Application of Info Index - "2"

Described here is an example of the Info Index. This past Friday night I had a list of galaxies I wanted to search for but it turned out that I only observed one: NGC7331. The illustration below is an image I marked up from the cd-rom set of Real Sky. On the galaxy I overlaid an oval that approximates the size and shape I saw. NGC7331 companion galaxies can be seen below it.


I first hopped off of eta Peg where the galaxy is just under 4.5° to the NNE. In a low power eyepiece of 32x, I was unable to see it. It was assigned a "0" with a sensation in the general area. At 63x and greater powers the galaxy was observed with direct observation, and I settled on 97x for most of the observation to assign a "2".

With a rating of "2" I was able to easily locate the galaxy relative to the starfield and determine its orientation and size. The orientation was north to south with a brightness profile of __^_. The brightest part of the galaxy observed was off center toward the southern side. Using the closer pair of two horizontal stars below, I was able to deduce that the galactic nucleus and core were about 2 arc minutes in length. Its width was a fraction of this, appearing long and slender. The surface brightness of the inner 2.0 arc minutes is 20.2 mag/sq" based on info in Rachford's table (described below).

The three bright galaxies below NGC 7331 were not seen.

I compiled a list of candidate galaxies with a good probability of detection. I am still refining this list to find a suitable cutoff. It has been NGC6946 but this is to be revised, and declination needs to be taken into account. The list is based on the work of Brian Rachford.

I found reference to this from Tony Flanders' Astronomy Site, after reading his abbreviated version of the information within the site in a Sky & Telescope article concerning urban/suburban astronomy and observation reports for Messier objects. A very good article.

Urban Astronomy: Confident Seeing

Extended deep sky objects which are measured in magnitudes per arc second squared, present a challenge in balancing contrast and size in the effort to detect it againsta background sky. When reading an online article on averted vision, I couldn't help but think of how an observer's skills can be associated with their confidence in their abilities.

"... seeing is an acquired ability, perfected through practice, and the more eyepiece time you accumulate, the more acute your eyes become to faint objects and subtle details..."

I appreciate these words from BINOCULAR ASTRONOMY by Craig Crossen and Wil Tirion, in their perfunctory "getting started" section, entitled Observing Techniques, on page 29. To add to this, in a Sky & Telescope column article by Gary Seronik regarding seeing M57 in binoculars he states that the observer must set their expectations of what they will see. With some of this advice, in addition to others, it is true how one's ability to see with increasing degrees of details improves over time. I look back at my logs seeing how the notes from early sessions lack the detail that I record now. Over time, my seeing ability has improved and certain level of confidence that can be found in the vocabulary that I use: sense, detect, observed. Concerning the faint deep sky objects, notably galaxies and bright nebulae, detection is the goal, and observation is icing on top.

So when I discovered the Averted Vision Scale at http://www.eyegasms.com/ it got me wondering about the level of confidence I have when stating that I have detected an object. I don't think my seeing skills have evolved to the point of AV3 or greater in the copied scale below. When talking with friends about detecting an object, we have tried to limit it to a binary function: one sees it or not. Fuzzy logic is hard a fit, and one's confidence in their seeing ability will partially determine if an object was detected. The other, of course, is that the listener/receiver accepts the report as truth and with trust.

AV1 Object is seen with averted vision, however, once found, the object could occasionally be seen with direct vision.

AV2 Object is seen only with averted vision, however, it is held steady.

AV3 Object is only occasionally seen with averted vision as it “comes & goes” with the seeing conditions. In this case the object is seen more than 50% of the time.

AV4 Object is only occasionally seen with averted vision as it “comes & goes” with the seeing conditions. In this case the object is seen less than 50% of the time.

AV5 Object is only glimpsed with averted vision after continuously viewing the field for a few minutes or more.


As a shorthand aid in my logging, I created an Information Index to assign a value to deep sky objects. In a glance it tells me how much information I was able to obtain from the observation. The index assignment is temporal and dependent upon the local, immediate conditions - weather, scope, fitness, etc - when the object was observed. Over time an average can be fit that provides a detection predictability value for our skies. Below is the table for review.

"0" is an attempt with no detection.
"1" is a detection of object, location described relative to starfield.
"2" is an observation location, size, and/or shape.
"3" is an observation location, size, orientation (PA), magnitude, brightness profile and a subjective description.

When reading through it I reflected on my seeing abilities. I consider an object detected at AV1 or AV2. Applying this scale with the Information Index, I confidently report a "1”- detected based on seeing an object with a maximum AV2. I don't think I have neither the experience nor the confidence to state an object's detectabililty of AV3 or greater. I fear that I may be mistaken for "averted imagination" when the desire to detect an object is strong.

One example is NGC6946, a galaxy in Cepheus. This was prior to assigning an info index value. In my notes on a day that I suspected it, there was a remark saying "not certain." One of the principal criteria that I rely on when stating that I see an object is its location relative to the star field. Dimension, size, orientation are attributes that can be described with increasing information. On that day I recall that I sensed, suspected, the object relative to the starfield. It was a very small faint unfocused spot which I sketched in my notebook. Later I would check with software to see if this was the object. As a result, I have stated that I have seen this but upon reflecting I don't think so. If I had used the index, a certain measure of discipline could have played a role in the observation. Its surface brightness value exceeds what I have be an able to detect, and on subsequent attempts they all have been marked as "0".

So for now since we have agreed to say that we "see" or "not see", I rely on poetic license to use the terms sense or suspect to address that fuzzy ground. By noting that, it encourages me to return to an object hoping that one day a "1" will turn up.

20051125 - Riveting Saturn

Session Name: 20051125.1906


Saturn holds a special meaning for me. It is the hour hand counting the time that I began an active observing program. Prior to the fall of 2003, I dabbled with astronomy, the Tele Vue Ranger spending more time in the closet than outside. Some can appreciate this. Then returning from a trip to Japan in the early fall of 2003, I began to go to the park more often. By late fall, I purchased a Takahashi FS102 refractor and it was apparent that I was going out regularly on clear nights. Saturn would become the beat that I count my time exploring the skies.

