Peter. It was great because there were many familiar people including team TotL, feeling as if we assembled for a meeting. Great interaction and got a demo of the Celestron SkyScout and their new hybrid spotting scope/camera, VistaPix IS70.
I've yet to to report on the weekend observations, predominantly Moon and Saturn. Very favorable libration tipped the eastern seaboard into view and the section of Moon along the terminator from craters Bailly to Shickard was fantastic.