Greenwich 28-inch refractor
The Greenwich 28-inch refractor is a telescope at the Royal Observatory, Greenwich, where it was first installed in 1893. It is a 28-inch ( 71 cm) aperture objective lens telescope, otherwise known as a refractor, and was made by the telescope maker Sir Howard Grubb. The achromatic lens was made Grubb from Chance Brothers glass. The mounting is older however and dates to the 1850s, having been designed by Royal Observatory director George Airy and the firm Ransomes and Simms. The telescope is noted for its spherical dome which extends beyond the tower, nicknamed the "onion" dome. Another name for this telescope is "The Great Equatorial" which it shares with the building, which housed an older but smaller telescope previously.
The dome of Greenwich 28-inch Great refractor | |
| Location(s) | Royal Observatory Former Great Equatorial Building, Royal Borough of Greenwich, Greater London, London, England |
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| Coordinates | 51°28′40″N 0°00′04″W |
| Telescope style | optical telescope |
| Diameter | 28 in (0.71 m) |
Location of Greenwich 28-inch refractor | |
| Related media on Commons | |
The telescope was re-commissioned by Queen Elizabeth II in May 1975 after it was brought back from Herstmonceux in Sussex. It was placed in the renovated original dome at Greenwich for the tricentennial celebration of the observatory.