Observing June 29, 2002
by Jane Houston Jones
There sure were alot of people and telescopes at Lake Sonoma on a short observing night Saturday, June 29th. With sunset at 8:39 p.m and moonrise at 12:18 a.m., well, you can do the math yourself. It was going to be a short night for deep-sky observing. Mojo and I decided to bring refractors - four of them, in fact - and compare views with a friend who had just become the proud owner of a brand new TV-102, Tele Vue's 4-inch, 2-element f/8.6 APO air-spaced doublet. We helped him unpack and set it up on his new Gibralter mount the night before for first light.
We brought four of our five refractors, a Bushnell 50mm f/12 on a funky dobsonian alt/az mount which screws onto a camera tripod. Thisss was a Sky and Telescope project from years back - and this telescope and mount are both available as a loaner scope, by the way :-) but you'll need your own camera tripod. The other three were our TV Ranger, a sleek 70mm ED glass doublet with an elegant helical focuser, and our two Astro-Physics refractors, the Traveler, a 105 mm f/6 EDFS apochromatic triplet, and our AP180EDT, a 180mm EDT apochromatic triplet. We left the Orion Short Tube 80 at home, mainly because we didn't have enough mounts for them all, and I figured (correctly) that someone else would bring an 80mm refractor.
After a burger/dog/corn BBQ, our group set about setting up. Suddenly, refractor after refractor were unloaded from this car and from that car. Pretty soon there were ten refractors lined up in a row. For those of you painting a visual image of this, interspersed with all those ten refractors were a couple of other telescopes. There was a NexStar GPS 11 Schmidt Cassegrain (the owner/operators had their NexStar 8 GPS in the car, but didn't set it up), an 8-inch home-made dob which is our Sidewalk Astronomers loaner telescope #1, a Meade LX50 8-inch SCT and a StarMax 102, Orion's stubby and very portable Maksutov. Across the way were the rest of the telescopic alignment - a home-built 17.5 refractor on a home-built equatorial platform, a 17.5-inch Discovery reflector on a dob mount, a 14.5 inch Starmaster and a 10-inch Orion Skyquest reflector. At the end of the big dob row were a pair of 16 x 70 Fujinon binoculars on a binocular mount. Several people had brought their own binos, including a new pair of Canon Image Stabilizer 15 x 50's. Our own Celestron 9 x 63 Ultimas were turned into North America Nebula spotters with the aid of an O-III filter placed in one eyecup later in the evening.
I didn't really have a project in mind for the short night, but as I contemplated the availability of all these refractors, I decided to try to observe one object in them all during the night, and make some notes - and maybe some sketches - of some object in the summer sky. Nothing scientific, mind you. This wasn't a refractor shootout or anything. It was just for fun and for my own refractor education.
As it became dark, the Milky Way appeared overhead. From horizon to horizon the glow of a billion stars lit the summer sky ablaze. The pipe nebula was visible to the naked eye, indicating a pretty dark night. I was drawn to M8, and then I knew this was the object I would observe, if the owners would allow me to mooch their views for a while. M8 (NGC6523) is the 5,000 light-year distant Lagoon Nebula and within its border are many other objects. One of these objects is more visible without the O-III and UHC filters people (including me) like to use on the Lagoon Nebula. Collinder 362 aka NGC 6530, a magnitude 4.6 open cluster of about 50 to 100 extremely young stars is striking without the filters, and almost invisible with the filters. The Lagoon is also home to several dark nebulae, sporting names such as B88, B89 and B286, the B being Mr. Barnard, naturally.
I started my observing run by walking to the end of the refractor row.
The first scope in the line was an AP130 f/8 doublet, circa 1994, which was having its second light, the first being the night before at the owners' place. The owner had a 15 Panoptic and no filter in the focuser for a 69x view. It was really nice. The open cluster was prominent in this view, which I liked alot.
