M 47 OPEN CLUSTER in Puppis
(ra 07:36.6/ dec -14:30)
March 2013, Collaboration with Ezequiel Bellocchio AstroPilar (RGB) - Home Backyard in Martinez, Buenos Aires, Argentina
TYPE: Open Cluster
Apparent Magnitude: 4.4
Apparent Diameter: 30 arc minutes
DISTANCE: 1600 lights years
SCOPE: Carbon Fiber Ritchey Chrétien 8" f8
CAMERA: QSI 583 WS
FILTERS: Baader LRGB, IDAS LPS for Luminance
SKY CONDITIONS: urban skies
EXPOSURES: L (40) - Sergio Eguivar LRGB (30,18,18,18) - Ezequiel Bellocchio
OBJECT DESCRIPTION AND IMAGE SESSION
Open cluster M47 is a coarse cluster of bright stars, and contains about 50 stars in a region 12 light years in diameter; in the central portion, the stellar density is about 16 stars per cubic parsec while the average density of the whole cluster is only 0.62 stars per cubic parsec, according to Wallenquist (as quoted by Kenneth Glyn Jones). Its distance is about 1,600 light years (values scatter from 1,560 to 1,750 light years), so that the stars of M47 appear scattered over an area in the sky of the same size as the full moon, 30 arc minutes.
While testing the RC 8" and of axis guiding I was able to acquire 4 light frames of 10 minutes each which gave me a nice luminance to combine Ezequiel's LRGB image. The frame was cropped to match the stars of the LRGB image taken in Pilar 50 away from Buenos Aires.