Tuesday, August 21, 2007

many moons ago ... and recently

Click image for larger marked up version.

Came across a lunar photo taken by astromick "moon earlier this month" (displayed to the left). When I saw it , it struck a nerve. Looked familiar. It did because it resembles the same image on my desktop photo. My photo was originally posted in the "Team TotL Assembles" posted back in November of 2006.

Overlooking the differences in quality, one can recognize and compare distinctive landmarks along the terminator, from north to south: crater Bürg in the center of Lacus Mortis, east of Aristoteles/Eudoxus pair with smaller craters Plana & Mason on the shore of the lake; Posidonius on the eastern shore of Mare Serenitatis, Fracastorius on the southern edge of Altai Scarp and Piccolomini a little bit south.

If one looks at the western limb past crater Grimaldi, one sees on astromick's image that libration is more favorable for Mare Orientale. Those little dark squiggles with mare colored floors are two lakes, Lacus Autumni & Veris, I look for when trying to locate and identify Mare Orientale.

Moving north along the western limb, Oceanus Procellarum shows more area as it is rocked in. Sinus Roris and Mare Frigoris appear farther from the limb. The triangle created with Aristarchus, Copernicus, and Kepler also appears rocked in farther from the limb.

image credit: astromick "moon earlier this month"
image credit: tags "Team TotL Assembles"


Saturday, August 18, 2007

20070818 - Venus from Drip Rock

Session name:20070818.1020

Last night, I was worried that air traffic controllers wouldn't let the plane land that carried my wife and daughter. It was storming pretty hard with heavy rain, darkened skies, and lightening bolts scrawled across the sky. In due time it did land and that brief, torrential storm was the remedy for hazy and overcast skies we had for the last couple days.

I awoke this morning seeing cerulean blue in the opening of the window shades. I opened the living room window to see the New Jersey horizon crystal clear. It wouldn't be long after breakfast that I announced to the wife that I'd be going to the park for about an hour. Venus was on mind but a feeling of guilt passed since they just returned. It was only to be an hour.

As I approached Drip Rock, I counted 10 homeless men around the lawn and on the rock. I ascended the rock and setup nearby a homeless man with an umbrella that shielded the sunlight. Within minutes I had the Thousand Oaks filter on one barrel of the Takahashi bins pointing at the Sun. I saw nothing on the Sun. Instead I used the sun to calibrate the scale on the Bogen 410 geared tripod head. I intended to find Venus relying in this as I have had with great success in the past.

(shot of crescent Venus on spaceweather.com)
Venus is magnitude 4.0, 1.0% illuminated, 58.4" in size, and 8°07' west of the Sun. This is pretty close to the Sun and out in the field, Venus was about 3.5° below the Sun and a little more than 10° to the right fo the Sun.

To find Venus in the field of view, I first located the Sun in the solar-filtered tube (the other tube was covered with the lens cap). Placing the Sun outside the edge of the field of view where it would drift in, I marked the 15°-incremented scale on the altitude gear. Moving the Sun diametrically across the field of view, I marked this point on the scale, now have an idea of what a 2° step looks on the scale. From here on it was a breeze. I twisted the altitude gear for about 3.5° lower and panned in azimuth towards the south. I removed the solar filter and the lens covers from the objectives. Carefully approaching the eyepieces so as not to be caught by any glaring reflections, I got my eyes right in to the field. Seeing nothing I retreated the bins back up the sky where a large, bright, crescent Venus was just off the field of view. What a pleasing view. The crescent was tipped in a 1:30 ~ 7:30 orientation in my field of view.

Observing through a slot on the binocular tripod adapter I was able to shield the Sun and look at a very narrow piece of the sky. Coincidentally, some cumulus clouds passed which allowed me to pick a specific spot on the sky through the slot and detect Venus naked eye. I did it twice but after the clouds passed I was unable to duplicate the naked eye sighting. I even looked down the edge of the barrel with the greater part of the bins shielding the Sun but with no luck. In both of these cases, the clear blue sky yielded no glare.