My next view was through a Takahashi Sky 90, an f/5.6 apo. This was my second favorite view of the whole night! The owner had borrowed a TV binoviewer from the next telescope on the list (TV-85) and had a pair of 19mm Panoptics and no filter for a lovely 56x view. This view was just amazing! The cluster, the dark lanes, the bright stars, the faint glowing nebula. Wow!
Third was a view through a TV-85 f/6.8 doublet APO with TV binoviewer. I failed to record the eyepieces used but they were real low power so both M20 and M8 fiit within the binoviewer field of view. Maybe 15x or so. The owner was just thrilled with the views, and just loves his binoviewer! I'll admit that it was a great view, and those binoviewers are easy on the eyes and sure make for a relaxing observing session, until you get so relaxed that you fall off your adjustable observing chair, that is!
Fourth was our friend's new TV102 f/8.6 refractor. He was alternating between our 31 Nagler and his new 35 Paanoptic. This was a lower power view with the O-III filter - 28x, nearly the lowest power view of the night for me. It was a nice view, and I'd like to see it with more power through this telescope. Luckily, I'll get that chance!
Fifth was our 50mm Bushnell (Model 78). I sort of brought this as a joke, but had some fun with it, thanks to Jay Freeman. A few months ago, Jay gave me a box of .96-inch/1.25-inch adapters so I could use normal 1.25-inch barrel eyepieces in this little telescope. I wanted to see if it was worth hanging on for loaning out to someone, or if it would be a crime to dissappoint someone with such a bad scope. The eyepiece view of the lagoon I liked the best was with a 1.25-inch 12mm Vixen Lanthanum in Jay's adapter. The view actually was not bad! And earlier, I could detect the phase of Venus through this telescope. I still haven't decided wether to keep it. I'll try the moon next.
Then I put that telescope back in the car, and mounted our 70mm f/6.8 TV Ranger on the Bogen camera tripod for view number six. I loved this view and I am so glad I have this little telescope. It came as the "finder" on our AP180EDT, so its name is "Little Rod". Maybe I should call it "Mini Rod" :-) The view was one of the best of the whole night! Both the 21mm and 12mm Vixen Lanthanums gave great views of the Lagoon - 23x and 48x respectively.
Seventh, our own AP 105mm f/6 Traveler. This was just about the perfect view, and much more to my liking, being a little higher power. I used a 6mm Radian eyepiece for 105x, with and without the O-III filter. The cluster, the dark lane(s) and different clumps of nebulosity were more pronounced and distinct than in any other telescope I'd looked through.
Eighth, a view through the Stellerview 80, a F/9. This was the only one using a UHC filter, and I liked it better than the O-III on this object.
The O-III is harsh, in my opinion. I like the view through the UHC and no filter the best. The 32x view through a 22mm eyepiece and filter was nice. But aperture helps!
Ninth and next to last, a view through the Orion Astroview f/10 90 mm refractor using a 17mm Sirius Plossl for 53x. I think the view at higher power would have been nicer. Not much detail, but a nice view anyway.
Last but certainly not least, a view through The Rod, our AP180EDT f/9 refractor. This was the largest aperture I viewed through, and so it comes as no surprise that I could see more detail. The brightest part of the nebula, surrounding the O star, Herschel 36 was more prominent and had a three dimensional "bulge" look to it. Other dark lanes were more prominent, too. I guess I have to say this was my favoorite view even though we were observing with the 31 Nagler and O-III filter for a low 52 power vview. But since it is my telescope, I'll get a chance to crank up the power any time I want!
I had run out of refractors! So I went back to my own telescope for the night, the AP Traveler, and completed the Small Scope Sampler project in Ophiuchus from the July Sky and Telescope Magazine. Soon the moon
rose, and we headed off for a Sunday morning hot fudge sundae half way to home.
Sketches of the Lagoon Nebula through all ten telescopes are here in the deep-sky section: http://www.whiteoaks.com/sketches/
Another nice summertime project in this area was published in the SJAA Eephemeris in the summer of 1999. I hope you enjoy it! http://ephemeris.sjaa.net/9907/j.html
Jane, observing from 38N 123W, Lake Sonoma, CA, June 29, 2002