• NGC 6838 or Messier 71 in Sagitta
    • M71
    M71
  • NGC 6838, M71, is a small globular cluster
  • located in the constellation Sagitta.
  • It contains over 20 000 stars and
  • is 13 kly from us.
  • Hover over the picture for an annotated version
  • Date:  29 June 2025
  • FOV:  approximately 45' × 30'; the angular size of M71 is about 7'
  • Telescope:  Orion 127mm Mak-Cass (1382mm, nominally 1540mm, f/12.1)
  • Guiding:  ZWO ASI120MM mini mono guide camera,
  • SVBony SV165 Mini 40mm f/4 guide scope
  • Computer:  ASIair pro Raspberry Pi
  • Mount:  ZWO AM5
  • Camera:  ZWO ASI071MC Pro Cooled (-10°C) Color CMOS with gain 90
  • Pixel size:  4.78 μm
  • Resolution:  0.713 arcsec/pixel
  • Filter:  no filter
  • Stacking:  forty-seven 240 second frames using PixInsight
  • Calibration:  20 darks, 20 flats, and 20 bias
  • Total Time:  3 hours and 8 minutes
  • Processing:  Pixinsight – SPCC, DBE, SPCC, BlurXT, NoiseXT, HST, GHS, MStr
  • PMath Mstr + GHS + HST, HDR4, Sat, DynCrop/Scale
  • Location:  Darling Hill Observatory near Vesper, NY