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MELOTTE 71 AKA COLLINDER 155

OPEN CLUSTER IN PUPPIS (THE POOP DECK)

(Image centered at: ra 07 h: 38m / dec -12º 07')

CLICK THE IMAGE FOR A HIGH RESOLUTION VIEW

February - 2025, Home Backyard in Martinez, Buenos Aires, Argentina

DATA

TYPE: Open Cluster 

APPARENT DIAMETER: 10 arc minutes

APPARENT MAGNITUDE (V): 7.1

DISTANCE: 9100 light years

IMAGE INFORMATION

INSTRUMENT: 6" ORION OPTICS UK (Ultra Grade Optics) w/Sky Watcher Coma Corrector (0.9x) working at at f4.5

CAMERA: QHY 183 MONO

MOUNT: VIXEN GDPX, OAG with Starlight Xpress Lodestar

FILTERS: BAADER LRGB Set

SKY CONDITIONS: urban skies - Bortle 8

EXPOSURES: LRGB (45,45,45,45)

OBJECT DESCRIPTION AND IMAGE SESSION

Mel 71 is an open cluster located in the border of Puppis Constellation close to de limits of Monoceros and Canis Minor. It was classified by Trumpler in 1930 as a type 2IIm meaning 2: a moderate range of brightness: II: cluster with little central concentration and "m" the cluster has a medium number of stars (from 50 to 100). Mellote 71 is a medium intermediate age cluster. Studies performed in 1985 estimated an age of 9100 Million year old.

Philibert Jacques Melotte was a British astronomer who catalogued 245 star clusters. His work was published in 1915 containing 161 Open Clusters, 81 Globular Clusters and 2 asterisms. The prefix is Mel as "Mel 71" in this case.