COLLINDER 399 AKA COATHANGER CLUSTER

 ASTERISM IN THE CONSTELLATION OF VULPECULA (LITTLE FOX)

(Image centred at: ra 19h:25m / dec 20º 11')

CLICK THE IMAGE FOR A HIGH RESOLUTION VIEW

AUGUST 2026, Observatorio Cielos Albertnos, Buenos Aires, Argentina

DATA

TYPE: Asterism

APPARENT DIAMETER: 60 degrees

APPARENT MAGNITUDE (V): 3.6

DISTANCE: in average 300 to 420 light years

IMAGE INFORMATION

INSTRUMENT: ASKAR 180 FMA

CAMERA: QSI 583 WS Mono Camera

MOUNT: Vixen GPDX Guided ded off axis with QHY 5II Mono Camera 

FILTERS: Baader LRGB Set 

SKY CONDITIONS: Bortle 3 to 4 skies

OBJECT DESCRIPTION AND IMAGE SESSION

Collinder 399 is an asterism of ten stars. Six of the stars appear in a row, across 1.3° of the night sky. The cluster is in the south of the constellation Vulpecula, near the border with Sagitta. Its nickname is the Coathanger. None of these ten stars are believed to be gravitationally bound to each other, thus they are not a star cluster, a fact established by measurements taken by the Hipparcos satellite in 1997. An additional 30 or so much fainter stars are considered by some to be part of the asterism.

I was looking for a chance to imagine this object for some time. Always missed the chance for one reason or other. The Askar 180 FMA behaved quite well and gives a wider field of view that suits this large asterism. There is a hint of the reflection nebulas LBN 130 and GN 19.25.0 at the left of the asterism. Those nebula are very faint thought. At the bottom right we have Sharpless 2 -82 also known as the Little Trifid. Another object which i am planning to image some day with larger focal lenght