Bigger Mirror... Better Views - Hobbs Observatory Update!

By: Mike Brown, CVAS Volunteer and Local Astronomer

The large reflector telescope in the west dome at Hobbs Observatory features a 24-inch-diameter, 4-inch-thick quartz mirror. A mirror of this size gathers nearly 5,000 times more light than the unaided human eye, allowing us to see faint galaxies, glowing nebulae, and intricate lunar detail. Simply put, the bigger the mirror, the brighter and more detailed the view.
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A reflector telescope uses a mirror instead of a lens to collect light. Its concave surface has been precisely ground and polished to within millionths of an inch in the shape of a parabola. The front surface of the mirror is coated with an extremely thin layer of aluminum,  just 1/300th the thickness of a human hair,  which makes it reflective. The polished quartz itself is very stable, but the delicate aluminum coating slowly loses reflectivity over time. As that happens, image brightness and contrast decline. To restore peak performance, the old coating must occasionally be chemically stripped and a fresh layer of aluminum applied.

The Hobbs mirror was last recoated in 2005, so it was time for renewal. At the end of February, members of the Chippewa Valley Astronomical Society and the UW–Eau Claire Physics and Astronomy Department carefully removed the mirror, crated it, and shipped it to a recoating facility in California. The total cost for recoating, shipping, and insurance is estimated at $4,000, covered by UW–Eau Claire.

The refreshed mirror will be reinstalled and aligned in time for the start of the public observing season.

Hobbs Observatory is open to the public, free of charge, on clear Saturday evenings from May through October (except July 18 and September 12), beginning about an hour after sunset and continuing until 11:00 p.m. We invite you to visit this summer and see the universe come alive through the eyepiece.

Bluebird Monitor Training: Knowledge Can Come Out of the Blue!

 By Everix Machan, UWEC Writing Intern

On Saturday, February 21st, Beaver Creek welcomed local bird lovers for their Eastern Bluebird Monitor Training! 

Beaver Creek has offered bluebird monitoring for over ten years now, and the practice still has a huge draw. Last year, 51 bluebird boxes were logged, including 192 bluebirds born and fledged, meaning they are able to fly! This year, we hope for an even more successful year for our feathered friends, with volunteers surveying all of our routes in the county. 

At the training, volunteers received a monitoring toolkit and training on how to best track the data collected through NestWatch, a free program developed by Cornell Lab of Ornithology through Cornell University. You can download it right onto your phone! This monitoring lasts from March to August while our local birds nest and raise their young. Through our training, volunteers learned to care for nest boxes to protect bluebirds, and through NestWatch, important research is collected by civilians about tens of thousands of Eastern bluebirds a year, especially throughout the Midwest and Eastern United States. Because these bluebirds nest in tree cavities in grasslands or open woodlands, they aren’t as visible as other nests, so it is important to have as many volunteers monitoring as possible!

While we can help our bluebirds by monitoring their nests and young, a nest can “fail” in many ways, including abandonment, inability to find food, encountering predators, or bad weather displacing or destroying nests. Bluebirds are protected under the Migratory Bird Treaty Act, meaning we are not allowed to touch nests without a permit, but our nest monitor volunteers take precautions to avoid stressing out our local feathered friends or leading predators to the nests. To prevent nest failure in our county, we can put up predator guards on poles where there are nest boxes and check on the boxes before storms to ensure they will stay dry and intact. Finally, it helps to keep cats inside. Even cats who are well-fed hunt by nature, and you might not even know it if they don’t take the prey back to you!

If you’re interested in learning more about identifying bluebirds or any other feathered friends, feel free to download the Merlin Bird ID app, developed by the Cornell Lab, which can help you identify birds by their plumage and calls. Also, keep an eye out for other bluebird-related events this spring and summer, including April’s bluebird house building program and May’s bluebird watercolor paint and sip!

If you’d like to get involved with Eastern Bluebird Monitoring, but missed the training, feel free to email our wonderful AmeriCorps Avian Field Technician, Santiago Tabares Erices at santiago@beavercreekreserve.org!