Telescope Data Center Harvard Plate Collection Harvard-Smithsonian Center for Astrophysics
Harvard Observatory Plate Stacks
BM Series Characteristics


Plate Size Plate Scale Telescope Focal Length
8x10 391"/mm 3-inch Ross Fecker 21 inches


Plate nos.LocationDates
1-3222Cambridge, Massachusetts1934-01-30 - 1941-02-05


Plate SizeLocationNumbers
8x10first floor, Patrol Series 1all

Record Books:

(2) 1-3222
Online: [01] [02]


Instrument moved to Mexico, February 7, 1941.

Plates 1-410 were taken with the 3-in Ross-Lundin lens previously used for the MB series (which see).

Plates 411 ff. were taken with a 3-in Ross-Fecker lens. Two new Ross-Fecker lenses were tested, with numbers in this series in February 1937. The first plates were taken with the BM on the old 8-in I mount in Cambridge until this was reclaimed by the I in October 1934.