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Name / Constellation

Melotte 15

 Other: Cr26

Cas
Coordinates AR: 02h 32m 35.6s - Dec: +61° 29′ 02″
Optics Officina Stellare 10" f8 Richtey-Cretien
Camera-Mount PLAYERONE POSEIDON M-PRO - ZWO ASI 1600M (ONAG)- 10Micron GM2000 QCI Mount
Filters Antlia V-Pro LRGB
Exposure
  • Ha
  • O3
  • Red
  • Green
  • Blue
  • 60 x 300 sec - 5h
  • 52 x 300 sec - 4h 20m
  • 17 x 300 sec - 1h 25m
  • 12 x 300 sec - 1 h
  • 12 x 300 sec - 1 h
  • Binning 3
  • Binning 3
  • Binning 3
  • Binning 3
  • Binning 3
Location / Date Promiod (Valle D'Aosta-Italy) "TLP" Remote Observatory - Nov 2025
Seeing 2.6" @ 1.17 arcosec/pixel binning 3
Note Drizzle 2X in postprocessing (Pixinsight))
Acquisition N.I.N.A.
Processing Adobe Photoshop CC -
Comment

 

The open cluster Melotte 15 is located at the center of IC1805, known as the Heart Nebula because of its shape. This is the largest of the three main nebulae of the W3/W4/W5 complex, a star-forming region in the constellation of Cassiopeia, which also includes the Soul Nebula (IC1848 or W5). The brightest stars in the cluster are blue dwarfs, 24 of which have a mass greater than 10 solar masses, with an age between 1 and 3 million years. Among these blue stars there are 9 of spectral class O, enclosed within a radius of 10 parsecs, while the total radius of the open cluster is 18 parsecs. The nebula is composed essentially of SII, Ha and OIII, gases ionized by the stellar winds of the stars also present within Melotte 15.