Pleiades (M45)

The Pleiades (M45) are a cluster of young blue stars in a distance of about 430 ly (Light-years). The bluish dust which scatters the light from these stars lies about 1 to 2 ly in front of them, see [1]. The nebula probably belongs to the Taurus Molecular Cloud which also extends within a distance of about 420 ly to 645 ly, see [2].

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Pleiades (M45) with SDSS I', R' and G' filters
Wider view captured with instrument 1. The image is a false color composite using SDSS I' (mapped to red), R' (mapped to green) and G' (mapped to blue) filters.

The artifacts around the bright stars are caused by star reduction by factor 10. The red and blue spots are probably caused by internal reflection of the lens.

Pleiades (M45) in NIR, red and blue
Higher resolution view captured with instrument 2. The image is a false color composite from near infrared (NIR, mapped to red), red (mapped to green) and blue (mapped to blue).

Click on the image and zoom in in order to see all the background galaxies. They appear orange because a point in the nebula has been used for white balance. (With white balance according the average star light or galaxies the nebula would look even more bluish.)

Pleiades (M45) in true colors
A true color version captured with instrument 2. The contrast between the colors is much lower compared to the images above because this version only covers the spectral range of 420nm to 640nm (vs. 420nm to 850nm).

Image data, Instrument 1

FOV: 6.33° × 3.88°
Date: 12/2021 to 01/2022
Location: Pulsnitz, Germany
Instrument: 2-3 × 100mm lens at f=300mm (3× array was not fully operational at beginning)
Camera Sensor: 2-3 × IMX455 (3× array was not fully operational at beginning)
Orientation: North is up (exactly)
Scale: 3 arcsec/pixel (at full resolution)
Total exposure times:
SDSS G': 5.0 h
SDSS R': 6.9 h
SDSS I': 5.1 h

Image data, Instrument 2

FOV: 4.2° × 2.6°
Date: 01/2020 to 02/2022
Location: Pulsnitz, Germany
Instrument: 2 × 200mm Newton at f=850mm
Cameras / Sensors:
RGB: Consumer camera with on-sensor color filter array (CFA) and unknown 36mm × 24mm, 38MP sensor
NIR: IMX455 Sensor
Orientation: North is up (exactly)
Scale: 1.5 arcsec/pixel (at full resolution)
Total exposure times:
RGB: 54.4 h
NIR: 9.2 h

Image processing

All image processing steps are deterministic, i.e. there was no manual retouching or any other kind of non-reproducible adjustment. The software which was used can be downloaded here.

Image processing steps where:

  1. Bias correction, dark current subtraction, flatfield correction, noise estimation
  2. Alignment and brightness calibration using stars from reference image
  3. Stacking with masking unlikely values and background correction
  4. Star subtraction
  5. Denoising and deconvolution
  6. Color composition
  7. Dynamic range compression using non-linear high-pass filter
  8. Tonal curve correction


  1. Gibson, S.J.; Nordsieck, K.H. (2003). "The Pleiades Reflection Nebula. II. Simple Model Constraints on Dust Properties and Scattering Geometry". The Astrophysical Journal. 589 (1): 362–377.
  2. P. A. B. Galli 1, L. Loinard 2,3 H. Bouy 1, L. M. Sarro 4, G. N. Ortiz-León 5, S. A. Dzib 5, J. Olivares 1, M. Heyer 6, J. Hernandez 7, C. Román-Zúñiga 7, M. Kounkel 8, and K. Covey, (2019). "Structure and kinematics of the Taurus star-forming region from Gaia-DR2 and VLBI astrometry". Astronomy & Astrophysics 630: A137.