Tag Archives: Hastings-Byrne

Telescope Longevity

by John Church Our historic 6¼-inch Hastings-Byrne refractor, with its objective lens dating from 1879, was ready for the morning of May 9th and the transit of Mercury. We comfortably followed and photographed the transit with a 55-mm Plossl eyepiece … Continue reading

Posted in June 2016, Sidereal Times | Tagged , | Leave a comment

Testing the Hastings-Byrne Refractor

by John Church Since some members had reported seeing a decline in the optical performance of the 6-1/4 inch Hastings-Byrne refractor, I conducted a thorough test of it on the night of April 18. Dave and Jen Skitt and Gene … Continue reading

Posted in May 2015, Sidereal Times | Tagged , | Leave a comment

From the Observatory Co-Chairs

by David Skitt, Observatory Co-Chair The Hasting-Byrne refractor has been successfully mounted to the “new” Paramount ME mount and the existing cast iron pier! The roll-off roof clears the mount with just over an inch to spare. Keyholders, please be … Continue reading

Posted in April 2015 | Tagged , , , | Leave a comment

Geometrical Optics and the Hastings-Byrne Refractor: Part II

John Church Last month I reviewed the “lens-maker’s formula” that allows one to calculate the focal length (the inverse of the “power”) of a thin lens, provided that one knows the refractive index of the glass and the radii of … Continue reading

Posted in April 2012 | Tagged , , , , | 1 Comment