On 20031014.0030, Saturn was J2000 RA: 6h56m26.82s DE:+22°03'56.5"
On 20051126.0030, Saturn is J2000 RA: 8h55m18.11s DE:+17°55'35.7"

In Starry Night v4.5, a check of the angular separation, reveals a distance of 28° 26'. Almost 30°, that is one twelfth of a full circuit of a 29.6 year sidereal period, the conventional length of a zodiacal sign, is the period of time that I have been observing. When I recently spoke with Andy, the amateur astronomer from Ohio, one afternoon at the Rock, he spoke of how he has seen the rings tilt up and down and up and down, and Jupiter was already during circuits around the zodiac - he has been at it for some time. I want to say 50 years or so from a statement that he made talking about donating a 6" reflector telescope to a local high school, Xavier, and wondering if they still have it.

When first observing Saturn it was between the knees of the twins, and M35 was little more than 10° short hop to the north. On 20040127, I noted that Saturn and NGC2420 were in the same fov, the open cluster on Titan's side. Comet Machholz was seen near the Steeple of Perseus. A few months later, I noted on 20050219, that Saturn was 1° east of Eskimo Nebula, NGC2392; Comet Machholz was a very faint binocular object in Camelopardalis. Recently Saturn has passed the Beehive Cluster, M44, still visible in the same fov of 7x50 binoculars. On a very wet, dew-ridden landscape at Custer Institute in Long Island, Charlie, Kin and I saw Saturn 1° south of M44 in a 2.2° fov. It was the first time, I definitively saw the North Polar Cap poking out from beneath the rings. C/2004 Q2, Comet Machholz now faded into memory, observations left in my notebook, recalling that it was responsible for the move from Turtle Pond Observatory on the south side of the Great Lawn to where we now regularly observe.

So here we are today and Saturn continues to impress. I feel that I have exhausted words to describe seeing it, fail to express its magnificence. Anyone who has seen Saturn in his glory will rightly know what I describe.

At TotL, Saturn needs to rise above 30° altitude to comfortably clear the trees to our east, moving the gear most west provides a lower horizon but the dull, blemished sky doesn't help matters. And this evening, after having packed the scopes up, Saturn did climb as the sky cleared. Around 12:30 with curfew approaching, the Teleport was unpacked, collimated quickly, and pointed on Saturn. A remarkable, welcomed sight.

The views were crisp up to 250x. The following sketch, transcribed from notes, was made at eyepieces producing 140x and 250x. It is a snapshot from a larger notebook, not having a scanner. The color on the disk is a bit overdone with yellow as the disk really appeared a creamy white with a faint peach-colored stripe running across the disk south of its equator. South is up and east is to the left in this drawing. Among the polar cap, the traversing stripe, and the shadow of the planet on the rings, the shape of the planet really stands out. 5 moons were noted, Iapetus escaped detection because we didn't know where to look for it, but well within reach of the TP10's capabilities.

Looking forward to more sights as the winter skies allow Cancer to rise at more reasonable times for us. While I think that time passes quickly, I can simply slow down, remembering that Saturn slumbers along his annual orbit at pace considerably slower than ours, and my hour hand has justed barely started in its path across the zodiacal clockface seen in the night sky.

20051123 - Clear Sky for Sun

Took a quick look out my daughter's bedroom window to see Sun rising in a clear blue sky. Looking through the filter built for the Tak102, I held it up to see that Sunspot 822 has rotated close to the limb. It was apparent without magnification but not as easy as days before.

Using Fujinon 7x50 bins, I held them up to the filter and could see 822 near the upper right limb, and 824 low and central to the disk. In this quick look, I didn't think it was past a central meridian. No detail, like penumbra, was seen at this low magnification.

*********

Last night when browsing the web and blogs, I discovered a new site, Vern's Astronomy Weblog. Some fantastic work there and within his website. After enjoying the amazing photos and information, meander through the "Map Projections" to see some fantastic programming work that benefits the astronomer. The Solar maps section shows what visible on the Sun - earthside & farside. A very cool site in my opinion!

20051120 - Sunday's Sun

Session name: 20051120.1000

This session turned out to be day 4 with Sun. As I told a few of the folks that stopped by, I have been observing changes on Sun. Our star, the one we can see through the veiwing window and through the scope has indeed showed change over the days. I brought only the Tak102 with me to lighten the load. I didn't expect to stay out long nor did I see any value to bring the TVR.

Lotsa folks came through and I don't know if they were New Yorkers or just travelling through. I kind thought that most were tourists, a hunch. Many had stated that this was the first time seeing Sun. Sunspot group 822 was the easiest for most to see and the cyclone-shaped dark umbra continued to be visible as dot on the disk without any magnification. I was somewhat surprised that many noticed the mirror reversal seen through the refractor. Many picked up on this quickly and commented, sort of confirming that they could see the spot through the viewing window.

I didn't attempt to take any pictures today since 2 days resulted in blurry images. So instead I transcribed my notes and sketches to an Alias Sketchpad drawing, as I did in the previous post. I wish I could upload pages from my log directly to the web like Charlie & davep do; it's that "write once, read many" thing.



I felt that the seeing was steadier today, though 91x with the Nagler 9mm eyepeice still required moments of steadiness. The wait didn't seem as long and this seeing would hold for longer periods of time. The sketch above is based on 63x (Nagler 13mm) and 91x. (Venus looked very crisp today and was able to hold up well for 91x).

Sunspot group 824 appeared on the SE limb. It was really foreshortened, most evident by the shape of the penumbra as it hugged the sides of the umbra. The umbra appeared foreshortened as well, and a second umbra was detected below and just outside the penumbra. Faculae was discernable along the area between the sunspots and the limb. For me, the upper part was a loose, script y-shaped and below it was an arc which appeared granualted or spotted, in other words, the faculae was not an evenly bright line, but spotted marks of brightness. Could have been an effect of seeing, though I saw it on more than one occasion.

