AZ Observing – A Darker View

A Winter Star Party

In Arizona, during the heat of summer we would head for the mountains. We knew dozens of fire roads and meadows where a telescope could be set up under the stars among the cool forest pines. When the weather chilled, we headed to the low desert, our favorite site was Sentinel, Arizona. A desolate volcanic field just off Interstate 8 between Gila Bend and Yuma. It was still cool at night, a beautiful place to enjoy the desert skies…

Deep Violet at Sentinel, Arizona for the 2015 Pierre Schwarr Star Gaze

2005 Sentinel-Schwaar Star Gaze

With the first cold weather of the year I planned a trip to Sentinel, one of our favorite winter observing sites. The site features dark skies and good company. The forecast was for clear skies, so Saturday afternoon I packed up my big dob and headed down the freeway.

Dob Silhouette — Steve Dillinger’s 20″ Dob awaiting full dark at Sentinel, AZ with Venus and the Moon shining behind

The sky started a little rough, with high cirrus and contrails scarring the blue lit by the the glow of sunset. The thin crescent Moon and Venus were gorgeous among the bright gold wisps. Shortly after dark these annoyances quickly cleared leaving a clean sky. Seeing was soft all night, transparency was decent, but poor at low altitude as views into Fornax or lower demonstrated.

Violet Awaiting — The author’s setup awaiting a dark December sky with Deep Violet

I counted over 20 vehicles a little before sunset, but a least 10 more rolled in at sunset or just after. After a few hours there was a steady rate of departure as the cold night took its toll on Arizona observers.

I spent the first half of the night touring old friends and a couple new objects, but was basically killing time waiting for H400 objects to rise. After midnight the objects I had been waiting for had risen high enough to appreciate properly and I started to work, cleaning out Pyx, Lyn and Pup of a few remaining H400 objects as well as chewing on western UMa a little. It looks like I have 28 objects left, almost all in UMa, the end is in sight!

Around 0300 the breeze had become a steady cold biting wind and I finally packed it up and pulled out. I had already had around nine hours of good observing so I can call it a success. I wasn’t the last, there were at least two observers still going when I pulled out.

Telescope Line — The telescope line at Sentinel for the 2005 Sentinel-Schwaar Star Gaze

2005 All Arizona Messier Marathon

A Messier Marathon, one of the crazier ways we celebrate our love of the night sky. Try to find all 110 objects on Charles Messier’s catalog in a single night. It is possible, barely, to do this. It is a challenge of skill and perseverance, and a lot of fun. In 2005 I joined a group of friends at Arizona City at the 2005 All Arizona Messier Marathon. This site has hosted the most successful marathons anywhere, a great site and a large group of very skilled observers makes the competition tough.

Ready to Marathon — The author waiting for dark

My immediate competition was my young friend Carter Smith. Carter and I marathoned together, often racing on objects and comparing scores through the night. I had meant to quietly work on H400 galaxies in Virgo, but Carter sucked me into marathoning with him. Great night with good transparency and for once this winter and spring, NO clouds. Seeing was great at sunset with wonderful views of Saturn while we waited for full dark. The seeing deteriorated badly after dark with cool and warm breezes warring over the site. But transparency is what you want for a perfect marathon which is what we got.

Marathon Briefing — Briefing the attendees on the rules of our messier marathon

I managed to stay ahead of Carter most of the night using my 18″ while he was using a 10″. Actually parts of the marathon are much harder with a big scope, particularly the Virgo cluster where a big scope sees all of the dimmer galaxies and not just the M’s you want. I used the setting circles only to confirm objects a few times, so both of us ran this one manually. We ran on purist rules, Telrad and charts the only tools allowed to find the object! The All Arizona Messier Marathon allows setting circles and GOTO scopes, but we are free to make our own rules a little tougher.

Late in the night Carter found my weakness, the 18″ will not depress below 5 degrees elevation, so he could get objects coming over the horizon before I did, after that he was ahead most of the time. Except a few occasions when guile won out against youthful enthusiasm and young, sharp eyesight. In the end we both scored a 109, the best that was possible with M30 being impossible. We had to work on M74, M73 and M72 together to be sure, but the spottings were confirmed by both of us. All in all a great marathon!!!

Messier Marathon Mosiac — The observing field at the Farnsworth Ranch, with the Silverbell Mountains in the background and Kitt Peak just visible at far right. The field is unusually green after heavy spring rains. The clouds are rapidly departing to the east.