John J. McCarthy Observatory

There are three telescopes currently installed at the John J. McCarthy Observatory on a large vibration-free pier, Two specialized auxiliary telescopes are mounted on the main instrument.

The main instrument is a Meade Instruments LX200. This Schmidt-Cassegrain reflecting telescope has an aperture of 0.41 meters (16 inches) and a focal length of just over 4 meters (13.3 feet) yielding a focal ratio of f/10.

The telescope is mounted on a custom-made permanent equatorial pier that was machined to the latitude of the JJMO or 41.5 degrees. The telescope is fully computerized and can be commanded to go to any object in the sky.

This "go to" capability can be used from the telescope's own on-board computer or the Observatory's control computers, located in the Control Room. This very versatile instrument can be easily transformed to a telescope with a focal ratio of anywhere between f/10 and f/3.3 by using a telecompressor lens or focal reducer.

A Takahashi FSQ-106, 106mm (4.2 inch) aperture refracting astrograph, with a four-element fluorite glass objective lens is mounted under the LX200.

This exquisite instrument has a focal length of 530mm (20.7 inches) giving a fast focal ratio of f/5. This enables wide-angle imaging of the sky to be done at the JJMO.

A dedicated solar telescope is mounted above the LX200. It is a 5” Meade achromatic refractor, with a Cornado 90mm (3.54”) “SolarMax” hydrogen-alpha filter system integrated.

This filter removes all wavelengths of light entering the telescope except the light of hydrogen. The filter's central wavelength is 6562.8 angstroms and its bandpass range is less than 0.7 angstroms. This wavelength of light is perceived by the human eye as a bright red. This special filter allows solar prominences, sunspots, coronal mass ejections and many surface features to be studied.

Additional smaller visitor telescopes and celestial binoculars are also available for group visits and special events

Click here to review the observatory's other equipment.

Return to the top of this form