Sunspot group 822 seems to be losing the faint smaller spots. Is the large umbra/penumbra eating them up or are they short lived? Dunno, some more learning, food for thought. The large umbra is a cool looking cyclone shape, the curving tail twisting up. When seeing was grand, the edge of the umbra appeared uneven, jagged, as it intruded in the penumbra.

Lastly, Sunspot group 823, two days old, now appeared as three spots. The inner one appeared as two the previous session and seems to have merged. The elongated spot could be suffering foreshortening or the joining of the two.

Spaceweather.com's picture for Sunday's sun.

I'm back to work and the weather is overcast - good timing. While Moon has been up in so-so evenings, intruding on some of the deepsky stuff, Sun was fun to watch. I do want to get back to the dark skies in the north of the park . And I hope that some of the folks I met during these day runs will come by to see the sky at night up at Top of the Lawn.

peter

20051119 - Groundhog Day? with Sunspots & Venus

Session name: 20051119.1000
Location: The Rock, Central Park

Eqpt:
:: Televue Ranger (TVR), Obj-70mm, FL-480mm; Thousand Oaks Solar filter
:: Takahashi FS102 (Tak102), Obj-102mm, FL-820; Homemade Baader Film filter

I returned to the Rock for a third day in a row to observe Sun & Venus. If it weren't for the different people who came by and the addition of sunspot group 823, I would have thought it was "Groundhog Day."

Just after setting up the scopes, Andy, an amateur astronomer from Ohio, stopped by. We spoke of scopes, astronomy, dark skies and facilities in New Mexico, mirror making, and how he donated a homemade 6" scope to a local school here in NYC a good time ago. While we were talking a Dad and his son were looking in the scopes. The little guy was able to see all the spots, he went to eyepiece a few times and each time mentioned a new feature he noticed - a very skilled observer. Andy spoke of his observatory and I was thinking along the terms of Megan's outfit.

Alex, the photographer, returned to say hello and look at Sun. He told me how he brought his scope out last night to observe Moon. On another topic, he described how he is working with photographic prints on canvas. I was thinking how cool it would be to have a photo of the Moon on canvas. I can just imagine the texture to the eyes of the rough, cratered south polar region, a dimple of smooth Plato, and the mountains of the Alpes, Caucasus and Appeninus. I think that could be pretty cool.

Later another photographer, Salem, would stop by. I think he may have been running and caught site of the astro setup on the hill. After looking at the different filtered solar images, we talked for a while. I tried to describe how magnificent Orion's Nebula is in the eyepiece. I have yet to see a photograph that can capture the dynamic range that M42 offers. Also, the sheer, visceral experience of the photons hitting the rods and cones has no equal from a photograph. Salem sounds interested in trying a hand at astrophotog, or at least seeing M42, so I told him I'll let him know when I head back to TotL.

I took these two photos with Group 822 & 823 visible. To assist in seeing the smaller spots between the large, central spot and the one to the right, I also included a negative of the shot for a little contrast. Of all the photos, the old adage holds: Garbage In, Garbage Out. My setup is not up to snuff to take those million dollar images. (For anyone interested check out Dirty Skies blog for some pretty good images and Rob's progress with astrophotography.)

On davep's blog, he has a link to his fine sketch of yesterday's group. I don't have scanner so I sketched this up on the tablet in Alias SketchPro. I included some notes. The sketch is based on views through the Tak102 with Plossl 32mm, Nagler 13mm, and Nagler 9mm. Again the seeing was not great, so the 13mm provided better views. The 9mm required waiting for moments of good seeing, so I didn't use it often.

The spot below the second largest spot to the left went undetected until the last looks. I threw the 32mm eyepiece in to focus the scope before looking for Venus. The low power offered nice crisp views, not accentuating the turbulence, and here that spot popped out. While there I swapped in the 13 & 9mm EPs, but the spot was not as obvious. The little stroke to the right of "b"was where I saw 4 small spots yesterday but was unableto detect today.

Sunspot Group 823 , noted with a red comment, appeared as three spots. The upper one was sensed as a double in the 13mm and was resolved with the 9mm. I sketched this before going to spaceweather.com. One can see a photograph of today's Sun at that site.

When Venus cleared the horizon-obstructing trees and buildings, I observed it. It appeared much better than yesterdayand I was able to push the magnifcation to 90x, using the 9mm with the Tak. I took more photos of it again but they do not do justice. Crescent Venus looks like a little moon.

A young couple, Markus & Daniella, had stopped to have some looks. In addition to observing Venus, they observed Sun and spots through the viewing window and both scopes. Perched at the edge of the rock, overlooking the street, we talked for a while about how one can find Venus, why sunspots and what is the best object observed - Saturn!!

So these last three days have been fun at this new location. With 3 days of vacation, which 2 were good weather days, and a Saturday made for pleasant times. I met a lot of new faces, and George's words, a gentleman from yesterday when a small crowd gathered , resonated today: "How can people fight when there are wonderful things like this. " So true. So true.

20051118 - Sunspot 822 & Venus on the Rock

Session name: 20051118.1030
Location: The Rock, a hilltop at the southern end of Central Park.

Equipment:
:: TeleVue Ranger (TVR), Obj-70mm, FL-480mm; Thousand Oaks Solar filter
:: Takahashi FS102 (Tak102), Obj-102mm, FL-820; Homemade Baader Film filter

Today I setup on The Rock again with the TVR and Tak102. Each scope was filtered as noted above. Actually, there were 3 ways to observe; the Tak filter has a viewing window cut out with Baader film. I snapped a few photos while a passerby, Alex, stopped to have some looks through each. Alex also stayed while snapping photos through both scopes and we chatted about different public astronomy events around town. It was difficult to get focus on the small LCD display on the Canon PowerShot S200. The setup is a just a hack job using a piece of black folder plastic cut to the size of the eye relief of a TV Plossl 20mm eyepiece. The camera is held in place by rubber bands. Both scopes and filters performed fine though the Tak photo came out better, maybe because the image is larger at 41x versus 24x in the TVR.