A couple of women from BRC homeless outreach approached and spoke with the man near me. They asked him if everything was okay. He removed the umbrella and sat up, squinting his eyes in the sun. I kept my back to them so the homeless man would think I was minding my own business. As they left him, they looked my way. When I responded to the womens' question that I was observing Venus, he echoed, "He's looking at planets." It sounded more like a statement than a question. I invited all to the eyepiece where the acknowledged seeing the crescent. The tempered excitement made me think this was their first time looking at a planet, especially Venus in the daytime.

Afterward, I finished my notes and packed up. Gerard, I overheard the homeless man's name, looked up from the beneath the umbrella he had returned to and said good bye. I responded with the astronomer's farewell, "Keep looking up."

Gerard had the last words. "Thank you."

Tuesday, August 14, 2007

20070813 - Globular Clusters were stunning

Session name: 20070813.2120

Coming off a long and rewarding experience with the previous Saturday/Sunday session and knowing from the forecast that the week ahead was not looking good, I decided to observe this Monday evening again with the Teleport 10" reflector. I sent Charlie email but received no reply. Shortly after I arrived Charlie showed up with bins and tripod. As we setup in the usual spot, we chatted about good Saturday was and looked forwad to the night ahead.

Tonight the seeing was phenomenal! For a summer sky - or any season sky - this was a clear, steady, transparent night. Never having assigned a perfect rating for Seeing or Transparency, this was as good as it gets. I was looking at Jupiter with exceptional clarity.

I was a little confused (and still am) at what I saw. In recent observations with the Tak refractor (north up, mirror reversed), I've called the dark thick band easily observed the Northern Equatorial Belt (NEB). I have been unable to the see the Southern Equatorial Belt nor the Great (pale) Red Spot because of poor seeing conditions. This session Charlie and I could see the prominent NEB and three partial belts on the southern hemispere. Parts of the SEB as well as the Southern Tropical Belt, Southern Temperate Belt, the Southern Polar Hood and the interleaving zones were all seen clearly. On the northern hemisphere, the NEB and the Northern Polar region were the two remarkable features. However, when I looked at the marked up photograph of Jupiter in Peterson Field Guide Stars and Planets, it appears that the northern hemisphere belts are more contrasty and dark, whereas the south is pale and subdued. In the 10" reflector, north should be on the bottom, thus leaving me an impression from Peterson's that contradicts notes and memory. Maybe I got it all wrong in my notebook so I'll wait for another evening.

The ecliptic and Jupiter are low in the southern sky. The Dob felt as if it was horizntal and being too close it was looking through the fence surrounding the lawn. I moved the scope across the sidewalk and Charlie asked if I was setting up there. It was temporary for Jupiter and the scope would go back to the normal side. While Charlie and I were observing Jupiter in the scope two dog owners and their dogs came up. Unleashed the dogs began to play in our area and close to Charlie's gear. The dogs began rough housing and one, maybe both, knocked Charlie's tripod. One owner tried to reach for the tripod but missed sending his bins to the ground. Charlie quickly recovered the bins and setup thre tripod but the bins turned out to be damaged. No broken glass, but scratches on the housing an dthe optics were totaly out of alignment. What a shame!

If it wasn't for the magnificent views of the globular clusters it could have been a downer all evening long. Remarkably, Charlie didn't lose much spirit (or he didn't show it) and we continued to observe into the wee hours like last session leaving at 3:30AM.

M57 in the 10" is unlike looking through the 4" refractor or taking the challenge of find it in 50mm - 60mm optics. The Ring Nebula is that bright, fanciful smoke ring that all could see clearly, even the pedestrians. While in Lyra, we observed epsilon Lyr, the Double Double but slightly disagreed on the resolution. This pair is bright for a 10" reflector and the glare from the stars can be a nusance. Charlie saw pinching and tangentailly touching pairs; I saw each double fully resolved in the same orientation as he. Afterwards, pushed the scope to Albireo, Beta Cyg, the beautiful golden yellow and blue pair. Nudging the scope towards Sulafat, gamma Lyr, found M56 in short order. M56 is a faint globular cluster where maybe 3 stars resolved above a fiant, pale glow.

