Tucson Mountain Park Ironwood Picnic Area

[Skylook123]

Date: Saturday, October 22, 2016
Event: Pima County Natural Resources Ironwood Star Party
Location: Tucson Mountain Park Ironwood Picnic Area, Tucson, AZ
Weather: Mostly cloudy at sunset, later cleared somewhat.
Seeing and Transparency: Not very good at sunset with clouds over most of the sky, but later partial clearing allowed operations..
Equipment: 10" Meade SCT on Atlas EQ-G mount, Mallincam Xterminator video system, 19" QFX LCD monitor.

This event was one of the regularly scheduled Pima County Natural Resources Parks and Recreation Department’s star parties at the Tucson Mountain Park Ironwood Picnic Area.  Usually we get about 40 or 50 visitors and schedule two or three volunteer astronomers to support it.  This time we had four volunteers: along with myself, we had Tucson Amateur Astronomy Association members Paul Ross, George Hatfield, and Rob Halberg.

All day, the weather, which had been predicted to be favorable, was getting progressively worse with clouds rolling in from the South.  With the sky about ¾ obscured at 4:15 PM, I talked the situation over with Yajaira Gray, the PCNR point of contact, and we decided we’d show up and give the other astronomers the option of coming.  I got there about 5:15 and the sky was mostly obscured with rain in the distant south and east.  There was some promise of clearing after 7:30 PM, so I set up all of my equipment with hopes that things would clear up some.  By 6 PM , just after sunset, all four of us were present along with two visitors.  Things did not look good, and were getting worse.

Frankly, as cruddy and obstructed as the sky looked at sunset around 5:45 PM, I was surprised that we had all four astronomer volunteers present.  The sky had a big sucker zone to the North, with the remaining sky occluded.  We all set up and waited to see what would happen.  I need to have a pretty accurate polar alignment for my setup, or the drift will kill the very narrow field of view with the camera installed, as well as it allows a single star alignment.  Eventually, Paul was able to get his SCT aligned, but George's setup needed more of an open sky, and it kept getting worse.  I went over to Venus, it was great for a while, Paul and Rob were jumping to open spaces and initial planetary discovery, but eventually I lost Venus in the clouds and, since we started with two visitors and grew to a half dozen or so early on, we were kind of overkill.  George's lack of a good enough sky to find a coordinated set of stars to complete an alignment meant his station was out of the game.  So, we did some talking about the night sky, some ecliptic vs. zodiacal discussion and the use of the sky, and I introduced my little bit of Celtic history and Paul did a great discussion on the general accession of one culture's mythology by another, dominating culture and really put the Celtic and other Roman-dominated cultures and the succeeding Christianity incursions into context.

After about 90 minutes or so, George was out of options for aligning, so he had departed.  This was very disappointing; I was looking forward to his great knowledge and experience to have around.  Then, after about 7:15 or so, holes started opening up.  I could hear Paul doing the planetary tour including Uranus, plus Mizar when it opened up.  I did a new arena for me; with a 1-star alignment on Schedar in Cassiopeia, I was able to do The Owl Cluster, and then each element of the Double Cluster; fortunately, I nailed the exposure on the camera and was able to pull true color out of stars in the clusters.

My time ended after I went over to the always gorgeous Ring Nebula in full color.  As always, it was a lot of fun explaining the stellar evolution process with the great Xterminator putting the Ring at about the size of a quarter with the outer red hydrogen zone, the strong blue-green inner ionized oxygen region, overlapping of the colors leaving a yellow region, and a crisp carbon white dwarf showing off in the center, a cosmic diamond with the mass of a star but at the size of the Earth.  Thermal energy in the ultraviolet was doing the electron stripping that caused the gorgeous view as replacement electrons snapped into their atomic locations. 

I heard Paul was on M13, the Hercules Globular Cluster, and I wanted to jump over to it just to show the red giant stars in its membership, in color, or try the Dumbbell Nebula, but in mid-slew to M13 all power failed.  We were breaking up anyway, so I did some trouble shooting and found the battery supply was still up near 13V, but the power converter light was dimly flickering.  Later I recalled that one of the 12V lines in the distribution harness has an intermittent short in an unused line; I hooked the wrong line to the mount, and the internal short disabled the power converter.  I ran a separate line from the battery to the mount and when I pulled out the bad line, the monitor and camera came alive and the AC inverter showed the right draw.  I re-parked the mount head and let the camera go through its three minute shut down since I had the cooler going and wanted a stable ending.  Many thanks to Paul and Rob who stuck around for my laborious pack out with the troubleshooting equipment to deal with along with getting the mount and camera back to a known and stable state.

What started as the appearance of a lost night turned out great for the 10 or 12 (I think!) visitors who joined us.  PCNR point of contact, Yajaira, was doing her first of these events and was great at continuing forward to salvage what turned out to be a pretty good session of education for the visitors with the Xterminator on Venus, three open clusters, and a planetary nebula.

[alan potts]

Very nice report Jim even if the weather didn't deliver what it could have, you really do get to some lovely places on these outreach events.

Alan

[Skylook123]

Thanks, Alan.  The desert environment is like having a tremendous beach.  Just missing an ocean!  Most of the year, the humidity is under 20% and dewpoints in negative numbers.