The gear atop of "The Rock". I consider this location off the beaten path yet more than a dozen passersby would come around and have looks through the scopes and viewing window. Almost everyone saw the large spot "naked eye" through the viewing window.

It was cold and breezy under a clear blue sky. The seeing was not good at all. To see fine details, I had to wait for steady air.

Here the viewing window is rotated down for unaided view, i.e. no magnification. The large, dark spot of Sunspot 822 was clearly visible almost central to the solar disk. TVR is pointed at Venus.

Sunspot, Tak102 w/Baader Film. This image appears white and black. I observed mostly at 63x, sometimes at 91x. In the Tak102 I was able to see 18 spots, this includes two small spots detached from the large, dark spot within the penumbra. The smaller, lighter spot with 3 umbra surrounded by a narrow penumbra was toward the east limb. There were four, very small spots the northeast of the central pair of spots. 13 spots plus some "contrast lines" were observed between the two framing large spots. One of the spots that apparently had a tail, occasionally appeared as two spots.

Sunspots, TVR w Thousand Oaks Filter. Despite that I wasn't able to get focus for the snapshot, the image was very good when seeing permitted. Almost all the features that I could see with the Tak were apparent here, except those 4 small spots neear the middle. I was able to clearly resolve the 3 spots in the eastern spot (the blur below the large spot). The diagonal and camera were rotated causing the image to rotate 40° ~ 60° clockwise.

I finished up the afternoon on Venus. I never saw it naked eye but it was easy in handheld bins and the scopes. In the scopes it really suffered from the turbulent air as focus was nearly impossible to get. This photo was taken about 1:00pm.

20051117 - Sunspot 822 & Solar System Objects

Today went out for two sessions: first in the morning for the Sun; later to observe Venus, Mars and Moon. The morning session was atop a rocky hilltop nearby Firefly Garden but further into the park. Observed the Sun with Tak 22 x 60 binoculars and a TV Ranger with Plossl 20mm (24x) and 8mm (60x) eyepieces. The seeing was not the best and a breeze would cause some unsteady views, but when the the view was steady it was a real treat. One prominent umbra with a detached smaller umbra was surrounded entirely by penumbra. The second most prominent spot had a tone about the same as the larger spot's penumbra. At 60x I could see two umbra embedded within this elongated penumbra. 6 small spots, 2 with small tails trailing down, were observed between these two larger ones and one additional one on the following side of the second large spot. These 6 interior spots seemed to be arranged in two groups and I could see a lighter brighter surrounding area in low power but didn't get the same strong impression with the higher power.

SpaceWeather.com has a good picture of what one can see. SpaceWeather.com refers to a photo by Andreas Murner. In this photo what appears brighter between the two spots was what I consider seen between the spots today.

Later in the day went to the promenade in Carl Schurz Park (CSP) and met Charlie. Went here to observe Venus and Mars, and moonrise. Saw Venus naked eye as early as 12:45pm but it was difficult at times later at CSP. The sky is substantially bigger so nearby foreground landmarks are not as plentiful nor were there many useful clouds. Clearly a waning crescent now.

Moonrise was beautiful tonight. I've seen some great fiery sunrises from here before and the (nearly full) moonrise was a gorgeous orange ball rising behind the Triborough Bridge. I preferred the naked eye view or the handheld bins rather than the scope. The seeing is horrible down this low but one could see the cars driving over Moon.

Crater Rebecca

Session Name: 20051111.1500


Each observing session is unique and there is always something that I take away, whether it is an object observed for the first time, seen with a different appreciation, events that occur around me, even happenings with the observing party. Each session has something and today's was a little girl who named her own crater on the nearly 10-day Moon.

Being on the beaten path, my observing allows me to meet many persons. Over the course of the evening, I meet many people, some out-of-towners passing through whom I'll never see again and others whom are familiar welcomed faces. Given that the evenings are dark, I rarely get to see faces, usually remembering people from what they say or how they sound. Sometimes they introduce themselves, yet I try to remember all. However, in the daytime it is quite different. Here I stand face to face in broad daylight with the passersby, explaining how one can do astronomy in the daylight. Again I point to the sky, as today, Sun is setting to the west, Venus is brilliant to the southwest, and Moon is rising in the east.

Daytime observing can be completed in a small amount of time. The sport of finding Moon and/or Venus and observing their phases and observing sunspot activity are completed in less than hour. If Venus presents a real challenge, which it hasn't been these days, then the program can take a bit longer. Otherwise, I am preoccupied with sketching Moon. After completing this, I remain for any interested passers by. In the daytime, I am little more open and invite people to have a look.

I looked at Sun briefly today. Peering through the solar-filtered right barrel of the 22x60 binoculars, I inspected the disk for any signs of sunspots, discovering none. Our star, 150 million kilometers away, seemed at peace radiating light and heat to a cool late terrestrial afternoon.

When the clouds permitted Venus was boldly visible by 3:30pm due celestial South. In the binoculars, Venus clearly is beginning to crescent, a very shallow arc present in center of an apparent last quarter, two pointed horns on the poles. It takes a steady view and crisp focus to detect the intruding sunset past the Venetian last quarter. Over the course of the hours, I noticed how its orientation, referencing the terminator, tipped from vertical (terminator noon to 6:00 if Venus was a clock, to a little forward towards a 12:30/1:00 - 6:30/7:00.) The clouds would eventually cover the skies to the south.

The first spectators to happen by were a young couple asking if they could look at Moon. It was suspended in a patch of clear, blue sky. The young woman asked if I believed in any correlation between us and the phases of Moon. I replied no, and the young man stated that woman is more attuned to them, proposing their monthly cycle as an example. The young lady remarked that she was not having the best of days. They both enjoyed many looks, taking pleasure in observing our neighbor - our nearest celestial sibling. We chatted for a bit while each shared time at the eyepieces. I described some of the major features, particularly how the maria displayed well in this light. I mentioned the fact Moon tips and rocks to show us earthlings features that are present themselves at opportune times. My attention was on the eastern limb, but one could not ignore stately Copernicus just east of the morning terminator, and not enough angle from the Sun to overwhelm its walls and floors with the great rays splashing across the disk. No this was time for the maria and great craters. Sinus Iridum was in the terminator, its arching northwestern rim rising above the black of lunar night, catching the rays of sunlight. Part of its floor was still in the night giving evidence of the Moon's sphericity.

