Object name: PARSAMYAN 21

Designation(s): PARSAMYAN 21,

Parsamyan 21/Parsamian 21 is a reflection nebula caused by the outflow from the young FU Orionis star HBC 687. Coming from its south end is the Herbig Haro object HH221 which may be the little jet seen below the bright cloud that hides the star. This nebula is located in Aquila. I was unable to find a distance estimate for it. Some papers likened this nebula to the far more famous Hubble's Variable Nebula. Though about the only similarity I see is the faint southern jet. It certainly doesn't have the ringlike shape of Parsamyan 21. See also Jim Shuder's fine image of this object at: .

The illuminating and creating star is listed as a variable but photometric data in one paper found only a very tiny fluctuation in its brightness over the years so while it varies it is barely noticeable. The star itself is hidden by the dust and gas around it though it can be seen in IR light according to one paper which had a picture showing just the star and no hint of nebulosity. If you look very closely at my image it appears there is a bit of faint nebulosity to the northeast and north-northwest. It would take a lot of hours to bring that out at my image scale. Except for that, it appears there may be dark dust not illuminated by the star around the nebula as it sits in a slightly dark hole in the stars. Some of the lack of stars matches where the faint nebulosity is in my image. WISE shows a red circular blob that is centered on the star, not the nebula or the dark cloud that I see. Enter Parsamian 21 in the search box and hit search. Click on the Multi-color tab above the IRAS image. The circle in all images is centered on the illuminating star according to their position cursor. The longer the wavelength the larger the blob and the cooler the dust it is seeing.

I imaged this one at 0.5" per pixel. The professional images I found on the net show it bluer than either Jim or I saw it. I can't explain the difference.

14" LX200R @ f/10, L=6x10'x1 RGB=2x10'x2, STL-11000XM, Paramount ME

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