Winer ObservatorySite Description
The observatory site provided by Winer to its customers is located at latitude N 31° 39' 56.08"
and longitude W 110°36' 06.42" at an elevation of 1515.7 meters (4973 feet) as measured by GPS
(WGS 84 Datum). This site is approximately 27 km (17 miles) east and 2.7 km (1.7 miles) south of
the MMT Observatory on Mt. Hopkins, and is 5 km (3 miles) east of the town of Sonoita, Arizona
(population approximately 1200).
The altitude is a compromise between good sky transparency and good weather. Although higher elevations can provide better transparency, they also are subject to lower temperatures, more freezing precipitation, higher winds, and more frequent lightning strikes. These mountaintop conditions can exact a heavy toll on observatory, telescope, and instrument systems which makes operation of a fully automatic observatory and telescope more difficult and expensive. Such expenses must, inevitably, be passed along to those whose telescopes are located at the site. Our view is that mountain tops are financially viable for large telescopes with large operating budgets, but not for smaller telescopes with proportionally smaller operating budgets.
The site enjoys good weather - roughly 60% of the total hours without lunar interference are usable, with half of these being of all-sky photometric quality. Most cloudy nights occur in July and August during the summer rainy ("monsoon") season. Operation of the site includes keeping accurate logs of the weather, and we plan to install a seeing monitor during the coming year.
Customers should be aware that with a roll-off roof, telescopes are more subject to wind and dust than if they were mounted in a dome. Consequently, critical parts (drives and encoders in particular) should be enclosed, and optics should be protected by motorized covers when not in use. Truss assemblies for secondary mirror support are favored over tubes for reduced wind loading, which places greater demands on proper optical baffling.
Our land is zoned General Rural, which permits cattle grazing, sheep ranching, agriculture, and residential structures. The zoning does not permit a high level of vehicular traffic. Consequently, we cannot permit observers to visit their telescopes to observe on a regular basis. Our facility is designed for remote, robotic observing using the Internet to transfer command and data files.
The location in southern Arizona, famed for its clear skies and dry air, coupled with the experience of the staff in astronomy and electronics, gives you the best combination of site and service to meet your research and education needs.
Climate Summary from the Western Regional Climate Center
The data in the table below were taken over the period January 1, 1910 through March 31, 2003 at the Canelo 1 NW station (station number 021231).
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Average Max. Temperature (F) | 57.9 | 61.4 | 66.2 | 73.7 | 81.7 | 90.4 | 88.2 | 85.5 | 83.7 | 76.5 | 65.9 | 58.1 | 74.1 |
| Average Min. Temperature (F) | 26.1 | 28.2 | 31.7 | 36.7 | 43.4 | 52.4 | 59.8 | 58.4 | 52.6 | 41.9 | 31.8 | 26.7 | 40.8 |
| Average Total Precipitation (in.) | 1.22 | 1.19 | 0.92 | 0.45 | 0.20 | 0.73 | 4.41 | 4.04 | 1.69 | 1.04 | 0.84 | 1.40 | 18.13 |
| Average Total Snowfall (in.) | 1.6 | 1.3 | 0.9 | 0.2 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.2 | 1.2 | 5.4 |
| Average Snow Depth (in.) | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
Information
Percent of possible observations for the entire recording period:
Max. Temp.: 78.7%, Min. Temp.: 79%, Precipitation: 97.3%, Snowfall: 96.4%, Snow Depth: 95.9%
Table of Open Nights by Month
The data in the table below show the number of nights each month of each year listed the roof was open for more than half the night. In 2004, the roof was operated manually, while in 2005 through 2007, it was operated automatically by computer, but was not closed by weather sensors. During these years, when the roof was open, it was open the entire night. Also during these years, the roof was closed throughout most of July and August and at least half of September to avoid the annual summer monsoon season. The "Closed" column includes those nights outside the Monsoon season when the Observatory was closed due to weather (the usual cause), equipment failures, or vacation by the Winer staff in 2004 through 2006. In 2007, we began keeping separate records of vacation days outside the monsoon season (vacation taken during the monsoon season does not count, as we are shut down during that time).
| Year | J | F | M | A | M | J | J | A | S | O | N | D | Open | Monsoon | Closed | Vacation |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 2004 | 10 | 18 | 20 | 20 | 29 | 23 | 0 | 0 | 8 | 25 | 17 | 19 | 193 | 83 | 89 | n/a |
| 2005 | 18 | 7 | 20 | 28 | 18 | 21 | 3 | 0 | 11 | 23 | 25 | 26 | 200 | 73 | 92 | n/a |
| 2006 | 26 | 21 | 18 | 24 | 25 | 13 | 0 | 0 | 15 | 22 | 26 | 23 | 213 | 78 | 74 | n/a |
| 2007 | 17 | 19 | 27 | 23 | 24 | 26 | 3 | 0 | 10 | 28 | 21 | 24 | 222 | 76 | 58 | 9 |
| 2008 | 19 | 21 | 25 | 29 | 24 | 19 | 0 | 0 | 14 | 24 | 24 | 20 | 219 | 85 | 42 | 10 |
| 2009 | 24 | 22 | 22 | 24 | 24 | 15 | 0 | 0 | 15 | 27 | 22 | 26 | 221 | 82 | 49 | 13 |
| 2010 | 22 | 16 | 26 | 26 | 29 | 25 | 0 | 0 | 10 | 22 | 29 | 23 | 228 | 81 | 54 | 2 |
| 2011 | 28 | 22 | 30 | 23 | 27 | 28 | 0 | 0 | 11 | 28 | 18 | 15 | 230 | 80 | 55 | 9 |
| 2012 | 27 | 22 | 27 | 23 | 26 | 20 | 0 | 0 | 14 | 30 | 23 | 22 | 234 | 85 | 41 | 6 |
| 2013 | 24 | 18 | 27 | 26 | 24 | 13 | 0 | 0 | 14 | 28 | 19 | 24 | 217 | 93 | 48 | 7 |
| 2014 | 28 | 22 | 26 | 23 | 13 | 30 | 1 | 0 | 6 | 25 | 28 | 21 | 223 | 83 | 38 | 21 |
| 2015 | 19 | 22 | 20 | 25 | 25 | 15 | 0 | 0 | 8 | 10 | 24 | 21 | 272 | 93 | 76 | 7 |
Page last updated on: January 2, 2016