The man asked about a feature "that would be where the forehead is", he even touched his own. I was thinking that he was describing Mare Serenitatis or Mare Tranquilitatis, however, later I would think he was describing Mare Frigoris, a serpentine feature lighter than the other maria, but still evident working its way from just above Sinus Iridum past Plato and arcing slightly up towards the north pole. If this were the feature, he had a good eye in picking up the not so obvious.

As they were leaving, the woman remarked how this made her day and now she was feeling better. The utility of sunlight served her well, even though it was hidden by the trees shortly before sunset, reflecting its warmth and light on an orb 370 kilometers distant. Today the sun's utility enabled me to see the pedestrians, and gain a little more appreciation from our interactions.

When looking naked eye at Moon the previous night, Ben remarked that libration may not be favorable for the east because Mare Crisium looked close to the limb. I didn't observe Moon so I really didn't know. With Ben's remarks still resonating today, I was surprised by the fact that Moon's eastern limb was librated, as noted earlier. Mare Humboldtianum to M. Marginis, M. Smythii, and, I think, M. Australe were all visible along the limb. Looking farther south, Clavius dominated the cratered polar region. Clavius appeared to share the same rim with one of two conspicuous craters below it. As it turns out that crater is Blancanus, Scheiner is the neighboring crater to the west. Both are elliptical shaped, liked two footsteps, from so much foreshortening.
Other features noted were: Mare Anguis just above the much larger M. Crisium; color variation in Sinus Medii, Sinus Aestum, and arts of Mare Insularum and Mare Vaporum, almost a rusty brown; Bullialdus prominent in Mare Nubium below Copernicus, and Aristotle with a ghostly large rim in Mare Imbrium.



I changed locations from the northwestern side of the Great Lawn back to the top. The Moon had risen above the trees and with Venus setting, lost behind the trees, TotL allows a better vantage point. Over the course of the session I met and shared with a number of people including a very attractive pair of women accompanied by two children, a birder, Mark, whom I've met once before with his wife Janice, Blair & Jackie who were walking across the Great Lawn, and many others. Daylight what a wonderful concept. Today, being a holiday and late in the afternoon, there were a lot of children around. Perhaps a dozen would stop as the tripod was collapsed to their height. It stayed like this for a good portion of the session to let them have peeks.

A dad and daughter stopped by. I recognized the dad from another sunset event in the summer, the conjunctions of Mercury, Venus, and Saturn - 22 June 2005. That was the day when the most unpleasant, authoritative maintenance worker radioed to his supervisor: "The situation is under control. The astronomers have complied with my instructions." This father was visibly upset at that time. I don't know if he recalled me nor did mention that I recognized him. Today, both have a look at the Moon - glorious, magnificent - against the sunset blue in the east.

The little girl steps away and taps the barrel of the bins, asking if we can get "some". He asked what and she replied binoculars. Dad shook his head, looking at her then me. When I asked, she told me her name was Rebecca. I suggested something even better that Dad could name a crater for her. He prompted her to look in the eyepieces and look for a smiley face. She stood peering into them, inspecting Moon's surface. She found a candidate, and then promptly named it Crater Rebecca. Hopefully, one day we can turn the pages of Sky & Telescope, or a new Moon atlas, to see which one is named for Rebecca and learn of her contributions to the science that earned her a name on Moon. For the time being, reaching out into space from Central Park, admiring that beauty can come from a rock, inspecting its surface of features, and expressing her fascination is more than enough to earn a named crater on the Moon.

20051107 - M1 & the Milky Way

Session name: 20051107.2000

From our open observatory at the top of the lawn, not all nebulae type have equality. The various bright diffuse nebulae suffer most from our bright sky background which I estimate to be around 19.5 mag/(arc second^2). Having tried for M1, a supernova remnant from 1054, unsuccessfully a number of times with the Tak102 and TP-10, it wasn't on my target list until Ben had mentioned it. I shrugged off the idea to go for it, but since I was in the neighborhood observing NGC1647, what the heck.

Following the classification for nebulae types that Erich Karkoschka outlines in his atlas they are listed by increasing difficulty:
Open Clusters, Globular Clusters, Planetary Nebula, Galaxy, Diffuse Nebula

These bright diffuse nebulae, excluding M42, can be very difficult to detect and observe. Even M43 or M8, the Lagoon Nebula, prove difficult. Even more difficult are supernova remnants (SNR), which Karkoschka classifies as filamentary supernova remnant, the likes of M1, the Crab Nebula and NGC6960/6992, parts of the Cygnus Loop.

Under dark sky I've seen this "pea-sized" object in the same fov with zeta Tau in the Pentax XW 40mm eyepiece; a fov about 2.3° with 32x magnification; however, as expected, it was not to be seen at all. I swapped the EP to a Nagler 17mm, 1.1° with 75x magnification. I was shocked to sense a very large and very, very, faint object in the area. At 75x, the surface brightness was so faint that it barely provided enough contrast to be detected. It best appeared with averted vision and scope shake. Under higher power, the contrast improved considerably, where M1 held up to direct vision, and I sensed a brightening along the following edge (eastern side). Both Ben and Charlie observed it, with Ben stating confidently that he saw it and was just as impressed by the size. I am not certain if Charlie saw it. He described its location properly at 75x, but was not confident he saw it under the higher powers.

We completed the observation by changing focus to a nearby bright star that turned out to be the double STF 742. Information from Cartes du Ciel states the magnitudes as 7.09/7.47 and the separation and position for epoch 2000 at 4.0"/273°.

