PG 2246+103 region in Pegasus
Seeing the Unseen
Published 25 Oct 2022

Stacks Image 4832

Click on images for higher resolution

Stacks Image 5604
About this object

PG 2246+103 is a magnitude 15.5 blue, hot, sub dwarf star in the constellation Pegasus. It's positioned very close to the brighter magnitude 7.63 orange G5 star HD 215975 near the center of the image. Earlier, in spring of 2022 I was contacted by amateur astronomer Dana Patchick, who has many planetary nebula discoveries and co discoveries and is part of the Deep Sky Hunters team ( The thought was that this star, PG 2246+103, being a hot sub dwarf, may be the progenitor star of a very faint planetary nebula in this area which is mostly unseen in normal broadband data although a very faint area of nebulosity was seen in some survey plates. He asked if I could do a deep image of this area during the summer season. As it turn out, summer is a tough time to image along the Gulf Coast of the US as it is typically cloudy and rainy a lot of the time. Luckily I had a few nights in July and Aug but didn't finish the exposures until the end of September when I attended the Okie Tex Star Party and had 7 good nights to image. When the data was put together it seemed as if there might be something here as a roundish and very faint area of nebulosity was present near and extending around 30 arc minutes from PG 2246+103. The area was very diffuse and both HII and OIII data showed very faint nebulosity. The total exposure time was 51.5hrs. We sent the data to Marcel Drechsler, another amateur astrophotographer from Germany who works closely with planetary nebula researchers and who himself is co-discover of many planetary nebula. He checked out our data and unfortunately it turns out that most likely this very faint nebula is more broadband in nature and not being caused by the ionizing radiation from the small sub dwarf star PG 2246+103. However, in the end, this very faint nebula has probably always been "unseen" and the image offers a, most likely, never seen new view into this area of the constellation Pegasus.
Image Details

  • Optics : Stellarvue SVX 152T refractor @f8 1200mm FL
  • Mount: Paramount MYT
  • Camera: ZWO ASI6200
  • Filters: 50mm, Chroma RGB, 5nm Chroma OIII and 5nm Astrodon Ha
  • Exposure (min): RGBHaOIII 80:80:98:1180:1680, 51.5 hrs, 2x2 binning
  • Automation Control: The Sky X, Voyager, PrimaluceLab Eagle 4
  • Guiding: StarlightXpress Lodestar X2
  • Processing Software: PixInsight, PS CC
  • Location: Stark Bayou Observatory, Ocean Springs, MS, Okie Tex Star Party, Kenton OK.
  • Sky: Typical SQM 19.6-20.1, Bortle 5, Suburban, Okie Tex SQM 21.8
  • Date: 24 July - 30 Sep 2022
Stacks Image 5599
Stacks Image 74
Stacks Image 75
Stacks Image 5333