Crater Lake and Oregon Star Party 2006

by Bob Jardine

Observing Report -- Crater Lake and Oregon Star Party -- 23-26 March 2006

My trip to OSP is covered in a separate trip report. So on to the observing.

My main project at this time is the Astro. League Planetary Nebulae program. It is a list of 100 PNs, mostly NGCs, but with a pretty large number of others thrown in. I started it at Mt. Lassen in July.

At OSP, I took a partial detour on Thursday night to do their “Oregon Sky 25” list. These were all repeats (all H-400 objects), but I thought it would be nice to see them all together in one night. I observed 22 out of the 25. I won’t repeat the list of objects here -- you can see it on the OSP web site. The three I didn’t do include two low South globs that I didn’t bother with, because I had observed them at SSP earlier this year, and because I didn’t travel 7 degrees North of home to observe stuff down at the Southern horizon. The other object I didn’t bother with was NGC 2403 in Cam, which was “nadiring” (is that the opposite of transiting?) this time of year -- even though it is circumpolar up there in the frozen North, it wasn’t very well placed all night long -- I don’t know why it is on the list.

Coordinates at Crater Lake were: N 42 deg, 55.502’; W 122 deg, 03.614’, elev 7264’

Coordinates at OSP were: N 44 deg, 18.018’; W 120 deg, 08.526’; elev 4909’

I observed with my 12.5” f/5 Mag1 Portaball. Most observations were with 7mm (226X) and 9mm (176X) Naglers, with/without O-III filter. Limiting mag for me was 6.0 to 6.3 every night, with good to very good seeing.

Here’s a selection of PNs that I observed:

Shingletown:

NGC 6210 -- PN, Her -- small to medium size, very bright, central star not seen for sure.

NGC 6741 -- PN, Aql -- quite small, pretty dim, but direct; needed filter to confirm .

IC 4846 -- PN, Aql -- quite small, pretty dim; easy location.

NGC 6790 -- PN, Aql -- very small, pretty dim, needed filter to confirm at first, but then finally saw a disk at 226X.

NGC 6807 -- PN, Aql -- very small, pretty dim; needed filter to confirm; just a hint of a non-stellar disk at 226X.

NGC 6818 -- PN, Sgr -- "Little Gem"; medium size, very bright, round, uniformly bright. This is a good one! Central star not seen.

Crater Lake:

NGC 6803 -- PN, Aql -- Tried this for several nights; finally I can claim it. I verified many stars in the field against the DSS image. All but stellar, medium bright.

NGC 6881 -- PN, Cyg -- DNF; You’ve got to be kidding! Mag 13.6 and Stellar? And in a rich Ozerway star field?? Need a better chart, for sure.

NGC 6894 -- PN, Cyg -- this one is different! pretty large, very low surface brightness; with AV, I can see a darker center, but only occasionally.

IC 4997 -- PN, Sge -- very small, but pretty bright; blinked with O-III filter to confirm. Star field matches the photo; brightest “star” of a little flat triangle.

NGC 6905 -- PN, Del -- an easy one, pretty large, quite bright, round. Some mottling at 226X. Central star seen, but only occasionally. Elongated a little bit N/S??

OSP:

NGC 6543 -- PN, Dra -- "Cat’s Eye"; very bright and high surface brightness; medium size; slightly elongated -- 1.5:1? with 226X, darker center is seen with direct vision (not with AV); central star seen 75% of the time with direct vision (not with AV).

NGC 6826 -- PN, Cyg -- "Blinking Planetary"; very bright, round, high surface brightness; bright central star, visible even with slight AV; with direct concentration, nebula shrinks and/or disappears altogether.

NGC 7009 -- PN, Cap -- "Saturn Nebula"; medium size, very bright, blue-green; elongated 1.5:1, but wait! not just oval; with AV, it definitely looks like an out-of-focus Saturn.

NGC 7662 -- PN, And -- "Blue Snowball"; medium size, very bright, round blue disk, uniformly bright, no detail seen.

NGC 7008 -- PN, Cyg -- a strange one; largish (but not Dumbell-large), medium bright, easily seen, but pretty low surface brightness; kind-of C-shaped; maybe seeing a central star, but difficult to be sure, because of odd-shape; maybe just a foreground star.

NGC 7026 -- PN, Cyg -- medium size, pretty bright; easily seen fuzzy star right next to a pretty bright star, immediately following. shape seems strange -- not circular, but difficult to pin down.

NGC 7048 -- PN, Cyg -- difficult. pretty large, pretty dim, low surface brightness; roundish, but not perfect; a pretty dim star just off one edge; seems close to uniformly bright.

NGC 7094 -- PN, Peg -- difficult, due to dim, low surface brightness, no finder/chart stars nearby; not far from M15; shows up only with filter; pretty large, low surface brightness, round glow; can barely hold with direct vision.

NGC 7354 -- PN, Cep -- medium size, pretty bright, medium surface brightness; round, uniform; filter doesn’t seem to help much.

IC 5217 -- PN, Lac -- very small, pretty bright, high surface brightness; suspected due to slightly different color than the other stars of similar magnitude; slight response to blinking with O-III filter, but confirmed mainly by careful matching of all stars in the field against photo.

M76 -- PN, Per -- "Little Dumbell"; large, pretty bright, medium surface brightness; elongated 2:1 or more, roughly N/S; pinched in middle, like a bow-tie or peanut; south lobe looks a bit brighter; filter doesn’t help with detail.

IC 1747 -- PN, Cas -- pretty small, medium bright, high surface brightness; surprisingly easy -- seen as non-stellar at 176X & no filter -- small fuzzy; blinking is dramatic -- all of the stars in the field are gone, leaving only the small round fuzzy; easy location near Epsilon Cas, but that star isn’t in the 176X FOV, so it doesn’t interfere.

NGC 7027 -- PN, Cyg -- medium size, very bright, high surface brightness; obvious little blue disk without filter; uniformly bright, round.

IC 5117 -- PN, Cyg -- stellar, pretty bright; neat! a little isosceles triangle of about mag 11 “stars”; with O-III blink, the apex star disappears completely, and the other two “stars” reverse in brightness.