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Earlier in the evening, we were talking about John Pazmino's sighting of the Milky Way. I brought up again the topic of seeing it with bins or a scope in Cassiopeia. Ben's novae hunting search areas are in the band and he never mentioned seeing or sensing it. We played around in the square of Cas, noticing both NGC225 and, NGC129. The sky was "milky" white, not really granular as it was faintly pixilated across the field.

To contrast what we were seeing in that area, we swept the scope to another area without aid from an atlas to see if we could detect the absence of this brightness. We both agreed on an area northeast of eps Cas where we could almost isolate a border where the sky changed. Ben noticed another cluster and left it in the EP. Another pleasant surprise - he left Trumpler 1, a small open cluster with a conspicuous double, when observed at 75x or higher.

I find it interesting to note that NGC225 is a nearby cluster within our local arm, also called Orion-Cygnus Arm, NGC129 is located in the inter-arm gap between our arm and the next further outlying Perseus Spiral arm. Lastly, Tr1 is situated in the distant Perseus Arm, nearly 11,000 ly away. It turns out that M1 is also within the Perseus Arm, and it is a good head turn away from Cassiopeia. It’s a treat to benefit from the efforts of others who rose to the challenge of discovering the structure of our Galaxy.

20051105 - Accretion from sidewalk astronomy

Session Name: 20051105.1330

Note: Cloud cover passed through resulting in 2 sessions. The first was from 1:30 ~ 2:15pm and the second was 3:40 ~ 7:30pm. Venus was obviously naked eye during the second session.

Accretion- growth by accumulation and adhesion.

Yes, that sounds just right to describe a process that occurs from sidewalk astronomy in Central Park on a Saturday afternoon. Initially one or two passersby stop and ask what's of interest. I point out Moon and Venus in the sky. I ask if they can see them naked eye and invite them to the binocular eyepieces. In spite of the lack of contrast, they marvel at the magnified sight and relief often present on a waxing Moon. Today, one needs to observe with a critical eye just to make out Mare Crisium. I see Venus naked eye and describe her location relative to Moon - about 5 moon lengths at 1 o'clock. Many are able to spot it naked eye and thrilled by the fact that one can see a planet during the day. I adjust the binoculars focused on Venus, on casual glance she is clearly last quarter phase. "It looks like a little moon." "Exactly."

These folks stand around asking questions and share stories of their contact with astronomy. Soon enough another group of people will stop and question what is going on. I pause waiting to hear if one of the prior arrivals shares what’s going on, which they often do. It's the Moon and Venus as they gesture towards the sky. The amateur astronomer can only smile at the fact that the outreach is effective. Soon enough this small mass acquires more energy as it grows, gravitationally attracting others with curiosity and interest. The gravity well is centered on a pair of tripod-mounted binoculars as the center of mass. An observer will even see that among the chaos a hint of order can be recognized. The crowd rotates around the bins in a counterclockwise movement, either to allow someone else to have a look or they orbit to the front of the bins to see the glass.

Globulars, persons who stick but at a distance safely from the center, but remain attracted. They have been around a while, and they, too can describe what is happening in the sky, attracting questioning passersby. The globular’s influence sometimes attracts these interlopers enough to change their direction towards a new center of gravity.

Some persons have a visible outburst at the eyepiece, like a supernova explosion, energy and matter to cause new stars form. The crowd grows larger and larger. There is a lively spirit here on Earth.

Okay enough of that.

One thing I like about the tripod-mounted binoculars is the convenience of the Bogen tripod. Children come by with parents and it is simple enough to readjust to their heights. After the children get to look, the adults have no problem stooping over to get theirs in. Also, with the mutliple shoes, I can swap bins for a 22x magnified image or a 7x wide field view. The wide field helps those that don't see Venus right away but now get an idea of where to look.

Check out Ian Musgrave’s photograph of Saturday’s at Astroblog. His image appears different from our view on Saturday, probably because his is of the setting Moon in the southern hemisphere. We would later watch Moon set into one of the buildings. Fast action, similar to a sunset, but into the building. As it continued to sink, the lower horn appeared partially between two buildings. One of the buildings reflected Moon on the other building, appearing as if we could see Moon through the windows of that second building.

That time of the year...new atlases

This is the time of the year where printed things labeled 2006 begin to appear. My wife is a regular with updating her Zagat guides, and I with my astronomy almanacs. The information within is easily found on the Internet, and can be more accessible than the books. That really doesn't matter for me because I'm the faithful consumer to books and brands that I like:

Guy Ottewell's Astronomical Almanac
RASC Observer's Handbook (OH)

At first glance, it doesn't appear that much changes signifcantly from year to year except the monthly events and empherides. But I find enough nuggets of changes that justify the expense of say an expensive magazine. This annual collecting marks the years of my interest and records events from scribbled notes in the OH. And so is the same for Junko whose Zagats go back much farther.

Meeting up with John Pazmino to pickup my new issue of OH is an event that I look forward to each year. Like last year, we met at the New York Public Library on 5th &42nd. We work not far from one another, so meeting from time to time should not be any inconvenience but so far it has been year to year with these one-on-ones. On these occasions, we sit outside on the chairs and chat of things astro and non-astro. After we part company, I wonder why we don't meet more often since I always leave with a sense of satisfaction and fulfillment. Just a call or email away.

John holds a little celebrity~ism for me. Stock 23, an open cluster in Camelopardalis, is a.k.a. Pazmno's Cluster. It turns out he submitted a letter to Sky & Telescope (March 1978), Scotty Houston's column about finding this cluster. Apparently, Stock 23 was unknown to many so it took a while before (if I remember the story) a man from South America pointed out this object's original catalog name. So John's 'discovery' bagged him a name during this interval. It wasn't long ago where I showed this off to the public and described its significance as named after a New York amateur, It drives home the point that one can see the stars, in more ways than one, in New York City.

