GSSP Observing Report (7/11/2007-7/14/2007)

by David Cooper

GSSP 2007 provided us with 4 nights of superb observing. Indeed Lassen is a special place not only for the glorious night skies but also for the beautiful scenery and lovely day hikes – an excellent choice for a starparty.

This year I actually spent more time than usual planning my observing sessions. Normally my “planning” consists of gathering up the usual charts and references, such as Sky Atlas 2000, Uranometria, and The Night Sky Observers Guide, and making the best of things at the observing site – generally not a recommended procedure. This time using the on-line database provided by the Saguaro Astronomy Club, I printed out lists of all objects brighter than 12th magnitude for every spring, summer, & fall constellation visible this time of year and put them into an indexed three-ring binder for easy reference (also in 14 point font for easy reading at night!). My plan for each evening was to select specific constellations for early, mid- and late evening perusal. For each selected constellation I worked down my list until it was complete or it was time to move on. I also included a generous number of brighter eye candy objects to spice up the list of dimmer objects. Also, using Sissy Haas “Double Stars for Small Telescopes” as a reference and planning tool, I began each evening session viewing double stars until the end of twilight permitted hunting of fainter quarry.

Two of the nights provided excellent sub-arc-second seeing and cloudless dark skies. The other two nights were plagued somewhat by high clouds, but nevertheless provided hours of rewarding observation. Below are some of my more memorable observations made from the Bumpass Hell and Lassen Peak parking lots with my AP refractor.

Epsilon Lyrae – I start almost every summer observing session with this double-double in Lyra, partly to gauge the seeing conditions and, of course, mostly just to enjoy this beautiful pair of brilliant white doubles. On the nights of best seeing, my scope resolved each star into a sharp point with one well defined diffraction ring at 209x. All four stars appeared to me to be white with no obvious color contrast and nearly equal brightness. On one evening, however, the seeing was so bad that I could barely resolve each close pair at the same magnification! Nu Scorpii – This second double-double in Scorpius is always a treat when the seeing is good. One night at Bumpass, Bob Jardine reminded several of us to gaze once again at this multiple star system. The CD pair of this system is easy at 2.4” separation. The AB pair is harder at 1.3” with the primary distinctly brighter than the companion. Both pairs were easily split in the refractor at 209x – a wonderful sharp view of an uneven pair of doubles. 2 Canes Venatici – A lovely 11.3” double consisting of a bright yellow primary with a faint, pale blue-green secondary. A fainter and somewhat subdued version of beta Cygni.

25 Canes Venatici – A challenging 1.8” pair consisting of a brilliant white primary and a fainter pale white secondary. Both were sharp and well resolved at 209x.

Sigma 305 (Corona Borealis) – A 5.6” double consisting of a vivid orange 6.4 mag primary with a tiny white mag 10.4 companion. Both were easy sharp pinpoints at 103x.

Jupiter – My views of Jupiter seemed to get progressively better with each evening at GSSP. The best view was provided at the observing finale on Saturday 14 July from the Bumpass Hell parking lot. The highlight was a beautiful shadow transit of Ganymede in the early evening. In the refractor at 209x the shadow was seen as a sharp black disc against the pale yellow northern limb of the planet. At 209x and 355x I counted some 10 distinct cloud bands and several knots, festoons, and small ovals in some of the southern bands. I found the Bader Contrast Booster filter to be a great help in picking out cloud band features, but it does give the planet a slight yellow cast. I generally preferred the more natural, if somewhat less contrasty, unfiltered views. 4631 – A large bright, elongated galaxy in Draco, sometimes referred to as the Whale galaxy (and a well fed one at that!). It’s a stunning object from a dark sky site, even in an aperture-limited “small” refractor like mine. At low power (52x) with a 1.26 degree field I could pick out two other galaxies in the same field. According to Uranometria these were 4656 and 4657, two nearby 10.5 mag galaxies. I could not see 4627, the 12.4 mag companion galaxy to 4631 (need to get one of those big dobs some day!).