A couple passed by and stopped. The young woman told us how her father builds research-grade telescopes for a living and that she has had many experiences looking through scopes and visiting observatories. I don't think her male friend has the least bit of experience. She agreed that M56 was a faint fuzzy and he struggled to find it. For his benefit, I swung the scope to M13 (photo at Atsromick), the Great Hercules Globular Cluster, where he could observe another of its kind. With a faint, consistent glow, stars were popping out. This globular was 3-D. At Charlie's suggestion, we threw M92 in the eyepiece. Wow!! that globular cluster, though smaller, was much brighter and exhibited more detail and variation in its brightness profile than M13. Like M13 this globular resolved beautifully like a fireworks cluster halted in time. Diamond chips on to top of diamond chips.

Sagittarius was directly south for us, that is seeting in the celestial southwest sky. Typically, I stop on M22 but this session I stopped on M28 since we were doing the globulars. This was nondescript, a challenge to the discerning eye but not worthwhile like the previous ones. Pushed teh scope up higher in the sky to locate M24 but found it to be a large sparse scattering of some bright stars. I've never gotten a view of this star cloud that I could appreciate.

With the Fall sky rising and the Perseids still around, I decided to look manhattan-north, the area of the sky we call The Corridor. This section of sky falls roughly between celestial North and East and is the darkest part of sky line. This is where Charlie and I have seen 12 ~ 13 stars of Pleiades and on good nights a NELM of ~5.2 without a hint of the Milky Way (that is naked eye, in optics is another story.)

Monday, August 13, 2007

20070811 - 10" into the Fall sky

Session name: 20070811.1920

Arriving at TotL before sunset with the Teleport 10" reflector is a sure way to gather a crowd. A congregation grows gradually while I leave the scope to acclimate to the outside temperature. People stop and wonder. The silvery, reflective cover that's velcroed to the side draws comments from cold beer to hot pizza. Soon enough even before it's dark a crowd of people assemble in a line to see Jupiter and his four moons. Omega Ophiuchi sits closeby as a fooler. The pedestrian traffic remained pretty steady until midnight as I watched the summer sky travel across the Manhattan skyline carrying Jupiter along with it.

Seeing was poor. Jupiter appeared as if it's on the bottom of the brook. Yet, a semi-regular and one of the only females, Nedia and myself witnessed Io ingress onto the jovian disk. We would lose it as it left the interior of the limb. My experience with observing ingresses and egresses is that the satellites' sun-facing side is much brighter than the jovian limb. Later with another couple, we watched the shadow ingress on the jovian disk around a 6 o'clock position in our field of view.

My original plan was to mimic Charlie's session from last week where he covered a lot of ground in summer constellations, Scorpio and Ophiuchus. But the steady traffic prevented me from locating and showing these objects. Showing fainter, more challenging objects in the city sky would be casting pearls before the swine. Observing DSOs in an urban sky is an acquired taste.

It feels as if a long time passed since I've observed deep sky objects. Usually equipped an equatorial-mounted Takahashi refractor I stay inside the solar system, especially with hazy, humid skies and short summer evenings. However, the weather forecast was positive and I decided on bringing out the 10" reflector.

I think this may have been the first time seeing M57 this year. It was so "bright" (in urban terms) that most could clearly see the smoke ring. M57, Jupiter and M31 (NGC224)/M32 (NGC221) were the three bright objects I showed to the public. For some, I showed M39 (NGC7092) and M29 (NGC6913) but these are not so spectacular; yet, it provided an opportunity to diversify the type of objects on display.

Charlie would arrive around midnight and the pedestrian traffic had thinned out. The Fall sky had risen appreciably in a clear dark "Corridor" to the north - northeast. Using 10" of glass, we looked outside of the solar system to outer reaches of our galaxy, and occasionally looking at others.

