Above is a new rendition: June 2023
NGC 7129 & NGC 7142
NGC 7129 is a reflection nebula located 3,300 light years away in the constellation Cepheus. A young open cluster is responsible for illuminating the surrounding nebula. A recent survey indicates the cluster contains more than 130 stars less than 1 million years old.
The nebula is rosebud-shaped; the young stars have blown a large, oddly shaped bubble in the molecular cloud that once surrounded them at their birth. The rosy pink color comes from glowing dust grains on the surface of the bubble being heated by the intense light from the young stars within. The ultra-violet and visible light produced by the young stars is absorbed by the surrounding dust grains.
NGC 7142 is located near the reflection nebula NGC 7129, which is a first indication that the cluster may be obscured by an interstellar cloud. Many studies have demonstrated this to be true dating back to the earliest investigations of this cluster. A thorough study of the Cepheus region concluded "that no part of the field may be considered unobscured."
Other astronomers have noted that the reddening across the face of this cluster is likely to be uneven. The visibility of several background galaxies in the NW corner of the cluster indicate that the obscuring medium may be lowest here. Estimates of the amount of reddening range from 0.18 magnitudes to as high as 0.41 magnitudes.
Due to the uncertain amount of interstellar reddening, precise determination of age for this cluster has been especially difficult. Based on NGC 7142's Color-magnitude diagram, it is believed that this cluster is close in age to the old open clusters M 67 and NGC 188 (although age determinations for these two clusters varies wildly in the literature). This makes it one of the oldest open clusters currently known.
The nebula is rosebud-shaped; the young stars have blown a large, oddly shaped bubble in the molecular cloud that once surrounded them at their birth. The rosy pink color comes from glowing dust grains on the surface of the bubble being heated by the intense light from the young stars within. The ultra-violet and visible light produced by the young stars is absorbed by the surrounding dust grains.
NGC 7142 is located near the reflection nebula NGC 7129, which is a first indication that the cluster may be obscured by an interstellar cloud. Many studies have demonstrated this to be true dating back to the earliest investigations of this cluster. A thorough study of the Cepheus region concluded "that no part of the field may be considered unobscured."
Other astronomers have noted that the reddening across the face of this cluster is likely to be uneven. The visibility of several background galaxies in the NW corner of the cluster indicate that the obscuring medium may be lowest here. Estimates of the amount of reddening range from 0.18 magnitudes to as high as 0.41 magnitudes.
Due to the uncertain amount of interstellar reddening, precise determination of age for this cluster has been especially difficult. Based on NGC 7142's Color-magnitude diagram, it is believed that this cluster is close in age to the old open clusters M 67 and NGC 188 (although age determinations for these two clusters varies wildly in the literature). This makes it one of the oldest open clusters currently known.
Imaging telescopes or lenses: Takahashi FSQ130ED
Imaging cameras: QSI 6120i
Mounts: Takahashi EM 400 Temma 2M
Guiding telescopes or lenses: Takahashi FS60CB
Guiding cameras: QHY CCD QHY 5 II
Focal Extender / Reducer: None
Software: Sequence Generator Pro SGP (for capture) PHD 2 (guiding), Astro Pixel Processor & PixInsight,
Filters: Astrodon RGB,
Accessories: Robofocus Focuser, ATIK EFW3
Original Resolution: 4215 x 2775
Dates: 29th & 30th May 2019
Frames:
Astrodon R 26 x 5'
Astrodon G 21 x 5'
Astrodon B 21 x 5'
Total integration = 5 hours 40 mins.
Center (RA, Dec):(325.651, 65.943)
Center (RA, hms):21h 42m 36.179s
Center (Dec, dms):+65° 56' 33.718"
Size:69.2 x 45.6 arcmin
Radius:0.691 deg
Pixel scale:0.985 arcsec/pixel
Orientation:Up is 268 degrees E of N
Sky Map
Annotated Image