6520/B86 – A favorite Sagittarius object from a dark sky site. A lovely small open cluster right next to a black ink spot, both set in a distinctly luminous part of the milky way. The cluster stars were sharp points and the ink spot showed several wisps that extended into the surrounding dense and deep star fields. My best view was at 103x, with the 10.5 mm Pentax eyepiece yielding a pleasant 65 degree field (0.63 degree true field) and providing a nice detailed view of this object and the surrounding regions.

M106 – A favorite somewhat “fattened” elongated galaxy in Canes Venatici. (It’s fatter than the Whale galaxy, 4631!). The view at 103x shows a distinctly brighter core region. A careful scan of the surrounding region at 103x also revealed several companion galaxies as small faint fuzzies – 4217, 4248, and 4231/4232, the latter pair as an unresolved faint glow in the AP155.

6818 – A small intensely blue mag 9.3 planetary in Sagittarius just offset and midway between a pair of equal 8th mag stars set like a fine sapphire between two silver white pins. A view at 209x failed to reveal a central star or any discernable detail in the planetary – it appeared as a fairly uniform blue oval. A memorable view from a dark site even in a small scope.

M109 – I spent a considerable amount of time scanning the wonderful galaxy fields of Ursa Major attempting to identify numerous small galaxies with the help of Uranometria. One of my jumping off points was the galaxy M109, about half a degree southwest of the bright dipper star gamma UMa. The view at 103x revealed 109 to be a distinct oval with a bright but non-stellar core. A scan of about 2 degrees south of gamma revealed two fainter galaxies, 3953 and 3917. A scan of a few degrees north of gamma swept up 3982 and 3998 as well as an additional pair of fainter galaxies to the NE, most likely 3990 and 3972. Overall a very rewarding area of the sky to sweep up faint fuzzies!

M20 – Another favorite piece of eye candy in reliable Sagittarius. The view at 103x from Bumpass showed three distinct dark lanes crossing the nebula and separating it into three distinct luminous regions. Some structure was seen in both the dark lanes and in the nebula itself. The beautiful multiple star in the center is an added bonus! Veil Nebula – Always a rewarding view through any telescope equipped with an OIII filter. I observed the veil at magnifications in the 27x to 52x range. The views with my 40 mm Paragon eyepiece (2.5 degree field) easily encompassed the waterfall (6992) arc in its entirety. A slight eastward adjustment brought into the field the complete “dagger” nebula (6960) that stabs right through the star 52 Cygni. Several other veil components were also observed during numerous wide field low power scans including 6974/79. Views of the waterfall with my 32 mm televue widefield and 21 mm Pentax eyepieces revealed numerous wisps and tendrils. What an object!

7000 – The North American Nebula could just about fit into the field provided by the 40 mm Paragon. What a difference the OIII filter makes for this object! Subtle variations in the nebula’s brightness were easy and the background stars provided a fitting complement to this delectable object. The Mexican peninsula and the entire gulf region showed remarkable detail with distinct twists and knots in the nebula. A hop of a few degrees SE brings the pelican nebula (IC5070) into view as an extra reward.

5907 (plus comet VZ13) – On the evening of July 12th the comet VZ13 was in the same field as the Draco galaxy 5907 (thanks to Steve Gottleib for pointing this one out to us all at Bumpass). The galaxy is a beautiful elongated needle with a bright stellar-like core. A truly wonderful object to observe and wonder at! The comet appeared as a nearby unresolved globular cluster. Both objects were in the same stunning field at 52x.

Turley/Neuschafer 3 – Returning to campsite at ~3 AM Sunday morning found an animated Jim Turley and a tired Rich Neuschafer engaged in deep conversation over a bottle of white wine at one of the camp tables. Discussion topics were classified (what do men often talk about over a glass of wine?) – I’d have joined them if there had been any wine left. I had none to offer and went to bed instead.

What a collection of evenings. I thank and feel deeply indebted to all of the folks, Richard Ozer, Jane Smith, Mark Wagner, Jamie Dillon, and many others who helped to make this event happen. Thanks and I’m looking forward to CalStar!