My observing began in earnest around this time. Details of observations in my logbook begin at this time starting with Caroline's Cluster, NGC7789. It's no wonder that this object is difficult in the 4" refractor. It appears mostly as a soft unresolved glow of stardust. The 10" glass improves the observation by showing a bed of fainter stars beneath strings of brighter stars that crisscross like diagonal of a rectangle. The stardust is more concentrated to the south. While in Cassiopeia, I dropped in on M52 (NGC7654). Usually, I drop the scope right on top of this cluster but rusty muscle memory made for a few unsuccessful attempts. Persistence and PleiadAtlas succeeded by finding one of the prettier clusters in the sky. Charlie and I commented about three levels of stellar brightness.

Similar to M110 (NGC205), the light of NGC6946, a galaxy in Cygnus, is too feeble to stimulate the rods of the eye distinct from the background sky. Only 39 arc minutes away, open cluster NGC6939 sits within the boundary of Cepheus and is more revealing to the eye. In medium powers it is still faint with 8 ~12 stars resolving.

Other open clusters we would observe through the night included NGC752, M34 (NGC1039), and NGC1528. These open clusters ranged from large, bright and sparse to fine, dusty and challenging. NGC1528 is located just off the Fish Hook, an asterism in Perseus. We use the Fish Hook as a test of naked eye limiting magnitude and sky transparency.

The usual route to the asterism Kemble's Cascade which hosts NGC1502, a pretty, little open cluster at the bird's foot, is to starhop from the Steeple of Perseus past a naked eye pair magnitude ~4.2+ stars. As I am looking in the eyepiece during this pan I search for the bright trail of stars. On this session, I stumbled upon Pazmino's Cluster (Stock23). This cluster reminds a little of M29 but much larger and just as bright. I'm struck with the same impression of an open box.

After observing Kemble's and the cluster, the last object we sought for the night was a nearby planetary nebula, NGC1501. I have a few observations of this PNe but it os difficult. We had the field of view, one which Sebastian depicts as we saw. Try as we did, we couldn't get the planetary to reveal itself beside the quadrilateral of stars to to the right.

As usual we were packed and the scanned the our urban night sky before leaving it to the day just beyond the horizon in the middle Winter sky. This was the opportunity to correct a mistaken identity. Originally, we identified the bright red object in the treetops as Aldebaran. At 3:30AM, the red star had risen higher above the trees with another red star below it. It was at this time we noted that Mars was situated midway between Pleiades and the Hyades.

Other objects we stopped on included the double Mesarthim, gamma Ari and triple Struve2816 & double Struve 2819 in the open cluster Trumpler37, IC1396. Spreading from the Garnet Star, mu Cep, TR37 appears as a large sparse collection of brighter stars upon a dim, resolving bed. I wouldn't call it rich nor did I see any nebulosity but that is a pretty triple out there in space.

Didn't mimic Charlie's hop but we panned for gold and took home the rich sights harvested from the Summer and Fall skies. In short time we'd be back at it with slightly different targets.

Saturday, August 11, 2007

Crescent Venus

Session name: 20070811.1030

Crescent Venus snapped in the morning sky with a Nikon Coolpix 995 coupled to a Tele Vue Ranger (TVR) and Tele Vue plossl 20 mm eyepiece.

A short session from Drip Rock where I started with the Sun using the Takahashi 22x60 bins. Detected one small sunspot in the upper leading quadrant of the solar disk after some effort. Otherwise, would have thought that the disk was blank of any activity.

Spent some time hunting for the waning crescent Moon with no luck. I thought there was a chance with 16° elongation and 2.0% illuminated disk. Charlie and I exchanged emails earlier in the week about catching the rising last crescent but slept in not checking the weather for this morning. It may have been a cooperative sky. When I awoke the skies looked really clear and I could see very far across NJ to the horizon. Yesterday's rain washed the haze from our skies. I'll check his blog to see if he reported anything.

Abandoning any further effort on the moon I moved onto Venus. Simply aligned the bins on the Sun and then used the scaled markings on the geared Bogen 410 tripod head to measure off to Venus. Voila. First shot and there was a striking upside down, crescent Venus about 12° below the Sun. Continued to observe in the Tak bins, hand held 7x50 bins, and then the TVR with 32mm plossl eyepiece. Lastly swapped the 32mm for the Nikon setup and snapped some photos.

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