20051031 - Touring the bright stuff - Commentary

Session Name: 20051031.1930

Location: TotL, Central Park, NYC
Site Classification: Urban
Date/time: 31 Oct. 2005, 7:30pm ~ 1:15am

Last night I forgot my watch, this evening I forgot my Palm.

I have become so dependent upon my Palm, primarily for PleiadAtlas for starhopping. I realized I forgot it when I went to reach for it after looking at NGC1502, at the bird's foot* of Kemble's Cascade. I wanted to hop to NGC1501 but forgot which side to hop towards. Well no PleiadAtlas, so I stuck to bright familiar objects, Messier objects, that I know how to starhop with relative ease.

Often I feel as if I observe these same objects time and time again, but I quickly remind myself that I have only observed the skies three times at most and I under appreciate the fact that I can locate these objects pretty easily; but I hunger for detecting and observing new objects as well and developing the sense of ease to locate these.. Actually, this is the beginning of my third season with Fall to Winter skies.

Altogether, it was a successful night where I considered my "game" was good in locating the objects.
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Public
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Tonight happened to coincide with the assembly of the Amateur Astronomers Association (AAA) of New York City. It is the official club in this area. None of the team TotL'ers is a members but the AAA knows of our activity in the park. Apparently they have adopted the north side of the Great Lawn to be their observing location after their astronomy class. 10 or more AAA members showed up with two scopes (6" equatorial mounted Newtonian & Tele Vue Pronto) and handheld large bins. My scope, being the largest, became indoctrinated as one available to them. It attracted lines, which quite honestly I wasn't prepared for. I don’t even think anyone announced that Charlie & I are not part of the club and that we happened to be there coincidently.

It was such an awkward position. I am accustomed to treating the public with some views. It’s touch-n-go, as the folks stop take a look, sometimes chat and move on. However, this was an organized event that setup right where I was, and then as the group grew larger over time, the expectation that the 10” was available to them was already established. Even one of the members was offering views through my scope to the others.
There are three things that perturb me: persons asking how much my equipment costs; persons looking down the tube; and, persons inviting people to take a look through my scope. No one was rude, just very crowded. In the moment, I went along by sharing views of the brighter objects. The beginning of the observing session consisted of pointing the Pronto and the Teleport to the same object, providing folks an opportunity to compare-n-contrast the views in small and large optics. Examples of this included: M31/32, M34, M15, and Kemble’s Cascade.

The AAA disembarked from the celestial voyage around 10:30pm, I think, leaving Charlie & I on our own. As they prepared to leave they talked among themselves and said how successful an evening it was! I hope they bring more and bigger equipment than what they came with tonight.

Charlie & I continued to a little past curfew. With a clear night, Mars high in the celestial SW, Saturn rising above the trees to the ENE, and all of Orion cleared of the trees to the ESE, I could have put an all-nighter in. As of late, the cops have been prompt to remind us that the park closes at 1:00am. Tonight, none came by, but the paranoia of that parental reminder persists; enough to have changed my behavior to leave close to curfew. For tonight, at least.

* Charlie's term which describes one end of K.C. where it splits off in two trails.

20051031.1930 - Touring the bright stuff - Observations

Session Name: 20051031.1930

Location: TotL, Central Park, NYC
Site Classification: Urban
Date/time: 31 Oct. 2005, 7:30pm ~ 1:15am

Seeing/Transparency/Darkness: 3/3

Conditions: Clear, moonless night. Some gusty breezes later in the evening, frequent and heavy enough to make the back of my neck cold. Mild temperature. Rockfeller Center building continues with light show that is very annoying and definitely adds brightness to the manhattan south sky. Weather history for 31 Oct. 2005 at wunderground.com


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Equipment
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Teleport 10 reflector, F/5 254mm reflector
Eyepieces
Pentax 40mm :: 72° :: 2.3° :: 32x
Nagler 17mm :: 82°:: 1.1° :: 75x
Nagler 13mm 82° 0.8° 98x 0.8°
Nagler 9mm :: 82° :: 0.6° :: 141x
Nagler 5mm ::82° :: 254x
Tele Vue 1 1/4" Barlow 2x

Objects
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Solar System

- Mars -
Last night and tonight some amazing views of Mars with the 10". I was saying this after using the 4" because I could magnification but the resolution and contrast diminished. From the 2003 opposition, I am a more experienced observer, have a larger scope and the altitude reached has provided some very rewarding views of Mars. I can use mprovement in learning the features.

This night, I observed Mars on 4 separate occasions, watching it rise above our horizon when Syrtis Major was rotating on to the disk. Same as yesterday, the "gully" between Mare Tyrrhenum and Mare Cimmerium was evident central on the disk. Early on it required moments of steady seeing but as Mars rose, seeing it improved considerably. A section of Phaetonius inside of the northeastern limb was visible as a small crescent shape, just as yesterday. Amazonis, on both nights, struck me as a yellowy-orange color - an ochre hue. On subsequent observations, Syrtis Major moved across the face of Mars, faint darker toned wisps like taffy pulled upward towards the South Pole. On both nights, I had a difficult time identifying Hellas. I could only detect it by the contrast to the north where Iapygia wraps it and Mare Serpentis reaches around. The southern side has yet to pop into definition for me. The final observation was when Syrtis Major was central on the disk, Mare Serpentis and a dark toned stretch to Mare Erythraeum on the western limb, the “y” shape more pronounced.

- Saturn -
Yeah!! Saturn is coming back. Last time I saw it was late, late morning just prior to sunrise from Custer. Tonight around 1:00am, it cleared the trees, but was awfully low. It was difficult to get focus on it with 5mm and I quickly swapped to the 9mm. Still Saturn suffered but not enough that I could make out the North Pole peeking out from behind the rings. Titan and Rhea were apparent to the west. Charlie was able to pick out a band of color running across the face.


Stellar & Deep Sky

The list of seen and attempted (*) objects. I enjoyed staying with the low power eyepiece, 32x, for observing open clusters. I swapped to 75x to increase the number of stars and to inspect them for doubles, color, or any other detail that may appear. Only the globular and planetary nebula were observed under high power.

