ObjetFiltresBinTemps PoseNombres PosesTemps Total
NomNGC 4631 et NGC 4656Luminance1 x 15 mn53265 mn
ConstellationChiens de chasseRouge1 x 15 mn25125 mn
Distance25 à 30 millions alVert1 x 15 mn25125 mn
Détail prise de vueBleu1 x 15 mn25125 mn
LieuMaison-Maugis 61 FranceS21 x 1
Date acquisition26/03 au 01/06/20191 x 1
SetupO31 x 1
InstrumentNewton Skyvision Mtn 250Totaux12810 hrs 40 mn
Diamètre250 mmBias99
Focale900 mmDark19
Rapport F/D3,6Flat11
MontureEQ8 SkywatcherAcquisition faite parFrancis Bozon
Caméra acquisitionMorovian G2 4000Traitement fait parFrancis Bozon
Caméra de guidageAtik 314LLogiciels utilisés
Montage de guidageDO SkymecaAcquisitionTheSkyX – Software Bisque, Focusmax, Maxpilote
Echantillonage1,7 arcsTraitementPixinsight, Photoshop


NGC 4631 is a beautiful spiral galaxy seen from the slice located only 25 million light years from Earth to the small northern constellation of the Hunting Dogs (“Canes Venatici” in Latin).

This slightly twisted, wedge-shaped galaxy is reminiscent to some people of a cosmic herring or whale from which it takes its nickname. In any case, it is the same size as our own Milky Way.

In this beautiful colour picture, the yellowish bulb, dark clouds of interstellar dust, young bright blue star clusters and the purple star-forming regions of the Whale are easy to spot. A companion galaxy, the small elliptical galaxy NGC 4627 is visible to the left of the centre, the Whale galaxy.

In the lower right corner is another deformed galaxy, NGC 4656, which is shaped like a hockey stick. It is also about 25 million light years away. The deformations and mixed gas and dust trails detected at other wavelengths suggest that the three galaxies have encountered each other closely during their history. The Whale galaxy is also known to eject a halo of hot gas that glows in X-rays.

Click to enlarge


DECLINAISON:+32°32′ 29s