Tuesday, March 18, 2008

Scouting for ISAN v.2 location

Columbus Circle, New York City.

Given its location and the amount of ambient light it is not all that bad for a northeastern to southeastern exposure. Central Park, the foreground when looking opposite this view, is favorable to a low horizon across that eastern view. Saturn and the Moon were unaffected by bright lights. Naked eye limiting magnitude is somewhere between 2.5 and 3.0. The killer is the subway beneath and perhaps all the street traffic that cause a great amount of scope shimmer and shake. For that very reason I'll abandon this spot for the second annual International Sidewalk Astronomy Night on 12 April 2008.

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Sunday, March 02, 2008

Performance observing kit

This is my grab-n-go kit when I need a convenient, portable means to observe the heavens. By portable I mean easy to pack, light to carry, quick to setup and strike. This kit fits the bill 100% with very satisfying views, ranging from low power, wide field to greater magnification with a narrower field of view. It takes less than 5 minutes to pack everything up in the Kelty backpack which includes:

Takahashi 22x60 binoculars
Fujinon 7x50 binoculars
Thousand Oaks Solar Filter
Manfrotto/Bogen 410 on Manfrotto/Bogen 3221s
Karkoschka's Observer's Sky Atlas
Towels and bull dog clips
Observing accessories like red lamp, rubber bands, notebooks, sketching utensils, etc.

The Takahashi binoculars are both attractive and a terrific performer. Impressive optics and effective baffling provide high contrast views even for the the faint fuzzies on New York City skies. As noted in a recent post, M81 was clearly observed and M82 requiring averted vision and visual confidence, was detected in the field. On another recent outing, Saturn, his rings were discerned with 3 moons (Titan, Tethys, & Rhea) to boot.

The Takahashi's 2.1° field of view is narrow compared to other high power bins that offer in the area of 4°. yet, I really enjoy some particular views like Orion's Sword. This field of view nicely frames the entire region from the open cluster NGC 1981 past Orion's Nebula, M42, down to the multiple star, iota Ori. The Trapezium is resolved with clear, steady skies, components A & B separated by a mere 8.7 seconds of arc, amid the magnitude 5.4 brightness of nearby C-component. Initially, it looks like Mickey Mouse but closer inspection, one will discern the narrow valley of black between the A & B stars.

I don't think these are friendly bins for pedestrians because of the small exit pupil and short eye relief. It is important not to touch the tripod to limit any scope shake, however, people often hold the center post (maybe for balance). I remind them that if they see the stars or planets dancing, that releasing the tripod will steady the view.

The Fujinon 7x50 binoculars hang from my neck. Despite being heavy, these bins perform reliably and respectably. I use them to sweep the sky when looking for faint stars from which to starhop, scan the arm of the Milky Way for open clusters, pickup the brighter globular clusters, search for crescent Moons less than 24 hours from New Moon, and locate Venus during the day.

Larger stellar systems like Pleiades, Hyades, and Alpha Persei Association and asterism Kemble's Cascade, I prefer the 7½° wide field of view that gives some breathing room around these large objects.

These bins accompany me on every session.

I am a brand loyalist when I am satisfied with product quality, performance, and service. Concerning the list above, I own multiple products from Kelty, Takahashi, and Bogen. I also highly recommend the Fujinon brand as the bins have served me reliably since 2001 ~ 2002.
People often ask me how much all this "stuff" costs, but I rarely speak in dollars. Instead, I suggest they google the brand from home and emphasize that looks through the eyepieces are free.

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