Iota Cas
Milky Way
Messier Catalog: 15, 31, 32, 110*, 34, 35, 36, 37, 38, 42/43*, 45
NGC Catalog: 1023*, 1502, 1907*, 2281, 2392
Asterisms: Cheshire Cat, Kemble's Cascade


- Milky Way -
After Charlie had setup and observed for a while, I asked him to swing his bins into Cassiopeia. Earlier when I was aligning the Rigel finder on alpha Cas with the low power Pentax 40mm EP, I could sense the Milky Way. This is the second evening in a row where I feel confident that I am seeing the Milky Way. The night before, I noticed it when observing the starfield around mu Cep with the handheld bins and tonight it was apparent in the field within the upper "square" [beta-, alpha-, gamma-, kappa Cas] of Cassiopeia. It is unmistakable as soft glow that doesn't resolve but provides a grainy white background that brighter stars emerge from.

- Kemble's Cascade - NGC1502 - NGC1501* -
One of the first objects that everybody turned their optics to was the asterism Kemble's Cascade. In my scope, I can't get a large enough field so one has to meander along its length with two fov's. At the end, one of my most favorite clusters, NGC1502, is perched at the tip of the E end of the "bird's foot". Faint star specks resolve beneath and around the bright double that dominates. The concentration of fainter stars runs along a NW to SE line, cheating towards eastern star of the bright pair.

I wanted to observe NGC1501, but not recalling which way to go relative to the bird's foot, and unable to recall the starfield in low power, I abandoned an attempt to locate this planetary nebula.

- M31 - M32 - M110 -
Mike O'Gara & I observed M31 and spoke of how large Andromeda appeared when we described the extent of its core. The nucleus is nearly stellar and the core has a slight, gradual diminishing 2nd level and then the edge continues on with a faint wispy glow. I would guesstimate that the length was better than a degree and half, maybe two, and the width could easily have been a half a degree or better. In the same fov, M32 contrasts nicely with its brightness profile as it is fairly even across and then ends abruptly after a small diffuse edge. We observed with 32x and, predominantly, 75x magnification.

As usual, I looked for M110, which was not detectable. I follow a trail of mag9 stars on the NE edge of M31 wrapping around to a triangle of mag9 & -10 stars. In the fov, it should be sitting right below them.

- M38 - M36 - M37, 1907* - NGC2281 -
Charlie and I observed these objects at 32x and 75x. We compared contrasted their size, light profiles, range of stellar magnitudes, and described the shapes/patterns we see of or within them. I like M37 with its even glow of mostly equally bright stars. There are a few that shine brighter but this open cluster is dense, rich with stars. In the scope, mostly at low power, M37 retains that nebulous character as opposed to M38 and M36. Both of these are blown into resolution displaying a broad range of stellar magnitudes. Charlie prefers M36. I assume it’s because of its brightness and ease to see in the bins. Tonight I was able to see all 3 with the handheld 7x50 bins. M38 which I normally don't see excited a sensation on my left eye where I was able to describe it, in agreement with Charlie, as an equilateral triangle as described above. M36 is easy and M37 is more difficult, though not as difficult as M38.
Recalling from a recent trip to Custer Institute, NGC1907 was a very conspicuous knot of stars next to M38. Tonight I was looking for it but nothing stood out. Not having the Palm, I had nothing to reference. I looked in the field and notice a clustering of stars further south where the Cat's nose is. What I identified as NGC1907 was incorrect as I looked too far south. It is much closer to M38. Thus, at 75x I was unable to detect and identify it.

While in the neighborhood of Auriga, I happened over to NGC2281. Last night, we observed this in Ben's 10x70 bins, as an obvious cluster embedded on the leg of small triangle. This open cluster is an easy, obvious open cluster to locate. It makes an isosceles with beta- and theta Aur, where I estimated about 7 degrees, four or five bright stars which I was able to make out a 2 degree long right triangle. This points right to 2281.

What was nice about this double Y-shaped cluster was that the diamond, or as Charlie described as a parallelogram, making the stem of the Y were two doubles. One was an equal pair, while the other was a closer unequal pair. The unequal pair had a nice color contrast.

- M35 - NGC2392 -

I starhopped through Gemini consistent with tonight's strategy: Stay with bright and easy to locate objects. M35 easily falls into this category, as it was visible in the handheld bins and easy to place a large fov into the general area of the twins foot and sweep to this large, bright, somewhat loose cluster.

From there, using Erich Karkoschka's atlas, I went to to the planetary nebula, NGC 2392, also called the Eskimo Nebula. This was one of the rare times where I stepped up the magnification and observed a DSO at 141x and 254x. This nebula did not exhibit a strong blinking effect where direct and averted only changed the nebulosity’s size slightly. The nucleus is brilliantly stellar compared to the surrounding nebula. I sensed neither color nor any change in brightness from the nebula.


- M42 - M43* -

One of the last deep sky objects, Charlie and I finished up on was M42. This was a magnificent view, in spite of Orion still rising from out of our horizon. Nice undulations of light and dark rip through this nebula, appearing like billowing clouds. Dark, thick bands impede one very noticeable one in the NNE. Charlie described this very dark band (dust?) as a large "cavity" in this tooth-shaped nebula. Beyond this intruding dark lane, the nebula reappears and extends farther into space. The Trapezium resolved with ease, however, we were unable to resolve cleanly the E & F stars. Perhaps it was because this was still low in the sky, but I think the scope alignment was off at this time. One noticeable artifact was that one of the spider diffraction spikes was doubled. There was even brightness and length among all of these spikes with exception that that one had dimmer, conspicuous partner subtending an angle of say 10° ~ 15° from the center. The scope had been raised and lowered an number times when observing objects low and high, undoubtedly causing the mirror to move around. Nonetheless, M42 was a beautiful sight!

I looked for M43. I consider this nebula as difficult under our city skies. When it is present it is a curled shape tear drop about a star north from M42. I didn't take notice of it tonight and only looked briefly for it, not giving the effort that it normally requires.